Cai Guohua, Zang Yunxiao, Wang Zhongqian, Liu Shuoshuo, Wang Guodong
School of Biological Sciences, Jining Medical University, Rizhao 276800, China.
Biology (Basel). 2024 Jul 26;13(8):561. doi: 10.3390/biology13080561.
Drought stress significantly impacts plant growth, productivity, and yield, necessitating a swift fine-tuning of pathways for adaptation to harsh environmental conditions. This study explored the effects of BTB-A2.1, BTB-A2.2, and BTB-A2.3, distinguished by their exclusive possession of the Broad-complex, Tramtrack, and Bric-à-brac (BTB) domain, on the negative regulation of drought stress mediated by abscisic acid (ABA) signaling. Promoter analysis revealed the presence of numerous ABA-responsive and drought stress-related -acting elements within the promoters of , , and . The , , and transcript abundances increased under drought and ABA induction according to qRT-PCR and GUS staining. Furthermore, the triple mutant exhibited enhanced drought tolerance, supporting the findings from the overexpression studies. Additionally, we detected a decrease in the stomatal aperture and water loss rate of the mutant, suggesting the involvement of these genes in repressing stomatal closure. Importantly, the ABA signaling-responsive gene levels within significantly increased compared with those in the wild type (WT) under drought stress. Based on such findings, BTB-A2s negatively regulate drought stress via the ABA signaling pathway.
干旱胁迫显著影响植物生长、生产力和产量，因此需要迅速微调适应恶劣环境条件的途径。本研究探讨了以独特拥有Broad-complex、Tramtrack和Bric-à-brac（BTB）结构域为特征的BTB-A2.1、BTB-A2.2和BTB-A2.3对脱落酸（ABA）信号介导的干旱胁迫负调控的影响。启动子分析显示，BTB-A2.1、BTB-A2.2和BTB-A2.3的启动子中存在大量ABA响应和干旱胁迫相关的顺式作用元件。根据qRT-PCR和GUS染色，BTB-A2.1、BTB-A2.2和BTB-A2.3的转录丰度在干旱和ABA诱导下增加。此外，BTB-A2s三突变体表现出增强的耐旱性，支持了过表达研究的结果。此外，我们检测到BTB-A2s突变体的气孔孔径和失水率降低，表明这些基因参与抑制气孔关闭。重要的是，在干旱胁迫下，BTB-A2s内ABA信号响应基因水平与野生型（WT）相比显著增加。基于这些发现，BTB-A2s通过ABA信号通路对干旱胁迫进行负调控。
