The noncoding RNA HIDDEN TREASURE 1 promotes phytochrome B-dependent seed germination by repressing abscisic acid biosynthesis
The noncoding RNA HIDDEN TREASURE 1 promotes phytochrome B-dependent seed germination by repressing abscisic acid biosynthesis
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非编码 RNA HIDDEN TREASURE 1 通过抑制脱落酸生物合成促进光敏色素 B 依赖性种子萌发
DOI：
10.1093/plcell/koac334
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发表时间：
2022-11-25
期刊：
影响因子：
11.6
通讯作者：
Zhu, Danmeng
中科院分区：
文献类型：
--
作者：
Wang, Yuqiu;Fan, Yangyang;Zhu, Danmeng
光照是种子萌发的主要环境因子。红光激活光敏色素B（phyB）通过调节赤霉素（GA）和脱落酸（阿坝）两种植物激素的动态平衡来促进种子萌发。phyB如何在感知光信号后调节阿坝的生物合成还没有很好的理解。在这里，我们确定了非编码RNA隐藏库1（HID 1）作为抑制剂的阿坝生物合成作用下游的phyB在拟南芥种子萌发。HID 1功能的丧失导致phyB依赖的种子萌发延迟。光活化phyB促进吸胀48 h内HID 1在胚根中的积累。我们的转录组学分析表明，HID 1和phyB共调节一组共同的基因参与阿坝和GA代谢的转录。通过正向遗传筛选，我们确定了三个阿坝生物合成基因，阿坝缺乏1（ABA 1），ABA 2和ABA 3，作为抑制剂的HID 1。我们进一步证明，HID 1直接抑制9-顺式-环氧胡萝卜素二加氧酶（NCED 9）的转录，NCED 9是编码阿坝生物合成的关键限速酶的基因。HID 1与一种H3 K4 me 3甲基转移酶ARABIDOPSIS TRITHORAX-DELATED 7（ATXR 7）相互作用，抑制其在NCED 9基因座的占据和H3 K4 me 3修饰。我们的研究揭示了phyB信号通过HID 1传递的核机制，以控制阿坝和GA的内部动态平衡，从而在种子萌发过程中逐渐优化转录网络。
Light is a major environmental factor for seed germination. Red light-activated phytochrome B (phyB) promotes seed germination by modulating the dynamic balance of two phytohormones, gibberellic acid (GA) and abscisic acid (ABA). How phyB modulates ABA biosynthesis after perceiving a light signal is not yet well understood. Here, we identified the noncoding RNA HIDDEN TREASURE 1 (HID1) as a repressor of ABA biosynthesis acting downstream of phyB during Arabidopsis thaliana seed germination. Loss of HID1 function led to delayed phyB-dependent seed germination. Photoactivated phyB promoted the accumulation of HID1 in the radicle within 48 h of imbibition. Our transcriptomics analysis showed that HID1 and phyB co-regulate the transcription of a common set of genes involved in ABA and GA metabolism. Through a forward genetic screen, we identified three ABA biosynthesis genes, ABA DEFICIENT 1 (ABA1), ABA2, and ABA3, as suppressors of HID1. We further demonstrated that HID1 directly inhibits the transcription of 9-CIS-EPOXYCAROTENOID DIOXYGENASE (NCED9), a gene encoding a key rate-limiting enzyme of ABA biosynthesis. HID1 interacts with ARABIDOPSIS TRITHORAX-RELATED7 (ATXR7), an H3K4me3 methyltransferase, inhibiting its occupancy and H3K4me3 modification at the NCED9 locus. Our study reveals a nuclear mechanism of phyB signaling transmitted through HID1 to control the internal homeostasis of ABA and GA, which gradually optimizes the transcriptional network during seed germination.