Physiological and biochemical response of tomato plants treated with Trichoderma harzianum T-22 and infected by Cucumber mosaic virus

The study of the host-pathogen-antagonist interaction from a biochemical and molecular point of view is of key importance for understanding the dynamics of infectious processes, and can be useful for the development of new strategies to control phytopathogens, particularly viruses, against which chemical treatments have no effect. Herein, we demonstrate the activity of the fungus Trichoderma harzianum strain T-22 (T22) against Cucumber mosaic virus (CMV) in tomato plants (Solanum lycopersicum var. cerasiforme). Plants treated with T22 and inoculated with CMV did not show the typical symptoms induced by CMV, such as stunting or necrosis, and maintained high values of net photosynthesis and stomatal conductance. Furthermore, T22 also had the ability to control CMV infection in tomato plants by inhibiting CMV, as assessed by the absence of the CMV RNA-dependent RNA polymerase gene (RdRp) in the oldest plants. In conclusion, our data indicate that the T22-based strategy is a largely practicable way to pursue the goal of an effective control measure against CMV