Leaves are the main places for photosynthesis and organic synthesis of cotton.  Leaf shape has important effects on the photosynthetic efficiency and canopy formation, thereby affecting cotton yield.  Previous studies have shown that LMI1 is the main gene regulating leaf shape. In this study, the LMI1 gene (LATE MERISTEM IDENTITY1) was inserted into the 35S promoter expression vector, and cotton plants overexpressing LMI1(OE) were obtained through genetical transformation.  Statistical analysis of the biological traits of T₁ and T₂ populations showed that compared to wild type (WT), OE plants had significant larger leaves, thicker stems and significantly increased dry weight.  Furthermore, plant sections of the main vein and petiole showed that the number of cell in those tissues of OE plants increased significantly.  In addition, RNA-seq analysis revealed differential expression of genes related to gibberellin synthesis and NAC gene family (genes containing the NAC domain) in OE and WT plants, suggesting that LMI1 is involved in secondary wall formation and cell proliferation, and promotes stem thickening.  Moreover, GO (Gene Ontology) analysis enriched the terms of calcium ion binding, and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis enriched the terms of fatty acid degradation, phosphatidylinositol signal transduction system, and cAMP signal pathway.  These results suggested that LMI1 OE plants were responsive to gibberellin hormone signals, and altered messenger signal (cAMP, Ca²⁺) which amplified this function, to promote the stronger above ground vegetative growth.  This study found the LMI1 soared the nutrient growth in cotton, which is the basic for higher yield.

The mirid bug Apolygus lucorum (Hemiptera: Miridae) is a polyphagous pest that affects a wide range of host plants. Its control remains challenging mainly due to its rapid reproduction, necessitating an understanding of sex pheromone communication. The recognition of sex pheromones is vital for courtship and mating behaviors, and is mediated by various chemosensory-associated proteins. Among these, sensory neuron membrane protein (SNMP), a CD36-related protein, is suggested to play crucial roles in detecting sex pheromones. In this study, we employed transcriptomic and genomic data from A. lucorum and phylogenetic approaches, and identified four putative SNMP genes (AlucSNMP1a, AlucSNMP1b, AlucSNMP2a, and AlucSNMP2b) with full open reading frames. Expression analysis revealed the ubiquitous presence of AlucSNMP transcripts in multiple tissues, with only AlucSNMP1a exhibiting male-biased expression in the antennae, suggesting its potential role in male chemosensation. Functional analysis using the Xenopus oocyte expression system, coupled with two-electrode voltage clamp recording, demonstrated that the co-expression of AlucSNMP1a with specific pheromone receptors (PRs) and the co-receptor (Orco) significantly enhanced electrophysiological responses to sex pheromones compared to the co-expression of PRs and Orco alone. Moreover, the results indicated that the presence of AlucSNMP1a not only affected the responsiveness to sex pheromones but also influenced the kinetics (activation and inactivation) of the induced signals. In contrast, the co-expression of AlucSNMP1b with AlucPR/Orco complexes had no impact on the inward currents induced by two pheromone compounds. An examination of the selective pressures on SNMP1 genes across 20 species indicated strong purifying selection, implying potential functional conservation in various insects. These findings highlight the crucial role of AlucSNMP1a in the response to sex pheromones.

Maize (Zea mays L.) is a monoecious grass species with separate male and female inflorescences which form the tassel and ear, respectively.  The mature ear inflorescences usually bear hundreds of grains, thus directly influence maize grain production and yield.  Here, we isolated a recessive maize mutant, tasselseed2016 (ts2016), which exhibits pleiotropic inflorescence defects and a reduction in grain yield.  These defects include loss of determinacy and identity in meristems and floral organs, as well as a lack of the lower floret abortion in maize ear, and the smaller grain size.  Using map-based cloning and allelic test, we identified and confirmed a microRNA gene MIR172e as the target gene controlling these related traits.  Furthermore, our evidence uncovered a new potential miR172e/ETHYLENE RESPONSIVE ELEMENT BINDING197 (EREB197) regulatory module which controls the abortion of lower floret in maize ear. Transcriptome analysis revealed that the mutation of MIR172e represses multiple biological processes, particularly the flower development and hormone-related pathways in maize ear.  Additionally, we found the mutation in the DNA sequence of MIR172e affects in RNA transcription, resulting in elongation blockage at the mutant site.  Our results reveal the function and molecular mechanism of MIR172e in maize inflorescences and grain yield, and this study deepens our knowledge of maize inflorescence development.

Dry-hot wind stress causes losses in wheat productivity in major growing regions worldwide, especially for winter wheat in the Huang-Huai-Hai Plain of China, and both the occurrence and the severity of such events are likely to increase with global climate change.  To investigate the recovery of physiological function and yield formation using a non-commercial new chemical regulator (NCR) following dry-hot wind stress, we conducted a three-year field experiment (2018-2021), and sprayed tap water (control), monopotassium phosphate (CKP), NCR at both the jointing and flowering stage (CFS), and NCR only at the jointing stage (FSJ) or flowering stage (FSF).  The leaf physiology, biomass accumulation and translocation, grain-filling process, and yield components in winter wheat were investigated.  Among the single spraying treatments, the FSJ treatment was beneficial to accumulation of dry matter before anthesis, and to a larger increase of maximum grain-filling rate and mean grain-filling rate.  The FSF treatment performed better in maintaining a high relative chlorophyll content as SPAD value, and low rate of excised leaf water loss in flag leaves, promoting dry matter accumulation and contribution to grain after anthesis, prolonging the duration of grain filling, and inducing the period until maximum grain-filling rate to be reached earlier.  The CFS treatment was better than any other treatments in relieving effects of dry-hot wind.  The exogenous NCR treatments significantly increased grain yields by 12.45–18.20% in 2018–2019, 8.89–13.82% in 2019–2020, and 8.10–9.00% in 2020–2021.  The conventional measure of CKP treatment only increased grain yield by 6.69% in 2020–2021.  The CFS treatment had the greatest mitigating effect on loss of yield under dry-hot wind stress, following by the FSF and FSJ treatments, and the CKP treatment had a minimal effect.  In summary, the CFS treatment could be used as the main chemical control measure for wheat stress resistance and yield stability in areas with high incidence of dry-hot wind.  This can effectively regulate green retention and water status of leaves, promote dry matter accumulation and efficient translocation, improve grain-filling process, and ultimately reduce yield losses.

