Abiotic stress is one of the main factors causing global grain yield reduction. It is of great significance to study the function and response mechanisms of plant stress-related proteins to improve crop stress resistance. Pentatricopeptide repeat (PPR) proteins, belong to the largest family of nuclear coding proteins in higher plants and are named because they contain highly specific PPR motifs. Depending on motif type and arrangement, PPR proteins can be classified as P and PLS, and PLS proteins can be further classified as PLS, E, E+, DYW, and other subclasses based on their carboxyl-terminal domains. PPR proteins are widely distributed in terrestrial plants, mainly in chloroplasts and mitochondria, and a few in the nucleus. As sequence-specific RNA binding proteins, PPR proteins are involved in multiple aspects of plant RNA processing, including RNA editing, splicing, stabilization, and translation. PPR protein plays a variety of important roles in the whole life process of plants, but the mechanism of its action in plant stress resistance is not well understood. Based on the localization and function of PPR proteins related to abiotic stress reported, the mechanism of PPR proteins involved in regulation of abiotic stress, including post-transcriptional regulation and retrograde signaling, was reviewed and discussed in this paper. Post-transcriptional regulation is related to the role of PPR proteins in the modification of RNA after transcription. It is generally believed that PPR affects stress resistance in plants by regulating the expression of stress-related genes via binding RNA and by regulating the metabolism of organelle RNA. In terms of retrograde signaling, damage to PPR proteins can lead to impaired mitochondrial or chloroplast function, and then produce various retrograde signals (such as ROS), thereby regulating the expression of related genes and resisting adversity. However, since plastid signaling is affected by many environmental factors, some of which are still unclear, the mechanism of the PPR protein in retrograde signaling remains to be clarified. In addition, PPR proteins are pleiotropic and some have important effects on plant growth and reproduction while acting on stress resistance. Finally, this paper further analyzed the current research status of PPR protein as an RNA editing tool, discussed the remaining problems and research prospects of PPR protein in the direction of abiotic stress, and pointed out the key points and difficulties that need to be paid attention to in future research, to provide references for further research on PPR protein and crop abiotic stress resistance breeding.

Wheat is the most important cereal crop, and drought is the most significant abiotic stress factor that severely affects wheat growth and development. Plant root system, as a primary organ for crops to acquire water and nutrients, directly determines the efficiency of soil water utilization. In recent years, increasing evidence has shown that plant root system architecture (RSA) plays an important role in plant tolerance to drought stress. This review summarizes the current research progress on the regulation of wheat drought tolerance determined by RSA. First, we present how root tropism especially root gravitropism shapes the RSA, summarize the relevant genes and molecular regulatory mechanism involved in root gravitropic growth, and explain how the root tropism-regulated RSA is implicated in wheat adaptation to drought stress. In addition to root tropic growth, the root development also participates in the RSA formation and the plant adaptability to drought stress. Therefore, this review further summarizes how wheat regulates root development to alter its root system morphology (including increasing root length, modifying lateral root number and root hair density, etc.), thereby enhancing its water acqusition from the soil and its adaption to drought environment. The identified genes involved in wheat root development under drought stress conditions are also systematically summarized. Furthermore, as the underground part of plants, the revelation of RSA has always been a challenging task, which hinders our understanding of the relationship between RSA and plant drought tolerance. Therefore, this review also summarized the available techniques used to analyze the RSA at two- and three-dimension levels. These techniques can measure and analyze wheat root length, density, growth direction, and morphology parameters, laying technical support for an insightful understanding of the relationship between wheat RSA and drought resistance. Finally, we discuss the prospect of the improvement of RSA in breeding wheat drought-resistant varieties, as well as provide an outlook for how to identify genes regulating wheat RSA and pinpoint their regulatory mechanism. In summary, the relationship between wheat RSA and drought resistant is closely associated. The continuous development of sequencing techniques, along with the deepening research on the regulatory mechanism of wheat RSA, will provide new means and strategies for the further breeding of drought-tolerance wheat varieties.

Sorghum is the fifth largest grain crop in the world and can be used for food, feed, brewing and bioenergy. Sorghum genetic transformation technology is an essential and important tool in the research of sorghum functional genomics and can also serve as an important complement to traditional breeding methods. In this review, we summarize the research progress of sorghum transformation in recent years, analyze the problems in sorghum genetic transformation and propose strategic solutions to them in order to provide a reference for further improvement of sorghum genetic transformation technology. By summarizing more than 50 literatures on sorghum tissue culture and genetic transformation in recent years, we introduced the current research status of sorghum genotypes, explant sources, and regeneration system construction for genetic transformation, and compared the advantages and disadvantages of four commonly used methods for sorghum genetic transformation: electroporation, pollen-mediated transformation, particle bombardment and Agrobacterium-mediated transformation, summarized the effects of the main components of genetic transformation vectors, including promoters, target genes, selective marker genes and reporter genes, on transformation efficiency, explained the current application status of sorghum genetic transformation, analyzed the main bottleneck problemns in sorghum genetic transformation technology, and studied countermeasures. Sorghum genotypes have a significant influence on tissue culture and P898012 and Tx430 are the most widely used. Gene bombardment and Agrobacterium-mediated transformation are the most commonly used methods for sorghum genetic transformation, and the advantages of Agrobacterium-mediated transformation are gradually emerging. In vector construction, CaMV35S and ubi1 are the most commonly used promoters, and antibiotic resistance genes (nptII, hpt), herbicide resistance genes (bar), and nutrient assimilation genes are the three commonly used selection markers. With the development of sorghum genetic transformation technology and CRISPR/Cas9-mediated gene editing technology, some genes with important agronomic traits have been successfully transferred into sorghum. However, strong genotype dependence, long tissue culture cycle, and poor genetic transformation stability are the main bottlenecks that limit the genetic transformation of sorghum. By introducing morphogenesis regulatory factors, somatic cell generation can be directly performed, which shortens the tissue culture cycle, improves the transformation efficiency, and expands the source of explants. This has become a major breakthrough in sorghum genetic transformation technology. The use of morphogenesis regulatory factors and adoption of cut-dip-budding (CDB) delivery system can further improve the sorghum genetic transformation technology. Combined with the application of CRISPR/Cas9 gene editing technology, they will surely provide an important technical basis for the sorghum molecular breeding and gene function identification.

【Objective】 Livestock production is one of the important emission sources of greenhouse gases, while China is a major country in pig farming. Scientifically assessing the carbon footprint of pig farming system can provide a reference for further promoting carbon emission reduction of animal husbandry. 【Method】 This paper reviewed the research status of carbon footprint assessment of pig breeding system, including model, results and composition. The results of carbon footprint assessment were related to many factors, such as system boundary, emission sources, accounting methods and functional unit. In this study, we considered the main factors which affect the evaluation results, and analyzed the reasons for the difference of results. 【Result】 Through reviewing the domestic and foreign literature on carbon footprint assessment, it was realized that the assessment model of livestock had been constructed well in developed country. The carbon footprint of 1 kg functional unit product was 2.2-10.3 kg CO_2-eq. The assessment results varied due to the different evaluation methods in various studies. Different system boundaries and functional units were the important reasons for different results. The different emission sources, accounting parameters selected for the same emission source, or diverse allocation methods under the same system boundary also led to great differences. For the contribution to the carbon footprint of the pig production system, feed production was the largest link, accounting for 49%-83%; the second was manure management, accounting for 12%-41%. 【Conclusion】 In order to widely precise the carbon footprint of China’s pig production system, the suggestions were as follows: monitoring the key parameters of greenhouse gas emissions for various feeding modes in all regions of China should be carried out; the Chinese carbon footprint assessment database according to the development status of Chinese pig breeding systems should be established; the unified and standardized evaluation methods should be appeared publicly; an carbon footprint assessment model fit for different regions of Chinese production practice should be created to provide data reference support for the sustainable development of Chinese pig production system.

Wheat stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating disease threaten food security in China and worldwide. Epidemics of wheat stripe rust have been under control through applying resistant cultivars and crop protection approaches. However, due to climate change, innovation of cropping system, improvement of breeding technology, yield level enhancement of wheat cultivars, variation in structure and frequency of virulence genes in Pst populations in the new era, the current status of stripe rust resistance genes in wheat breeding programs need to be evaluated. The results could provide useful information for applying stripe rust resistance genes to develop new wheat cultivars with broad-spectrum and durable rust resistance. After multiple year’s stripe rust resistance survey, genetic analysis, molecular tagging and mining of stripe rust resistance genes in wheat cultivars and advanced breeding lines, the current status of major stripe rust resistance genes utilization was reviewed. We summarized the present situations of major stripe rust resistance gene discovery and germplasm innovation, the most frequently used stripe rust resistance genes, new strategy for pyramiding adult plant partial resistance and all stage resistance, and molecular marker assisted selection for developing wheat cultivars with broad spectrum and durable resistance in China. This review also proposes the major research areas in wheat stripe rust resistance breeding in the new era.

Map-based cloning is a classical and effective method to identify candidate genes for specific phenotypic variants. Map-based cloning of functional genes plays important roles in the innovative utilization of germplasm resources, molecular design breeding and improving breeding efficiency. In recent years, the whole-genome sequencing of Gossypium raimondii, Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense has been completed and improved. Map-based cloning has entered into a crucial period. In 2016, the dominant glandless gene Gl₂^e (GoPGF) was the first map-based cloning gene in cotton. So far, 20 qualitative traits genes and 5 quantitative traits genes have been identified by map-based cloning technology. In this paper, research progress was systematically reviewed in fiber, gland, nectary, leaf type, plant architecture, plant color, and fertility in terms of gene symbols, names, chromosomal positioning, and candidate genes. Moreover, map-based cloning strategies were systematically reviewed in mapping populations and bulked segregate analysis-sequencing (BSA-seq). With the reduction of sequencing cost and utilization of BSA-seq, it is believed that more and more genes will be cloned by map-based cloning technology. In addition, transformation and genome editing have been successfully used to evaluate the function of the candidate gene in the target interval. It is believed that map-based cloning could provide a theoretical basis and genetic resources for molecular design breeding in cotton.

Pre-harvest sprouting (PHS) refers to the germination of cereal crops on the spike in high humidity conditions before grain harvest. Wheat PHS is a significant problem that affects both the yield and quality of wheat. Seed dormancy level is a major factor influencing the resistance of wheat PHS, and domesticated crops often exhibit reduced seed dormancy levels, making cultivated wheat more prone to PHS compared to its wild ancestors. Wheat PHS is mainly regulated by external environmental factors such as temperature and humidity, as well as internal plant hormones (GAs, ABA, IAA, MeJA, ET, BR). Researchers have identified a range of materials resistant to PHS, cloned key genes regulating PHS resistance, such as PM19, MFT, MKK3, Myb10-3D, Vp1. New wheat materials resistant to PHS have been successfully developed through molecular marker-assisted selection, artificial synthesis of wheat, and CRISPR/Cas9 gene editing technology. This article reviews the genetic mechanism of PHS resistance in wheat and the latest progress in PHS resistance breeding research. In the future, it is necessary to continue exploring key genes related to PHS resistance, and employ biotechnological breeding methods to cultivate new PHS-resistant wheat varieties.

