He Jiayue, Hao Yanrong, He Yuqi, Li Wei, Shi Yaliang, Khurshid Muhammad, Lai Dili, Ma Chongzhong, Wang Xiangru, Li Jinbo, Cheng Jianping, Fernie Alisdair R, Ruan Jingjun, Zhang Kaixuan, Zhou Meiliang
National Key Facility for Crop Gene Resources and Genetic lmprovement/Key laboratory Grain Crop Genetic Resources Evaluation anaUtlization Ministry of Agriculture and Rural Affairs. P. R. China, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
College of Agriculture, Guizhou University, Guiyang, 550025, People's Republic of China.
Plant J. 2024 Dec;120(6):2398-2419. doi: 10.1111/tpj.17119. Epub 2024 Nov 3.
Tartary buckwheat is known for its ability to adapt to intricate growth conditions and to possess robust stress-resistant properties. Nevertheless, it remains vulnerable to drought stress, which can lead to reduced crop yield. To identify potential genes involved in drought resistance, a genome-wide association study on drought tolerance in Tartary buckwheat germplasm was conducted. A gene encoding pectin methylesterase inhibitors protein (FtPMEI13) was identified, which is not only associated with drought tolerance but also showed induction during drought stress and abscisic acid (ABA) treatment. Further analysis revealed that overexpression of FtPMEI13 leads to improved drought tolerance by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. Additionally, FtPMEI13 interacts with pectin methylesterase (PME) and inhibits PME activity in response to drought stress. Our results suggest that FtPMEI13 may inhibit the activity of FtPME44/FtPME61, thereby affecting pectin methylesterification in the cell wall and modulating stomatal closure in response to drought stress. Yeast one-hybrid, dual-luciferase assays, and electrophoretic mobility shift assays demonstrated that an ABA-responsive transcription factor FtbZIP46, could bind to the FtPMEI13 promoter, enhancing FtPMEI13 expression. Further analysis indicated that Tartary buckwheat accessions with the genotype resulting in higher FtPMEI13 and FtbZIP46 expression exhibited higher drought tolerance compared to the others. This suggests that this genotype has potential for application in Tartary buckwheat breeding. Furthermore, the natural variation of FtPMEI13 was responsible for decreased drought tolerance during Tartary buckwheat domestication. Taken together, these results provide basic support for Tartary buckwheat breeding for drought tolerance.
苦荞以其适应复杂生长条件的能力和强大的抗逆特性而闻名。然而，它仍然容易受到干旱胁迫的影响，干旱胁迫会导致作物产量下降。为了鉴定参与抗旱的潜在基因，对苦荞种质的耐旱性进行了全基因组关联研究。鉴定出一个编码果胶甲酯酶抑制剂蛋白（FtPMEI13）的基因，该基因不仅与耐旱性相关，而且在干旱胁迫和脱落酸（ABA）处理期间表现出诱导作用。进一步分析表明，FtPMEI13的过表达通过改变抗氧化酶的活性和渗透活性代谢物的水平来提高耐旱性。此外，FtPMEI13与果胶甲酯酶（PME）相互作用，并在干旱胁迫下抑制PME活性。我们的结果表明，FtPMEI13可能抑制FtPME44/FtPME61的活性，从而影响细胞壁中的果胶甲酯化，并在干旱胁迫下调节气孔关闭。酵母单杂交、双荧光素酶测定和电泳迁移率变动分析表明，ABA响应转录因子FtbZIP46可以结合到FtPMEI13启动子上，增强FtPMEI13的表达。进一步分析表明，与其他苦荞种质相比，具有导致更高FtPMEI13和FtbZIP46表达的基因型的苦荞种质表现出更高的耐旱性。这表明该基因型在苦荞育种中具有应用潜力。此外，FtPMEI13的自然变异导致了苦荞驯化过程中耐旱性的降低。综上所述，这些结果为苦荞耐旱育种提供了基础支持。
