RNA seq analysis of a novel fish pathogenic fungus, Fusarium oxysporum: In quest of unveiling the virulence factors associated with fish infection

Abstract

In the present study, a novel species of Fusarium oxysporum involved in the disease outbreak among freshwater murrel, Channa striatus was identified from natural lake in India and the pathogenesis was confirmed by infection studies. Using Illumina paired-end sequencing technology, we have sequenced, assembled and annotated the transcriptome of F. oxysporum isolate. A total of 53,397,192 high quality paired-end reads were assembled into 27,886 unique reads and gene ontology (GO) analysis revealed that the transcripts of F. oxysporum belonged to 1656 unique GO terms. An in-depth search for the genes with putative virulence functions revealed well-represented virulence-associated domains containing proteins such as cellulose binding proteins, proteases, kinases, kinase inhibitor and toxins. Sequence alignment revealed clear insights into the diversity and similarity of those virulence genes with plant pathogens. qRT-PCR analysis of five genes with putative virulence genes confirms the virulence roles of those genes in the pathogenesis of F. oxysporum in C. striatus. This study provides novel information regarding the transcriptome of fungal pathogen and delivers insights into the virulence genes associated with the pathogenesis of the F. oxysporum isolate which might be useful for the control of the fungal pathogenesis.