Zhao Hongjiao, Sun Piaoyun, Tong Can, Li Xiangbao, Yang Tongwen, Jiang Yanxin, Zhao Bosi, Dong Junyang, Jiang Biao, Shen Junjun, Li Zheng
College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Guangdong Key Laboratory for New Technology Research of Vegetables, Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, 510640, China.
New Phytol. 2025 Feb;245(4):1528-1546. doi: 10.1111/nph.20309. Epub 2024 Dec 13.
Plant height is a critical agronomic trait that affects crop yield, plant architecture, and environmental adaptability. Gibberellins (GAs) regulate plant height, with DELLA proteins acting as key repressors in the GA signaling pathway by inhibiting GA-induced growth. While DELLA phosphorylation is essential for regulating plant height, the precise mechanisms underlying this process remain incompletely understood. In this study, we identified a cucumber mutant with delayed growth, which exhibited reduced sensitivity to GA treatment. Through bulked segregant analysis (BSA-seq) combined with molecular marker linkage analysis, we successfully identified and cloned the gene responsible for the dwarf phenotype, CsIREH1 (INCOMPLETE ROOT HAIR ELONGATION 1), which encodes an AGC protein kinase. Further research revealed that CsIREH1 interacts with and phosphorylates DELLA proteins, specifically targeting CsGAIP and CsGAI2. We propose that IREH1-dependent phosphorylation of DELLA proteins prevents their excessive accumulation, thereby maintaining normal plant growth. Therefore, investigating the role of IREH1-mediated DELLA phosphorylation provides valuable insights and theoretical foundations for understanding how plants regulate growth mechanisms.
株高是一个关键的农艺性状，影响作物产量、植株形态和环境适应性。赤霉素（GAs）调节株高，DELLA蛋白通过抑制GA诱导的生长，在GA信号通路中作为关键阻遏物发挥作用。虽然DELLA磷酸化对于调节株高至关重要，但该过程的精确机制仍未完全清楚。在本研究中，我们鉴定了一个生长延迟的黄瓜突变体，其对GA处理表现出降低的敏感性。通过混合分组分析法（BSA-seq）结合分子标记连锁分析，我们成功鉴定并克隆了导致矮化表型的基因CsIREH1（不完全根毛伸长1），其编码一种AGC蛋白激酶。进一步研究表明，CsIREH1与DELLA蛋白相互作用并使其磷酸化，特别是靶向CsGAIP和CsGAI2。我们提出，IREH1依赖的DELLA蛋白磷酸化可防止其过度积累，从而维持植物正常生长。因此，研究IREH1介导的DELLA磷酸化的作用，为理解植物如何调节生长机制提供了有价值的见解和理论基础。
