Genome-wide identification of GAD family genes suggests GhGAD6 functionally respond to Cd2+ stress in cotton
Hui Huang, Yunxin He, Aihua Cui, Liangqing Sun, Mingge Han, Jing Wang, Cun Rui, Yuqian Lei, Xiaoyu Liu, Nan Xu, Hong Zhang, Yuexin Zhang, Yapeng Fan, Xixian Feng, Kesong Ni, Jie Jiang, Xingping Zhang, Chao Chen, Shuai Wang, Xiugui Chen, Xuke Lu, Delong Wang, Junjuan Wang, Zujun Yin, Bobokhonova Zebinisso Qaraevna, Lixue Guo, Lanjie Zhao, Wuwei Ye
Abstract
Glutamate decarboxylase (GAD) mainly regulated the biosynthesis of γ-aminobutyric acid (GABA) and played an important role in plant growth and stress resistance. To explore the potential function of GAD in cotton growth, the genome-wide identification, structure, and expression analysis of GAD genes were performed in this study. There were 10, 9, 5, and 5 GAD genes identified in G. hirsutum , G. barbadense , G. arboreum , and G. raimondii , respectively. GAD was divided into four clades according to the protein motif composition, gene structure, and phylogenetic relationship. The segmental duplication was the main way of the GAD gene family evolution. Most GhGADs respond to abiotic stress. Clade Ⅲ GAD was induced by Cd 2+ stress, especially GhGAD6 , and silencing GhGAD6 would lead to more serious Cd 2+ poisoning in cotton. The oxidative damage caused by Cd 2+ stress was relieved by increasing the GABA content. It was speculated that the decreased expression of GhGAD6 reduced the content of GABA in vivo and caused the accumulation of ROS. This study will further expand our understanding of the relationship between the evolution and function of the GhGAD gene family and provide new genetic resources for cotton breeding under environmental stress and phytoremediation.