Zeng Mingyang, Wu Yan, Lin Shunfa, Zhang Fang, Jiang Haiyan, Ma Lixia, Liu Dong
Ministry of Education Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Jiangxi Agricultural University, Nanchang 330045, China.
Plants (Basel). 2025 Jun 20;14(13):1905. doi: 10.3390/plants14131905.
The AP2/ERF transcription factor ABSCISIC ACID INSENSITIVE 4 (ABI4) plays diverse roles in plant development and responses to abiotic stress. However, its potential involvement in regulating anthocyanin biosynthesis is not fully understood. In this study, three different loss-of-function alleles (, , and ) were employed to investigate the role of ABI4 in the regulation of anthocyanin accumulation in seedlings. These mutants exhibited significantly increased anthocyanin accumulation, which was associated with elevated expression of genes involved in anthocyanin biosynthesis. HY5 (LONG HYPOCOTYL 5), a central component of photomorphogenesis, acts as a key light-regulated molecular switch. Further analysis revealed that ABI4 requires HY5 to function as a negative regulator of anthocyanin biosynthesis. Additionally, loss of resulted in heightened light sensitivity, leading to increased light-induced chlorophyll accumulation and chloroplast development, along with upregulation of photosynthesis-related genes. Interestingly, the light-hypersensitive phenotype of mutants was partially rescued by the loss of HY5 function. Taken together, these findings demonstrate that negatively regulates anthocyanin accumulation in seedlings through a HY5-dependent light signaling pathway.
AP2/ERF转录因子脱落酸不敏感4（ABI4）在植物发育和对非生物胁迫的响应中发挥着多种作用。然而，其在调控花青素生物合成中的潜在作用尚未完全明确。在本研究中，使用了三个不同的功能缺失等位基因（、和）来研究ABI4在调控拟南芥幼苗花青素积累中的作用。这些拟南芥突变体表现出花青素积累显著增加，这与花青素生物合成相关基因的表达上调有关。HY5（长下胚轴5）是光形态建成的核心成分，作为关键的光调控分子开关。进一步分析表明，ABI4需要HY5作为花青素生物合成的负调控因子发挥作用。此外，的缺失导致光敏感性增强，导致光诱导的叶绿素积累和叶绿体发育增加，以及光合作用相关基因的上调。有趣的是，HY5功能的缺失部分挽救了突变体的光超敏表型。综上所述，这些发现表明通过依赖HY5的光信号通路负调控拟南芥幼苗中的花青素积累。