Cropland nitrate leaching is the major nitrogen (N) loss pathway, and it contributes significantly to water pollution. However, cropland nitrate leaching estimates show great uncertainty due to variations in input datasets and estimation methods. Here, we presented a re-evaluation of Chinese cropland nitrate leaching, and identified and quantified the sources of uncertainty by integrating three cropland area datasets, three N input datasets, and three estimation methods. The results revealed that nitrate leaching from Chinese cropland averaged 6.7±0.6 Tg N yr⁻¹ in 2010, ranging from 2.9 to 15.8 Tg N yr⁻¹ across 27 different estimates. The primary contributor to the uncertainty was the estimation method, accounting for 45.1%, followed by the interaction of N input dataset and estimation method at 24.4%. The results of this study emphasize the need for adopting a robust estimation method and improving the compatibility between the estimation method and N input dataset to effectively reduce uncertainty. This analysis provides valuable insights for accurately estimating cropland nitrate leaching and contributes to ongoing efforts that address water pollution concerns.

Chinese cabbage is an important leafy vegetable crop with high water demand and susceptibility to drought stress.  To explore the molecular mechanisms underlying the response to drought, we performed a transcriptome analysis of drought-tolerant and -sensitive Chinese cabbage genotypes under drought stress, and uncovered core drought-responsive genes and key signaling pathways.  A co-expression network was constructed by a weighted gene co-expression network analysis (WGCNA) and candidate hub genes involved in drought tolerance were identified.  Furthermore, abscisic acid (ABA) biosynthesis and signaling pathways and their drought responses in Chinese cabbage leaves were systemically explored.  We also found that drought treatment increased the antioxidant enzyme activities and glucosinolate contents significantly.  These results substantially enhance our understanding of the molecular mechanisms underlying drought responses in Chinese cabbage.

Maize (Zea mays L.) can exhibit yield penalties as a result of unfavorable changes to growing conditions.  The main threat to current and future global maize production is heat stress.  Maize may suffer from heat stress in all of the growth stages, either continuously or separately.  In order to manage the impact of climate driven heat stress on the different growth stages of maize, there is an urgent need to understand the similarities and differences in how heat stress affects maize growth and yield in the different growth stages.  For the purposes of this review, the maize growth cycle was divided into seven growth stages, namely the germination and seedling stage, early ear expansion stage, late vegetative growth stage before flowering, flowering stage, lag phase, effective grain-filling stage, and late grain-filling stage.  The main focus of this review is on the yield penalty and the potential physiological changes caused by heat stress in these seven different stages.  The commonalities and differences in heat stress related impacts on various physiological processes in the different growth stages are also compared and discussed.  Finally, a framework is proposed to describe the main influences on yield components in different stages, which can serve as a useful guide for identifying management interventions to mitigate heat stress related declines in maize yield.

The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.  Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.  ‘Kenong 9204’ (KN9204) is a candidate foundation parent characterized by ideotype, high yield potential, and particularly high nitrogen fertilizer utilization.  To better understand the genetic basis of its high yield potential, high throughput whole-genome re-sequencing (10×) was performed on KN9204, its parental lines and its derivatives.  A high-resolution genetic composition map of KN9204 was constructed, which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci (QTL) from a bi-parental mapping population.  Xiaoyan 693 (XY693), a wheat–Thinopyrum ponticum partial amphidiploid, contributed a great deal to the high yield potential of KN9204, and three major stable QTLs from XY693 were fine mapped.  The transmissibility of key genomic segments from KN9204 to its derivatives were delineated, indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.  Evidence for selection sweeps in the breeding programs was identified.  This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.

Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors.  In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice.  OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process.  OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein.  Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.  Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines.  Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay.  Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.

Rapeseed (Brassica napus L.) is the second most widely grown premium oilseed crop globally, mainly for its vegetable oil and protein meal.  One of the main goals of breeders is producing high-yield rapeseed cultivars with sustainable production to meet the requirements of the fast-growing population.  Besides the pod number, seeds per silique (SS), and thousand-seed weight (TSW), the ovule number (ON) is a decisive yield determining factor of individual plants and the final seed yield.  In recent years, tremendous efforts have been made to dissect the genetic and molecular basis of these complex traits, but relatively few genes or loci controlling these traits have been reported thus far.  This review highlights the updated information on the hormonal and molecular basis of ON and development in model plants (Arabidopsis thaliana).  It also presents what is known about the hormonal, molecular, and genetic mechanism of ovule development and number, and bridges our understanding between the model plant species (A. thaliana) and cultivated species (B. napus).  This report will open new pathways for primary and applied research in plant biology and benefit rapeseed breeding programs.  This synopsis will stimulate research interest to further understand ovule number determination, its role in yield improvement, and its possible utilization in breeding programs. 

