Morphological, Transcriptional, and Epigenetics Alterations due to L-arginine and L-methionine Treatment in Fusarium culmorum

Fusarium culmorum is a worldwide phytopathogenic fungus of small-grain cereals. Struggling strategies such as fungicide treatment and biocontrol agent usage are not long-term solutions due to the potential adverse effects on ecological environment and resistance development in fungal pathogens. In this study, potential suppressive effects of amino acid supplementation on F. culmorum were investigated. Potato dextrose agar (PDA) medium amended with 1 mg mL-1 and 2 mg mL-1 concentrations of L-arginine and L-methionine were used as experimental sets. PDA with no supplement and PDA amended with nicotinamide of 1 mg mL-1 and 2 mg mL-1 concentrations were used as negative and positive control sets, respectively. While L-arginine treatment led to significant increase in linear growth rate (LGR) with p<0.01, L-methionine decreased LGR values (p<0.001). Coupled Restriction Enzyme Digestion-Random Amplification (CRED-RA) essays yielded very similar alterations in terms of genomic template stability within the experiment groups of L-arginine and L-methionine treated sets. UPGMA-dendrogram (unweighted pair group method with arithmetic mean) revealed co-clustering of L-methionine and nicotinamide treated sets. Methylation-specific PCR (MSP) analysis showed that there was Type-II and Type-III methylation present in 2 mg mL-1 L-methionine treated sets. Gene expression analysis showed that L-methionine and L-arginine treatment led to contrast alteration in expressions of tri6 and FcStuA genes with significant differences (p<0.05-p<0.0001). Our results showed that L-methionine treatment could suppress potential aggressiveness of F. culmorum at phenotypic, epigenetics, and transcriptional levels