Effect of chitosan on gene expression and activity of enzymes involved in resistant induction to fusariuse of wheat

In this research, the role of chitosan as a bio-inducer of defense mechanism in infected wheat by Fusarium graminearum, the causal agent of Fusarium head blight was investigated. To investigate the expression of genes associated with pathogenicity and enzymatic activity, a factorial experiment in a completely randomized design with four replications was done under greenhouse condition. The adjusted solution containing different concentrations of chitosan (0, 100, 200 and 500 mg l-1) were used via spray. Treated plants after 24 hours with a spore suspension (at a concentration of 106 Macro conidia ml-1) were inoculated by spikelet injection and were kept under greenhouse conditions. Sampling was performed at various time points after inoculation and then the expression level of some genes involved in resistance and activity of relative enzyme was studied. Data analysis showed that disease severity was reduced in treated plants compared with control plants. Enzyme measurement showed the greatest variation for peroxidase and polyphenol oxidase enzymes. The results of molecular analysis by qRT-PCR showed significantly increased mRNA expression levels of beta-1, 3-glucanase and oxalate oxidase genes. The results of this research indicate that chitosan could influence plant resistance against pathogenic fungi through induction of systemic acquire resistance.