A Dual-Function Transcription Factor, AtYY1, Is a Novel Negative Regulator of the Arabidopsis ABA Response Network
A Dual-Function Transcription Factor, AtYY1, Is a Novel Negative Regulator of the Arabidopsis ABA Response Network
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DOI：
10.1016/j.molp.2016.02.010
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发表时间：
2016-05-02
期刊：
影响因子：
27.5
通讯作者：
Liu, Jin-Yuan
中科院分区：
文献类型：
--
作者：
Li, Tian;Wu, Xiu-Yun;Liu, Jin-Yuan
脱落酸(ABA)在植物的生长发育以及对各种环境胁迫的响应中起着至关重要的作用。到目前为止，许多参与ABA反应网络的调控基因已经被鉴定出来，然而，它们的作用仍然没有完全阐明。在这项研究中，我们发现AtYY1，一个与哺乳动物C2H2锌指转录因子阴阳1(YY1)同源的拟南芥，是ABA反应的新的负调控因子。AtYY1是一种具有抑制和激活结构域的双功能转录因子。AtYY1基因的表达受ABA和高盐、脱水等胁迫条件的诱导。YY1突变体对ABA和氯化钠的敏感性高于野生型，而高表达AtYY1的植株对ABA和盐的敏感性较低。ATYY1的缺失也提高了ABA诱导的气孔关闭和抗旱性。此外，AtYY1还可以与ABA REPRESSOR1(ABR1)启动子结合，直接上调ABR1的表达，负调控ABA和盐响应基因的表达。进一步的分析表明，ABA INSENSITIVE4(ABI4)可能正向调节AtYY1的表达，而ABR1可以拮抗这种调节。我们的发现提供了直接证据，表明AtYY1是ABA响应网络的一个新的负调控因子，并且ABI4-AtYY1-ABR1调控通路可能微调拟南芥中ABA响应基因的表达。
Abscisic acid (ABA) plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we identified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 (YY1), as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yy1 mutant was more sensitive to ABA and NaCl than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYY1 can bind the ABA REPRESSOR1 (ABR1) promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA-and salt-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 (ABI4) might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis.