Trichoderma gamsii T6085, a biocontrol agent of Fusarium head blight, modulates biocontrol-relevant defence genes expression in wheat

Abstract

[EN]To enhance the framework of the mechanisms of action used by Trichoderma gamsiiT6085 for the control of Fusarium head blight (FHB), this work investigated its abil-ity to modulate the expression of defence-related genes of wheat (Triticum aestivum‘Apogee’) in response to endophytic colonization of plant tissues. Changes in relativeexpression of pal1, pr1, pgip2 and lox1 genes were assessed over time in wheat roots,in spikes colonized by T6085 alone and both T6085 and Fusarium graminearum, and inleaves from wheat seedlings root-inoculated with T6085. Results indicate the ability ofT6085 to induce local and systemic defence responses in wheat plants in the presenceof one of the causal agents of FHB. There was a general significant up-regulation ofthe plant defence-related genes analysed, especially in the first days after the applica-tion of T6085. According to these results, modulation of plant defence genes could beincluded within the arsenal of mechanisms used by T6085 when applied to wheat, anadditional feature of interest in the management of FHB. To evaluate the effect of theplant genotype on the ability of T6085 to endophytically colonize roots, root coloniza-tion was assessed on four cultivars of T. aestivum and two cultivars of T. durum. Datashowed that roots of only two T. aestivum cultivars were endophytically colonized byT6085, similar to cv. Apogee used here as control, thus demonstrating an effect of thehost genotype on the endophytic ability of T6085.