Songyue Zhou, Xuke Lu, Xiugui Chen, Yupeng Cui, Hui Huang, Kang Zhao, Jing Wang, Hao Lan, Ruize Song, Fan Wu, Xinrui Zhang, Xin Yu, Junshan Zhu, Jinkai Liu, Lei Xiao, Xiaoyu Tian, Mengru Wei, Shuai Wang, Junjuan Wang, Lixue Guo, Xiaoping Zhu, Xiaowei Wang, Jihua Yang, Xue‐Rong Zhou, Lanjie Zhao, Guanyin Zhou, Wei Wang, Wuwei Ye
Soil salinization poses a significant threat to global cotton production. Enhancing salt tolerance in cotton requires a deep understanding of its underlying molecular mechanisms. Lignin, a crucial component of the plant cell wall, plays a vital role in stress adaptation, with Cinnamoyl-CoA Reductase (CCR) serving as the key rate-limiting enzyme in its biosynthesis. However, the function of CCR genes in cotton remains largely unexplored. Here, we conducted a genome-wide analysis and identified 34 CCR genes in Gossypium hirsutum. Among them, GhCCR24 was highly induced by salt stress, particularly in roots. Virus-induced gene silencing (VIGS) of GhCCR24 resulted in compromised plant growth, reduced lignin deposition, and thinner secondary cell walls. Under salt stress, GhCCR24-silenced plants exhibited severe oxidative damage, ion homeostasis disruption (elevated Na⁺ / K⁺ ratio), and a significant decline in salt tolerance. Our findings demonstrate that GhCCR24 acts as a core positive regulator of cotton's response to salt stress by mediating lignin biosynthesis, which reinforces cell walls and thereby maintains ion and oxidative homeostasis. This study provides a valuable gene resource for the genetic improvement of salt-tolerant cotton.