The physiological and metabolic differences in maize under different nitrogen (N) levels are the basis of reasonable N management, which is vital in improving fertilizer utilization and reducing environmental pollution.  In this paper, on the premise of defining the N fertilizer efficiency and yield under different long-term N fertilization treatments, the corresponding differential metabolites and their metabolic pathways were analyzed by untargeted metabolomics in maize.  N stress, including deficiency and excess, affects the balance of carbon (C) metabolism and N metabolism by regulating C metabolites (sugar alcohols and tricarboxylic acid (TCA) cycle intermediates) and N metabolites (various amino acids and their derivatives).  L-alanine, L-phenylalanine, L-histidine, and L-glutamine decreased under N deficiency, and L-valine, proline, and L-histidine increased under N excess.  In addition to sugar alcohols and the above amino acids in C and N metabolism, differential secondary metabolites, flavonoids (e.g., kaempferol, luteolin, rutin, and diosmetin), and hormones (e.g., indoleacetic acid, trans-zeatin, and jasmonic acid) were initially considered as indicators for N stress diagnosis under this experimental conditions.  This study also indicated that the leaf metabolic levels of N2 (120 kg ha^–1 N) and N3 (180 kg ha^–1 N) were similar, consistent with the differences in their physiological indexes and yields over 12 years.  This study verified the feasibility of reducing N fertilization from 180 kg ha^–1 (locally recommended) to 120 kg ha^–1 at the metabolic level, which provided a mechanistic basis for reducing N fertilization without reducing yield, further improving the N utilization rate and protecting the ecological environment.

Natural rubber (NR) is an irreplaceable biopolymer of economic and strategic importance owing to its unique physical and chemical properties.  The Pará rubber tree (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.) is currently the exclusive commercial source of NR, and it is primarily grown in plantations restricted to the tropical and subtropical areas of Southeast Asia.  However, current Pará rubber production barely meets the sharply increasing global industrial demand for rubber.  Petroleum-based synthetic rubber (SR) has been used to supplement the shortage of NR but its industrial performance is not comparable to that of NR.  Thus, there is an urgent need to develop new productive rubber crops with broader environmental adaptability.  This review summarizes the current research progress on alternative rubber-producing plants, including horticultural plants (Taraxacum kok-saghyz Rodin and Lactuca L. species), woody plants (Parthenium argentatum A. Gray and Eucommia ulmoides Oliv.), and other plant species with potential for NR production.  With an emphasis on the molecular basis of NR biosynthesis revealed by a multi-omics approach, we highlight new integrative strategies and biotechnologies for exploring the mechanism of NR biosynthesis with a broader scope, which may accelerate the breeding and improvement of new rubber crops. 

Plant height (PH) is one of the most important components of a plant ideotype, affecting plant biomass, yields, lodging resistance, and the ability to use mechanized harvesting. As many complex pathways controlling plant growth and development remain poorly understood, we are still unable to obtain the most ideal plants solely through breeding efforts. Plant height can be influenced by genotypes, plant hormone regulations, environmental conditions, and interaction with other plants. Here, we comprehensively review the factors influenced PH, including the regulation of PH-related development processes, the genetics and QTLs contributing to PH, and the hormone-regulated molecular mechanisms for PH. Additionally, the symbiotic influence of grafting on PH was discussed focusing on molecular regulation of gene expressions and genetics. Finally, we proposed strategies on how to apply recent findings to breeding for better PH, highlighted some knowledge gaps, and suggested potential directions for future studies.

Antimicrobial resistance has become a global problem that poses great threats to human health.  Antimicrobials are widely used in broiler chicken production and consequently affect their gut microbiota and resistome.  To better understand how continuous antimicrobial use in farm animals alters their microbial ecology, we used a metagenomic approach to investigate the effects of pulsed antimicrobial administration on the bacterial community, antibiotic resistance genes (ARGs) and ARG bacterial hosts in the feces of broiler chickens.  Chickens received three 5-day courses of individual or combined antimicrobials, including amoxicillin, chlortetracycline and florfenicol.  The florfenicol administration significantly increased the abundance of mcr-1 gene accompanied by floR gene, while amoxicillin significantly increased the abundance of genes encoding the AcrAB-tolC multidrug efflux pump (marA, soxS, sdiA, rob, evgS and phoP).  These three antimicrobials all led to an increase in Proteobacteria.  The increase in ARG host, Escherichia, was mainly attributed to the β-lactam, chloramphenicol and tetracycline resistance genes harbored by Escherichia under the pulsed antimicrobial treatments.  These results indicated that pulsed antimicrobial administration with amoxicillin, chlortetracycline, florfenicol or their combinations significantly increased the abundance of Proteobacteria and enhanced the abundance of particular ARGs.  The ARG types were occupied by the multidrug resistance genes and had significant correlations with the total ARGs in the antimicrobial-treated groups.  The results of this study provide comprehensive insight into pulsed antimicrobial-mediated alteration of chicken fecal microbiota and resistome.

Pre-harvest sprouting (PHS) adversely affects wheat quality and yield, and grain color (GC) is associated with PHS resistance.  However, the genetic relationship between GC and PHS resistance remains unclear.  In this study, 168 wheat varieties (lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array.  Genome-wide association study (GWAS) based on a mixed linear model showed that 67 marker-trait associations (MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation.  In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation.  Subsequently, two cleaved amplified polymorphic sequences (CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B, were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4 controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively.  Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments (P<0.05).  Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4.  The new CAPS marker CAPS-356 was then developed based on the SNP (T/C) in the coding sequences (CDS) region of TraesCS5B02G545100.  The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines (RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4.  These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.