【Objective】Spike length (SL) plays an important role in determining spike structure and yield potential of wheat. Quantitative trait loci (QTL) for spike length were excavated and their genetic effects were further analyzed to provide theoretical basis for molecular breeding. 【Method】This study consisted of a population of 198 F₆ recombinant inbred lines (RIL) derived from the cross between the natural mutant msf and the cultivar Chuannong 16 (MC population). The MC population and its parents were planted in five different environments including Wenjiang in 2021 and 2022 (2021WJ and 2022WJ); Chongzhou in 2021 and 2022 (2021CZ and 2022CZ); and Ya’an in 2021 (2021YA) for spike length measurement. The 16K SNP chip-based constructed high-quality and high-density genetic linkage maps were used to map QTL for spike length. Additionally, the genotype of the flanking markers for the major spike length QTL was used to analyze its genetic effect on yield-related traits and thus to evaluate its potentiality for yield improvement.【Result】A total of 14 QTL for spike length were identified and they were mainly distributed on chromosomes 1A (one), 1B (one), 2B (one), 3D (three), 4A (one), 4D (two), 5A (one), 5B (one), 7A (one), 7B (one), and 7D (one). Among them, QSl.sau.1A was detected in four environments and the best linear unbiased prediction (BLUP) value, explained 6.46% to 20.12% of the phenotypic variation, and thus was regarded as a major QTL. The positive allele at QSl.sau.1A came from the parental line msf. QTL analysis across multiple environments also detected QSl.sau.1A, indicating it exhibits minimal environmental influence and represents a major and stably expressed QTL. The effect of QSl.sau.1A was successfully verified in two populations with different genetic backgrounds. Genetic effects analysis showed that the positive allele of QSl.sau.1A showed a significant effect on improving grain number per spike (12.68%), grain weight per spike (14.99%), 1000-grain weight (5.79%), flag leaf width (2.94%), spikelet number (1.48%), and flowering date (0.61%), and a significant effect of reducing plant height (-6.47%) and effective tiller number (-36.11%).【Conclusion】A major and stably expressed spike length QTL, QSl.sau.1A, was detected on chromosome 1A. Its positive allele significantly increased grain number per spike, grain weight per spike, thousand grain weight, and spikelet number per spike, indicating its great breeding value.

【Background】It is of great importance to improve the quality of cotton fiber to meet the improvement of cotton textile production and the pursue of people for high quality cotton. Fasciclin-like arabinogalactan proteins (FLAs) play an important role in the initial development of cotton fibers and secondary wall synthesis. 【Objective】Comprehensive identification and analysis of cotton FLA gene family members to reveal their common characteristics and specific expression patterns, provided a reference for the function study of FLAs in cotton fiber development.【Method】According to the whole genome data of cotton, members of FLA gene family were identified by HMMER3.0 and further verified by online softwares of Pfam and Smart. Physical and chemical properties and transmembrane domains of these proteins were analyzed by ExPASy and TMHMM. Phylogenetic tree construction, chromosome localization, collinearity analysis and protein conserved domain sequence alignment were conducted and displayed using GSDS, MCScanX, MEGA, MEME, TBtools and Jalview. Expression of FLA genes in different tissues were analyzed by cotton transcriptome data. Expression differences of GhFLAs in different developmental stages of ovules and fibers between different fiber quality materials was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Function of GhFLA05 was verified by virus induced gene silencing (VIGS). 【Result】A total of 41, 40, 20 and 21 FLA family members were identified in G.hirsutum, G. barbadense, G. arboreum and G. raimondii, respectively. The phylogenetic tree showed that cotton FLA proteins could be divided into four groups. Gene structure and motif composition were relatively conserved in each group. Further analysis of FLA proteins in Gossypium hirsutum showed that all 41 FLA members had 1-2 AGP-like glycosylation regions and 1-2 fasciclin-like domains (FAS), 37 of which contained signal peptide (SP) and 25 contained glycosylphosphatidylinositol anchored protein (GPI) anchoring signals. Subcellular localization showed that GhFLA05_D showing aggregated granules in the cytoplasm was probably localized in endoplasmic reticulum, and GhFLA18_A and GhFLA22 were expressed in cell membrane/wall, cytoplasm and nucleus. Transcriptome sequencing results showed that FLA proteins in Group A and B were mainly highly expressed in fibers, which may be involved in the process of cotton fiber elongation development and secondary wall thickening. In general, group A and B members had a similar expression pattern in two materials with significant differences in fiber quality and expressed mainly in the secondary wall development stage, especially in 20-25 DPA period. GhFLA05 exhibited specific expression at the secondary wall thickening stage with significant differences between two materials, which expressed with a high maximum value in earlier stage of secondary wall thickening stage in high specific strength material RIL229, suggesting GhFLA05 may take a part in the regulation of cotton fiber strength difference formation. The fiber strength and micronaire value decreased in GhFLA05 gene-silenced cotton plants by VIGS.【Conclusion】A sum of 122 FLA family members were identified in Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium raimondii, which could be divided into four groups. Members of different groups had high structural and functional similarities, and the genes related to cotton fiber development were identified. It was clarified that GhFLA05 specifically expressed in the secondary wall synthesis stage, and closely related to the difference in fiber strength of different upland cotton materials.

Duckweed (Lemna minor L.) is a floating microscopic plant that is usually found in standing water. Climate change is characterized by rising temperature, which is mainly due to increasing atmospheric CO₂ concentration, and it poses potential risks to food production. Owing to factors such as climate warming and/or the eutrophication of water, duckweed growth in paddy fields has shown an increasing trend year by year in China. This paper focused on the impacts of duckweed on paddy fields and highlighted some vital trends. Duckweed reduced the water temperature of paddy by 0.86-2.76 ℃ and the pH value by 0.10-0.45, changed the structure of microbial community, reduced the NH₃ volatilization by 18.2%-59.0%, and increased the nitrogen utilization rate by 17.2%-78.0%. As a result, the nitrogen sink of paddy increased and the rice yield rose by 9.0%-34.6% upon duckweed growing in paddy. Duckweed grew and reproduced rapidly, and its annual biomass could reach 8×10³-13×10³ kg·hm^-2, making its carbon sink almost equal to that of rice in the same season. The mutualism between duckweed and rice was greater than its competition, and the coexistence of duckweed and rice in paddy showed an adaptation of the rice field ecosystem to environmental changes. Future research in this field should focus on the effect and its mechanism of duckweed on the paddy environment changes, rice growth, yield, and quality, and the risks which might bring to the paddy fields, especially the interaction with environmental factors (elevated temperature and CO₂ concentration, etc.). Such research would provide theoretical support for the sustainable agricultural development of rice farming technology based on biological collaboration, such as rice-duckweed, which can adapt to future changes in climate and environment.

【Objective】β-tubulin is the basic structural unit of cotton fiber, regulates fiber cell morphogenesis, and plays a vital role in fiber development. But there is less understood how β-tubulin gene influenced the distinct characteristic of fiber quality traits in cotton. In this study, members of the β-tubulin gene family were identified in cotton, their expression profiles were analyzed, and role of β-tubulin genes were explored for fiber quality. 【Method】BLAST method was used to identify members of the β-tubulin gene family in the genomes of four cotton species. ProtParam tool was utilized to analyze physicochemical properties, MEGA7.0 to construct phylogenetic tree, Mapchart2.2 to draw chromosomal localization map, MEME to analyze conserved motif, and PlantCARE to analyze promoter cis-acting elements. Expression levels of β-tubulin genes were characterized by using transcriptome data from 39 studies on fiber development. Spearman correlation analysis was used to identify candidate genes for fiber quality traits. 【Result】Importantly, 36, 37, 19 and 18 β-tubulin genes were identified in the genomes of Gossypium hirsutum (AD₁), Gossypium barbadense (AD₂), Gossypium arboretum (A₂) and Gossypium raimondii (D₅), respectively. The number of β-tubulin genes in tetraploid cotton species is almost double than that of diploid cotton species. Phylogenetic analysis classified these genes into 5 main clusters. Phylogenetic and collinearity analysis revealed that β-tubulin genes in Gossypium barbadense is closely related to Gossypium arboretum and Gossypium raimondii as compared to Gossypium hirsutum. Furthermore, all genes have typical conservative domains with Tubulin and Tubulin-C. The genes physicochemical properties showed amino acids range from 421 to 508 with isoelectric point of 4.68 to 5.09. The analysis of promoter cis-acting elements identified growth responsive, hormone responsive, and stress responsive elements which showed β-tubulin mediates various mechanisms of cell growth regulation. Interestingly, cluster analysis on 36 β-tubulin gene expression profiles showed 42% genes in cluster П had dominant expression in fiber. In particular, 1, 6, and 11 β-tubulin genes exhibited significant correlation with fiber micronaire value, fiber strength, and fiber length, respectively. Four genes were found to influence fiber length and fiber strength traits simultaneously. 【Conclusion】A total of 110 β-tubulin gene family members were identified in the four cotton species. Their physicochemical properties and sequences of amino acids were highly conserved and the promoter sequence had diverse regulatory elements. This study characterized the expression profiles as well as molecular function of β-tubulin gene family in cotton fiber. Further discovered the potential candidate genes that probably regulate fiber quality traits in cotton. Our results may have great potential for cotton fiber quality improvement by genetic engineering.

