Functional Genetics of Trichoderma Mycoparasitism

Mycoparasitism of Trichoderma (Hypocreales, Ascomycota) on plant pathogenic fungi is used for the biological control of such pests. To develop next-generation technology-driven Trichoderma-based products, recent studies have addressed the molecular mechanisms of Trichoderma mycoparasitism. In this chapter, we review the studies of functional genetics of mycoparasitism. Currently, among the 382 species in the genus Trichoderma, only 8 species have been studied for their mycoparasitism activities at the genetic level. The molecular mechanisms employed by Trichoderma include genes required for the attack and virulence (fungal cell wall-degrading enzymes, biosynthetic gene clusters, etc.), self-defense (small secreted cysteine-rich proteins, secondary metabolites, etc.) and various regulatory genes (methyltransferase, MAPKs, etc.). We conclude that future studies would benefit from expanding the range of host fungi to ecologically justified fungi that are also parasitized by Trichoderma in vivo. It will allow a better understanding of gene function and lead to newer and safer Trichoderma-based products.