Crop improvement is crucial for addressing the global challenges of food security and sustainable agriculture.  Recent advancements in high-throughput phenotyping technologies and artificial intelligence (AI) have revolutionized the field, enabling rapid and accurate assessment of crop traits on a large scale.  The integration of AI and machine learning algorithms with high-throughput phenotyping data has unlocked new opportunities for crop improvement.  AI algorithms can analyze and interpret large datasets, extracting meaningful patterns and correlations between phenotypic traits and genetic factors.  These technologies have the potential to revolutionize plant breeding programs by providing breeders with efficient and accurate tools for trait selection, reducing the time and cost required for variety development.  However, further research and collaborations are needed to overcome the challenges and fully unlock the power of high-throughput phenotyping and AI in crop improvement.  By leveraging AI algorithms, researchers can efficiently analyze phenotypic data, uncover complex patterns, and establish predictive models that enable precise trait selection and crop breeding.  The aim of this review is to explore the transformative potential of integrating high-throughput phenotyping and AI in crop improvement.  The review will encompass an in-depth analysis of recent advancements and applications, highlighting the numerous benefits and challenges associated with high-throughput phenotyping and intelligence.

Elevating soil water content (SWC) through irrigation was one of the simple mitigation measures to improve crop resilience to heat stress.  The response of leaf function such as photosynthetic capacity based on chlorophyll fluorescence during the mitigation has received limited attention, especially in field condition. The 2-yr field experiment with three treatments (control treatment (CK); high temperature treatment (H); high temperature together with elevating SWC treatment (HW)) was carried out during grain filling with two maize hybrids at a typical station in North China Plain.  Averagely, the net photosynthetic rate (P_n) was improved by 20% in HW treatment and a 1-3°C decrease in canopy temperature compared with H treatment in two years. Furthermore, the higher SWC in HW treatment significantly improved actual photosynthetic rate (Phi2), linear electron flow (LEF), variable fluorescence (F_v) and maximal potential quantum efficiency (F_v/F_m) for both hybrids.  Meanwhile, different responses in chlorophyll fluorescence between hybrids were also observed.  The higher SWC in HW treatment significantly improved thylakoid proton conductivity (gH⁺) and maximal fluorescence (F_m) for the hybrid ZD958.  For the hybrid XY335, the proton conductivity of chloroplast ATP synthase (vH⁺) and minimal fluorescence (F₀) was increased by the SWC.  The SEM model further showed that SWC had significantly positive relationships with P_n, LEF, and F_v/F_m.  The elevating SWC alleviated heat stress with the delayed leaf senescence to prolong the effective period of photosynthesis and enhanced leaf photosynthetic capacity by improving Phi2, LEF, F_v and F_v/F_m.  This research demonstrates that elevating SWC through enhancing leaf photosynthesis during grain filling would be an import mitigation measure to adapt to warming climate in maize production.

Streptococcus agalactiae is one of the most common pathogens that cause bovine mastitis worldwide. Identifying pathogen prevalence and virulence factors is critical for developing prevention and control approaches. Herein, 1161 milk samples from various dairy farms in China (n=558) and Pakistan (n=603) were collected between 2019-2021 and were subjected to S. agalactiae isolation. Prevalence, serotyping, virulence genes, and antibiotic-resistant genes of S. agalactiae were evaluated by PCR assay. All isolates were characterized for haemolysis, biofilm production, cytotoxicity, adhesion, and invasion on bovine mammary epithelial cells. The prevalence of S. agalactiae-induced mastitis in cattle was found to be considerably higher in Pakistan than in China. Jiangsu and Sindh provinces had the highest area-wise prevalence in China and Pakistan, respectively. Serotypes Ia and II were prevalent in both countries, whereas serotype III was found only in Pakistan. Moreover, all isolates tested positive for PI-2b gene but negative for PI-1 and PI-2a genes. All isolates harboured cfb, cylE, hylB, and fbsB virulent genes, whereas many of them lacked bibA, rib and bca. However, the absence of bac and scp genes in Chinese isolates and cspA in Pakistani isolates was noted, while spb1 and lmb were not detected in isolates of both countries. Pakistani isolates, particularly serotype Ia-positive, had a considerably higher ability to produce biofilm, haemolysis, cytotoxicity, adhesion, and invasion than Chinese isolates. Most of the isolates were phenotypically resistant to tetracycline, erythromycin, and clindamycin and genotypic resistance was confirmed by the presence of ermA, ermB, tetM and tetO genes. Our study highlights the antimicrobial resistance profile and virulence-related factors contributing to the epidemiological spread of mastitis-causing S. agalactiae in China and Pakistan. The findings may facilitate future studies designed to develop improved treatment and control strategies against this pathogen. 

