摘要
Bacteria equipped with virulence systems based on highly bioactive small molecules can circumvent their host's defense mechanisms.Pathogens employing this strategy are currently threatening global rice production.In the present study,variations in the virulence of the highly destructive Barkholderiaplantarii were observed in different rice-producing regions.The environment-linked variation was not attributable to any known host-related or external factors.Co-occurrence analyses indicated a connection between reduced virulence and 5-Amino-l,3,4-thiadiazole-2-thiol(ATT),a non-bactericidal organic compound.ATT,which accumulates in rice plants during metabolization of specific agrochemicals,was found to reduce virulence factor secretion by B.plantarii up to 88.8%and inhibit pathogen virulence by hijacking an upstream signaling cascade.Detailed assessment of the newly discovered virulence inhibitor resulted in mechanistic insights into positive effects of ATT accumulation in plant tissues.Mechanisms of virulence alleviation were deciphered by integrating high-throughput data,gene knockout mutants,and molecular interaction assays.TroK,a histidine protein kinase in a two-component system that regulates virulence factor secretion,is likely the molecular target antagonized by ATT.Our findings provide novel insights into virulence modulation in an important plant-pathogen system that relies on the host's metabolic activity and subsequent signaling interference.
基金
This work was supported by the National Natural Science Foundation of China(Grants No.32122074,31501684)
National Key Research and Development Program of China(Grants No.2021YFE0113700,2017YFD0202100,2017YFE0102200)
Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ16C140001)
Zhejiang Provincial Key Research and Development Program of China(Grant No.2015C02019)
Strategic Research on“Plant Microbiome and Agroecosystem Health”(Grant No.2020ZL008
Cao Guangbiao High Science and Technology Foundation,Zhejiang University)
the Fundamental Research Funds for the Central Universities(Grant No.2021FZZX001-31,Zhejiang University).
