Botrytis cinerea hypovirulent strain ΔBcSpd1 induced Panax ginseng defense

Background: Gray mold, caused by Botrytis cinerea, is one of the major fungal diseases in agriculture. Biological methods are preferred over chemical fungicides to control gray mold since they are less toxic to the environment and could induce the resistance to pathogens in plants. In this work, we try to understand if ginseng defense to B. cinerea could be induced by fungal hypovirulent strain ABcSpd1. BcSpd1 encodes Zn(II)2Cys6 transcription factor which regulates fungal pathogenicity and we recently reported ABcSpd1 mutants reduced fungal virulence. Methods: We performed transcriptomic analysis of the host to investigate the induced defense response of ginseng treated by B. cinerea ABcSpd1. The metabolites in ginseng flavonoids pathway were determined by UPLC-ESI-MS/MS and the antifungal activates were then performed. Results: We found that ABcSpd1 enhanced the ginseng defense response when applied to healthy ginseng leaves and further changed the metabolism of flavonoids. Compared with untreated plants, the application of ABcSpd1 on ginseng leaves significantly increased the accumulation of p-coumaric acid and myricetin, which could inhibit the fungal growth. Conclusion: B. cinerea ABcSpd1 could effectively induce the medicinal plant defense and is referred to as the biological control agent in ginseng disease management. (c) 2023 The Korean Society of Ginseng. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study found that the gray mold fungus ABcSpd1 can enhance the defense response of ginseng to the pathogen by altering the accumulation of flavonoid metabolites in ginseng.