Plant height is a key plant architectural trait that affects the seed yield, harvest index and lodging resistance in Brassica napus L., although the genetic mechanisms affecting plant height remain unclear.  Here, a semi-dwarf mutant, df34, was obtained by ethyl methanesulphonate-induced mutagenesis.  Genetic analysis showed that the semi-dwarf phenotype is controlled by one semi-dominant gene, which was located on chromosome C03 using a bulked segregant analysis coupled with whole-genome sequencing, and this gene was named BnaSD.C3.  Then BnaSD.C3 was fine-mapped to a 297.35-kb segment of the “Darmor-bzh” genome, but there was no potential candidate gene for the semi-dwarf trait underlying this interval.  Furthermore, the interval was aligned to the Zhongshuang 11 reference genome.  Finally, combining structural variation analysis, transcriptome sequencing, phytohormone analyses and gene annotation information, BnaC03G0466900ZS and BnaC03G0478900ZS were determined to be the most likely candidate genes affecting the plant height of df34.  This study provides a novel major locus for breeding and new insights into the genetic architecture of plant height in B. napus

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a devastating pest of citrus fruits.  After successful mating, adult females insert their eggs into the ripened fruit, resulting in moldy and rotten fruit and causing great economic losses for the citrus industry.  In the field, flies initiate copulatory behaviors as twilight approaches, and decreasing light intensity in this period is the normal stimulus for copulation.  In this study, ten light intensities ranging from 0–30 000 lux were set to identify the typical intensity that strongly regulates the copulation behavior of B. dorsalis.  Three light intensities found to regulate the copulation behavior were then selected to verify their effects on adult male wing fanning and female chemotaxis towards 2,3,5-trimethylpyrazine (TMP).  At last, strong light and complete darkness were artificially combined in the lab to verify whether they could prevent copulation to inform behavioral manipulation of oriental flies in the future.  The results indicated that adult flies generally initiated copulatory behaviors at low light intensity (<1 000 lux).  
Stronger light significantly prevented copulation in proportion to intensity, with nearly no copulation events initiated when light intensity was above 20 000 lux.  Both male wing fanning and female chemotaxis towards TMP were attenuated as light intensity became stronger.  However, at 10 000 lux, males still fanned their wings to a certain extent while TMP completely lost its attractiveness to females.  In the darkness, adults did not initiate any sexual behaviors, e.g., copulation, wing fanning, or chemotaxis to TMP.  One hour of strong light (10 000 lux) combined with continuous darkness completely prevented mating.  These results show that light condition is an essential factor for copulatory behaviors in the oriental fruit fly.  Researchers could thus manipulate light conditions artificially or disrupt the molecular target in flies’ light transduction pathway to develop environmentally-friendly techniques to control this pest.

Increasing prolificacy is an important aim in the pig industry.  Regions associated with litter size have been revealed, but detailed molecular mechanisms are unclear.  The Meishan pig is one of the most prolific breeds, with higher prolificacy than the Yorkshire pig, which exhibits high feeding efficiency and lean meat yield.  The ovary is the key organ determining reproductive traits during pregnancy by synthesizing and secreting reproductive hormones essential for conceptus maintenance.  In this comparative multi-omics study of the ovary transcriptome, proteome, and metabolome on day 49 of pregnancy, we aimed to identify genomic, proteomic, and metabolomic differences between the ovaries of Meishan and Yorkshire pigs to reveal potential molecular mechanisms conferring high prolificacy.  Meishan pigs demonstrated general downregulation of steroid biosynthesis and butanoate metabolism in the ovary during mid-pregnancy at both transcriptome and proteome levels but exhibited higher serum cholesterol, estradiol, and progesterone levels than Yorkshire pigs.  We also identified several single-nucleotide polymorphisms in the genes of the steroid hormone pathway associated with litter number, average birth weight, and total litter weight.  Lower biosynthesis rates but elevated serum levels of reproductive hormones during mid- and late pregnancy are essential for the greater prolificacy of Meishan pigs.

Banana is a significant crop, and three banana leaf diseases, including Sigatoka, Cordana and Pestalotiopsis, have the potential to have a serious impact on banana production. Existing studies are insufficient to provide a reliable method for accurately identifying banana leaf diseases. Therefore, this paper proposes a novel method to identify banana leaf diseases. First, a new algorithm called K-scale VisuShrink algorithm (KVA) is proposed to denoise banana leaf images. The proposed algorithm introduces a new decomposition scale k based on the semi-soft and middle course thresholds, the ideal threshold solution is obtained and substituted with the newly established threshold function to obtain a less noisy banana leaf image. Then, this paper proposes a novel network for image identification called Ghost ResNeSt-Attention RReLU-Swish Net (GR-ARNet) based on Resnet50. In this, the Ghost Module is implemented to improve the network's effectiveness in extracting deep feature information on banana leaf diseases and the identification speed; the ResNeSt Module adjusts the weight of each channel, increasing the ability of banana disease feature extraction and effectively reducing the error rate of similar disease identification; the model's computational speed is increased using the hybrid activation function of RReLU and Swish. Our model achieves an average accuracy of 96.98% and a precision of 89.31% applied to 13021 images, demonstrating that the proposed method can effectively identify banana leaf diseases.

非洲猪瘟在我国爆发，给我国养殖业带来巨大的经济损失，目前无可用的商业化疫苗和药物，其相关研究限定于在高等级生物安全实验室中完成，生物安全防护中消毒剂的合理使用尤为重要。MICRO-CHEM PLUS（MCP）作为一种复合型季铵盐类消毒剂在高等级生物安全实验室广泛使用，而针对非洲猪瘟病毒（African swine fever Virus，ASFV）的灭活效果未见相关报道。本文我们探究不同病毒载量、不同消毒剂浓度、不同作用时间及不同作用温度对于灭活非洲猪瘟病毒效果的影响。研究结果表明高病毒载量需要更高浓度的MCP才能将ASFV完全灭活，较低浓度的MCP需要延长作用时间才能达到完全灭活ASFV的效果，不同的作用温度对于MCP灭活ASFV的效果无影响。应用干雾消毒机将5%MCP进行房间喷雾消毒，当浓度达到0.06L/m3，用ASFV、大肠杆菌和金色葡萄球菌作为生物指示剂，可以达到终末消毒效果，但对于枯草芽孢杆菌作为生物指示剂还有部分活菌残留；当浓度为0.03L/m3时，对于大肠杆菌或金黄色葡萄球菌作为生物指示剂，也可以达到了终末消毒效果。该研究为在特定环境中合理使用 MCP 提供了科学依据，可以用于操作ASFV的高等级生物安全实验室的消毒以及猪场非洲猪瘟感染的预防。

