Wang Zheng, Ouyang Yinghui, Ren Huimin, Wang Shuo, Xu Dandan, Xin Yirui, Hussain Jamshaid, Qi Guoning
State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, Zhejiang, China.
Department of Biotechnology, COMSATS University Islamabad, Abbottabad, Pakistan.
Front Plant Sci. 2022 Sep 20;13:987606. doi: 10.3389/fpls.2022.987606. eCollection 2022.
Plants adjust their stomatal aperture for regulating CO uptake and transpiration. S-type anion channel SLAC1 (slow anion channel-associated 1) is required for stomatal closure in response to various stimuli such as abscisic acid, CO, and light/dark transitions etc. Arabidopsis mutants exhibited defects in stimulus-induced stomatal closure, reduced sensitivity to darkness, and faster water loss from detached leaves. The global transcriptomic response of a plant with defective stimuli-induced stomatal closure (particularly because of defects in SLAC1) remains to be explored. In the current research we attempted to address the same biological question by comparing the global transcriptomic changes in Arabidopsis mutant and wild-type (WT) under dark, and dehydration stress, using RNA-sequencing. Abscisic acid (ABA)- and dark-induced stomatal closure was defective in Arabidopsis mutants, consequently the mutants had cooler leaf temperature than WT. Next, we determined the transcriptomic response of the mutant and WT under dark and dehydration stress. Under dehydration stress, the molecular response of mutant was clearly distinct from WT; the number of differentially expressed genes (DEGs) was significantly higher in mutant than WT. Dehydration induced DEGs in mutant were related to hormone signaling pathways, and biotic and abiotic stress response. Although, overall number of DEGs in both genotypes was not different under dark, however, the expression pattern was very much distinct; whereas majority of DEGs in WT were found to be downregulated, in majority were upregulated under dark. Further, a set 262 DEGs was identified with opposite expression pattern between WT and mutant under light-darkness transition. Amongst these, DEGs belonging to stress hormone pathways, and biotic and abiotic stress response were over-represented. To sum up, we have reported gene expression reprogramming underlying mutation and resultantly defective stomatal closure in Arabidopsis. Moreover, the induction of biotic and abiotic response in mutant under dehydration and darkness could be suggestive of the role of stomata as a switch in triggering these responses. To summarize, the data presented here provides useful insights into the gene expression reprogramming underlying mutation and resultant defects in stomatal closure.
植物通过调节气孔孔径来调控二氧化碳吸收和蒸腾作用。S型阴离子通道SLAC1（慢阴离子通道相关蛋白1）是气孔响应脱落酸、二氧化碳以及光/暗转换等多种刺激而关闭所必需的。拟南芥突变体在刺激诱导的气孔关闭方面存在缺陷，对黑暗的敏感性降低，离体叶片水分流失更快。具有缺陷性刺激诱导气孔关闭（特别是由于SLAC1缺陷）的植物的整体转录组反应仍有待探索。在当前研究中，我们试图通过RNA测序比较拟南芥突变体和野生型（WT）在黑暗和脱水胁迫下的整体转录组变化，以解决相同的生物学问题。拟南芥突变体中脱落酸（ABA）和黑暗诱导的气孔关闭存在缺陷，因此突变体叶片温度比野生型低。接下来，我们确定了突变体和野生型在黑暗和脱水胁迫下的转录组反应。在脱水胁迫下，突变体的分子反应与野生型明显不同；突变体中差异表达基因（DEG）的数量显著高于野生型。突变体中脱水诱导的DEG与激素信号通路以及生物和非生物胁迫反应有关。虽然在黑暗条件下两种基因型的DEG总数没有差异，但是表达模式非常不同；野生型中的大多数DEG被发现下调，而突变体中的大多数在黑暗条件下上调。此外，在光-暗转换过程中，鉴定出一组262个在野生型和突变体之间具有相反表达模式的DEG。其中，属于胁迫激素途径以及生物和非生物胁迫反应的DEG过度富集。总之，我们报道了拟南芥中突变以及由此导致的气孔关闭缺陷背后的基因表达重编程。此外，突变体在脱水和黑暗条件下生物和非生物反应的诱导可能暗示气孔作为触发这些反应的开关的作用。综上所述，这里呈现的数据为突变以及气孔关闭缺陷背后的基因表达重编程提供了有用的见解。
