Arabidopsis MADS-Box Transcription Factor AGL21 Acts as Environmental Surveillance of Seed Germination by Regulating ABI5 Expression
Arabidopsis MADS-Box Transcription Factor AGL21 Acts as Environmental Surveillance of Seed Germination by Regulating ABI5 Expression
复制标题
拟南芥 MADS-Box 转录因子 AGL21 通过调节 ABI5 表达对种子萌发进行环境监测
DOI：
10.1016/j.molp.2017.04.004
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发表时间：
2017
期刊：
影响因子：
27.5
通讯作者：
Xiang Cheng-Bin
中科院分区：
文献类型：
--
作者：
Yu Lin-Hui;Wu Jie;Zhang Zi-Sheng;Miao Zi-Qing;Zhao Ping-Xia;Wang Zhen;Xiang Cheng-Bin
种子萌发是植物在不利环境条件下生存的关键。脱落酸（阿坝）信号在整合环境信息调节种子萌发中起着重要作用。众所周知，MCM 1/AGAMOUS/DEFICIENS/SRF（MADS）-box转录因子是拟南芥种子和花发育的关键调控因子。然而，很少有人知道它们在种子萌发中的功能。本文报道了MADS盒转录因子AGL 21通过调控ABA-不敏感5（ABI 5）基因的表达，对拟南芥种子萌发和萌发后生长起负调控作用。在种子萌发和萌发后早期生长过程中，AGL 21过表达植株对阿坝、盐和渗透胁迫高度敏感，而AGL 21突变体则不太敏感。我们发现AGL 21正调控种子中ABI 5的表达。遗传分析表明，AGL 21对ABI 5的控制作用是上位性的。染色质免疫沉淀实验进一步证明AGL 21可以直接与植物细胞中的ABI 5启动子结合。此外，我们还发现AGL 21在种子萌发过程中对多种环境胁迫和植物激素有反应。总之，我们的研究结果表明，AGL 21作为一个监视集成器，将环境线索和内源激素信号阿坝信号调节种子萌发和早期萌发后的生长。
Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Abscisic acid (ABA) signaling plays a vital role in integrating environmental information to regulate seed germination. It has been well known that MCM1/AGAMOUS/DEFICIENS/SRF (MADS)-box transcription factors are key regulators of seed and flower development inArabidopsis. However, little is known about their functions in seed germination. Here we report that MADS-box transcription factor AGL21 is a negative regulator of seed germination and post-germination growth by controlling the expression ofABA-INSENSITIVE 5(ABI5) inArabidopsis. TheAGL21-overexpressing plants were hypersensitive to ABA, salt, and osmotic stresses during seed germination and early post-germination growth, whereasagl21mutants were less sensitive. We found that AGL21 positively regulatedABI5expression in seeds. Consistently, genetic analyses showed thatAGL21is epistatic toABI5in controlling seed germination. Chromatin immunoprecipitation assays further demonstrated that AGL21 could directly bind to theABI5promoter in plant cells. Moreover, we found thatAGL21responded to multiple environmental stresses and plant hormones during seed germination. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.