HY5-HDA9 Module Transcriptionally Regulates Plant Autophagy in Response to Light-to-Dark Conversion and Nitrogen Starvation
HY5-HDA9 Module Transcriptionally Regulates Plant Autophagy in Response to Light-to-Dark Conversion and Nitrogen Starvation
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HY5-HDA9 模块转录调节植物自噬以响应光暗转换和氮饥饿
DOI：
10.1016/j.molp.2020.02.011
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发表时间：
2020
期刊：
影响因子：
27.5
通讯作者：
Gao Caiji
中科院分区：
文献类型：
--
作者：
Yang Chao;Shen Wenjin;Yang Lianming;Sun Yun;Li Xibao;Lai Minyi;Wei Juan;Wang Chaojun;Xu Yingchao;Li Faqiang;Liang Shan;Yang Chengwei;Zhong Shangwei;Luo Ming;Gao Caiji
光可以说是决定植物生长和发育的几乎所有方面的最重要的环境因素之一，但光信号传导和自噬途径之间的分子联系尚未在植物中阐明。在这项研究中，我们证明，自噬是激活在光到暗的转换，通过自噬相关基因（ATG）的转录上调。我们发现，耗尽伸长下胚轴5（HY5），光信号的关键组成部分，导致增强的自噬活性和对延长黑暗和氮饥饿处理的抗性，有助于更高的ATG表达。HY5与组蛋白脱乙酰酶9（HDA 9）相互作用并将其募集至ATG 5和ATG 8位点，以通过组蛋白3的Lys 9和Lys 27的脱乙酰化来抑制其表达。此外，我们发现黑暗和氮耗尽都诱导HY5通过26S蛋白酶体降解，并伴随着HDA 9与ATG 5和ATG 8 eloci的解离，导致它们的抑制，从而激活自噬。遗传分析进一步证实，HY 5和HDA 9具有协同作用，并在自噬途径的上游发挥作用。总的来说，我们的研究揭示了一个以前未知的转录和表观遗传网络，该网络调节植物中自噬以响应光暗转换和氮饥饿。
Light is arguably one of the most important environmental factors that determines virtually all aspects of plant growth and development, but the molecular link between light signaling and the autophagy pathway has not been elucidated in plants. In this study, we demonstrate that autophagy is activated during light-to-dark conversion though transcriptional upregulation of autophagy-related genes (ATGs). We showed that depletion of the ELONGATED HYPOCOTYL 5 (HY5), a key component of light signaling, leads to enhanced autophagy activity and resistance to extended darkness and nitrogen starvation treatments, contributing to higher expression ofATGs. HY5 interacts with and recruits HISTONE DEACETYLASE 9 (HDA9) toATG5andATG8eloci to repress their expression by deacetylation of the Lys9 and Lys27 of histone 3. Furthermore, we found that both darkness and nitrogen depletion induce the degradation of HY5 via 26S proteasome and the concomitant disassociation of HDA9 fromATG5andATG8eloci, leading to their depression and thereby activated autophagy. Genetic analysis further confirmed that HY5 and HDA9 act synergistically and function upstream of the autophagy pathway. Collectively, our study unveils a previously unknown transcriptional and epigenetic network that regulates autophagy in response to light-to-dark conversion and nitrogen starvation in plants.