Beauveria bassiana rewires molecular mechanisms related to growth and defense in tomato.

Plant roots can exploit beneficial associations with soil inhabiting microbes, promoting growth and expanding the immune capacity of the host plant. In this work, we aimed to increase information on changes occurring in tomato interacting with the beneficial fungus Beauveria bassiana. Tomato leaf proteome revealed perturbed molecular pathways during the establishment of the plant-fungus relationship. In the early stages of colonization (5-7 days), proteins related to defense responses to fungus were down-regulated and proteins related to calcium transport were up-regulated. At later time points (12-19 days after colonization), up-regulation of molecular pathways linked to protein/amino acids turn-over and to biosynthesis of energy compounds suggests beneficial interaction enhancing plant growth and development. At the later stage, the profile of leaf hormones and related compounds was also investigated highlighting up-regulation of those related to plant growth and defense. Finally, B. bassiana colonization was found to improve plant resistance against Botrytis cinerea, impacting plant oxidative damage. Overall, our findings further expand current knowledge on the possible mechanisms underlying the beneficial role of B. bassiana on tomato plants.