Zheng Feng, Ou Wenli, Deng Ling, Wang Yahan, Chen Hangcong, Chen Yiting, Peng Tao, Yang Yongyi, Teixeira da Silva Jaime A, Liu Xuncheng
Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Mol Plant. 2025 Sep 1;18(9):1567-1586. doi: 10.1016/j.molp.2025.08.002. Epub 2025 Aug 6.
The shift from skotomorphogenesis to photomorphogenesis, a developmental transition in seed plants, involves dramatic proteomic changes. Lysine acetylation (Lys-Ac) is an evolutionarily conserved and recognized post-translational modification that plays a crucial role in plant development. However, its role in seedling deetiolation remains unclear. In this study, we conducted a comparative lysine acetylomic analysis of etiolated Arabidopsis seedlings before and after red (R) light irradiation, uncovering that exposure to R light mainly led to protein lysine deacetylation during seedling deetiolation. Phytochrome A (phyA), a unique far-red (FR) light photoreceptor, was deacetylated at lysine 65 (K65) when etiolated seedlings were moved to light. This residue is a critical ubiquitination site that regulates phyA stability. Moreover, K65 deacetylation facilitates phyA ubiquitination and 26S proteasome-mediated degradation, and is required for the function of phyA in FR light signaling and seedling photomorphogenesis. Furthermore, we identified a plant-specific lysine deacetylase HDT2 that interacts with and deacetylates phyA in the nucleus to promote its ubiquitination and degradation during seedling deetiolation. Genetic analysis revealed that HDT2 is critical for phyA-mediated photomorphogenic growth. Taken together, these findings reveal that lysine deacetylation of phyA by HDT2 plays a crucial role in modulating phyA turnover in response to light, suggesting that Lys-Ac might be central to the reprogramming of plants for photomorphogenic growth.
从暗形态建成到光形态建成的转变是种子植物中的一种发育转变，涉及显著的蛋白质组变化。赖氨酸乙酰化（Lys-Ac）是一种进化上保守且公认的翻译后修饰，在植物发育中起关键作用。然而，其在幼苗去黄化过程中的作用仍不清楚。在本研究中，我们对红光（R）照射前后的拟南芥黄化幼苗进行了赖氨酸乙酰化组比较分析，发现暴露于R光主要导致幼苗去黄化过程中蛋白质赖氨酸去乙酰化。光敏色素A（phyA）是一种独特的远红光（FR）光感受器，当黄化幼苗移至光照下时，其赖氨酸65（K65）位点发生去乙酰化。该残基是调节phyA稳定性的关键泛素化位点。此外，K65去乙酰化促进phyA泛素化和26S蛋白酶体介导的降解，并且是phyA在FR光信号传导和幼苗光形态建成中发挥功能所必需的。此外，我们鉴定出一种植物特异性赖氨酸脱乙酰酶HDT2，其在细胞核中与phyA相互作用并使其去乙酰化，以促进其在幼苗去黄化过程中的泛素化和降解。遗传分析表明，HDT2对phyA介导的光形态建成生长至关重要。综上所述，这些发现揭示了HDT2介导的phyA赖氨酸去乙酰化在响应光照调节phyA周转中起关键作用，表明Lys-Ac可能是植物光形态建成生长重编程的核心。
