Citrate accumulation mediated through GhCS6 enhances antioxidant modulation under Cd2+ stress in cotton

Xinrui Zhang; Xuke Lu; Maohua Dai; Yapeng Fan; Zhining Yang; Yuping Sun; Xin Yu; Ruize Song; Menghao Zhang; Hao Lan; Xiugui Chen; Shuai Wang; Junjuan Wang; Lixue Guo; Lin Li; Ying Li; Lanjie Zhao; Fushun Hao; Wuwei Ye

doi:10.1016/j.plaphy.2025.110226

Citrate accumulation mediated through GhCS6 enhances antioxidant modulation under Cd²⁺ stress in cotton

Plant Physiol Biochem. 2025 Jul 8:228:110226. doi: 10.1016/j.plaphy.2025.110226. Online ahead of print.

Authors

Xinrui Zhang¹, Xuke Lu², Maohua Dai³, Yapeng Fan², Zhining Yang², Yuping Sun², Xin Yu², Ruize Song², Menghao Zhang², Hao Lan², Xiugui Chen², Shuai Wang², Junjuan Wang², Lixue Guo², Lin Li⁴, Ying Li², Lanjie Zhao², Fushun Hao⁵, Wuwei Ye⁶

Affiliations

¹ Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Anyang, 455000, Henan, China; State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, Henan, China.
² Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Anyang, 455000, Henan, China.
³ Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Sciences / Hebei Key Laboratory of Crops Drought Resistance, Hengshui, 053000, Hebei, China.
⁴ Shandong Zhongli Cotton Industry Technology Co., Ltd, Dongying, 257500, Shandong, China.
⁵ State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, Henan, China. Electronic address: haofsh@henu.edu.cn.
⁶ Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Anyang, 455000, Henan, China. Electronic address: yew158@163.com.

PMID: 40652880
DOI: 10.1016/j.plaphy.2025.110226

Abstract

Citrate synthase (CS) catalyzes the biosynthesis of citrate (CA), a tricarboxylic acid metabolite that serves as a pivotal biochemical regulator in plant cellular metabolism. This investigation conducted systematic genome-wide identification of CS family, integrating structural, phylogenetic relationships, collinearity analysis, cis-acting elements and expression analysis. GhCS6 protein is localized in the mitochondria. The pivotal cadmium-responsive regulatory candidate gene GhCS6 was identified, followed by its silencing mediation through virus-induced gene silencing (VIGS), silenced plants displaying phenotypic evidence of enhanced Cd²⁺ susceptibility. Simultaneously, CA content in the silenced plants was also significantly decreased, which reduced the chelating capacity for Cd²⁺ and consequently exacerbates the accumulation of Cd²⁺. The silenced plants showed an imbalance in the reactive oxygen species (ROS) scavenging system, as evidenced by lower superoxide dismutase (SOD) activity and a marked increase in H₂O₂ content, causing increased oxidative damage. This oxidative stress further compromised the integrity of cellular membranes, resulting in elevated malondialdehyde (MDA) content and compromised cellular structure. These changes ultimately impaired photosynthetic efficiency and plant growth and development. This study contributes significantly to understanding the function of the GhCS6 in plant Cd²⁺ tolerance, and identifies potential gene targets for breeding Cd²⁺ tolerant cotton varieties.

Keywords: Cd(2+) stress; Citrate; Citrate synthase; GhCSs; ROS.