Malus prunifolia Borkh. ‘Fupingqiuzi’ has significant ecological and economic value and plays a key role in germplasm development and resistance research.  However, its long juvenile phase and high heterozygosity are barriers to the identification of ‘Fupingqiuzi’ progeny with excellent traits.  In-vitro regeneration techniques and Agrobacterium-mediated genetic transformation systems can efficiently produce complete plants and thus enable studies of gene function.  However, optimal regeneration and genetic transformation systems for ‘Fupingqiuzi’ have not yet been developed.  Here, we evaluated the factors that affect the in-vitro regeneration and transformation of ‘Fupingqiuzi’.  The best results were obtained when transverse leaf sections were used as explants, and they were grown in dark culture for three weeks with their adaxial sides contacting the culture medium (MS basal salts, 30 g L⁻¹ sucrose, 8 g L⁻¹ agar, 5 mg L⁻¹  6-benzylaminopurine (6-BA), 2 mg L⁻¹ thidiazuron (TDZ), and 1 mg L⁻¹ 1-naphthlcetic acid (NAA), pH 5.8).  A genetic transformation system based on this regeneration system was optimized: after inoculation with A. tumefaciens solution for 8 min, 4 days of co-culture, and 3 days of delayed culture, the cultures were screened with cefotaxime (150 mg L⁻¹) and kanamycin (15 mg L⁻¹).  We thus established an efficient regeneration and genetic transformation system for ‘Fupingqiuzi’, enabling the rapid production of transgenic material.  These findings make a significant contribution to apple biology research

Passion fruit (Passiflora edulis Sims) is a vine of the Passiflora genus in the Passifloraceae family.  The extracted components include flavonoids and terpenoids, which have good anti-anxiety and anti-inflammatory effects in humans.  In this study, we analyzed the transcriptomes of four tissues of the ‘Zixiang’ cultivar using RNA-Seq, which provided a dataset for functional gene mining.  The de novo assembly of these reads generated 96 883 unigenes, among which 61 022 unigenes were annotated (62.99% yield).  In addition to its edible value, another important application of passion fruit is its medicinal value.  The flavonoids and terpenoids are mainly derivatives of luteolin, apigenin, cycloartane triterpenoid saponins and other active substances in leaf extracts.  A series of candidate unigenes in the transcriptome data that are potentially involved in the flavonoid and terpenoid synthesis pathways were screened using homology-based BLAST and phylogenetic analysis.  The results showed that the biosynthesis of triterpenoids in passion fruit comes from the branches of the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathways, which is different from the MVA pathway that is used in other fruit trees.  Most of the candidate genes were found to be highly expressed in the leaves and/or flowers.  Quantitative real-time PCR (qRT-PCR) verification was carried out and confirmed the reliability of the RNA-Seq data.  Further amplification and functional analysis of these putative unigenes will provide additional insight into the biosynthesis of flavonoids and terpenoids in passion fruit.

Ear-related traits are often selection targets for maize improvement.  This study used an immortalized F₂ (IF₂) population to elucidate the genetic basis of ear-related traits.  Twelve ear-related traits (namely, row number (RN), kernel number per row (KNPR), ear length (EL), ear diameter (ED), ten-kernel thickness (TKT), ear weight (EW), cob diameter (CD), kernel length (KL), kernel width (KW), grain weight per ear (GW), 100-kernel weight (HKW), and grain yield per plot (GY)), were collected from the IF₂ population.  The ear-related traits were comprised of 265 crosses derived from 516 individuals of the recombinant inbred lines (RILs) under two separated environments in 2017 and 2018, respectively.  Quantitative trait loci (QTLs) analyses identified 165 ear traits related QTLs, which explained phenotypic variation ranging from 0.1 to 12.66%.  Among the 165 QTLs, 19 underlying nine ear-related traits (CD, ED, GY, RN, TKT, HKW, KL, GW, and KNPR) were identified across multiple environments and recognized as reliable QTLs.  Furthermore, 44.85% of the total QTLs showed an overdominance effect, and 12.72% showed a dominance effect. Additionally, we found 35 genomic regions exhibiting pleiotropic effects across the whole maize genome, and 17 heterotic loci (HLs) for RN, EL, ED and EW were identified.  The results provide insights into genetic components of ear-related traits and enhance the understanding of the genetic basis of heterosis in maize. 

The crown root system is the most important root component in maize at both the vegetative and reproductive stages.  However, the genetic basis of maize crown root traits (CRT) is still unclear, and the relationship between CRT and aboveground agronomic traits in maize is poorly understood.  In this study, an association panel including 531 elite maize inbred lines was planted to phenotype the CRT and aboveground agronomic traits in different field environments.  We found that root traits were significantly and positively correlated with most aboveground agronomic traits, including flowering time, plant architecture and grain yield.  Using a genome-wide association study (GWAS) coupled with resequencing, a total of 115 associated loci and 22 high-confidence candidate genes were identified for CRT.  Approximately one-third of the genetic variation in crown root was co-located with 46 QTLs derived from flowering and plant architecture.  Furthermore, 103 (89.6%) of 115 crown root loci were located within known domestication- and/or improvement-selective sweeps, suggesting that crown roots might experience indirect selection in maize during domestication and improvement.  Furthermore, the expression of Zm00001d036901, a high-confidence candidate gene, may contribute to the phenotypic variation in maize crown roots, and Zm00001d036901 was selected during the domestication and improvement of maize.  This study promotes our understanding of the genetic basis of root architecture and provides resources for genomics-enabled improvements in maize root architecture.

