Genome-wide analysis of the caffeic acid O-methyltransferase gene family reveal the role of PnCOMT1 in phytomelatonin biosynthesis and biotic stress tolerance in Panax notoginseng

作者：Jianbin Li, Leilin Li, Jiae Hou, Mingtao Ai, Tiantai Liu, Xiuming Cui, Qian Yang · 发表于：Environmental and Experimental Botany · 年份：2025 · DOI：10.1016/j.envexpbot.2025.106212 · 被引用次数：6 · 研究领域：Ginseng Biological Effects and Applications、Polysaccharides and Plant Cell Walls、Plant Molecular Biology Research

Panax notoginseng , a traditional Chinese herbal medicine, is renowned for its rich and diverse triterpenoid saponins. P. notoginseng is extremely vulnerable to pathogens during cultivation due to its unique growth conditions. Phytomelatonin (N-acetyl-5-methoxytryptamine, MT), a ubiquitous signaling molecule essential for plant biotic resistance, is catalyzed by Caffeic acid O-methyltransferase (COMT) from N-acetyl-serotonin in the cytoplasm. However, information on COMT with N-acetylserotonin O-methyltransferase (ASMT) activity was lacking in P. notoginseng . In this study, twelve putative PnCOMT genes were identified in P. notoginseng . Furthermore, its physiochemical characteristics, phylogenetic relationship, chromosomal distribution, gene collinearity and promoter cis -element were investigated. Among them, Pno01G002223.t1 ( PnCOMT1 ) was considered a potential MT biosynthesis gene based on its high similarity to AtCOMT1 , which is involved in MT biosynthesis in Arabidopsis thaliana . The PnCOMT1 protein is localized in the cytoplasm. Notably, P. notoginseng caffeic acid O-methyltransferase 1 ( PnCOMT1 ) showed a high transcript level after MT treatment and black blot disease infection. To further evaluate PnCOMT1 function in MT biosynthesis, we overexpressed or complemented the PnCOMT1 gene in the A. thaliana comt mutant and P. notoginseng callus. Overexpression/complementation of PnCOMT1 significantly increased the concentration of phytomelatonin in P. notoginseng call...