Biological Control of Grapevine Crown Gall Disease, Caused by Allorhizobium vitis, Using Paraburkholderia phytofirmans PsJN

Controlling crown gall in grapevine (Vitis vinifera L.) caused by the pathogenic bacterium Allorhizobium vitis is a major challenge for global viticulture, as this pathogen is highly persistent in vineyards once infected. The bacteria can enter the plant through open wounds during pruning and then systemically colonize the plant. This study aimed at evaluating the potential of Paraburkholderia phytofirmans PsJN, a beneficial endophytic bacterium able to colonize the xylem of grapevine, the same ecological niche as A. vitis, to control grapevine crown gall disease. P. phytofirmans PsJN was root-inoculated on grapevine plantlets before infection by A. vitis S4 on shoots. A. vitis S4 level in planta, vitopine production, accumulation of lignin in tumors, and symptoms of crown gall were investigated on grapevine prebacterized or not with PsJN. The expression of 28 grapevine genes involved in defense mechanisms was also simultaneously determined by quantitative real-time PCR. Despite a direct antibacterial effect against AvS4, PsJN has no significant impact on the incidence of crown gall or disease severity. However, PsJN leads to a stronger accumulation of vitopine in tumors and significantly reduced the population level of the pathogen in planta. [Figure: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.