Laboratory of Genetics, University of Wisconsin-Madison, Madison, United States.
Wisconsin Institutes for Discovery, University of Wisconsin-Madison, Madison, United States.
Elife. 2016 Nov 22;5:e17214. doi: 10.7554/eLife.17214.
Leaf senescence is an essential part of the plant lifecycle during which nutrients are re-allocated to other tissues. The regulation of leaf senescence is a complex process. However, the underlying mechanism is poorly understood. Here, we uncovered a novel and the pivotal role of HDA9 (a RPD3-like histone deacetylase) in promoting the onset of leaf senescence. We found that HDA9 acts in complex with a SANT domain-containing protein POWERDRESS (PWR) and transcription factor WRKY53. Our genome-wide profiling of HDA9 occupancy reveals that HDA9 directly binds to the promoters of key negative regulators of senescence and this association requires PWR. Furthermore, we found that PWR is important for HDA9 nuclear accumulation. This study reveals an uncharacterized epigenetic complex involved in leaf senescence and provides mechanistic insights into how a histone deacetylase along with a chromatin-binding protein contribute to a robust regulatory network to modulate the onset of plant aging.
叶片衰老（leaf senescence）是植物生命周期中的一个重要组成部分，在此期间，营养物质被重新分配到其他组织中。叶片衰老的调控是一个复杂的过程，但基础机制尚未完全阐明。在这里，我们揭示了 HDA9（一种 RPD3 样组蛋白去乙酰化酶）在促进叶片衰老方面的新的、关键作用。我们发现 HDA9 与含有 SANT 结构域的蛋白 POWERDRESS（PWR）和转录因子 WRKY53 形成复合物发挥作用。我们对 HDA9 结合位点的全基因组分析表明，HDA9 直接结合到衰老关键负调控因子的启动子上，这种结合需要 PWR。此外，我们发现 PWR 对 HDA9 的核积累很重要。这项研究揭示了一个参与叶片衰老的未被描述的表观遗传复合物，并提供了关于组蛋白去乙酰化酶与染色质结合蛋白如何共同促进一个稳健的调控网络来调节植物衰老的机制见解。
