Silencing of the Mitogen-Activated Protein Kinases (MAPK) and in Reduces Growth and Virulence on Host Plants.

, causal agent of the black Sigatoka disease (BSD) of spp., has spread globally since its discovery in Fiji 1963 all the banana and plantain growing areas across the globe. It is becoming the most damaging and economically important disease of this crop. The identification and characterization of genes that regulate infection processes and pathogenicity in will provide important knowledge for the development of disease-resistant cultivars. In many fungal plant pathogens, the and are reported to be essential for pathogenicity. regulates filamentous-invasion pathways including the formation of infection structures, sporulation, virulence, and invasive and filamentous growth, whereas is involved in the cell-wall integrity pathway, virulence, invasive growth, and colonization in host tissues. Here, we used RNAi-mediated gene silencing to investigate the role of the and homologs in in pathogen invasiveness, growth and pathogenicity. The and silenced transformants showed significantly lower gene expression and reduced virulence, invasive growth, and lower biomass in infected leaf tissues of East African Highland Banana (EAHB). This study suggests that and MAPK signaling pathways play important roles in plant infection and pathogenic growth of fungal pathogens. The silencing of these vital fungal genes through host-induced gene silencing (HIG) could be an alternative strategy for developing transgenic banana and plantain resistant to BSD.