Rhodopseudomonas palustris PSB-06 Induces Plant Defense and Suppresses the Transmission of Tomato Chlorosis Virus by Bemisia tabaci MED

Tomato chlorosis virus (ToCV) is an RNA virus and a member of the Closteroviridae, Crinivirus, that is primarily vectored by Bemisia tabaci MED (B. tabaci MED). An outbreak of ToCV causes destructive damage to tomato plants and other solanaceous vegetables. Currently, ToCV has not been effectively controlled. Rhodopseudomonas palustris PSB-06 is a novel biological agent that is effective at controlling the tobacco mosaic virus (TMV). In this study, we investigated the role of PSB-06 in ToCV-infected tomato plants, and we studied the effects of PSB-06 on plant defense and plant photosynthetic pathways. Furthermore, the effect of PSB-06 on the acquisition and transmission of B. tabaci MED was determined. The results showed that compared with water-treated tomato plants, the contents of jasmonic acid increased, and the activities of catalase, peroxidase and superoxide dismutase increased significantly in tomato plants treated with PSB-06. The relative expression of genes involved in chlorophyll development, chlorophyll metabolism and photosynthesis also increased significantly. Simultaneously, treatment with PSB-06 reduced the acquisition and transmission of B. tabaci MED. We verified the hypothesis that PSB-06 is effective at controlling ToCV by promoting plant defense responses and reducing the amount of ToCV in tomato plants. We also confirmed the ability of B. tabaci MED to transmit ToCV. This study should help to control B. tabaci MED and reduce the spread of ToCV.