Identifying Beneficial Qualities of Trichoderma parareesei for Plants

Trichoderma parareesei andTrichoderma reesei (teleomorphHypocrea jecorina ) produce cellulases and xylanases of industrial interest. Here, the anamorphic strain T6 (formerlyT. reesei ) has been identified asT. parareesei , showing biocontrol potential against fungal and oomycete phytopathogens and enhanced hyphal growth in the presence of tomato exudates or plant cell wall polymers inin vitro assays. ATrichoderma microarray was used to examine the transcriptomic changes in T6 at 20 h of interaction with tomato plants. Out of a total 34,138Trichoderma probe sets deposited on the microarray, 250 showed a significant change of at least 2-fold in expression in the presence of tomato plants, with most of them being downregulated.T. parareesei T6 exerted beneficial effects on tomato plants in terms of seedling lateral root development, and in adult plants it improved defense againstBotrytis cinerea and growth promotion under salt stress. Time course expression patterns (0 to 6 days) observed for defense-related genes suggest that T6 was able to prime defense responses in the tomato plants against biotic and abiotic stresses. Such responses undulated, with a maximum upregulation of the jasmonic acid (JA)/ethylene (ET)-relatedLOX1 andEIN2 genes and the salt toleranceSOS1 gene at 24 h and that of the salicylic acid (SA)-relatedPR-1 gene at 48 h after T6 inoculation. Our study demonstrates that theT. parareesei T6-tomato interaction is beneficial to both partners.