【Objective】Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), significantly reduced wheat production worldwide. Breeding resistant wheat varieties is currently considered to be one of the most economical and effective ways to control this disease. Understanding the resistance level of Chinese and International Maize and Wheat Improvement Center (CIMMYT) wheat breeding materials and the distribution of known disease resistance genes will greatly helpful for discovering the new resistance resources and improving the utilization efficiency of disease resistance genes. 【Method】In the present study, we phenotyped 153 wheat breeding lines derived from China and CIMMYT at both seedling against prevalent Chinese Pst races CYR33 and CYR34. In 2018-2019, 2019-2020 and 2020-2021, using the Pst races CYR33 and CYR34 to identify the materials at the adult plant stages in Ezhou, Hubei. In addition, we used the gene-based or closely linked molecular markers of known stripe rust resistance genes Yr5, Yr9, Yr10, Yr15, Yr17, Yr18, Yr26, Yr29 and YrSP to genotype the whole set of wheat collections. 【Result】We found 10 lines immune against CYR33 at the seedling stage (IT: 0), including seven Chinese cultivars (Shannong 28, Luomai 163, Shimai 13, Zhongyi 6, Tanmai 98-2, Zhongmai 175, Taishan 21) and three CIMMYT lines (CIM-53, CIM-60 and CIM-71). However, only two cultivars, Tanmai 98-1 and Shannong 102, showed immune to CYR34 at the seedling stage. Based on the three years field tests, we found 64 lines showed highly resistance to stripe rust (final disease severity, FDS≤5%), including seven Chinese cultivars and 57 CIMMYT lines. The molecular marker analysis of known stripe rust resistance genes showed that there were 31, 23, 73, 2, 4, 50 and 2 lines carrying resistance genes Yr9, Yr10, Yr17, Yr18, Yr26, Yr29 and YrSP, respectively. None of any lines had Yr5 and Yr15. Based on the phenotype, only CIM-53 showed immune against two races at both seedling and adult plant stages (IT=0, FDS=0) and it might carry the known stripe rust resistance gene combination of Yr17+Yr29 based on the genotype. 【Conclusion】A total of 153 wheat collections from China and CIMMYT were showed adult plant resistance to the prevalent Pst races. Among these, Chinese wheat varieties mainly carry Yr9, Yr10 and Yr26, while CIMMYT wheat line mainly carry Yr17, Yr18 and Yr29, indicating that near-immunity resistance of CIMMYT wheat lines due to combinations of 1-2 moderate seedling resistance gene and 2-3 adult plant resistance genes resulting in durable resistance. Therefore, it is very urgent to expand the resistance sources and identify new resistance genes for pyramiding more genes biotechnology methods to develop new wheat varieties with durable rusts resistance and good agronomic traits. This plays an important role for controlling stripe rust in China by improving the resistance level of wheat variety overall.

【Objective】 Mining the key drought-resistant genes of maize, revealing its drought-resistant molecular mechanism, and providing genetic resources and theoretical guidance for the cultivation of new drought-resistant maize varieties.【Method】Transcriptome data combined with weighted gene co-expression network (WGCNA) and screening methods for physiological and biochemical indicators of drought resistance were used to identify ZmPAL genes associated with drought resistance and rewatering. Genome-wide analysis of the genes encoding PAL was performed using bioinformatics methods. Quantitative real-time fluorescence PCR (qRT-PCR) was used to detect the expression of ZmPAL genes under drought treatment conditions, as well as the expression characteristics of ZmPAL5 among different inbred lines and the expression patterns in different tissues. Finally, genetic transformation was used to analyze the drought resistance function of ZmPAL5 in maize, and the deletion-type Arabidopsis mutant was analyzed for drought resistance with the help of CRISPR/Cas9 technology for the PAL5 homologous gene.【Result】Nineteen maize ZmPAL genes were identified, six of which were clustered on chromosome 5 and encoded proteins that were mostly hydrophilic acidic proteins and relatively evolutionarily conserved in the PAL family of genes. The promoter region of ZmPAL genes contained a large number of cis-acting elements associated with hormonal and abiotic stress responses. Six core genes were identified, four of which were significantly up-regulated for expression after drought treatment. In particular, ZmPAL5 showed an 8.57-fold increase in expression after drought stress. The expression level of ZmPAL5 was found to be significantly higher in the drought-resistant inbred line Zheng 8713 than in the drought-sensitive inbred line B73 under both drought stress and rewatering treatments. Meanwhile, ZmPAL5, a constitutively expressed gene, showed a high level of expression in young stems. Overexpressed ZmPAL5 maize grew well under drought stress, and its relative water content, lignin, chlorophyll, soluble protein, proline content, and activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were 1.52, 1.49, 1.47, 1.43, 1.44, 1.41, 1.53, 1.41, and 1.35 times, but the malondialdehyde content was 0.65 times that of the wild type. The PAL5-deficient Arabidopsis mutant was sensitive to drought. Under drought stress, its physiological and biochemical indexes showed the opposite trend to those of overexpression of ZmPAL5 maize. 【Conclusion】 Six core genes (ZmPAL3, ZmPAL5, ZmPAL6, ZmPAL8, ZmPAL11, and ZmPAL13) were screened in response to drought stress, in which the expression of ZmPAL5 was positively correlated with drought resistance. ZmPAL5 positively regulated the drought resistance and resilience of the plant by influencing the content of osmotically regulated substances and antioxidant enzyme activities.

【Objective】Eestern and Southern Gansu is one of the epidemic centers of stripe rust and over-summering region for Puccinia striiformis f. sp. tritici (Pst) with continuous emergening of new Pst races in Northwestern China. The objective of this study is to analyze the genetic architecture of stripe rust resistance in winter wheat cultivars grown in those regions since 1990s for a better genetic diversity control of the disease, breeding of durable resistant cultivars, sustainable green and healthy ecological agriculture in Southern Gansu. 【Method】The seedling and adult plant stage resistance to the prevailing Pst races CYR33, CYR34, etc. of 117 wheat cultivars (lines) were evaluated at greenhouse in 2021 and field trials in Qingshui of Gansu and Pixian of Sichuan, respectively, during 2019-2020 and 2020-2021 cropping seasons. Molecualr markers for 15 Yr genes were also applied to detect the presence of known stripe rust resistant genes. 【Result】Of the 117 varieties and lines tested, thirty-four (29.1%) were found to perform adult plant stage resistance (APR) in the field, among these, 25.6% and 3.4% of cultivars were released in Southern Gansu, and Eastern Gansu, respectively. Another 25.6% susceptible cultivars from Southern Gansu exhibited slow rusting with disease severity (DS) less than 20%. Eighty-two cultivars (70.1%) were resistant to the race CYR33 of Pst at the seedling stage. Among them, 67 (57.3%) and 15 (12.8%) were planted in Southern and Eastern Gansu, respectively. However, only seven (6.0%) of the total entries were resistant to the dominant race CYR34 at the seedling stage, and all of these were cultivars from Southern Gansu, such as Lantian 131 etc. The stripe rusts resistant cultivars named as Lantian, Zhongliang, and Tianxuan series at both seedling and adult plant stages were mainly released after 2010. Molecular markers screening identified the presence of Yr9 (49.6%), Yr10 (1.7%), Yr17 (12.8%), Yr18 (7.7%), Yr26 (12.8%), Yr28 (20.5%), Yr29 (10.3%), Yr30 (34.2%), Yr41 (2.6%), Yr46 (16.2%), YrZH22 (15.4%) and YrZH84 (27.4%) in some cultivars, preferly as 2-5 genes combinations in 73 (62.4%) cultivars. Pyramiding of YrZH84, YrZH22, and Yr17 with other stripe rust resistance genes could provide better disease resistance than other gene combinations. In addition, high frequency of Yr10, Yr17, Yr18, Yr28, Yr29, Yr30, Yr41, and Yr46 was detected in wheat cultivars grown in the dry highland Pst oversummering region. However, Yr26, Yr30, YrZH22, and YrZH84 were mainly identified in wheat cultivars of the valley Pst overwintering region, indicating significant genetic architecture difference for the stripe rust resistance genes between the cultivars of the oversummering and overwintering regions. Higher genetic diversity of stripe rust resistance genes was found in the cultivars of the oversummering region, compared with that released in the overwintering region. 【Conclusion】Our results revealed the current status of stripe rust resistance genes and their utilization in winter wheat cultivars of Gansu, the northwest oversummering region for Pst of China, in the past 20 years. Diversification of stripe rust resistance genes have been successfully applied in the winter wheat breeding program to develop commercial wheat cultivars and lines for sustainable control of the stripe rust disease. The development of wheat cultivars with stacked stripe rust resistance genes has solved the historical problem of wheat cultivars with narrow genetic background and mono-resistance gene, domonstrating the successful control of wheat stripe rust epidemics using genetic diversity of wheat resistance gene in this region. The present study provides theoretical basis for genetic diversity control of stripe rust disease and set an example for the sustainable green ecological agriculture by breeding wheat cultivars with durable disease resistance.

【Objective】 This study aimed to investigate the impact of cover crops (wheat and common vetch) on the growth of Chinese cabbage seedlings and the structure of the soil microbial community. The findings could provide the theoretical and technical support for using wheat and common vetch cover crops to alleviate continuous cropping obstacles in Chinese cabbage production. 【Method】In this experiment, there were four treatments: wheat cover crop treatment (W), common vetch cover crop treatment (P), mixture of wheat and common vetch treatment (WP), and no cover crop treatment (CK). The effects of different cover crop treatments on the growth of Chinese cabbage seedlings were studied. Moreover, the effects of wheat and common vetch cover crops on the microbial community of Chinese cabbage rhizosphere were also investigated through qPCR and Illumina MiSeq techniques. In addition, Spearman correlation analysis was conducted to identify the key soil microbial taxa related to Chinese cabbage growth. Then, the changes in soil chemical properties on soil microbial community structure were explored by environmental factor correlation analysis. 【Result】Compared with CK, the cover crop treatments had positive effects on Chinese cabbage growth and decreased soil electrical conductivity (EC) value. The mixed cover crop treatment significantly decreased soil available potassium content, whereas wheat cover crop treatment increased soil pH. The qPCR results showed that the abundance of soil bacterial community was not significantly affected by the cover crop treatment, but increased the abundance of soil fungal community. Both common vetch cover crop treatment and mixed wheat and common vetch cover crop treatment significantly reduced the abundances of Bacillus spp. and Pseudomonas spp. communities. The Illumina MiSeq analysis showed that the relative abundance of genus TM7a was significantly increased by cover treatments, while the relative abundances of Leptolyngbya_EcFYyyy-00, Lophotrichus, Acaulium, and Sodiomyces were decreased. The mixed cover crop treatment significantly increased the relative abundance of Sphingomonas and Massilia and significantly decreased the relative abundance of Fusarium. Spearman correlation analysis showed that Sphingomonas, TM7a, Massilia, and Gemmatimonas were positively correlated with growth. Leptolyngbya_EcFYyyy-00, Acaulium, Lophotrichus, Sodiomyces, and Fusarium were significantly negatively correlated with the growth of Chinese cabbage. Moreover, these cover crop treatments influenced bacterial and fungal diversity indices. The Shannon index and inverse Simpson index for soil bacterial community and Shannon index of soil fungal community significantly decreased in cover common vetch treatment. In contrast, the inverse Simpson index of soil fungal community was increased. The mixed cover crop treatment increased the fungal Shannon index, while the inverse Simpson index of soil fungal community decreased. Principal Coordinates Analysis (PCoA) showed significant differences in soil microbial community structure, with soil EC value as a major environmental factor affecting the structure.【Conclusion】The cover crop treatments exhibited growth-promoting effects on Chinese cabbage seedlings, and the best effect was found in the mixed cover crop treatment. The relative abundances of some Sphingomonas, TM7a, Massilia, other potential growth-promoting bacteria were increased in the cover crop treatments. The relative abundances of some potential plant pathogens Leptolyngbya_EcFYyyy-00 and Fusarium were decreased and the relative abundance of potential biocontrol agent Chaetomium was increased in the mixed cover crop treatment.

