The low oxygen, oxidative and osmotic stress responses synergistically act through the ethylene response factor VII genes RAP2.12, RAP2.2 and RAP2.3
The low oxygen, oxidative and osmotic stress responses synergistically act through the ethylene response factor VII genes RAP2.12, RAP2.2 and RAP2.3
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DOI：
10.1111/tpj.12848
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发表时间：
2015-06-01
期刊：
影响因子：
7.2
通讯作者：
Szabados, Laszlo
中科院分区：
文献类型：
--
作者：
Papdi, Csaba;Perez-Salamo, Imma;Szabados, Laszlo
乙烯反应因子VII（ERF-VII）与APETALA相关的转录因子2.12（RAP 2.12）先前被鉴定为乙醇脱氢酶1启动子：：荧光素酶（ADH 1-LUC）报告基因的激活因子。在这里，我们表明，RAP 2.12及其同源物RAP 2.2和RAP 2.3的过表达维持ABA介导的ADH 1的激活，并在缺氧和常氧条件下激活缺氧标记基因。所有三个RAP 2的诱导表达赋予耐缺氧，氧化和渗透胁迫，并增强脱落酸（ABA）的敏感性。rap2.12 - 2 rap2.3 - 1双突变体对淹水和渗透胁迫均表现出敏感性。这些研究结果表明，ERF-VII型转录因子在拟南芥耐淹期间和之后依次发生的多重胁迫中发挥作用。RAP 2.12的氧依赖性降解先前被证明是由N端规则途径介导的。在淹水过程中，RAP 2.12、RAP 2.2和RAP 2.3稳定并积累在细胞核中，影响胁迫反应基因的转录。我们的结论是，稳定的RAP 2转录因子可以延长ABA介导的激活的一个子集的渗透压响应基因（如ADH 1）。我们还表明，RAP 2.12蛋白水平的影响，真正有趣的基因（环）结构域包含七缺席的拟南芥2（SINAT 2）。SINAT 1/2基因的沉默导致RAP 2.12丰度的增强，而与其N-末端降解决定子的存在或不存在无关。综上所述，我们的研究结果表明，RAP 2.12及其同源物RAP 2.2和RAP 2.3在多重应激反应中起冗余作用。替代的蛋白质降解途径可以为不同的胁迫提供RAP 2转录因子的输入。
The ethylene response factor VII (ERF-VII) transcription factor RELATED TO APETALA2.12 (RAP2.12) was previously identified as an activator of the ALCOHOL DEHYDROGENASE1 promoter::luciferase (ADH1-LUC) reporter gene. Here we show that overexpression of RAP2.12 and its homologues RAP2.2 and RAP2.3 sustains ABA-mediated activation of ADH1 and activates hypoxia marker genes under both anoxic and normoxic conditions. Inducible expression of all three RAP2s conferred tolerance to anoxia, oxidative and osmotic stresses, and enhanced the sensitivity to abscisic acid (ABA). Consistently, the rap2.12-2 rap2.3-1 double mutant showed hypersensitivity to both submergence and osmotic stress. These findings suggest that the three ERF-VII-type transcription factors play roles in tolerance to multiple stresses that sequentially occur during and after submergence in Arabidopsis. Oxygen-dependent degradation of RAP2.12 was previously shown to be mediated by the N-end rule pathway. During submergence the RAP2.12, RAP2.2 and RAP2.3 are stabilized and accumulates in the nucleus affecting the transcription of stress response genes. We conclude that the stabilized RAP2 transcription factors can prolong the ABA-mediated activation of a subset of osmotic responsive genes (e.g. ADH1). We also show that RAP2.12 protein level is affected by the REALLY INTERESTING GENE (RING) domain containing SEVEN IN ABSENTIA of Arabidopsis thaliana 2 (SINAT2). Silencing of SINAT1/2 genes leads to enhanced RAP2.12 abundance independently of the presence or absence of its N-terminal degron. Taken together, our results suggest that RAP2.12 and its homologues RAP2.2 and RAP2.3 act redundantly in multiple stress responses. Alternative protein degradation pathways may provide inputs to the RAP2 transcription factors for the distinct stresses.