The ethylene response factor AtERF11 that is transcriptionally modulated by the bZIP transcription factor HY5 is a crucial repressor for ethylene biosynthesis in Arabidopsis
The ethylene response factor AtERF11 that is transcriptionally modulated by the bZIP transcription factor HY5 is a crucial repressor for ethylene biosynthesis in Arabidopsis
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DOI：
10.1111/j.1365-313x.2011.04670.x
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发表时间：
2011-10-01
期刊：
影响因子：
7.2
通讯作者：
Huang, Rongfeng
中科院分区：
文献类型：
--
作者：
Li, Zhuofu;Zhang, Lixia;Huang, Rongfeng
植物激素脱落酸（阿坝）和乙烯在植物生长发育和逆境响应中起着重要作用。乙烯的生物合成受到多种因素的影响，包括干旱、寒冷和植物激素生长素，尽管阿坝的作用尚不清楚。在这项工作中，ABA响应突变体进行了筛选，并确定了bZIP转录因子HY 5作为一个负调节乙烯生物合成的乙烯生物合成基因ACS 2和ACS 5的表达通过调制。拟南芥中乙烯反应因子（ERF）家族的转录抑制因子被证明可以调节阿坝的反应，并且有三个ERF成员被发现携带推测的HY 5结合顺式作用元件。生物化学和分子生物学方法的分析表明，HY 5特异性结合AtERF 11启动子的G盒区域，以激活其转录。我们进一步证明，AtERF 11，其中包含一个阻遏物基序在其C-末端，相互作用的脱水反应元件在ACS 2/5启动子，抑制其表达，导致乙烯生物合成减少。此外，AtERF 11基因敲除突变体表现出增加的ACS 2/5的表达和乙烯排放水平，而阿坝处理大大抑制ACS 5的转录，但不ACS 2的表达和乙烯含量，表明AtERF 11是一个关键的负调节ABA介导的控制乙烯合成。此外，在乙烯过量生产突变体中，阿坝处理显示出抑制ACS 5转录和乙烯含量，从而影响生长和发育。基于这些数据，在这项研究中，我们提出了一个模型，表明HY 5-AtERF 11调节子是一个关键因素调节ABA调节乙烯生物合成。
The phytohormones abscisic acid (ABA) and ethylene are known to play multiple roles in plant development and stress responses. Ethylene biosynthesis is affected by several factors including drought, cold and the phytohormone auxin, although the role of ABA is unclear. In this work ABA-responsive mutants were screened and a bZIP transcription factor HY5 was identified as a negative regulator of ethylene biosynthesis via modulation of the expression of the ethylene biosynthesis genes ACS2 and ACS5. Members of the ethylene response factor (ERF) family of transcriptional repressors in Arabidopsis have been shown to modulate ABA responses and three ERF members were found to carry putative HY5-binding cis-acting elements. Analyses with biochemical and molecular approaches revealed that HY5 specifically binds to the G-box region of the AtERF11 promoter to activate its transcription. We further demonstrate that AtERF11, which contains a repressor motif at its C-terminal, interacts with the dehydration-responsive element in the ACS2/5 promoters, to repress its expression, resulting in decreased ethylene biosynthesis. Moreover, an AtERF11 knockout mutant showed increased levels of ACS2/5 expression and ethylene emission, while treatment with ABA greatly suppressed ACS5 transcripts but not ACS2 expression and the ethylene content, indicating that AtERF11 is a key negative regulator for ABA-mediated control of ethylene synthesis. In addition, in ethylene over-producer mutants, ABA treatment was shown to suppress ACS5 transcripts and ethylene content, thereby affecting growth and development. Based on these data, in this research we present a model suggesting that the HY5-AtERF11 regulon is a key factor modulating ABA-regulated ethylene biosynthesis.