【Objective】Canopy activity is an important indicator of wheat growth and development. Identification the loci for canopy activity related traits and their relationships with grain yield (GY) related traits can provide theoretical support for the dissection of genetic structure of yield trait and assisted wheat breeding.【Method】A total of 166 wheat varieties originating from both domestic and international sources were planted in Anyang of Henan province and Suixi of Anhui province in cropping seasons. With the integrated physical map containing 326 570 SNP markers from the wheat 90K and 660K chips, genome-wide association studies for normalized difference vegetation index at seedling stage (NDVI-S) and 10 days after flowering (NDVI-10), and chlorophyll content in flag leaf at 10 days after flowering (Chl-10) were carried out. The results were compared with the previous study for GY related traits using the same material. 【Result】Analysis of variance (ANOVA) showed highly significant effects (P<0.01) of genotypes, environments and genotype×environment interactions on NDVI-S, NDVI-10 and Chl-10, with broad-sense heritabilities (h2 b) of 0.81, 0.81 and 0.91, respectively. Thirteen, 12 and 15 loci were detected to be significantly correlated with NDVI-S, NDVI-10 and Chl-10, respectively, among which 12, 11 and 12 were new, and five loci were associated with two or more traits. The number of favorable alleles for NDVI-S, NDVI-10 and Chl-10 ranged from 4 to 11, 3 to 11 and 4 to 12, respectively, in the 166 wheat varieties, and the phenotypic values increased with the accumulation of favorable alleles. NDVI-S showed significant (P<0.01) and positive correlations with thousand-kernel weight, kernel length and kernel width. Chl-10 was significant positively correlated with GY and flag leaf width (P<0.01), whereas significant negatively correlated with spike number per unit area, plant height and uppermost internode length (P<0.01). Seven pleiotropic loci were detected co-related with both GY and canopy activity related traits.【Conclusion】NDVI-S can be directly used for selection of yield traits. The stable and pleiotropic loci detected in this study can be used for marker-assisted selection.

【Objective】In arid and semi-arid regions, the water and nutrients are scarce in the soil. The phosphorus use efficiency between different wheat genotypes varies greatly. Therefore, identification of low phosphorus-tolerant germplasm and mapping of related loci is helpful for genetic improvement of wheat. 【Method】Using 282 Shanxi wheat varieties as materials, twelve seedling morphological indicators were investigated under three phosphorus concentrations, including SDW, RDW, DW, SFW, RFW, FW, MRL, TRL, RS, RV, RD, and RN. Principal component analysis, membership function analysis, and cluster analysis were used to comprehensively evaluate the low phosphorus tolerance characteristics of different varieties at the seedling stage. On this basis, the trait evolution trend and biomass allocation at seedling stage were analyzed. At the same time, GWAS was used to identify significant loci related to the low phosphorus-related traits. 【Result】The response of different traits to low phosphorus at the seedling stage was different. Lower phosphorus concentrations led to changes in biomass allocation strategy, and shoot growth was less affected by change in phosphorus concentrations than root growth. The decrease in phosphorus concentration inhibited the growth of shoot, and SDW and SFW were significantly reduced. In contrast, low phosphorus promoted root growth, and the indicators of RDW, RFW, MRL, TRL, RV and RN increased significantly. According to the correlation analysis between D-value and morphological indicators, it was found that MRL and RD could be used as selection indicators for low phosphorus tolerance at seedling stage. Based on D-value clustering analysis, 9 low phosphorus tolerant varieties were selected, including Jinmai 46, Jinmai 61, Youmangdahongjing, Hongtumai, Hongheshang, Baikehong, Baixianmai, Huoshaotou, Baishanmai. Analysing trends in trait evolution showed that cultivars were not directly selected for their ability to tolerate low phosphorus. The ability to tolerate low phosphorus decreased first and then increased over time. Before 2010, there was a decreasing trend in the ability of varieties to tolerate low phosphorus, and after 2010, there was an increase in the ability of varieties to tolerate low phosphorus. GWAS stably detected eight loci with R²>10% in three environments, in which 1A_545074550, 2B_489279799, 6A_166899658 and 6A_273060644 were not reported previously.【Conclusion】The MRL and RD can be used as selection indicators for low phosphorus tolerance at seedling stage. A total of nine varieties were selected through comprehensive evaluation of ability in Shanxi wheat to tolerate low phosphorus during seedling stage. Association analysis detected four novel loci associated with low phosphorus tolerance on chromosomes 1A, 2B and 6A, and the results provide germplasm resources and QTL for future low phosphorus tolerance wheat breeding.

【Objective】Exploring the genetic loci and related genes that control cottonseed size traits to lay a foundation for subsequent study on the molecular mechanism cottonseed size formation. 【Method】The upland cotton recombinant inbred line (RIL) population composed of 300 lines was used as the research material. Seven phenotypic traits including cottonseed index (SI), seed length-cutting acreage (SLA), seed length-cutting perimeter (SLP), seed length (SL), seed width (SW), length-width ratio (LWR) and seed roundness (SR) were evaluated in four environments. The RIL population was genotyped by liquid phase chip strategy. The high-quality single nucleotide polymorphism (SNP) markers and phenotypic data were subjected to perform genome-wide association study (GWAS), and quantitative trait nucleotides (QTNs) associated with cottonseed size-related traits were mined. The genetic effects of QTNs were analyzed to identify candidate genes. 【Result】Seven cottonseed size-related traits showed a continuous normal distribution in four environments, which expressed a sizable phenotypic variation. The coefficient of variation ranged from 1.82% to 10.70%. The influencing effect on trait formation were basically as genotype>environment>genotype × environment, indicating suitability for GWAS analysis of these results. Correlation analysis showed that the seed index was significantly correlated with SLA, SLP, SL and SW, and LWR was significantly correlated with SR, indicating the possible existence of pleiotropic loci. GWAS was performed using the 3VmrMLM model, and a total of 47 QTNs were associated with these seven traits. A total of 11 QTNs were associated on chromosome A07, of which three physical loci in the region of 71.99-72.87 Mb, A07:71993462, A07:72067994 and A07:72198802 were very close and simultaneously associated with SI, SLA, SLP, SL and SW in four environments. The average value of R2 between markers was>0.8 (P<0.001), showing a large linkage disequilibrium. Genetic effect analysis showed that there were two haplotypes in this region. Among these cottonseed size relating traits, haplotype Ⅱ and haplotype I were significantly different, indicating that these loci directly affected cottonseed size traits and could be used for molecular marker-assisted selection. The expression patterns of the genes in the interval were analyzed using TM-1 transcriptome data. The results revealed that Gh_A07G1767 was preferentially expressed and Gh_A07G1766 specifically expressed at the stage of cottonseed development. These results speculated that these genes may play an important role in the growth and development of cottonseed.【Conclusion】47 QTNs were identified, and two candidate genes related to cottonseed development were screened.

Bt toxin is a macromolecular protein derived from Bacillus thuringiensis with special insecticidal function. Its preparation and transgenic crops have been widely used in pest control, and have produced huge economic and social ecological benefits. Exploiting and improving the application value of Bt toxin is a hot spot of continuous research. In particular, as the structure and function of Bt toxin and its mechanism of action appear clearer, it has created conditions for its functional modification and innovative application. As a result, the related research has flourished and achieved remarkable results. A large number of studies have shown that strategies such as site directed mutagenesis, domain replacement or fusion, and anti-idiotype antibody simulation are effective means to rationally design novel insecticidal proteins with higher activity, greater stability, wider insecticidal spectrum and higher non-target biosecurity. Those novel insecticidal proteins are different from parent Bt toxins, of which are mutants, structural heterozygotes and even functional effector antibodies. In addition, it is also an important approach to promote the application value of Bt toxin by use of innovative synergistic strategies such as catalytic toxin activation, driving toxin-targeted receptor binding, promoting toxin expression and the synergistic effect of combination or co-expression of homologous or heterologous insecticidal materials. This paper summarizes the structure and function of Bt toxin and its mechanism of action. It also reviews the research progress in rational design of novel insecticidal proteins such as mutants, structural heterozygotes and functional effector antibodies based on Bt toxin function modification, and innovative application strategies based on Bt toxin function enhancement. The future development trend and potential shortcut of rational design and innovative application strategy for insecticidal protein based on Bt toxin were discussed. Furthermore, the author’s team combined it with the latest achievements in targeting design and development of the insecticidal function effector antibodies simulating Bt toxin. This paper is expected to provide more comprehensive and valuable literature information and enlighten ideas for the related research based on Bt toxin.

【Objective】 In order to provide theoretical basis for molecular breeding of soybean drought resistance, the different evaluation indexes of drought resistance were comprehensively used to screen soybean germplasm with drought-resistance, and the candidate drought-tolerant genes were identified. 【Method】 In 2018, 2019, 2020 and 2021, a total of 188 soybean germplasm were used to determine pod number per plant, biomass per plant and yield per plant under well-watered and drought stressed conditions. Drought resistance index (DI), improved drought resistance index (IDI), weighted drought resistance coefficient (WDC) and weighted drought resistance index (WDI) were used to identify drought resistance of soybean germplasm. The single nucleotide polymorphisms (SNP) loci significantly associated with these parameters were detected by genome-wide association study (GWAS), and the candidate genes for drought resistance were screened by RNA-seq and qRT-PCR analysis of soybean seedling leaves under drought stress. 【Result】 The DI, IDI, WDC and WDI of 188 soybean germplasm varied widely, and five classification criteria for each drought resistance parameter were determined by hierarchical classification method. Among them, Liaodou 15, Liaodou 69, Liaodou 14, Jinzhangzi Huangdou, Zhonghuang 606, Kexin 3 and Koreane 4 were identified as first-grade drought resistant by all evaluation methods. By using GWAS for DI, IDI, WDC and WDI, a total of 15 significantly SNP loci were detected under multiple environments, and the contribution rate of these loci to phenotypic variation ranged from 12.46% to 25.60%. There are 226 annotated genes within 200 kb intervals of upstream and downstream for the significant SNP loci. According to RNA-seq and qRT-PCR analysis of drought-resistant cultivar Liaodou 14 and drought-sensitive cultivar Liaodou 21 under drought stress, a total of 32 annotated genes were significantly differentially expressed by drought stress. Among them, eight genes including Glyma.02G182900, Glyma.04G012400, Glyma.06G258900, Glyma.15G100900, Glyma.01G172600, Glyma.04G012300, Glyma.01G172200 and Glyma.04G010300, encodes calcium-dependent protein kinase, universal stress protein A-like protein, G-type lectin S-receptor-like serine/threonine-protein kinase, protein phosphatase 2C, isoflavone reductase, isoflavone reductase homolog, auxin-like protein, and bZIP transcription factor, respectively. 【Conclusion】 Seven germplasm were identified from 188 soybean germplasm by comprehensive application of different drought tolerance parameters. A total of 15 SNP loci significantly associated with drought tolerance parameters were identified by GWAS, and eight candidate genes were identified.

