A postgermination developmental arrest checkpoint is mediated by abscisic acid and requires the AB15 transcription factor in Arabidopsis
A postgermination developmental arrest checkpoint is mediated by abscisic acid and requires the AB15 transcription factor in Arabidopsis
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DOI：
10.1073/pnas.081594298
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发表时间：
2001-04-10
影响因子：
11.1
通讯作者：
Chua, NH
中科院分区：
文献类型：
--
作者：
Lopez-Molina, L;Mongrand, S;Chua, NH
种子休眠是一种具有重要适应意义的性状，因为它通过防止在不利条件下过早萌发来最大限度地提高幼苗存活率。了解种子如何打破休眠和启动生长也是巨大的农业和生物技术的兴趣。脱落酸（阿坝）在种子休眠的启动和维持中起着重要的调节作用。本文报道了碱性亮氨酸拉链转录因子AB 15在种子萌发、幼苗建立以及随后的营养生长过程中增强了对外源阿坝的反应。这些反应与总AB15水平相关。我们表明AB 15表达定义了萌发后一个狭窄的发育窗口，在此期间植物在开始营养生长之前监测环境渗透状态。AB15是维持萌发的胚处于静止状态所必需的，从而保护植物免受干旱。作为ABA触发过程中的关键参与者，AB15蛋白的积累，磷酸化，稳定性和活性在萌发和早期幼苗生长过程中受到阿坝的高度调节。
Seed dormancy is a trait of considerable adaptive significance because it maximizes seedling survival by preventing premature germination under unfavorable conditions. Understanding how seeds break dormancy and initiate growth is also of great agricultural and biotechnological interest. Abscisic acid (ABA) plays primary regulatory roles in the initiation and maintenance of seed dormancy, Here we report that the basic leucine zipper transcription factor AB15 confers an enhanced response to exogenous ABA during germination, and seedling establishment, as well as subsequent vegetative growth. These responses correlate with total AB15 levels. We show that AB15 expression defines a narrow developmental window following germination, during which plants monitor the environmental osmotic status before initiating vegetative growth. AB15 is necessary to maintain germinated embryos in a quiescent state thereby protecting plants from drought. As expected for a key player in ABA-triggered processes, AB15 protein accumulation, phosphorylation, stability, and activity are highly regulated by ABA during germination and early seedling growth.