Research on the Pathogenicity of Pseudomonas syringae to Three Moss Species

PurposeTo investigate the pathogenicity of Pseudomonas syringae to two desiccation tolerant mosses and one type of model moss, providing reference for the establishment of moss-pathogen interaction mechanism and an idea for screening of resistance genes.

MethodsTwo desiccation tolerant mosses, Syntrichia caninervis and Bryum argenteum, and one model moss species, Physcomitrella patens, were selected to study the pathogenicity of P. syringae in three mosses and the pathogenicity response of the three mosses, by morphological observation and plant disease resistance index monitoring.

ResultsThe number of moss cell death increased after infection of P. syringae, and most of the dead cells were concentrated in infection area. The results of hydrogen peroxide (H₂O₂) and superoxide anion in situ staining showed that the invasion of P. syringae could cause the immune reaction of three mosses, and the production of H₂O₂ and superoxide anion increased with the time of inoculation, the highest content was found in diseased spot and wilting plant. The qPCR results showed that the number of P. syringae in the three mosses were positively correlated with the inoculation time.

ConclusionThese three experimental mosses are successfully infected by P. syringae, the specific manifestations are the appearance of bacterial venereal spots, browning and chlorosis of stems. The results provide a reference for further study of plant-pathogen interaction mechanism under extreme drying environment.