【Background】MicroRNAs (miRNAs) are short RNA molecules of 18-25 nt in length that play an important role in the regulation of follicle development in mammalian ovary granulosa cells (GCs). The previous sequencing of the transcriptome of the ovaries of high and low kidding individuals in Yunshang black goats showed that miR-535 was able to influence the kidding number of goats, but the specific regulatory mechanism was not yet clear. 【Objective】 The aim of this study was to investigate the molecular mechanisms of miR-535 targeting the GRB2 associated binding protein 2 (GAB2) and its associated signaling pathway PI3K/AKT affected the proliferation of goat GCs, so as to further investigate the molecular biological regulation mechanism. 【Method】In this study, three high- and low-fertility Yunshang black goats with the kidding number record of more than two litters were selected, and their follicular ovarian tissues were collected after synchronous estrus treatment for collecting primary GCs. The expression of miR-535 and GAB2 in high- and low-yield ovary tissues of Yunshang black goats was detected by reverse transcription-quantitative PCR (RT-qPCR). The overexpression/inhibitor of GAB2 vector was constructed and the effect of candidate GAB2 on the proliferation of goat GCs was detected using RT-qPCR, Western blot, immunofluorescence, CCK8, EdU and Apoptosis, respectively. The prediction of the targeted relationship between miR-535 and GAB2 was performed with miRDB and miRanda software. The Wild-type and Mutant vectors of GAB2 were constructed and the targeting relationship between miR-535 and GAB2 was detected by the dual luciferase activity assay. The overexpression/inhibitor miR-535 vector was constructed to explore the effect of its GCs proliferation and downstream gene function. 【Result】 The RT-qPCR results showed that the expression of GAB2 was significantly lower in ovarian tissues of Yunshang black goats with high-fertility than that in low-fertility groups, and the expression of miR-535 was the opposite (P<0.05). The results of RT-qPCR and Western blot showed that the expression of CCND2, CDK4 and BCL2 was significantly increased (P<0.05), while the expression of BAX was significantly decreased (P<0.05) after overexpression of GAB2 in GCs, and the inhibition of their expression was the opposite. Both EdU and CCK8 assays showed that GAB2 overexpression significantly promoted the proliferation of granulosa cell, while inhibition of its expression was the opposite (P<0.05). Dual luciferase reporter assays showed that miR-535 inhibited dual luciferase activity in the 3'UTR region of the GAB2 gene. The results of RT-qPCR and Western blot showed that the expression of GAB2, CCND2, CDK4 and BCL2 in goat GCs was significantly decreased and the expression of BAX was significantly increased after miR-535 overexpression, while the opposite was true after miR-535 inhibition (P<0.05). Both EdU and CCK8 assays showed that miR-535 overexpression significantly inhibited the proliferation of GCs, while the opposite was true after miR-535 inhibition (P<0.05). Apoptosis assays showed that miR-535 overexpression promoted GCs proliferation and the opposite was true after inhibition of its expression. The expression levels of the PI3K/AKT signaling pathway marker AKT in goat GCs were significantly increased after inhibition of miR-535, respectively (P<0.05). 【Conclusion】 In conclusion, the results of this study suggested that miR-535 inhibited the proliferation of goat granulosa cells by suppressing the expression of GAB2. These results provided a theoretical basis for further investigation of the biological functions of miR-535 regulating goat GCs.

The self-sufficiency rate of edible vegetable oil is less than 31 percent in China, with a high degree of import dependence. Rapeseed is the only winter oilseed crop with a wide range of suitable planting region, and it is an important source of edible vegetable oil in China. Planting more rapeseed is an important measure to guarantee national edible oil supply security. Making full use of the winter fields in the southern double cropping rice area to promote “rice-rice-rapeseed” production is an important approach to expand the planting area of rapeseed. The area suitable for the “rice-rice-rapeseed” production mode is mainly distributed in the double cropping rice area of Hunan, Jiangxi, Guangxi and Hubei provinces in China, with a potential area of about 1.87 million hm². According to the conditions of temperature and light resources, three suitable areas for the “rice-rice-rapeseed” production include the ample area, tightly balanced area and the constrained area. All the areas require early-maturing rapeseed varieties with a growth period of around 180 days, which are suitable for being sown in mid- to late October and harvested in mid- to late April. Among a total of 75 new rapeseed lines participated in the early-maturity group of the national rapeseed variety trials from 2013 to 2022, the average growth period ranged from 169.3 to 185.5 days, and the average yield was 1 635.90-2 228.55 kg·hm^-2, with 22 varieties out yielded the check variety. There are 72 early-maturing winter oilseed rape varieties with a growth period less than 190 days were registered by the end of May 2023. These varieties are suitable to be used in the “rice-rice-rapeseed” mode, and most of them are hybrid varieties with low erucic acid and low glucosinolate quality. 11 varieties, Yangguang 131, Fengyou 730, Fengyou 320, Fengyou 847, Ganyouza 906, Shengguang 127, Xiangyou 420, Jingyou 69, Fengyou 112, Huayouza 652, Ganyouza 1009, are the most promoted and applied early-maturing winter rapeseed varieties in the “rice-rice-rapeseed” production area, with more than 135 hm² each in 2022. The present varieties can basically meet the early-maturation demand in the ample area. In the tightly balanced and constraint areas, however, the growth period of these varieties is too long. To expand the production and efficiency of rapeseed industry, it is urgently needed to strengthen the policy and financial security in the future, carry out joint breeding projects for short-growth-period winter rapeseed varieties to further improve the yield in the ample area and shorten the growth period in the tightly balanced and constrained areas. Meanwhile, to strengthen the research and promotion of supporting cultivation technology for elite varieties, match well early rice, late rice, and rapeseed varieties are also good measures to support the expansion of rapeseed production in the “rice-rice-rapeseed” production area. In addition, improving agricultural socialized services, expanding agricultural insurance and increasing subsidies for rapeseed planting to ensure production benefit will enhance the farmers’ enthusiasm for the “rice-rice-rapeseed” production.

【Objective】The F₁ hybrid sterility between XI/indica and GJ/japonica severely hinders the utilization of hybrid advantage between subspecies. Exploring the genetic mechanism and identifying new regulatory genes for XI/GJ hybrid sterility will provide theoretical basis for promoting genetic improvement of XI/GJ hybrid seed setting rate. 【Method】A series of stable genetic recombination inbred lines (RILs) containing 95 plant lines were derived from the cross between XI variety Habataki and GJ variety Sasanishiki after 10 generations inbred using single seed descent method. High throughput sequencing was performed on both parents and RILs on the Illumina platform, and the distribution of Habataki pedigree in RILs was analyzed at the whole genome level. The segregation distortion regions were identified, and hybrid sterile related gene loci were screened within the segregation distortion regions, then identified candidate genes through sequence alignment comparison. The targeted gene was knockout to verify the function using CRISPR gene editing technology. 【Result】The hybrid F₁ plants derived from the cross between Habataki and Sasanishiki showed significant heterosis in panicles, grains per panicle, and thousand grain weight, but its seed setting rate significantly decreased. I₂-KI microscopy revealed a significant decrease in F₁ pollen fertility. High throughput sequencing of the entire genome of RILs revealed significant segregation distortion on Chr.1, Chr.3, Chr.5, Chr.6, Chr.7, and Chr.12, indicating that the genotype in this region tends towards the Habataki. Sequence alignment comparison revealed that Sc, S5, and HSA1 are target genes for the segregation distortion on Chr.3, Chr.6, and Chr.12. The CRISPR gene editing mutants with a knock-out Sc-Haba-3 allele in Habataki successfully improved the pollen fertility and seed setting rate of F₁ hybrid with Sasanishiki. A complex structural variation was found between Sasanishiki and Habataki in the segregation distortion of Chr.1. A 24.7 kb segment containing 4 predicted genes in the Sasanishiki genome was replaced by a 64.8 kb segment containing 10 predicted genes in Habataki, the structural variation may involve in controlling the hybrid sterility of XI and GJ cross. 【Conclusion】This study detected multiple XI/GJ hybrid infertility related loci, and successfully improved F₁ fertility by using CRISPR gene editing to knock out multiple copies of Sc in Habataki, locking in the target gene in the Sd region of Chr.1.

【Objective】The two main types of allotetraploid cotton that are currently cultivated are upland cotton, known for its high yield and good adaptability, and island cotton, which boasts excellent fiber quality but lower yield. EXO70, a vital subunit of the exocyst complex, plays a significant role in plant growth, development, and stress response. By identifying and analyzing members of the EXO70 gene family in upland and island cotton at the whole-genome level, and studying their functions in fiber development and environmental adaptation, we can shed light on the molecular basis for the differences in traits between these two varieties. 【Method】The reference sequences of EXO70 protein in Arabidopsis were obtained from the TAIR database. HMMER, ExPASy, MEME, TBtools, and other analysis tools were used to identify and analyze the members of EXO70 gene family in the genomes of upland cotton TM-1 and island cotton Hai7124. The similarities and differences in gene expression patterns, correlations with crucial agronomic traits, and stress responses of this family were systematically compared. 【Result】Through genome-level analysis of upland cotton and sea-island cotton, 54 EXO70 family members were identified in both upland and sea-island cotton, which could be divided into eight subgroups based on phylogenetic analysis. Orthologous genes between upland cotton and sea-island cotton can be paired one-to-one and are distributed across the 20 chromosomes of both species. The majority of the members have single exons, while 12 pairs of homologous genes displayed significant differences in the reading frame sequences. Most orthologous genes in Gossypium hirsutum and Gossypium barbadense display similar expression patterns, but differences in expression levels are observed during the same fiber development stage, such as GH_A04G1208 and its orthologous gene GB_A04G1253 in subgroup A. Single gene association analysis revealed that more genes were associated with fiber quality traits in sea-island cotton, while more genes were associated with yield traits and environmental adversity sensitivity in upland cotton. Some trait association differences resulted from genetic structural differences between Gossypium hirsutum and Gossypium barbadense. Under different stresses, upland cotton showed a significantly higher number of induced genes compared to sea-island cotton. 【Conclusion】The sequence structure and gene expression patterns of the EXO70 family were found to be relatively conserved in both upland and island cotton during the formation, differentiation, and domestication of tetraploid cotton. However, in terms of EXO70 family members, island cotton had more genes related to fiber quality traits, while upland cotton had more genes related to yield traits and exhibited greater sensitivity to environmental stress.

