Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Plant Commun. 2019 Dec 3;1(2):100011. doi: 10.1016/j.xplc.2019.100011. eCollection 2020 Mar 9.
Primary seed dormancy is acquired during seed development and maturation, which is important for plant fitness and survival. DELAY OF GERMINATION1 (DOG1) plays a critical role in inducing seed dormancy. expression increases rapidly during seed development, but the precise mechanism underlying this process remains elusive. In this study, we showed that mutants with a loss or reduced function of the chromatin-remodeling factor PICKLE (PKL) exhibit increased seed dormancy. PKL associates with chromatin and inhibits its transcription. We found that PKL physically interacts with LUX ARRHYTHMO (LUX), a member of the evening complex (EC) of the circadian clock. Furthermore, LUX directly binds to a specific coding sequence of , and DOG1 acts genetically downstream of PKL and LUX. Mutations in either or () encoding another member of the EC led to increased expression and enhanced seed dormancy. Surprisingly, these phenotypes were abolished when the parent plants were grown under continuous light. In addition, we observed that loss of function of either or decreased H3K27me3 levels at the locus. Taken together, our study reveals a regulatory mechanism in which EC proteins coordinate with PKL to transmit circadian signals for directly regulating expression and seed dormancy during seed development.
初生休眠是在种子发育和成熟过程中获得的，这对植物的适应性和生存至关重要。延迟发芽 1（DOG1）在诱导种子休眠中起着关键作用。在种子发育过程中， 的表达迅速增加，但这一过程的确切机制仍不清楚。在本研究中，我们表明，染色质重塑因子 PICKLE（PKL）缺失或功能降低的突变体表现出增强的种子休眠。PKL 与 染色质结合并抑制其转录。我们发现 PKL 与生物钟的夜间复合物（EC）的成员 LUX ARRHYTHMO（LUX）物理相互作用。此外，LUX 直接结合到 DOG1 的特定编码序列上，并且 PKL 和 LUX 在遗传上位于 DOG1 的下游。编码 EC 另一个成员的 或 （）中的突变导致 表达增加和增强的种子休眠。令人惊讶的是，当亲本植物在连续光照下生长时，这些表型被消除。此外，我们观察到， 或 （）的功能丧失降低了 基因座处的 H3K27me3 水平。总之，我们的研究揭示了一种调控机制，即 EC 蛋白与 PKL 协同作用，传递昼夜节律信号，直接调节种子发育过程中 的表达和种子休眠。
