Functional analysis of an Arabidopsis heat-shock transcription factor HsfA3 in the transcriptional cascade downstream of the DREB2A stress-regulatory system
Functional analysis of an Arabidopsis heat-shock transcription factor HsfA3 in the transcriptional cascade downstream of the DREB2A stress-regulatory system
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DOI：
10.1016/j.bbrc.2008.01.134
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发表时间：
2008-04-11
影响因子：
3.1
通讯作者：
Yamaguchi-Shinozaki, Kazuko
中科院分区：
文献类型：
--
作者：
Yoshida, Takumi;Sakuma, Yoh;Yamaguchi-Shinozaki, Kazuko
转录因子DREB2A不仅在干旱胁迫反应中发挥关键调节作用，而且在热胁迫(HS)反应中也发挥关键调节作用，并激活许多与干旱和HS耐性相关的非生物胁迫响应基因的表达。HsfA3是高表达DREB2A转基因植物中表达上调最多的热诱导基因之一。在本研究中，HsfA3的表达谱分析和HsfA3的反式激活分析表明，在HS条件下，HsfA3的表达受到DREB2A的直接调控。利用高表达HsfA3的转基因植株进行的基因芯片分析也表明，HsfA3的过表达诱导了许多热诱导基因。此外，我们还发现hsfA3过表达的突变体的耐热性提高，而hsfA3T-DNA标记突变体的耐热性降低。这些结果表明，HsfA3在DREB2A逆境调节系统下游的转录级联中调节许多热诱导基因的表达，并在DREB2A级联调控下在获得耐热性方面发挥作用。(C)2008 Elsevier Inc.保留所有权利。
A transcription factor DREB2A functions as a key regulator not only in drought stress responses but also in heat stress (HS) responses, and activates expression of many abiotic stress-responsive-genes involved in drought and HS tolerance. HsfA3 is one of the most up-regulated heat-inducible genes in transgenic plants overexpressing DREB2A. In this study, the analyses of HsfA3 expression profile and the transactivation analysis of HsfA3 showed that the expression of HsfA3 was directly regulated by DREB2A under HS. Microarray analysis using transgenic plants overexpressing HsfA3 also showed that overexpression of HsfA3 induces many heat-inducible genes. Furthermore, we showed that thermotolerance of the HsfA3 overexpressors was increased, and that of the hsfA3 T-DNA tagged mutants was decreased. These results indicate that HsfA3 regulates expression of many heat-inducible genes in the transcriptional cascade downstream of the DREB2A stress-regulatory system and functions in acquisition of thermotolerance under the control of the DREB2A cascade. (c) 2008 Elsevier Inc. All rights reserved.