Wheat relative species are important for agriculture production, functional genomics study and wheat improvement as useful genetic resources.  In this study, a regeneration related wheat gene TaWOX5 was applied to establish the Agrobacterium-mediated transformation systems of Triticum monococcum, hexaploid triticale, and rye (Secale cereale L.) using their immature embryos.  Transgenic plants were efficiently generated.  During the transformation process, the Agrobacterium infection efficiency was assessed by histochemical staining for β-glucuronidase (GUS).  Finally, the transgenic nature of regenerated plants was verified by polymerase chain reaction (PCR)-based genotyping for presence of the GUS and bialaphos resistance (bar) genes, histochemical staining for GUS protein, and QuickStix strip assay for bar protein. The transformation efficiency of T. monococcum genotype PI428182 was 94.4%; the efficiencies of four hexaploid triticale genotypes Lin456, ZS3297, ZS1257, and ZS3224 were 52.1, 41.2, 19.4, and 16.0%, respectively; the transformation efficiency of rye cultivar Lanzhou Heimai was 7.8%.  Fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) analysis indicated that the GUS transgenes were integrated into the distal or near centromere (proximal) region of the chromosomes in transgenic T. monococcum and hexaploid triticale plants; in the transgenic hexaploid triticale plants, the foreign DNA fragment was randomly integrated into the AABB genome and RR genome.  Furthermore, the transgene was proved to be almost stably inherited in the next generation by Mendel’s law.  The findings in this study will promote genetic improvement for grain or forage production of the three plant species and for functional genomics study of cereal species including wheat.

Type I interferon (IFN-I) provides an important first line to protect avian species against pathogens invasion. IFN regulatory factor 7 (IRF7) has been identified as the most important regulator for both DNA and RNA virus-induced IFN-I production in chickens. Although four splicing variants of IRF7 have been identified in mammals, it is still unclear whether alternative splicing patterns and the function of IRF7 isoform(s) exist in chickens. In this study, we reported a novel short transcript isoform of chicken IRF7 (chIRF7), termed chIRF7-iso, which contained an intact N-terminal DNAbinding domain (DBD) and 14 amino acids different from chIRF7 in the C-terminal. Overexpression of chIRF7 in chicken leghorn male hepatocellular (LMH) cells activated the IFN-β promoter and significantly inhibited Newcastle disease virus (NDV) and fowl adenovirus serotype 4 (FAdV-4) replication. Conversely, overexpression of chIRF7-iso blocked the IFN-β promoter activity and was favorable for NDV and FAdV-4 replication in vitro. Collectively, our results confirm that a novel chIRF7 isoform-mediated negative regulates IFN-β production, which will contribute to understanding the role of chIRF7 in innate antiviral response in chicken.

Phenotypic screening of soybean germplasm suitable for high planting density is currently the most viable strategy to increase yield.  Previous studies have shown that soybean varieties with dwarf features and a short petiole often exhibit a compact plant architecture which could improve yield through increased planting density, although previously reported short petiole accessions were ultimately not usable for breeding in practice.  Here, we established a method to assess petiole length and identified an elite mutant line, M657, that exhibits high photosynthetic efficiency.  The agronomic traits of M657 were evaluated under field conditions, and appeared to be stable for short petiole across seven locations in northern, Huang–Huai, and southern China from 2017 to 2018.  Compared with the Jihuang 13 wild type, the mutant M657 was shorter in both petiole length and plant height, exhibited lower total area of leaf, seed weight per plant and 100-seed weight, but had an increased number of effective branches and the growth period was prolonged by 2–7 days.  Using M657 as a parental line for crosses with four other elite lines, we obtained four lines with desirable plant architecture and yield traits, thus demonstrating the feasibility of adopting M657 in breeding programs for soybean cultivars of high density and high yield.

The specificity of the double-stranded RNA (dsRNA) used in the RNA interference (RNAi) technique is crucial for the success of sequence-specific gene silencing.  Currently, RNAi-mediated insect control is a trending research topic.  However, the off-target effects of the dsRNA in RNAi are a major concern.  In this study, the dsHvβ´COPI (coat protein complex I, β´ subunit)-treated and untreated transcriptomes of the 28-spotted potato lady beetle (Henosepilachna vigintioctopunctata) were compared to understand its off-target gene silencing effects.  The RNA-seq results revealed that 63 and 44 differentially expressed genes (DEGs) were upregulated and downregulated, respectively, in the dsHvβ´COPI treated group as compared with the control.  Validation of the differential expressions of some selected DEGs via reverse transcription-quantitative PCR (RT-qPCR) analysis confirmed the reliability of the transcriptome analysis results.  Further downstream analysis revealed that there were no genes homologous with Hvβ´COPI in H. vigintioctopunctata.  Additionally, no genes with a >11 bp continuous match with dsHvβ´COPI were found in the H. vigintioctopunctata transcriptome.  Six genes (Hvcitron, Hvhelicase, Hvtransposase, Hvserine, Hvdynein, and HvE3 ubiquitin) were selected to examine the off-target activity of dsHvβ´COPI based on their potential involvement in various H. vigintioctopunctata metabolic pathways.  The severity of silencing these six off-target genes was evaluated by employing RNAi.  The RNAi results confirmed the downregulation of the expression of all six genes, although there was no significant lethality.  The findings of this study will be helpful in the risk analysis of future RNAi-mediated pest control experiments.

