Trichoderma-mediated transcriptional reprogramming affects tomato response to water stress

Trichoderma species are widely used in sustainable agriculture as biocontrol agents and for their ability to stimulate plant growth, defence and tolerance to environmental stresses. Using RNA-seq, we investigated transcriptomic responses of tomato (Solanum lycopersicum cv Crovarese) leaves from Trichoderma longibrachiatum MK1-inoculated and non-inoculated plants to short severe water stress (24h PEG 15%) induced by polyethylene glycol (PEG). In well-watered conditions, Trichoderma triggered extensive remodelling of the plant transcriptome, modifying the expression of genes involved in photosynthesis, antioxidant defences and maintenance of a juvenile state. During PEG-induced water stress, root pre-treatment with Trichoderma specifically affected genes involved in mitigation of stress damage.