The H3K27me3 demethylase REF6 promotes leaf senescence through directly activating major senescence regulatory and functional genes in Arabidopsis
The H3K27me3 demethylase REF6 promotes leaf senescence through directly activating major senescence regulatory and functional genes in Arabidopsis
复制标题
H3K27me3去甲基酶REF6通过直接激活拟南芥主要衰老调控和功能基因促进叶片衰老
DOI：
10.1371/journal.pgen.1008068
复制
发表时间：
2019-04-01
期刊：
影响因子：
4.5
通讯作者：
Kuai, Benke
中科院分区：
文献类型：
--
作者：
Wang, Xiaolei;Gao, Jiong;Kuai, Benke
组蛋白去甲基化在植物开花、抗病、节律反应和种子萌发等调控中的作用已被阐明，但组蛋白去甲基化如何影响叶片衰老仍不清楚。本研究利用酵母单杂交技术（Y1 H）筛选了NONYELLOWING 1（NYE 1）的上游调控基因，并鉴定了一种组蛋白H3赖氨酸27三甲基化（H3 K27 me 3）脱甲基酶RELATIVE OF EARLY FLOWERING 6（REF 6），它可能是NYE 1启动子的结合蛋白。通过体内和体外分析，我们证明了REF 6直接结合到基序CTCGYTY在NYE 1/2启动子通过其锌指结构域和积极调节其表达。REF 6的功能丧失延迟叶绿素（Chl）降解，而REF 6的过表达加速Chl降解。随后，我们发现REF 6通过直接上调乙烯不敏感2（EIN 2）、ORESARA 1（ORE 1）、NAC样、AP 3/PI激活（NAP）、丙酮酸正磷酸二激酶（PPDK）、植物抗毒素缺乏4（PAD 4）、脂加氧酶1（LOX 1）、NAC结构域蛋白3（AtNAC 3）和NAC转运因子样9（NTL 9）来积极调节一般衰老过程，主要参与发育叶片衰老调控的关键调控基因和功能基因。重要的是，REF 6的功能丧失增加了所有靶衰老相关基因（SAG）的H3 K27 me 3水平。因此，我们最终证明，H3 K27 me 3甲基化代表了一种表观遗传机制，禁止过早转录激活的关键发育上调衰老调控以及功能基因在拟南芥。
The roles of histone demethylation in the regulation of plant flowering, disease resistance, rhythmical response, and seed germination have been elucidated recently; however, how histone demethylation affects leaf senescence remains largely unclear. In this study, we exploited yeast one-hybrid (Y1H) to screen for the upstream regulators of NONYELLOWING1 (NYE1), and identified RELATIVE OF EARLY FLOWERING6 (REF6), a histone H3 lysine 27 tri-methylation (H3K27me3) demethylase, as a putative binding protein of NYE1 promoter. By in vivo and in vitro analyses, we demonstrated that REF6 directly binds to the motif CTCGYTY in NYE1/2 promoters through its zinc finger domain and positively regulates their expression. Loss-of-function of REF6 delayed chlorophyll (Chl) degradation, whereas overexpression of REF6 accelerated Chl degradation. Subsequently, we revealed that REF6 positively regulates the general senescence process by directly up-regulating ETHYLENE INSENSITIVE 2 (EIN2), ORESARA1 (ORE1), NAC-LIKE, ACTIVATED BY AP3/PI (NAP), PYRUVATE ORTHOPHOSPHATE DIKINASE (PPDK), PHYTOALEXIN DEFICIENT 4 (PAD4), LIPOXYGENASE 1 (LOX1), NAC DOMAIN CONTAINING PROTEIN 3 (AtNAC3), and NAC TRANSCRIPTION FACTOR-LIKE 9 (NTL9), the key regulatory and functional genes predominantly involved in the regulation of developmental leaf senescence. Importantly, loss-of-function of REF6 increased H3K27me3 levels at all the target Senescence associated genes (SAGs). We therefore conclusively demonstrate that H3K27me3 methylation represents an epigenetic mechanism prohibiting the premature transcriptional activation of key developmentally up-regulated senescence regulatory as well as functional genes in Arabidopsis.