Biological and molecular characterization of the response of tomato plants treated with Trichoderma koningiopsis

Tomato-Fusarium oxysporum f.sp. radicis-lycopersici pathosystem was used to study induced systemic resistance elicited by Trichoderma koningiopsis (Th003) using the split root model. The ability of the antagonist to promote plant growth was also established. Stem colonization by the pathogen was significantly reduced in treated plants. The induction of resistance was enhanced 6 days after elicitation and when the antagonist was used in a concentration of 105 conidia per ml. Th003 application in seed priming and nursery significantly stimulated plant growth. Gene expression induced by Th003 was evaluated using the tomato TOM1 microarray. Plant treatment with T. koningiopsis affected mRNA levels of 45 genes: 41 in roots and 4 in leaves. Of particular interest was the induction of genes involved in the jasmonic and ethylene transduction pathways found in the microarray analysis and qRT-PCR, which suggest a temporary increment of defense related gene expression response to T. koningiopsis Th003.