Decrypting biocontrol functions and application modes by genomes data of three Trichoderma Strains/Species

Area of Science:

• Genomics
• Biotechnology
• Plant Pathology

Background:

• Trichoderma species are vital biocontrol agents, yet their genomic information is often incomplete, hindering research into their mechanisms.
• Previous studies have primarily focused on scaffold-level genome assemblies, limiting in-depth analysis of biocontrol-related genes and pathways.

Purpose of the Study:

• To generate chromosome-level genome assemblies for three key Trichoderma strains: T. harzianum CGMCC20739 (Tha739), T. asperellum CGMCC11653 (Tas653), and T. atroviride CGMCC40488 (Tat488).
• To identify genetic differences contributing to variations in biocontrol efficacy, stress tolerance, and metabolic functions among these strains.

Main Methods:

• High-throughput sequencing and advanced bioinformatics tools were employed for genome assembly.
• Comparative genomic analysis was conducted to identify differences in gene content, transcription factors, and functional pathways.
• Analysis focused on genes related to signal transduction, antimicrobial compound synthesis, detoxification, nutrient utilization, and plant growth promotion.

Main Results:

• Chromosome-level genomes were successfully assembled for Tha739 (40 Mb, 10,611 genes), Tas653 (37.3 Mb, 10,102 genes), and Tat488 (36.3 Mb, 9,896 genes).
• Tha739 exhibited a higher number of genes related to signal transduction, antimicrobial compound production, detoxification, and nutrient utilization, suggesting superior stress tolerance and antagonistic capabilities.
• Significant differences were observed in transcription factor numbers and pathways for indole-3-acetic acid (IAA) synthesis, phosphorus, and nitrogen metabolism, indicating strain-specific functional adaptations.

Conclusions:

• The chromosome-level genomes provide a comprehensive resource for understanding the genetic underpinnings of biocontrol in Trichoderma.
• Genetic variations, particularly in signal transduction, antimicrobial synthesis, and metabolic pathways, explain the differential biocontrol functions and stress tolerance of Tha739, Tas653, and Tat488.
• These findings lay the groundwork for targeted strain improvement and the development of more effective biocontrol strategies, highlighting the potential for synergistic effects within the Trichoderma-biome.