【Objective】 As an important negative transcriptional regulator in cotton MADS-box gene family, AGL16 plays an important role in resisting drought and salt stress. Virus-induced gene editing (VIGE) was used to screen sgRNAs that knockout the cotton GhAGL16 and verify the specificity of these sgRNAs, which laid a foundation for the creation of cotton agl16 mutants.【Method】 Three sgRNAs could knockout GhAGL16 were predicted based on the actual GhAGL16 genomic sequence cloned on subgroup A and D in cotton YZ-1; Three CLCrV-AtU6-26::GhAGL16-sgRNAs vectors were constructed based on the cotton leaf crumple virus (CLCrV)-mediated VIGE system; The expression of Cas9 in Cas9 over-expression (Cas9-OE) plants was detected by qPCR to determine whether Cas9 was stably genetically expressed; Three CLCrV-AtU6-26::GhAGL16-sgRNAs vectors were transformed respectively into Cas9-OE cotton cotyledons and detected the mutations of the three targets by PCR/RE; The secondary structures of three GhAGL16-sgRNAs were analyzed by bioinformatics; Hi-TOM high-throughput sequencing was performed on mutant plants to determine the efficiency of gene editing. Meanwhile, the off-target rate of GhAGL16-sgRNA2 mutant plants were identified to detect the specificity of gene editing.【Result】 Three sgRNAs capable of simultaneously knocking out GhAGL16-A and D subgroups were successfully constructed. The detection results of Cas9 expression showed that Cas9 was stably expressed in different Cas9-OE cotton plants. PCR/RE mutation detection results showed that GhAGL16-sgRNA2 could be effectively used for the knockout of GhAGL16. Different mutation types with base deletions appeared at the target sites of cotton subgroups A and D, while GhAGL16-sgRNA1 and GhAGL16-sgRNA3 were two invalid sgRNAs. The secondary structure analysis results of three GhAGL16-sgRNAs indicated that GhAGL16-sgRNA1 and GhAGL16-sgRNA3 might have a phenomenon that the guide sequence was easy to pair with other sequences and difficult to unwind, which interfered with the recognition of the target site by the guide sequences and lead to the invalid sgRNA. To further quantify the editing efficiency of GhAGL16-sgRNA2 on GhAGL16, the mutation detection results of each Cas9-OE plant transformed with CLCrV-AtU6-26::GhAGL16-sgRNA2 showed that six of the nine Cas9-OE plants were mutated, with a mutation efficiency of 66.67%. In addition, Hi-TOM high-throughput sequencing results showed that the editing efficiency of GhAGL16-sgRNA2 for GhAGL16 was 13.69%-54.42%. The off-target identification results showed that no off-target phenomenon was detected at the four predicted off-target sites, indicating that GhAGL16-sgRNA2 not only has high gene editing efficiency, but also has specific gene editing specificity.【Conclusion】 A sgRNA that can effectively knocking out the GhAGL16 was obtained by transforming Cas9-OE cotton using the CLCrV-mediated VIGE system, providing an ideal sgRNA for creating cotton agl16 mutants.

【Objective】Long non-coding RNAs(lncRNAs) are a group of RNA molecules longer than 200 bp with no protein coding capacity, which are involved in various biological regulatory processes. In this study, we aim to analyze the RNA-sequencing data of two Gossypium arboreum isogenic lines, a fuzzless mutant (GA0149) and its wildtype (GA0146), to identify the lncRNA involved in early fuzz fiber development, providing a foundation for investigation the mechanism of fiber development. 【Method】We collected 0 DPA, 3 DPA and 5 DPA ovule and 8 DPA ovule and fiber from the G. arboreum fuzzless mutant GA0149 and its isogenic line GA0146 with normal fuzz and lint fibers, were used for RNA-seq to identify lncRNA and predict their target genes. Differentially expressed mRNA (DE-mRNA) and lncRNA(DE-lncRNAs) between the samples were identified. The KOBAS software was used to predict the KEGG enrichment pathways which DE-lncRNAs targets were involved in. To ensure the quality of high-through sequencing, 25 DE-lncRNAs were selected for RT-qPCR detection. 【Result】We identified 15 339 lncRNA-encoding transcripts that 11 595 lncRNAs were located to intergenic regions, 2 428 lncRNAs were classified as antisense lncRNAs, 350 were categorized as intronic lncRNAs and 966 belonged to sense lncRNAs. Compared to mRNAs, lncRNAs in Asian cotton showed shorter exons and lower GC content. Most of lncRNAs had cis-regulatory effects on their neighboring mRNAs. We identified 1 932 differentially expressed (DE) lncRNAs, with 8 134 predicted DE-lncRNA target genes. Further analysis showed that 788 genes (mRNA) were differentially expressed (DE-genes) during four fiber development stages. KEGG enrichment pathways analysis showed that DE-target-mRNAs were mainly enriched in plant hormone signal transduction and protein processing in endoplasmic reticulum. Co-expression network analysis revealed that lncRNA (MSTRG.454250.3) and its associated target genes showed identical expression trends during four fuzz fiber development stages, while lncRNAs (MSTRG.454261.4) and its associated target genes showed contrary expression tendency, exhibiting dramatic higher expression in fuzzless GA0149 compared to wildtype GA0146. The results of RT-qPCR analysis confirmed the authenticity of our RNA-seq data.【Conclusion】A total of 26 specifically expressed lncRNAs were identified which related to cotton fuzz fiber development process. We further confirmed that these lncRNAs affected the fuzz fiber development by regulating the expression of indole-3-acetic acid-amido synthetase (Ga03G2421) and Auxin-responsive protein (Ga05G1344) in the plant hormone signal transduction pathway.

【Objective】The study investigated the impact of salicylic acid (SA) priming on the germination vigor and physiological response of rice seeds under low temperatures. It aimed to reveal the expression patterns of genes related to abscisic acid (ABA) and gibberellin (GA) metabolic pathways as well as cell wall relaxation genes by SA priming. This research provided a theoretical basis for the study of rice seed germination at low temperatures.【Method】Using indica three-line hybrid rice Taifengyou 208 seeds as materials, the effects of SA on seed germination vigor and physiology responses under low temperature were analyzed through seed priming treatment, and the expression patterns of genes related to ABA, GA and expansin in response to SA were analyzed by qRT-PCR.【Result】Low temperature (15 ℃) significantly delayed the germination process of rice seeds. In seeds germinated at low temperatures for one day, the endogenous SA concentration was 1.7 times higher than that at normal temperatures (28 ℃). However, for five-day-old seedlings, the SA concentration under low temperature was only 0.6% of that at normal temperatures. SA could effectively enhanced germination vigor of seeds at low temperature, with the most significant effects observed at 2 000 μmol·L^-1 SA. This concentration significantly increased the germination index, vigor index, shoot length, root length, fresh weight, and dry weight of seeds under low temperature conditions. Notably, the vigor index was three times that of non-primed seeds (CK1) and two times that of water-primed seeds (CK2). In terms of physiological indexes, SA priming increased the contents of soluble sugar, proline and active oxygen, enhanced the activities of total amylase, β-amylase, superoxide dismutase (SOD) and catalase (CAT), and decreased the content of malondialdehyde (MDA). Compared with CK1, 2 000 μmol·L^-1 SA decreased the ABA content by 79%, and increased the IAA and GA₁ contents by 32.2% and 2.66 times, respectively. In terms of gene expression, the expression levels of ABA synthesizing genes OsNCED2 and OsNCED3 were decreased by 94.26% and 90.24% compared with CK1 in seeds primed by 2 000 μmol·L^-1 SA, respectively, whereas the expression levels of ABA decomposing genes OsABA8’ox2 and OsABA8’ox3 were 5.9 and 3.9 times higher than that of CK1, respectively. Compared with CK1, SA priming significantly upregulated the expression of GA synthesizing genes OsCPS1, OsKAO and OsGA20ox1, while it significantly downregulated the expression of GA decomposing genes OsGA2ox2 and OsGA2ox6. In several candidate genes encoding cell wall relaxation protein, e.t. expansin, all but OsEXPB11 were significantly upregulated to some extent by priming. Compared with CK1, 2 000 μmol·L^-1 SA increased the expression levels of OsEXPA2, OsEXPB4 and OsEXPB6 to 12.2, 5.9 and 6.1 times, respectively.【Conclusion】SA priming can significantly alleviate the impact of low temperatures on rice seed germination and seedling growth, which is likely due to SA enhancing the activity of antioxidant enzymes such as SOD and CAT, reducing the production of MDA, and increasing the content of soluble sugars and proline, thereby strengthening the tolerance of seeds and seedlings to low temperatures. On the other hand, SA priming decreases endogenous ABA content, increases GA₁ content, enhances the activities of total amylase and β-amylase, and promotes the expression of genes related to cell wall relaxation, thus facilitating seed germination and seedling growth at low temperature.

【Objective】 Analyzing the evolutionary patterns of genetic diversity of wheat germplasm resources, providing richer and more diverse original parental materials for parental selection and variety selection in wheat breeding in Shanxi Province.【Method】 Using 323 landraces and 105 cultivated varieties as natural populations, a 55K SNP chip was used to perform whole genome scanning on 428 natural populations, analyzing genetic diversity, genetic structure, principal components, genetic clustering, and phylogenetic relationships among varieties. 【Result】 The distribution of SNP loci on 21 chromosomes ranged from 329 to 1 639, with an average of 1 152. The distribution range of 7 partially homologous groups is 2 154-3 852, with an average of approximately 3 456. The distribution pattern of the genome is: B genome>A genome>D genome. Genomic annotation polymorphism markers have the highest distribution among gene regions, accounting for about 50%. Analysis shows that SNP loci cover 21 chromosomes, 7 homologous groups and 3 genomes, but their distribution varies, with a polymorphism rate of 45.60%. The average observed heterozygosity of the entire population (0.0185) was lower than the expected heterozygosity (0.4992). The changes in the average shannon wiener index and polymorphism information content of the entire natural population were not significant. Comparing the diversity parameters of natural populations, it was found that the genetic diversity of the population is not high, the genetic diversity of cultivated varieties is slightly higher than that landraces. The population structure analysis of natural populations divides the population into two major groups. Group I has 307 materials, mainly landraces. Group Ⅱ has 121 materials, mainly cultivated varieties. The natural groups were divided into five groups by both principal component and cluster analysis. The average genetic distance between the varieties in group I is 0.21831, with a range of 0.00127-0.72461. The average genetic distance between varieties in group Ⅱ is 0.14619, with a range of 0.00038-0.76489. The varieties in group Ⅲ the average genetic distance between the varieties of group Ⅳ is 0.16521, with a range of 0.00049-0.43033. The average genetic distance between varieties of group Ⅳ is 0.17643, with a range of 0.00118-0.60496. The average genetic distance between varieties of group V is 0.12039, with a range of 0.00042-0.37032. It can be seen that the variation of genetic distance between wheat varieties is large in Shanxi Province. However, the average genetic distance value is low, the clustering classification differentiation is obvious. The genetic relationship between varieties in the middle of the group is relatively close. Comparison shows that the average genetic distance of group I and group Ⅳ is higher than that of group Ⅱ, group Ⅲ and group V. The genetic distance variation of group I and group Ⅳ is higher than that of group Ⅲ and group V. It can be seen that the genetic distance of cultivated varieties is generally greater than that of landraces.【Conclusion】 The 55K SNP chip was used to analyze the genetic diversity of Shanxi winter wheat germplasm resources, clarifying the distribution characteristics of genetic diversity at the genomic level between Shanxi wheat cultivated varieties and landraces. The introduction of exogenous genes into cultivated varieties is beneficial for improving genetic diversity, while the genetic diversity of landraces is relatively low. At the same time, the genetic relationships of very few varieties are polarized, so it should be rationally used differently in subsequent utilization.

