Lei Xiao, Xiugui Chen, Yunxin He, Depei Kong, Junjuan Wang, Jihua Yang, Yupeng Cui, Hui Huang, Kang Zhao, Jing Wang, Hao Lan, Ruize Song, Fange Wu, Xinrui Zhang, Xin Yu, Junshan Zhu, Jinkai Liu, Songyue Zhou, Xiaoyu Tian, Mengru Wei, Shuai Wang, Lixue Guo, Ping Li, Xiaowei Wang, Xue-Rong Zhou, Wuwei Ye
Abstract Soil Cd 2+ pollution threatens agricultural safety. Branched-chain amino acid (BCAA) metabolism is involved in stress responses, but its role in cotton Cd 2+ tolerance remains unclear. Here, 16 GhBCAT genes were identified in Gossypium hirsutum , among which GhBCAT12 was significantly induced by Cd 2+ stress. Silencing GhBCAT12 increased Cd 2 + sensitivity, causing growth inhibition, oxidative damage, and cell death. Metabolomic analysis revealed the accumulation of leucine, isoleucine, and valine, with decreased acetyl-CoA, indicating that GhBCAT12 mediates BCAA degradation. This study reveals a novel pathway in which GhBCAT12 -mediated BCAA degradation provides acetyl-CoA precursors for the tricarboxylic acid (TCA) cycle, sustaining ATP production, which in turn powers vacuolar Cd 2 + sequestration. These findings provide a new target for improving heavy metal tolerance in crops.