Browse Articles

Article|08 Mar 2024|OPEN
Characterization of O-methyltransferases in the biosynthesis of phenylphenalenone phytoalexins based on the telomere-to-telomere gapless genome of Musella lasiocarpa 
Wanli Zhao1 ,† , Junzhi Wu1,2 ,† , Mei Tian1 , Shu Xu1 , Shuaiya Hu3 , Zhiyan Wei3 , Guyin Lin1 , Liang Tang1 , Ruiyang Wang1 , Boya Feng1 , Bi Wang1 , Hui Lyu4 , Christian Paetz4 , Xu Feng1 , Jia-Yu Xue3 , and Pirui Li1 , , Yu Chen,1 ,
1Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Jiangsu Province Engineering Research Center of Eco-cultivation and High-value Utilization of Chinese Medicinal Materials, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), 210014 Nanjing, China
2Nanjing University of Chinese Medicine, 210023 Nanjing, China
3College of Horticulture, Bioinformatics Center, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, 210095 Nanjing, China
4NMR/Biosynthesis Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
*Corresponding author. E-mail: xuejy@njau.edu.cn,lipirui@cnbg.net,ychen@jib.ac.cn
Both authors contributed equally to the study.

Horticulture Research 11,
Article number: uhae042 (2024)
doi: https://doi.org/10.1093/hr/uhae042
Views: 538

Received: 23 Nov 2023
Accepted: 02 Feb 2024
Published online: 08 Mar 2024

Abstract

Phenylphenalenones (PhPNs), phytoalexins in wild bananas (Musaceae), are known to act against various pathogens. However, the abundance of PhPNs in many Musaceae plants of economic importance is low. Knowledge of the biosynthesis of PhPNs and the application of biosynthetic approaches to improve their yield is vital for fighting banana diseases. However, the processes of PhPN biosynthesis, especially those involved in methylation modification, remain unclear. Musella lasiocarpa is a herbaceous plant belonging to Musaceae, and due to the abundant PhPNs, their biosynthesis in M. lasiocarpa has been the subject of much attention. In this study, we assembled a telomere-to-telomere gapless genome of M. lasiocarpa as the reference, and further integrated transcriptomic and metabolomic data to mine the candidate genes involved in PhPN biosynthesis. To elucidate the diversity of PhPNs in M. lasiocarpa, three screened O-methyltransferases (Ml01G0494, Ml04G2958, and Ml08G0855) by phylogenetic and expressional clues were subjected to in vitro enzymatic assays. The results show that the three were all novel O-methyltransferases involved in the biosynthesis of PhPN phytoalexins, among which Ml08G0855 was proved to function as a multifunctional enzyme targeting multiple hydroxyl groups in PhPN structure. Moreover, we tested the antifungal activity of PhPNs against Fusarium oxysporum and found that the methylated modification of PhPNs enhanced their antifungal activity. These findings provide valuable genetic resources in banana breeding and lay a foundation for improving disease resistance through molecular breeding.