蒙氏肠球菌ZC-05对猕猴桃细菌性溃疡病防效评价及生防机制初探OA

Kiwifruit bacterial canker,often termed the"cancer"of kiwifruit,currently lacks effective control methods.In this study,a potential biocontrol strain Enterococcus mundtii ZC-05,previously isolated from stem of Kiwifruit,was labeled with green fluorescent protein(GFP)to investigate its colonization characteristics.Results indicated that protoplast fusion was an effective method for transforming strain ZC-05,successfully yielding the GFP-labeled transformant ZC-05-GFP.Confocal microscopy observation revealed that ZC-05-GFP colonized kiwifruit stems two weeks after trunk injection and reach the leaf via the sap flow.Field trials demonstrated that injection of ZC-05 suspension significantly reduced the incidence of kiwifruit bacterial canker,achieving a control efficacy of 50.96％,which was substantially higher than that of the copper-based bactericide Thiodiazole-Copper(13.46％)(P＜0.05).Whole-genome sequencing of ZC-05 identified seven genes encoding type Ⅵ secretion system(T6SS)effector proteins.Furthermore,quantitative real-time PCR analysis indicated that the gene Gm-1574,encoding an antibacterial toxic protein,was significantly up-regulated after co-culture with Pseudomonas syringae pv.actinidiae(Psa-Y),the pathogen of Kiwifruit bacterial canker,suggesting its potential important role in the biocontrol activity of ZC-05.This study clarifies the colonization characteristics of ZC-05,confirms its field efficacy against kiwifruit bacterial canker,and preliminarily elucidates its biocontrol mechanisms.These findings provide a basis for the development and practical application of trunk-injected biocontrol agents in the future.