【Objective】The twin-screw extrusion process was used to produce extruded rice products with P. eryngii powder and rice flour as raw materials, and the predicted glycemic index of the products was analyzed to provide technical support for the development of edible mushroom extruded rice products with comprehensive nutrition and low glycemic index. 【Method】 The content of protein, crude fiber, amino acid and fat of extruded rice with 20%, 40% and 60% P. eryngii powder were determined. RVA rapid viscosity analyzer and rotary rheometer were used to analyze the gelatinization properties and rheological properties of P. eryngii powder with different additive amounts. The internal structure, color, texture properties, starch hydrolysis rate, predicted glycemic index (pGI) and sensory score of extrusion-rice with different dosage of P. eryngii were analyzed by scanning electron microscopy, colorimeter, texture analyzer, and in vitro digestion and sensory evaluation. 【Result】Compared with blank extruded rice, the content of protein, crude fiber and amino acid in extruded rice was significantly increased by adding P. eryngii powder, and the content of protein was increased by 71.84%, 70.19% and 96.70%, and the content of crude fiber was increased by 14.22%, 28.88% and 49.81%, respectively. The total amino acid content increased by 40.98%, 58.96% and 66.03%, respectively. The gelatinization and rheological properties of the mixed powder system showed a decreasing trend with the increase of the added amount of P. eryngii powder, and the peak viscosity, valley viscosity, final viscosity, disintegration value and recovery value gradually decreased, and G'and G" gradually decreased. The typical weak gel accounted for a large proportion of elasticity, and the added amount of 20% P. eryngii powder was the closest to the powder parameters of rice flour. Compared with the blank extruded rice, it was found by scanning electron microscopy that the cross section pores of extruded rice increased with the increase of the powder content, and the structure tightness decreased. Among them, 20% of extruded rice had tight structure and less cracks. The values of L^* and b^* in extruded rice of P. eryngii by colorimeter decreased significantly, and a^* increased first and then decreased. The water absorption rate and cooking loss rate after cooking increased with the addition of P. eryngii powder, but the expansion rate had no significant effect, and the cooking characteristics of 20% P. eryngii extruded rice were the best. The hardness, elasticity, adhesiveness and chewability of the extruded rice increased with the addition of P. eryngii powder, while the cohesiveness and resilience first decreased and then increased. Starch digestibility, rapidly digestible starch (RDS), slowly digestible starch (SDS) and predicted glycemic index (pGI) also increased with the increase of P. eryngii powder addition, but they were all lower than that of normal rice and blank extruded rice, while resistant starch (RS) content was greater than that of the two groups and increased with the increase. The predicted glycemic index (pGI) value of 20% P. eryngii extruded rice was the lowest 60.18, which was 20.60 lower than that of normal rice, and the content of resistant starch (RS) was the highest. Sensory evaluation showed that the appearance structure, palatability, taste, cold rice texture and comprehensive score of P. eryngii extruded rice decreased with the increase of the amount of P. eryngii powder, while the odor score decreased first and then increased. From the point of view of the score, 20% of P. eryngii extruded rice was 66.75 scores, which was the most acceptable to consumers. 【Conclusion】 20% of extruded rice with P. eryngii was nutrient-rich and had suitable texture indexes. The predicted glycemic index (pGI) was 60.18, which was 20.60 lower than that of normal rice. The nutritional value of extruded rice was significantly improved by adding P. eryngii powder, and the food quality was better.

【Objective】The aim of this study was to understand the variations of grain nitrogen (N) content and its relationships with yield formation as well as uptake, transfer and partitioning of nitrogen, phosphorus, and potassium (NPK) within high-yielding wheat cultivars, which was of great significance for screening and breeding superior wheat cultivars with high yield and grain N content, and for nutrient management in green production of wheat with high yield and high quality in drylands.【Method】Field experiments were carried out, and 14 high-yielding wheat cultivars of similar yields and different grain N content were cultivated on the typical dryland area of the Loess Plateau from 2017 to 2022. Differences in grain N contents of high-yielding wheat cultivars and its relation to yields, yield components as well as N, P and K content in different organs were analyzed. Meanwhile, biomass accumulation and yield formation as well as uptake, transfer and partitioning of NPK in response to fertilization were investigated.【Result】Significant positive correlation was found between the grain N content and 1000-grain weight of wheat cultivars, and for each 1.0 g increase of the 1000-grain weight, the grain N content increased by 0.3 g·kg^-1. The grain N content showed significant differences in the tested wheat cultivars, with the mean of high-N group being 24.9 g·kg^-1, and 16% higher than that of the low-N group (21.5 g·kg^-1), respectively, while the average yields were not significantly different from each other of the two groups. The yield, biomass and spike number of high-N group exhibited higher response to N and P fertilizer application. The grain P content and straw K content of the high-N group were higher than the low-N group under different fertilization conditions, and the increases of N, P and K uptake in grain and shoot were larger than that of low-N group after N and P application. The abilities of N transfer from glumes to grains in the high-N group was greater than that in the low-N group, but the capacities of K transfer from straws to grains and glumes was lower than that in low-N cultivars. The abilities of K transfer from straws to other organs decreased significantly after N application. Application of N, P and K was conducive to increase the partitioning of K from shoots to straws of the high-N group.【Conclusion】The high-yielding wheat cultivars exhibited significant differences in the grain N content. The 1000-grain weight and grain P content of high-N cultivars were higher, its straw K content was also higher, but its capacities of K transfer from straws to grains and glumes was lower. The N, P and K uptake of the high-N group in grains and shoots increased extremely after N and P application. Therefore, to screen and breed superior wheat cultivars with high grain N content on the basis of high yield, the attention should be paid to select the cultivars with high grain 1000-grain weight as well as the strong transferring and partitioning abilities of P to grains and K to straws. The efforts should be also made to cooperate the supply of P, K and N in wheat production, with the purpose to increase the grain N content.

【Objective】Sugarcane brown rust, caused by Puccinia melanocephala H. Sydow & P. Sydow, is one of the most destructive fungal diseases in sugarcane industry, leading to a reduction in sucrose content by 10% to 36%. Previous studies revealed that the major gene(s) for brown rust resistance was located in the Bru1 genomic region. The cloning of crucial candidate genes and their functional investigation should provide important candidate gene resources for breeding new sugarcane cultivars resistant to brown rust.【Method】In this study, the contig-level genomic information of sugarcane cultivar ROC22 was obtained by utilizing the PacBio Sequel Ⅱ sequencing platform, and the Bru1 region associated with brown rust candidate resistance gene was identified, annotated, cloned, and analyzed for tissue specificity, expression patterns in resistant and susceptible sugarcane cultivars, subcellular localization, and transient overexpression.【Result】The results demonstrated that, firstly, using tightly associated molecular markers R12H16 and 9O20-F4 within the Bru1 region, a total of 33 genes were annotated from this region, and five candidate resistance genes (Brrg99, Brrg103, Brrg108, Brrg115, and Brrg116) were selected based on the typical/conserved domains of the resistance genes. Secondly, the full-length sequence cDNA sequence of the Brrg116 gene with an open reading frame of 729 bp and encoding 242 amino acid residues, was cloned from sugarcane cultivar ROC22. The gene sequence was aligned with the genomic databases of Saccharum spontaneum, S. officinarum, and the closely related diploid species sorghum. A high degree of sequence similarity was observed between S. spontaneum and S. officinarum, exceeding 98%. In contrast, its similarity with sorghum was 93.77%. Phylogenetic tree analysis suggests that this gene may originate from S. spontaneum species during sugarcane domestication. qRT-PCR analysis showed its constitutive expression in various tissues of sugarcane cultivars, particularly with the highest expression level in the +1 leaf, which was 5.2 times higher than in the bud. Furthermore, significantly differential expression of Brrg116 was observed at 6 h and 72 h post-inoculation with the brown rust pathogen in resistant and susceptible sugarcane cultivars. Subcellular localization analysis indicated that the encoded protein of this gene was located on the cell membrane. Finally, the Brrg116 gene was transiently overexpressed in Nicotiana benthamiana leaves, followed by inoculation with Fusarium solani var. coeruleum. The color of Nicotiana benthamiana leaves showed a gradual deepening phenotype by 3,3'-diaminobenzidine (DAB) staining. The genes related to hypersensitive response, salicylic acid, and ethylene synthesis had a sustained upregulation pattern, evidencing that the expression of these genes can enhance plant disease resistance.【Conclusion】Brrg116 was constitutively expressed in different sugarcane tissues and in response to brown rust pathogen infection, it showed a rapidly induced expression pattern in the resistant sugarcane cultivar. Overexpression of Brrg116 could trigger defense responses through hormone signaling pathways such as salicylic acid and ethylene. It is thus hypothesized that this gene may play a significant regulatory role in enhancing plant disease resistance.

【Objective】The objective of this study is to perform the genome-wide identification of the maize ACO (1-aminocyclopropane- 1-carboxylate oxidase) gene family, analyze its expression patterns in different organs and developmental stages of maize, as well as in response to exogenous hormones and pathogen infection, and to lay the foundation for clarifying the function of the maize ACO gene family.【Method】Using bioinformatics methods, the ACO was identified in the genome of maize B73 inbred line, and its gene structure, protein physicochemical properties, phylogenetic relationships among family members, and conserved motifs were analyzed. The expression patterns of the ZmACO gene family were analyzed using real-time fluorescence quantitative PCR (qRT-PCR) technology.【Result】Except for ZmACO11, all members of the ZmACO family have Fe²⁺ binding sites and substrate ascorbic acid binding sites. The phylogenetic tree showed that ZmACO2 and ScACO are in the same branch and have a close genetic relationship, with a Bootstrap value of 98. The gene expression analysis indicated that ZmACO2, 5, 9, 15, 20 and 35 were actively expressed at various developmental stages and exhibited dominant expression in leaves, so the six genes mentioned above were selected for the next step of testing. Spraying ethephon resulted in fluctuations in the expression of all six genes mentioned above, the expression level of ZmACO2 was significantly affected, with a variation multiple of about 8 times. The expression levels of these six genes fluctuated within 0-24 h of ethephon treatment. But after 24 h of treatment, all gene expression levels were close to 0. After salicylic acid treatment, the expression level of ZmACO5 was significantly affected, with a variation multiple of about 2 times. The expression levels of other genes were close to 0 at 24 h after treatment. The expression levels of ZmACO9, 35 fluctuated between 3 to 12 h, and the expression levels of ZmACO2, 15, 20 showed a downward trend. In response to biological stress, the expression levels of ZmACO5, 9 showed the greatest changes after inoculation with the Setosphaeria turcica, and on the 10th day after inoculation, the expression levels of these two genes increased by 50 and 60 times, respectively, compared to the control group. After inoculation with the Cochlibolus heterostrophus, the expression level of ZmACO5 changed significantly, with a variation multiple of 40-90 times. After inoculation with Rhizoctonia solani, the expression levels of ZmACO5, 35 showed the greatest changes, reaching 200 times on the 3rd day of inoculation.【Conclusion】The expression changes of ZmACO2, 5, 20 and 35 are most active during the growth and development of maize; The application of exogenous ethephon and salicylic acid can significantly affect the expression level of ZmACO genes. The expression level of ZmACO genes significantly changes after bacterial infection in maize, which is closely related to the response to biological stress.

