State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
Plant Physiol. 2020 Jul;183(3):1281-1294. doi: 10.1104/pp.20.00503. Epub 2020 May 15.
The greening of etiolated seedlings is crucial for the growth and survival of plants. After reaching the soil surface and sunlight, etiolated seedlings integrate numerous environmental signals and internal cues to control the initiation and rate of greening thus to improve their survival and adaption. However, the underlying regulatory mechanisms by which light and phytohormones, such as abscisic acid (ABA), coordinately regulate greening of the etiolated seedlings is still unknown. In this study, we showed that Arabidopsis () DE-ETIOLATED1 (DET1), a key negative regulator of photomorphogenesis, positively regulated light-induced greening by repressing ABA responses. Upon irradiating etiolated seedlings with light, DET1 physically interacts with FAR-RED ELONGATED HYPOCOTYL3 (FHY3) and subsequently associates to the promoter region of the FHY3 direct downstream target (). Further, DET1 recruits HISTONE DEACETYLASE6 to the locus of the promoter and reduces the enrichments of H3K27ac and H3K4me3 modification, thus subsequently repressing expression and promoting the greening of etiolated seedlings. This study reveals the physiological and molecular function of DET1 and FHY3 in the greening of seedlings and provides insights into the regulatory mechanism by which plants integrate light and ABA signals to fine-tune early seedling establishment.
黄化幼苗的绿化对于植物的生长和存活至关重要。在到达土壤表面和阳光后，黄化幼苗整合了许多环境信号和内部线索来控制绿化的启动和速度，从而提高其存活率和适应性。然而，光和植物激素（如脱落酸（ABA））如何协同调节黄化幼苗绿化的潜在调节机制尚不清楚。在这项研究中，我们表明，拟南芥（）DE-ETIOLATED1（DET1）是光形态建成的关键负调控因子，通过抑制 ABA 反应正向调控光诱导的绿化。在光照下辐照黄化幼苗时，DET1 与 FAR-RED ELONGATED HYPOCOTYL3（FHY3）发生物理相互作用，随后与 FHY3 的直接下游靶标 （）的启动子区域结合。此外，DET1 将 HISTONE DEACETYLASE6 募集到 启动子区域，并减少 H3K27ac 和 H3K4me3 修饰的富集，从而随后抑制 表达并促进黄化幼苗的绿化。这项研究揭示了 DET1 和 FHY3 在幼苗绿化中的生理和分子功能，并为植物如何整合光和 ABA 信号来微调早期幼苗建立提供了深入了解。
