Introduction
Fungal strains of the genus Trichoderma are important
biocontrol agents successfully applied as biopesticides
worldwide, and are well-known producers of secondary
metabolites with antibiotic activity (Sivasithamparam and
Ghisalberti 1998; Reino et al. 2008; Vinale et al. 2008a).
Trichoderma spp. are known to be involved in complex
interactions with host plants and resident microbial communities,
which include an often beneficial combination
of antibiosis and other mechanisms, such as mycoparasitism,
competition for nutrients ⁄ space, promotion of plant
growth and induction of systemic resistance (Harman
and Kubicek 1998; Benı´tez et al. 2004; Harman et al.
2004; Vinale et al. 2008a). The involvement of secondary
metabolites in the ability of Trichoderma spp. to activate
plant defence mechanisms and regulate plant growth has
been recently studied in depth (Vinale et al. 2008b).