Abstracto

MicroRNA mediated regulation of defense against fungal phytopathogen in plants

Raj Kumar Josh

Non-coding RNAs are noticeable modulators of transcriptional and post-transcriptional expression of genes in a wide range of biological processes. However, the inventory and functions of microRNAs largely remains unexplored with respect to defense against fungal phytopathogens. We have performed a comparative small RNA profiling of susceptible (Arka Lohit-AL) and resistant (Punjab Lal-PL) chilli cultivars to identify 35 differentially expressed miRNAs responsive to Colletotrichum truncatum, the most belligerent anthracnose pathogen. Excitingly, a novel microRNA can-miRn37a was significantly expressed in PL but reduced in AL genotype post pathogen attack. Overexpression of can-miR37a in transgenic pepper revealed enhanced resistance to C. truncatum as evidenced by decreased fungal growth, up-regulated expression of defense-responsive genes and down-regulated expression of the target regulatory genes encoding ethylene response factors (ERFs). Furthermore, knock-out analysis of the ERF transcription factors revealed their role in fungal colonization and immune suppression in chilli. Overall, the present study authenticate the role of potential miRNAs in engineering resistance response against fungal phytopathogens.