PDF(Pubmed)
Abstract：
Strigolactones (SLs) represent a new group of phytohormones that play a pivotal role in the regulation of plant shoot branching and the development of adventitious roots. In cotton (Gossypium hirsutum, Gh), SLs play a crucial role in the regulation of fiber cell elongation and secondary cell wall thickness. However, the underlying molecular mechanisms of SL signaling involved in fiber cell development are largely unknown. In this study, we report two SL-signaling genes, GhMAX2-3 and GhMAX2-6, which positively regulate cotton fiber elongation. Further protein-protein interaction and degradation assays showed that the repressor of the auxin cascade GhIAA17 serves as a substrate for the F-box E3 ligase GhMAX2. The in vivo ubiquitination assay suggested that GhMAX2-3 and GhMAX2-6 ubiquitinate GhIAA17 and coordinately degrade GhIAA17 with GhTIR1. The findings of this investigation offer valuable insights into the roles of GhMAX2-mediated SL signaling in cotton and establish a solid foundation for future endeavors aimed at optimizing cotton plant cultivation.
摘要：
Strigolactone（SLs）代表了一类新的植物激素，在植物芽分枝和不定根发育的调节中起着关键作用。在棉花中(陆地棉，Gh),SLs在成纤维细胞伸长和次生细胞壁厚度的调节中起着至关重要的作用。然而,SL信号参与成纤维细胞发育的潜在分子机制尚不清楚.在这项研究中,我们报告了两个SL信号基因，GhMAX2-3和GhMAX2-6正调控棉纤维伸长。进一步的蛋白质-蛋白质相互作用和降解分析表明，生长素级联GhIAA17的阻遏物充当F-boxE3连接酶GhMAX2的底物。体内泛素化试验表明GhMAX2-3和GhMAX2-6泛素化GhIAA17并与GhTIR1协同降解GhIAA17。这项研究的结果为GhMAX2介导的SL信号在棉花中的作用提供了宝贵的见解，并为旨在优化棉花植物栽培的未来努力奠定了坚实的基础。
