Xiang Lu, Qian Zuo, Md. Nurul Huda, Yaliang Shi, Guangsheng Li, Xiangru Wang, Yawen Xiao, Muhammad Khurshid, Tanzim Jahan, Namraj Dhami, Dhurva Prasad Gauchan, Md. Arfan Ali, Jianping Cheng, Yu Meng, Jingjun Ruan, Meiliang Zhou
Accepted: 2025-04-07
Tartary buckwheat (Fagopyrum tataricum), an under-utilized pseudocereal, has important nutritional and pharmaceutical properties and is resistant to drought and nutrient deficiency. However, this environmentally friendly crop is sensitive to salt stress that can result in water loss, stomatal closure, affect photosynthesis and metabolism, and reduce yield and quality of Tartary buckwheat. Thus, it is important to understand the mechanism of salt stress tolerance in buckwheat. In this study, we identified a locus including 35 candidate genes on chromosome 2 that is significantly associated with salt tolerance of Tartary buckwheat by genome-wide association analysis (GWAS). Transcriptome analysis revealed that the serine/threonine-protein kinase Aurora-3 (FtAUR3) family gene was up-regulated in response to salt stress. The deletion of a single nucleotide in the FtAUR3 promoter leads to increased FtAUR3 expression and enhanced salt tolerance in Tartary buckwheat. Overexpression of FtAUR3 in buckwheat hairy roots leads to the accumulation of flavonoids, including rutin and cinnamic acid, as well as the induction of the expression of flavonoid biosynthesis genes, such as PAL, C4H, F3H and F3’H, under salt stress. In addition, it was shown that over-expression of FtAUR3 in Arabidopsis thaliana induced the expression of salt-resistant genes (SOS1, AVP1, etc.) and enhanced salt tolerance compared to wild type plants. Furthermore, under salt stress, FtAUR3 can significantly enhances the levels of reactive oxygen species pathway components, including superoxide dismutase, catalase, and peroxidase, thereby improving plant salt tolerance. Thus, we demonstrated that FtAUR3 interacts with the critical enzyme FtGAPB in the ROS pathway, suggesting a potential mechanism through which FtAUR3 contributes to ROS signaling. Taken together, these results demonstrated that FtAUR3 may play a critical positive role in Tartary buckwheat resistance against salt stress.