Wang Huiqin, Zhu Liping, Fan Mengyuan, Weng Shuangshuang, Zhou Xin, Zhao Hanxuan, Shen Yongcui, Chai Jiaquan, Hou Liyong, Hao Miaomiao, Tanvir Rezwan, Li Ling, Xiao Guanghui
College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
Dev Cell. 2025 Apr 7;60(7):1101-1117.e7. doi: 10.1016/j.devcel.2024.12.009. Epub 2024 Dec 27.
Strigolactone (SL) is a plant hormone required for plant development. DWARF53 (D53) functions as a transcription repressor in SL signaling. However, the role of D53 in cotton (Gossypium hirsutum, Gh) fiber development remains unclear. Here, we identify that GhD53 suppresses fiber elongation by repressing transcription of GhFAD3 genes, which control linolenic acid (C18:3) biosynthesis. Mechanistically, GhD53 interacts with SL-related transcriptional activate factor (GhSLRF) to prevent its binding on Omega-3 fatty acid desaturase gene (GhFAD3) promoters, thereby inhibiting GhFAD3 transcription. Upon SL exposure, GhD53 is degraded and leads to GhSLRF activation. This activation further promotes GhFAD3 transcription, C18:3 biosynthesis, and fiber elongation. Our findings identify the molecular mechanism of how SL controls cell elongation via D53 and offer potential strategies to improve cotton quality through SL application.
独脚金内酯（SL）是植物发育所需的一种植物激素。DWARF53（D53）在SL信号传导中作为转录抑制因子发挥作用。然而，D53在棉花（陆地棉，Gh）纤维发育中的作用仍不清楚。在此，我们发现GhD53通过抑制控制亚麻酸（C18:3）生物合成的GhFAD3基因的转录来抑制纤维伸长。从机制上讲，GhD53与SL相关转录激活因子（GhSLRF）相互作用，阻止其与ω-3脂肪酸去饱和酶基因（GhFAD3）启动子结合，从而抑制GhFAD3转录。暴露于SL后，GhD53降解并导致GhSLRF激活。这种激活进一步促进GhFAD3转录、C18:3生物合成和纤维伸长。我们的研究结果确定了SL如何通过D53控制细胞伸长的分子机制，并提供了通过应用SL改善棉花品质的潜在策略。
