Regulation and role of the Arabidopsis Abscisic Acid-Insensitive 5 gene in abscisic acid, sugar, and stress response
Regulation and role of the Arabidopsis Abscisic Acid-Insensitive 5 gene in abscisic acid, sugar, and stress response
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DOI：
10.1104/pp.005793
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发表时间：
2002-08-01
期刊：
影响因子：
7.4
通讯作者：
Finkelstein, RR
中科院分区：
文献类型：
--
作者：
Brocard, IM;Lynch, TJ;Finkelstein, RR
脱落酸（阿坝）和胁迫反应从胚胎生长后期到幼苗发育早期是由一个信号网络，其中包括拟南芥ABA不敏感（ABI）5基因，它编码一个碱性亮氨酸拉链转录因子调节。我们已经表征了ABI 5表达的遗传、发育和环境调节。虽然在种子中表达最强，但ABI 5启动子在营养和花组织中也有活性。营养体表达强烈诱导阿坝，弱胁迫处理在有限的发育窗口，约2天后层积，但阿坝和一些应力可以诱导表达在特定组织在后期阶段。在转基因植物和酵母（酿酒酵母）中，ABI 5的表达是自动调节的，胁迫反应似乎涉及ABI 5依赖和非依赖的机制。为了确定ABI 5是否是必需的和/或足够的阿坝或应激反应，我们测定了ABI 5表达增加对生长和基因表达的影响。尽管ABI 5的过表达赋予对阿坝和糖的超敏性，如先前对ABI 4和ABI 3过表达系所述，但其对增强ABA响应性基因表达的作用相对有限。八个ABI 5同源基因的表达比较显示ABI 3，ABI 4和AB 15的重叠调节，提示涉及正向和负向调节相互作用的组合网络。
Abscisic acid (ABA) and stress response from late embryonic growth through early seedling development is regulated by a signaling network that includes the Arabidopsis ABA-insensitive (ABI)5 gene, which encodes a basic leucine zipper transcription factor. We have characterized genetic, developmental, and environmental regulation of ABI5 expression. Although expressed most strongly in seeds, the ABI5 promoter is also active in vegetative and floral tissue. Vegetative expression is strongly induced by ABA, and weakly by stress treatments during a limited developmental window up to approximately 2 d post-stratification, but ABA and some stresses can induce expression in specific tissues at later stages. ABI5 expression is autoregulated in transgenic plants and yeast (Saccharomyces cerevisiae), and stress response appears to involve ABI5-dependent and -independent mechanisms. To determine whether ABI5 is necessary and/or sufficient for ABA or stress response, we assayed the effects of increased ABI5 expression on growth and gene expression. Although overexpression of ABI5 confers hypersensitivity to ABA and sugar, as previously described for ABI4 and ABI3 overexpression lines, it has relatively limited effects on enhancing ABA-responsive gene expression. Comparison of expression of eight ABI5-homologous genes shows overlapping regulation by ABI3, ABI4, and AB15, suggestive of a combinatorial network involving positive and negative regulatory interactions.