State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.
J Exp Bot. 2022 Apr 5;73(7):2222-2237. doi: 10.1093/jxb/erab555.
Cold stress is a major environmental factor affecting plant growth and development. Although some plants have developed resistance to cold stress, the molecular mechanisms underlying this process are poorly understood. Using genome-wide association mapping with 200 cotton accessions collected from different regions, we identified variations in the short chain alcohol dehydrogenase gene, GhSAD1, that responds to cold stress. Virus-induced gene silencing and overexpression in Arabidopsis revealed that GhSAD1 fulfils important roles in cold stress responses. Ectopic expression of a haploid genotype of GhSAD1 (GhSAD1HapB) in Arabidopsis increased cold tolerance. Silencing of GhSAD1HapB resulted in a decrease in abscisic acid (ABA) content. Conversely, overexpression of GhSAD1HapB increased ABA content. GhSAD1HapB regulates cold stress responses in cotton through modulation of C-repeat binding factor activity, which regulates ABA signalling. GhSAD1HapB induces the expression of COLD-REGULATED (COR) genes and increases the amount of metabolites associated with cold stress tolerance. Overexpression of GhSAD1HapB partially complements the phenotype of the Arabidopsis ABA2 mutant, aba2-1. Collectively, these findings increase our understanding of the mechanisms underlying GhSAD1-mediated cold stress responses in cotton.
冷胁迫是影响植物生长和发育的主要环境因素之一。尽管一些植物已经发展出对冷胁迫的抗性，但这一过程的分子机制仍不清楚。本研究利用来自不同地区的 200 个棉花品种进行全基因组关联图谱绘制，鉴定到短链醇脱氢酶基因 GhSAD1 的变异，该基因对冷胁迫有响应。在拟南芥中通过病毒诱导的基因沉默和过表达发现，GhSAD1 在冷胁迫反应中具有重要作用。在拟南芥中异位表达单倍型 GhSAD1（GhSAD1HapB）提高了耐冷性。GhSAD1HapB 的沉默导致脱落酸（ABA）含量降低。相反，GhSAD1HapB 的过表达增加了 ABA 含量。GhSAD1HapB 通过调节 C 重复结合因子的活性来调节 ABA 信号转导，从而调控棉花的冷胁迫反应。GhSAD1HapB 诱导冷调节（COR）基因的表达，并增加与冷胁迫耐受性相关的代谢物的含量。GhSAD1HapB 的过表达部分补充了拟南芥 ABA2 突变体 aba2-1 的表型。总的来说，这些发现增加了我们对 GhSAD1 介导的棉花冷胁迫反应机制的理解。
