Agroinfection-Mediated Virus Induced Gene Silencing of Fungal Pathogen Fusarium verticillioides CYP51 Gene to Reduce its Pathogenicity during Maize (Zea mays) Germination

Abstract

Fusarium verticillioidesis a fungal pathogen, resulting in devastating diseases in cereals, especially in maize (Zea mays) and causing massive economic losses in agriculture. F. verticillioides infections in the field are managed by chemical fungicides, mainly azoles which target cytochrome P450 lanosterol C-14 alpha-demethylase (CYP51). Alternative to chemical fungicide, this study evaluated the potential of agroinfection-mediated Virus Induced Gene Silencing (VIGS) approach in controlling F. verticillioidespathogenicity, which is based on naturally occurring RNA interference (RNAi) mechanism. For this purpose, F. verticillioides was co-cultivated with Agrobacterium tumefaciens transformed with a Brome Mosaic Virus (BMV3) derived vector carrying a 313 nucleotide length fragment common to the three existing F. verticillioides CYP51 genes and comparatively evaluated with the mock group treated similarly but with empty vector at morphologically, biochemically and transcriptionally. It was detected that agroinfection-mediated VIGS treatment of F. verticillioides reduced expression levels of CYP51A by 49%, CYP51B by 65% and CYP51C by 51% and the growth rate by 13% while the germination rate was 20% and ROS amount 56% higher compared to mock-treated F. verticillioides. These findings pointed out that silencing of CYP51 caused ROS accumulation in cells leading to inhibition of the pathogenicity of F. verticillioides. This study represented the potential of targeting CYP51 gene by agroinfection-mediated VIGS treatment as an agriculturally sustainable and environmentally friendly alternative method to control F. verticillioides-caused plant diseases.