XYLT1 and infection: Given the ability of the biocontrol agent to reduce the infection caused by the phytopathogen and given the activation of the defense mechanisms detailed above, the increase in plant hormonal levels in non-infected and XT1-treated plants could be due to priming. Although our findings, with respect to phytohormone content in non-infected and infected XT1-treated plants, suggest that the JA/ET system is involved in the improvement of these defense systems, this fact needs to be confirmed through a more detailed analysis of signaling mechanisms triggered by the biological control agent XT1.