Exploring conserved and novel MicroRNA-like small RNAs from stress tolerant Trichoderma fusants and parental strains during interaction with fungal phytopathogen Sclerotium rolfsii Sacc.

The study investigated potential microRNA-like small RNAs (milRNAs) from multi-stress-tolerant Tricho-fusants and parental strains (P1- Trichoderma virens NBAIITvs12 and P2- Trichoderma koningii MTCC796) for antagonistic activity during interaction with phytopathogen Sclerotium rolfsii. The Trichoderma was cultured in-vitro, with and without antagonism, against the pathogen and total RNA was extracted followed by small RNA library construction and sequencing. The milRNAs were identified by mapping high-quality unique reads against a reference genome. The milRNAs were recognized higher in antagonist Trichoderma during interaction with test pathogen compared to normal growth. The novel milRNAs candidates were found to vary during interaction with the pathogen and normal growth. The gene ontology and functional analysis illustrated that a total of 5828 potential targeted genes were recognized for 93 milRNAs of potent Fu21_IB and 3053 genes for 62 milRNAs of least fusant Fu28_IL. Functional annotation of milRNA-predicted genes integrating KEGG pathways indicates new insights into regulatory mechanisms, by interfering with milRNAs, associated with signal transduction, amino sugar metabolism, benzoate degradation, amino acid metabolism, and steroid and alkaloid metabolism for potential biocontrol of stress-tolerant Tricho-fusant FU21 during interaction with S. rolfsii. The present investigation is the first report of conserved and novel milRNAs from Tricho-fusants and parental strains interacting with S. rolfsii.