Evolution and comparative genomics of the most common Trichoderma species

Area of Science:

• Fungal genomics
• Evolutionary biology
• Mycology

Background:

• The fungal genus Trichoderma is ecologically and economically important, with diverse roles from biofertilizers to opportunistic pathogens.
• Understanding Trichoderma's evolutionary history is crucial given its varied ecological niches and industrial applications.
• Previous genomic analyses suggested mycoparasitism as an innate trait, but its evolutionary trajectory remains unclear.

Purpose of the Study:

• To investigate the genome-wide evolutionary patterns of 12 Trichoderma species.
• To establish a time-calibrated evolutionary history for Trichoderma clades and sections.
• To identify key genomic events, such as gene gain and loss, driving Trichoderma evolution.

Main Methods:

• Comparative analysis of genome sequences from 12 selected Trichoderma species.
• Phylogenetic analysis to determine evolutionary timelines and relationships.
• Identification and annotation of the Trichoderma core genome and specific gene families.

Main Results:

• Trichoderma originated around the Cretaceous-Palaeogene extinction event (66 ±15 mya), with diversification in the Oligocene.
• The Harzianum clade and Trichoderma section experienced significant gene gain, while the Longibrachiatum section ancestor underwent rapid gene loss.
• Genes involved in ankyrin, HET domain proteins, and transcription factors were frequently gained.

Conclusions:

• This study provides a time-scaled genomic evolutionary framework for 12 Trichoderma species.
• The findings reveal distinct evolutionary trajectories, including gene gain and loss, shaping Trichoderma's adaptation.
• Insights into the evolution of mycoparasitism towards a generalist lifestyle in Trichoderma are presented.