Abscisic Acid Regulates Early Seed Development in Arabidopsis by ABI5-Mediated Transcription of SHORT HYPOCOTYL UNDER BLUE1
Abscisic Acid Regulates Early Seed Development in Arabidopsis by ABI5-Mediated Transcription of SHORT HYPOCOTYL UNDER BLUE1
复制标题
脱落酸通过 ABI5 介导的短下胚轴转录调节拟南芥早期种子发育1
DOI：
10.1105/tpc.113.121566
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发表时间：
2014-03-01
期刊：
影响因子：
11.6
通讯作者：
Zhang, Xian Sheng
中科院分区：
文献类型：
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作者：
Cheng, Zhi Juan;Zhao, Xiang Yu;Zhang, Xian Sheng
拟南芥种子发育包括胚乳增殖的早期阶段和以胚乳为代价的胚生长的晚期阶段。脱落酸（阿坝）在种子发育后期具有已知的功能，但其在种子发育早期的作用仍然是难以捉摸的。在这项研究中，我们报告ABA缺陷突变体产生的种子的大小，质量和胚细胞数量增加，但延迟胚乳细胞化。ABA 2基因编码一种短链脱氢酶/还原酶，在阿坝生物合成中发挥作用，其表达模式与SHB 1基因在种子发育过程中的表达模式重叠。SHB 1 RNA积累显着上调aba 2 -1突变体和下调外源阿坝的应用。此外，在aba 2 -1中，参与阿坝信号传导的碱性/区域亮氨酸拉链转录因子ABSCISIC ACID-INSENSITIVE 5（ABI 5）的RNA积累减少。与此一致，种子大小也在abi 5中增加。我们进一步表明，ABI 5直接结合到SHB 1启动子中的两个离散区域。我们的研究结果表明，阿坝至少部分通过其下游信号成分ABI 5的作用来负调节SHB 1的表达。我们的研究结果提供了深入了解阿坝调节早期种子发育的分子机制。
Seed development includes an early stage of endosperm proliferation and a late stage of embryo growth at the expense of the endosperm in Arabidopsis thaliana. Abscisic acid (ABA) has known functions during late seed development, but its roles in early seed development remain elusive. In this study, we report that ABA-deficient mutants produced seeds with increased size, mass, and embryo cell number but delayed endosperm cellularization. ABSCISIC ACID DEFICIENT2 (ABA2) encodes a unique short-chain dehydrogenase/reductase that functions in ABA biosynthesis, and its expression pattern overlaps that of SHORT HYPOCOTYL UNDER BLUE1 (SHB1) during seed development. SHB1 RNA accumulation was significantly upregulated in the aba2-1 mutant and was downregulated by the application of exogenous ABA. Furthermore, RNA accumulation of the basic/region leucine zipper transcription factor ABSCISIC ACID-INSENSITIVE5 (ABI5), involved in ABA signaling, was decreased in aba2-1. Consistent with this, seed size was also increased in abi5. We further show that ABI5 directly binds to two discrete regions in the SHB1 promoter. Our results suggest that ABA negatively regulates SHB1 expression, at least in part, through the action of its downstream signaling component ABI5. Our findings provide insights into the molecular mechanisms by which ABA regulates early seed development.