Wang Qiongshan, Du Xueqiong, Zhou Ying, Xie Lijuan, Bie Shu, Tu Lili, Zhang Na, Yang Xiyan, Xiao Shi, Zhang Xianlong
Economic Crop Research Institute, Hubei Academy of Agricultural Sciences, Wuhan, Hubei, China.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China.
J Exp Bot. 2020 Sep 19;71(18):5615-5630. doi: 10.1093/jxb/eraa254.
Cold stress is a key environmental factor that affects plant development and productivity. In this study, RNA-seq in cotton following cold-stress treatment resulted in the identification of 5239 differentially expressed genes (DEGs) between two cultivars with differing sensitivity to low temperatures, among which GhKCS13 was found to be involved in the response. Transgenic plants overexpressing GhKCS13 showed increased sensitivity to cold stress. KEGG analysis of 418 DEGs in both GhKCS13-overexpressing and RNAi lines after treatment at 4 °C indicated that lipid biosynthesis and linoleic acid metabolism were related to cold stress. ESI-MS/MS analysis showed that overexpression of GhKCS13 led to modifications in the composition of sphingolipids and glycerolipids in the leaves, which might alter the fluidity of the cell membrane under cold conditions. In particular, differences in levels of jasmonic acid (JA) in GhKCS13 transgenic lines suggested that, together with lysophospholipids, it might mediate the cold-stress response. Our results suggest that overexpression of GhKCS13 probably causes remodeling of lipids in the endoplasmic reticulum and biosynthesis of lipid-derived JA in chloroplasts, which might account for the increased sensitivity to cold stress in the transgenic plants. Complex interactions between lipid components, lipid signaling molecules, and JA appear to determine the response to cold stress in cotton.
低温胁迫是影响植物生长发育和生产力的关键环境因素。在本研究中，对低温胁迫处理后的棉花进行RNA测序，结果在两个对低温敏感性不同的棉花品种中鉴定出5239个差异表达基因（DEG），其中发现GhKCS13参与了低温响应。过表达GhKCS13的转基因植株对低温胁迫的敏感性增加。对4℃处理后的GhKCS13过表达株系和RNA干扰株系中的418个DEG进行KEGG分析表明，脂质生物合成和亚油酸代谢与低温胁迫有关。电喷雾串联质谱（ESI-MS/MS）分析表明，GhKCS13的过表达导致叶片中鞘脂和甘油脂的组成发生改变，这可能会在低温条件下改变细胞膜的流动性。特别是，GhKCS13转基因株系中茉莉酸（JA）水平的差异表明，它可能与溶血磷脂一起介导低温胁迫响应。我们的结果表明，GhKCS13的过表达可能导致内质网中脂质的重塑以及叶绿体中脂质衍生的JA的生物合成，这可能是转基因植株对低温胁迫敏感性增加的原因。脂质成分、脂质信号分子和JA之间复杂的相互作用似乎决定了棉花对低温胁迫的响应。
