Plant-microbe interactions between Trichoderma and Brassica vegetables: Biostimulatory activity, biological control and molecular perspectives

Brassica crops are among the most economically important vegetable and oilseed plants worldwide, providing food and industrial resources. However, most Brassica species show limited or absent associations with arbuscular mycorrhizal fungi (AMF), restricting the use of mycorrhiza-based microbial inputs and emphasizing the need for alternative beneficial microorganisms. In this context, fungi of the genus Trichoderma have emerged as versatile plant-associated microbes with potential for sustainable agriculture. This review synthesizes current knowledge on Trichoderma-Brassica interactions, integrating evidence from plant physiology, fungal ecology, molecular signaling, and agronomic applications. The review first outlines the biological and agronomic relevance of Brassica crops, including their taxonomic diversity, global distribution, and production of bioactive metabolites. It then examines the ecological and biotechnological importance of Trichoderma, highlighting diversity, mechanisms of action, and use as a biological control agent and plant growth-promoting fungus. Particular emphasis is placed on the molecular and physiological processes underlying Trichoderma-Brassica interactions, such as root colonization strategies, modulation of plant defense pathways, nutrient mobilization, and enhanced tolerance to abiotic stresses. Finally, the review discusses challenges for the deployment of Trichoderma-based bioinoculants, including strain specificity, formulation constraints, and consistency under field conditions. Overall, advancing our understanding of Trichoderma-Brassica interactions offers opportunities to design microbial strategies to improve crop productivity, resilience, and sustainability in the context of climate change and environmentally responsible agriculture.