Insights into Metabolic Changes Caused by the Trichoderma virens-Maize Root Interaction.

Area of Science:

• Plant-microbe interactions
• Agricultural microbiology
• Metabolomics

Background:

• Endophytic microorganisms in crops are crucial for pest resistance and yield enhancement.
• Understanding host-endophyte interactions is key to optimizing agricultural practices.

Purpose of the Study:

• To investigate the metabolic interactions between Zea mays (corn) and the endophytic fungus Trichoderma virens.
• To analyze the role of specific fungal genes (tv2og1, vir4) in colonization and metabolic modulation.

Main Methods:

• Hydroponic cultivation of Zea mays inoculated with wild-type T. virens and two gene knockout mutants (∆tv2og1, ∆vir4).
• Metabolic fingerprinting of plant roots, fungal mycelia, and culture supernatants using ultrahigh performance liquid chromatography (UHPLC) coupled to mass spectrometry (MS).
• Analysis of gene expression in plant roots.

Main Results:

• Fungal mutants showed reduced root colonization compared to wild-type T. virens.
• All fungal genotypes suppressed root biomass.
• Metabolic profiling revealed significant differences in root composition between colonized and non-colonized plants, dependent on fungal genotype.
• Shikimate pathway metabolites, including amino acids and flavonoids, were modulated in colonized roots.
• Gene expression in plant roots was affected by the ∆vir4 mutant.
• Distinct metabolomes were observed in the mycelia and supernatants of different T. virens genotypes.

Conclusions:

• Endophytic colonization by T. virens induces substantial metabolic changes in Zea mays roots, influenced by specific fungal genes.
• Both fungal metabolites and plant metabolites modulated by the interaction contribute to the observed metabolic patterns.
• These metabolic shifts in plant tissues may underlie later systemic effects relevant to crop improvement.