【Objective】The global warming potential of agro-ecosystem is an important part of affecting global climate change. This study clarified the effects of biochar and straw application on the global warming potential of farmland through field experiments, in order to provide theoretical basis for mitigating climate change and agricultural waste resource utilization. 【Method】In our study, a three-year field positioning experiment was carried out in the winter wheat-summer maize rotation farmland in the Agro-ecosystem Experimental Station in Huantai County, Shandong Province. Four treatments were set up in the experiment: ① control (CK); ② biochar (C); ③ straw return(S); ④ straw return combined with biochar (CS). The nitrogen, phosphorus and potassium fertilizers were applied in all treatments. The nitrogen fertilizer was 200 kg·hm^-2·a^-1 urea, the phosphate fertilizer was 55 kg·hm^-2·a^-1 superphosphate and the potassium fertilizer was 40 kg·hm^-2·a^-1 potassium sulfate. We measured the flux of greenhouse gases (CO₂, N₂O and CH₄) by static chamber-gas chromatography method, calculated the net global warming potential (NGWP) and greenhouse gas emission intensity (GHGI), and analyzed the effect of biochar and straw on the greenhouse gas emissions and the net global warming potential. 【Result】(1) From the emission of greenhouse gases in the three-year experiment, the average annual cumulative Re emissions of S and CS treatments increased by 47.8% and 67.9% (P<0.05), respectively, compared with CK. The average annual cumulative N₂O emission under C treatment reduced by 20.3% than CK treatment (P<0.05), and the cumulative N₂O emission under S and CS treatments increased by 23.6% and 41.4% (P<0.05), respectively. (2) In comparison with CK treatment, soil organic carbon change (ΔSOC) of C, S and CS treatments increased significantly, and the largest increase was in the CS treatment by 150.6% (P<0.05). Compared with the first year, soil organic carbon change (ΔSOC) of C, S and CS treatments increased by 21.7%, 20.8% and 17.8% (P<0.05), respectively. There were significant differences in net global warming potential (NGWP) and greenhouse gas emission intensity (GHGI) among all treatments. Compared with CK treatment, the average annual NGWP of C, S and CS treatments decreased by 163.5%, 171.7% and 273.0% (P<0.05). Compared with the first year, the NGWP of C, S and CS treatments in the third year decreased by 73.4%, 58.8% and 54.7% (P<0.05), respectively. The annual average GHGI of C, S and CS treatments decreased by 236.2%, 253.3% and 388.9% than CK treatment (P<0.05), respectively. In comparison with the first rotation, the GHGI of C, S and CS treatments in the third rotation decreased significantly by 126.3%, 98.2% and 108.6% (P<0.05), respectively. The yield of C, S and CS treatments remained stable with a slight increase, but there was no significant difference between the yield of CK, C, S and CS treatments. 【Conclusion】Compared with applying chemical fertilizer alone, the methods of adding biochar, straw return and straw return combined with biochar could prevent the NGWP without reducing crop yield. Among these treatments, straw return combined with biochar could reduce the net global warming potential to the greatest extent. Therefore, straw return combined with biochar is an effective measure to enhance carbon sequestration and mitigate climate change.

【Objective】 Drought is one of the serious abiotic stresses influencing maize production worldwide. Understanding the molecular mechanisms underlying drought tolerance is of great importance in maize improvement. 【Method】 In the present study, representative maize inbred lines were selected for field drought experiment and the drought tolerance was estimated based on leaf relative water content and anthesis-silking interval. Two inbred lines with contrasting drought tolerance was used for genome resequencing and transposable element insertions were identified. The DNA methylation level of leaf and root tissues under different water treatments of the two lines were measured using Whole Genome Bisulfite Sequencing (WGBS). And the gene expression profiles of these samples were detected by RNA sequencing. The integrative atlas of transposable element insertion/deletion variants, differentially methylated regions and differentially expressed genes in the two lines were constructed. In addition, the transposable element insertion/deletion variant mediated epigenetic regulation of ZCN7, which has been conferred the drought tolerance function in our previous study, was analyzed. 【Result】 The field experiment showed inbred line H082183 showed highest drought tolerance, in which the leaf relative water content and anthesis-silking interval had no significant difference between drought and well-watered treatments. While the Lü28 displayed lowest leaf relative water content and largest anthesis-silking interval under drought. Thus, these two lines were selected for further analysis. A total of 333 754 and 333 296 transposable element insertions were identified in the genome of H082183 and Lü28, respectively. And 89 954 transposable element insertions were polymorphism between two lines. The transposable element insertions, introns and promoters showed higher CG and CHG methylation level than exons and untranslated regions. Furthermore, 41 352 differentially methylated regions were identified between H082183 and Lü28. And 60% of the differentially methylated regions were located in the transposable element insertion\deletion variants and 5 kb flanking regions. The gene expression level showed negatively correlated with CG and CHG methylation. Differentially expression analysis between H082183 and Lü28 obtained 4 196 and 3 500 differentially expressed genes in leaf and root under drought, respectively. The 19.5% and 19.7% of these differentially expressed genes were located in differentially methylated regions. Three LTR transposable element insertions were identified in the 34 kb region of ZCN7 in Lü28 but absent in the genome H082183. And the DNA methylation levels of CG and CHG in this genomic region were significantly higher in Lü28 than H082183 under both drought and well-watered environments, which conferred higher ZCN7 expression in the drought tolerant line H082183. 【Conclusion】 Our results highlight the important role of interplay of transposable element insertions, DNA methylation and gene expression under drought. And gene expression regulation mechanism of ZCN7 relied on the transposable element insertion/deletion variants mediated DNA methylation was proposed.

【Objective】As a new Plant growth regulator, 14-hydroxylated brassinosteroids（14-HBR） increase biological activity by 50% than the traditional Brassicin sterols, while the relation effect of 14-HBR on rapeseed growth, yield and seed coating pesticide were not clear. 【Method】In this study, 14-HBR regulator and pesticide are used to treat the seeds in mid-duration winter rapeseed variety (Yangguang 2009) and early-duration variety (Yangguang 131), investigated germination, seedling growth, insect resistance, and yield, to reveal the interaction effects of environment, variety genotype and 14-HBR. 【Result】0.0075 and 0.015 mg·L^-1 14-HBR treated seed increased significantly germination potential in medium duration rapeseed, but decreased germination potential and germination rate significantly as mixed with pesticide. 14-HBR treated seed had no significant effect on germination rate and germination potential in short duration rapeseed. The 14-HBR showed better biological activity in seedling growth and yield than that of Brassinolide, 0.0075 and 0.015 mg·L^-1Brassinolide increased by an average of 5.19% and 8.15%, 0.0075 and 0.015 mg·L^-1 14-HBR increased by an average of 11.98% and 5.50%, respectively. 14-HBR mixed with seed pesticide of Clothianidin and Thiamethoxam, also increased seedlings weight and yield. The yield of Thiamethoxam and Clothianidin seed treatments increased by 4.7% and 4.6% independently. The yield of mixed with 0.0075 and 0.015 mg·L^-1 14-HBR to Clothianidin increased 6.8% and 3.3%, mixed to Thiamethoxam increased by 3.5% and 8.2%, respectively. 14-HBR did not affect insecticidal activity of Thiamethoxam and Clothianidin to peach bud nymphs and phyllotreta striolata fabricius. 【Conclusion】The study revealed seed treatment with 14-HBR regulator has a positive effect on early growth of rapeseed and increased yield of rapeseed significantly, interacted with planting environment, pesticide type and varieties genotype as traditional regulators, it is necessary to optimize seed treatment technology of 14-HBR regulator to obtain higher harvest yield.

【Objective】In the context of intensified global climate change and frequent meteorological disasters, exploring the significance of meteorological factors on maize yield and accurately predicting maize yield is crucial for enhancing agricultural production and field management. This paper aims to quantitatively analyze the importance of meteorological factors during various growth stages of maize on yield and to establish a highly accurate and reliable maize meteorological yield stacking ensemble learning estimation model for yield prediction.【Method】Using the HP filter method and moving average method, trend yield models for various counties were determined, and county-level meteorological yields were isolated. Three ensemble learning methods (light gradient boosting machine (LightGBM), Bagging, and Stacking) were employed. By analyzing daily meteorological data and maize yield data over 34 years from 596 county-level administrative regions and meteorological observation stations across 12 provinces in China, three maize meteorological yield prediction models based on different ensemble learning frameworks (LightGBM, Bagging, and Stacking) were established.【Result】The HP filter method as the trend yield model was mainly applicable in the regions of Shaanxi, Henan, Jiangsu, and Anhui. Compared to the HP filter method, more counties were suitable for the moving average method, with most counties having the R² distribution above 0.8. Based on a 5-year sliding forecast and model accuracy evaluation indicators, the mean absolute percentage error (MAPE) for the three models on maize yield was below 6%. The Stacking model achieved a MAPE of 4.60%, indicating high prediction accuracy and strong generalizability. The results demonstrate that the maize meteorological yield stack-integrated learning prediction model has higher accuracy and stronger robustness. It effectively utilizes the characteristics and advantages of each base learner to improve prediction accuracy, making it the optimal model for predicting maize yield based on meteorological factors. Furthermore, a quantitative analysis of the impact of 27 meteorological factors during the maize growth stages in 12 provinces, using the random forest feature importance score, is of reference value for crop monitoring and field management.【Conclusion】The three ensemble learning methods, especially the stack-integrated learning model (Stacking), can accurately reflect the spatiotemporal distribution changes in maize yield. The stack-integrated learning model for maize yield based on meteorological factors provides a new method for field management and accurate prediction of maize yield.