GhCOMT33D modulates melatonin synthesis, impacting plant response to Cd2+ in cotton via ROS

作者：Menghao Zhang, Xiugui Chen, Ning Wang, Lijun Guan, Lidong Wang, Xiao Chen, Zhining Yang, Yuping Sun, Yapeng Fan, Yuan Meng, Mengyue Liu, Wen‐Hua Chen, Fan Wu, Ruize Song, Shuai Wang, Xuke Lu, Junjuan Wang, Lixue Guo, Lanjie Zhao, Hongyu Nan, Kunpeng Zhang, Keyun Feng, Wuwei Ye · 发表于：Physiologia Plantarum · 年份：2024 · DOI：10.1111/ppl.14647 · 被引用次数：8 · 研究领域：Plant responses to elevated CO2、Plant Stress Responses and Tolerance、Photosynthetic Processes and Mechanisms

Abstract Caffeic acid‐3‐ O ‐methyltransferase (COMT) serves as the final pivotal enzyme in melatonin biosynthesis and plays a crucial role in governing the synthesis of melatonin in plants. This research used bioinformatics to analyze the phylogenetic relationships, gene structure, and promoter cis ‐acting elements of the upland cotton COMT gene family members， which it identified as the key gene GhCOMT33D to promote melatonin synthesis and responding to Cd 2+ stress. After silencing GhCOMT33D through virus‐induced gene silencing (VIGS), cotton seedlings showed less resistance to Cd 2+ stress. Under Cd 2+ stress, the melatonin content in the silenced plants significantly decreased, while ROS, MDA, and proline accumulated in the plant cells. The stomatal aperture of the leaves was reduced, hindering normal photosynthesis, leading to cotton leaves withering and yellowing, and epidermal cells becoming twisted and deformed, with a large number of gaps appearing. The non‐silenced plants had a significantly higher melatonin content and were in better condition, providing important evidence for further research on how plant melatonin enhances the Cd 2+ resistance of cotton and its regulatory mechanisms.