A Regulatory Cascade Involving Class II ETHYLENE RESPONSE FACTOR Transcriptional Repressors Operates in the Progression of Leaf Senescence
A Regulatory Cascade Involving Class II ETHYLENE RESPONSE FACTOR Transcriptional Repressors Operates in the Progression of Leaf Senescence
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DOI：
10.1104/pp.113.218115
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发表时间：
2013-06-01
期刊：
影响因子：
7.4
通讯作者：
Sato, Fumihiko
中科院分区：
文献类型：
--
作者：
Koyama, Tomotsugu;Nii, Haruka;Sato, Fumihiko
叶片衰老是叶片发育的最后过程，涉及营养物质从老叶向新生长的组织的动员。尽管已经鉴定了几种参与调控这一过程的转录因子，但叶片衰老进程的潜在机制在很大程度上是未知的。在此，我们描述了蛋白酶体介导的调节II类乙烯反应因子（ERF）转录抑制因子和参与这些因素在拟南芥叶片衰老的进展。基于先前的结果表明，烟草（烟草）ERF 3（NtERF 3）特异性地与泛素结合酶相互作用，我们研究了NtERF 3在体外的稳定性，并证实其快速降解的植物蛋白提取物。此外，NtERF 3积累在植物蛋白酶体抑制剂处理。拟南芥II类ERFs AtERF 4和AtERF 8也受到蛋白酶体的调节，并随着植物衰老而增加。NtERF 3、AtERF 4或AtERF 8表达增强的转基因拟南芥植株表现出叶片早衰。我们的基因表达和染色质免疫沉淀分析表明，AtERF 4和AtERF 8靶向的表硫特异性蛋白/表硫特异性衰老调节基因和调节许多基因的表达参与叶片衰老的进展。相反，atef 4 atef 8双突变体表现出延迟叶片衰老。我们的研究结果提供了深入了解的重要作用，II类ERFs在叶片衰老的进展。
Leaf senescence is the final process of leaf development that involves the mobilization of nutrients from old leaves to newly growing tissues. Despite the identification of several transcription factors involved in the regulation of this process, themechanisms underlying the progression of leaf senescence are largely unknown. Herein, we describe the proteasome-mediated regulation of class II ETHYLENE RESPONSE FACTOR (ERF) transcriptional repressors and involvement of these factors in the progression of leaf senescence in Arabidopsis (Arabidopsis thaliana). Based on previous results showing that the tobacco (Nicotiana tabacum) ERF3 (NtERF3) specifically interacts with a ubiquitin-conjugating enzyme, we examined the stability of NtERF3 in vitro and confirmed its rapid degradation by plant protein extracts. Furthermore, NtERF3 accumulated in plants treated with a proteasome inhibitor. The Arabidopsis class II ERFs AtERF4 and AtERF8 were also regulated by the proteasome and increased with plant aging. Transgenic Arabidopsis plants with enhanced expression of NtERF3, AtERF4, or AtERF8 showed precocious leaf senescence. Our gene expression and chromatin immunoprecipitation analyses suggest that AtERF4 and AtERF8 targeted the EPITHIOSPECIFIER PROTEIN/EPITHIOSPECIFYING SENESCENCE REGULATOR gene and regulated the expression of many genes involved in the progression of leaf senescence. By contrast, an aterf4 aterf8 double mutant exhibited delayed leaf senescence. Our results provide insight into the important role of class II ERFs in the progression of leaf senescence.