First report on whole genome sequencing of Chaetomium strumarium BRFC4 and its antagonistic activity against Fusarium wilt of banana

Abstract

Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense is a globally devastating disease with limited control through conventional methods like crop rotation, soil amendments and fungicides. Biological control presents a sustainable alternative, especially Chaetomium species known for their multifaceted antagonistic mechanisms are gaining prominence. Nine Chaetomium isolates were obtained from the banana rhizosphere and characterized using internal transcribed spacer sequencing. The antagonistic potential of Chaetomium sp. against F. oxysporum f. sp. cubense was evaluated through dual culture and inverted plate assays. Among them, Chaetomium. strumarium exhibited strong antifungal activity showing direct hyphal interactions and structural damage to F. oxysporum f. sp. cubense under scanning electron microscopy. Pot culture experiments confirmed C. strumarium effectively suppressed wilt incidence and promoted plant growth. Whole genome sequencing of C. strumarium yielded a 33-megabase assembly with 54.58 per cent GC content and 10,045 protein-coding genes. Genome annotation revealed abundant carbohydrate-active enzymes particularly glycoside hydrolases and polysaccharide lyases along with 57 biosynthetic gene clusters linked to antifungal metabolite production. Gene Ontology enrichment analysis highlighted genes involved in stress response, metabolism and fungal antagonism. This study is the first to establish C. strumarium as a potent biocontrol agent against F. oxysporum f. sp. cubense, providing genomic insights into its mycoparasitism and specialized metabolite biosynthesis for sustainable banana wilt management.