Maize (Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018 and 2020 to identify the disease-causing pathogen. Based on morphological features; pathogenicity tests; and multi-locus phylogenetic analysis involving internal transcribed spacer (ITS), 18S small subunit rDNA (SSU), 28S large subunit rDNA (LSU), translation elongation factor 1-alpha (TEF), and β-tubulin (TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.

Sugarcane smut caused by Sporisorium scitamineum is a destructive disease responsible for significant losses in sugarcane production worldwide. However, the mechanisms underlying the pathogenicity of this fungus remain largely unknown. In this study, we found that the disruption of the SsRSS1 gene, which encodes a salicylic acid (SA) sensing regulator, does not affect phenotypic traits such as the morphology, growth rate, and sexual mating ability of haploid basidiospores, but rather reduces the tolerance of basidiospores to SA stress by blocking the induction of SsSRG1, a gene encoding a SA response protein in S. scitamineum. SsRSS1 deletion resulted in the attenuation of the virulence of the fungus. In addition to a significant reduction in whip formation, a portion of plantlets (18.3%) inoculated with the ΔSsRSS1 strains were found to be infected but failed to produce whips for up to 90 days post-inoculation. However, the development of hyphae and teliospore from the ΔSsRSS1-infected plants that formed whips seemed indistinguishable from that in the wild-type-infected plants. Combined, our findings suggested that SsRss1 is required for maintaining fungal fitness in planta by counteracting SA stress.

Large-scale crop mapping using remote sensing data is of great significance for agricultural production, food security and the sustainable development of human societies. Winter rapeseed is an important oil crop in China that is mainly distributed in the Yangtze River Valley. Traditional winter rapeseed mapping practices are insufficient since they only use the spectral characteristics during the critical phenological period of winter rapeseed, which are usually limited to a small region and cannot meet the needs of large-scale applications. In this study, a novel phenology-based winter rapeseed index (PWRI) was proposed to map winter rapeseed in the Yangtze River Valley. PWRI expands the date window for distinguishing winter rapeseed and winter wheat, and it has good separability throughout the flowering period of winter rapeseed. PWRI also improves the separability of winter rapeseed and winter wheat, which traditionally have been two easily confused winter crops. A PWRI-based method was applied to the Middle Reaches of the Yangtze River Valley to map winter rapeseed on the Google Earth Engine platform. Time series composited Sentinel-2 data were used to map winter rapeseed with 10 m resolution. The mapping achieved a good result with overall accuracy and kappa coefficients exceeding 92% and 0.85, respectively. The PWRI-based method provides a new solution for high spatial resolution winter rapeseed mapping at a large scale.

Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment, where they would compete for survival space with weeds. However, whether the expression of Bacillus thuringiensis (Bt) gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood. Thus, field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest controlled environment. Results showed that weed-rice competition in direct seeding field (DS) was earlier and more serious than that in transplanting field (TP), which resulted in the significant decrease of biomass and yield in DS. However, the yield between conventional Bt and non-Bt rice was not significant difference. The weed number, weed coverage ratio and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth stage and mature stage, especially in DS plots, suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity. Grain yield and weed number varied between different hybrid rice lines, but those differences were not significant between Bt and non-Bt rice. The number of insects increased with the increase of weeds in hybrid rice plots, whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice. Therefore, the ecological risk of transgenic Bt rice is comparable to non-Bt rice.

In the U.S., Helicoverpa zea (Boddie) is a major pest targeted by both transgenic maize and cotton expressing Bacillus thuringiensis (Bt) proteins. Resistance of insect to Bt maize and cotton containing cry1A and cry2A genes has widely occurred in the U.S. In this study, two trials were performed to investigate larval survival and development of a Cry1A.105/Cry2Ab2 dual-protein resistant (VT2P-RR), a susceptible, and an F1 heterozygous (VT2P-RS) populations of H. zea on ears of nine Bt and three non-Bt maize hybrids. The Bt maize hybrids evaluated represent five common pyramided traits expressing two or three of the Cry1A.105, Cry1Ab, Cry1F, Cry2Ab2, and Vip3Aa20 proteins. In the laboratory, neonates of the three H. zea populations were inoculated on silks of ears collected from maize at R1-R2 plant stages; and larval survivorship was checked 10 d after neonate release. All three insect populations survived normally on non-Bt maize ears. Varied numbers of VT2P-RR and VT2P-RS survived on ears of Cry1A.105/Cry2Ab2 maize, while all larvae of the three populations died or could not develop on ears of Vip3Aa20-expressing maize. The results demonstrated that the dual-protein resistant H. zea was not cross-resistant to Vip3Aa20-expressing maize, and thus traits with vip3Aa20 gene should be effective to manage Cry1A.105/Cry2Ab2-resistant H. zea. The resistance in VT2P-RR was determined to be incomplete on Cry1A.105/Cry2Ab2 maize. The effective dominance levels varied greatly, from recessive to incompletely dominant, depending on maize hybrids and trials, suggesting that proper selection of maize hybrids could be important for mitigating the Cry1A.105/Cry2Ab2 resistance. The data generated should aid in modeling multiple-protein Bt resistance in H. zea.