Progressive chromatin silencing of ABA biosynthesis genes permits seed germination in Arabidopsis
Progressive chromatin silencing of ABA biosynthesis genes permits seed germination in Arabidopsis
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ABA 生物合成基因的染色质渐进沉默允许拟南芥种子萌发
DOI：
10.1093/plcell/koac134
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Zhe Wu
中科院分区：
文献类型：
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作者：
Deyue Yang;Fengli Zhao;Danling Zhu;Xi Chen;Xiangxiong Kong;Yufeng Wu;Min Chen;Jiamu Du;Li-Jia Qu;Zhe Wu
摘要种子萌发是植物发育的一个重要环节，对农业生产至关重要，但这一过程在染色质水平上是如何控制的仍不清楚。在这里，我们证明，在拟南芥的成功萌发需要一个染色质机制，逐步沉默9-顺式-环氧胡萝卜素二氧合酶6（NCED 6），编码脱落酸（阿坝）生物合成的限速酶，通过RNA结合蛋白RZ-1和polycomb抑制复合物2（PRC 2）的合作行动。RZ-1和PRC 2的同时失活阻断了发芽，并协同去抑制NCED和数百个基因。在NCED 6，部分通过促进H3去乙酰化和抑制H3 K4 me 3，RZ-1促进转录沉默，也促进种子萌发和早期幼苗生长期间发生的H3 K27 me 3积累过程。全基因组分析表明，RZ-1是优先需要的转录沉默的许多PRC 2目标在种子萌发早期，当H3 K27 me 3尚未建立。我们提出RZ-1赋予一种新的沉默机制，以补偿并协同PRC 2。我们的工作强调了阿坝生物合成基因通过RNA结合蛋白RZ-1和PRC 2协同作用的进行性染色质沉默，这一过程对种子萌发至关重要。
Abstract Seed germination represents a major developmental switch in plants that is vital to agriculture, but how this process is controlled at the chromatin level remains obscure. Here we demonstrate that successful germination in Arabidopsis thaliana requires a chromatin mechanism that progressively silences 9-CIS-EPOXYCAROTENOID DIOXYGENASE 6 (NCED6), which encodes a rate-limiting enzyme in abscisic acid (ABA) biosynthesis, through the cooperative action of the RNA-binding protein RZ-1 and the polycomb repressive complex 2 (PRC2). Simultaneous inactivation of RZ-1 and PRC2 blocked germination and synergistically derepressed NCEDs and hundreds of genes. At NCED6, in part by promoting H3 deacetylation and suppressing H3K4me3, RZ-1 facilitates transcriptional silencing and also an H3K27me3 accumulation process that occurs during seed germination and early seedling growth. Genome-wide analysis revealed that RZ-1 is preferentially required for transcriptional silencing of many PRC2 targets early during seed germination, when H3K27me3 is not yet established. We propose RZ-1 confers a novel silencing mechanism to compensate for and synergize with PRC2. Our work highlights the progressive chromatin silencing of ABA biosynthesis genes via the RNA-binding protein RZ-1 and PRC2 acting in synergy, a process that is vital for seed germination.