Arabidopsis BRCA1 represses RRTF1-mediated ROS production and ROS-responsive gene expression under dehydration stress
Arabidopsis BRCA1 represses RRTF1-mediated ROS production and ROS-responsive gene expression under dehydration stress
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拟南芥 BRCA1 在脱水胁迫下抑制 RRTF1 介导的 ROS 产生和 ROS 响应基因表达
DOI：
10.1111/nph.16786
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发表时间：
2020
期刊：
影响因子：
9.4
通讯作者：
Xu Zheng-Yi
中科院分区：
文献类型：
--
作者：
Wang Jie;Nan Nan;Shi Lulu;Li Ning;Huang Shuangzhan;Zhang Ai;Liu Yutong;Guo Peng;Liu Bao;Xu Zheng-Yi
活性氧（ROS）作为脱落酸（阿坝）信号传导的重要第二信使，在干旱胁迫下诱导气孔关闭。乳腺癌易感基因1（BRCA 1）是动物中一种重要的肿瘤抑制基因，其主要功能是维持动物和植物基因组的完整性。然而，在脱水胁迫下，植物BRCA 1是否以及如何调节保卫细胞内ROS的稳态仍然是未知的。在这里，我们发现，拟南芥BRCA 1功能丧失突变体表现出脱水胁迫耐受性。atbrca 1的这种耐胁迫表型是阿坝和ROS诱导的气孔关闭的结果，与野生型相比，atbrca 1突变体的气孔关闭增强。AtBRCA 1下调ROS应答基因和标记基因的表达。值得注意的是，这些基因也是AP 2/ERF转录激活因子RRTF 1/ERF 109的靶基因。在正常条件下，AtBRCA 1与RRTF 1发生物理相互作用，并抑制RRTF 1与靶基因启动子中GCC‐box‐like序列的结合。在脱水胁迫下，AtBRCA 1的表达显著降低，RRTF 1的表达被激活，从而诱导ROS应答基因的表达，本研究揭示了AtBRCA 1在脱水胁迫下对细胞内ROS稳态的转录调控中的新的分子功能.
Reactive oxygen species (ROS) act as important secondary messengers in abscisic acid (ABA) signaling and induce stomatal closure under dehydration stress. The breast cancer susceptibility gene 1 (BRCA1), an important tumor suppressor in animals, functions primarily in the maintenance of genome integrity in animals and plants. However, whether and how the plant BRCA1 regulates intracellular ROS homeostasis in guard cells under dehydration stress remains unknown.Here, we found that Arabidopsisatbrca1loss‐of‐function mutants showed dehydration stress tolerance. This stress tolerant phenotype ofatbrca1was a result of ABA‐ and ROS‐induced stomatal closure, which was enhanced inatbrca1mutants compared with the wild‐type. AtBRCA1 downregulated the expression of ROS‐responsive and marker genes. Notably, these genes were also the targets of the AP2/ERF transcriptional activator RRTF1/ERF109.Under normal conditions, AtBRCA1 physically interacted with RRTF1 and inhibited its binding to the GCC‐box‐like sequence in target gene promoters. Under dehydration stress, the expression ofAtBRCA1was dramatically reduced and that of RRTF1 was activated, thus inducing the expression of ROS‐responsive genes.Overall, our study reveals a novel molecular function of AtBRCA1 in the transcriptional regulation of intracellular ROS homeostasis under dehydration stress.