The major facilitator superfamily efflux pump CcMFS1 from Colletotrichum camelliae promotes growth, virulence, and resistance to the phenazine produced by Pseudomonas silvicola

Tea anthracnose caused by Colletotrichum camelliae severely restricts the yield and quality of tea. The drug-resistance of pathogen, ecological and food safety issues associated with the use of chemical fungicides have driven endophytic bacteria as natural alternatives, providing assistance in improving disease resistance and stress tolerance of tea plants ( Camellia sinensis ). However, the biocontrol mechanism of microbial agents, as well as the resistance adaptors of C. camelliae to biotic stress, remain largely unknown. In this study, we identified C. camelliae as the pathogen of anthracnose on Ca. sinensis cv. Gougunao2 and obtained a highly efficient antagonistic bacterium ( Pseudomonas silvicola PSM6) by plate assays. PSM6 gathered around the stomata and damaged the hyphae, thereby preventing pathogen invasion. Morphology observation and transcriptome analysis jointly indicated that the PSM6 metabolites mediate global transcriptional disorders of C. camelliae , including genes related to growth, membrane dynamics, metabolism, stress response, and detoxification. The sensor CcMFS1, a major facilitator superfamily transporter from C. camelliae , and its substrate phenazine with EC 50 value of 20.81 μg/mL produced by P. silvicola , were identified and docked. Functional analysis confirmed that CcMFS1 positively regulates hyphal growth, appressorium development and virulence. In addition, CcMFS1 relied on hydrophobic pocket and binding residue G524 to maintain its membrane localization and phenazine resistance of C. camelliae . Together, the colonization and antagonism of P. silvicola , as well as the phenazine efflux model of the growth and virulence enhancer CcMFS1 in C. camelliae , providing a new strategy, bio-fungicide and target for tea anthracnose control.