miRNA Mediated Defense Responses in Wheat during Puccinia graminis f.sp. tritici Invasion

Plants have evolved various mechanism to counter defend pathogen invasion by triggering defense responses which alter host cellular function regulated by endogenous, small, non-coding miRNAs. To understand the mechanism of miRNAs regulated cellular functions during Puccinia graminis f.sp. tritici infection in wheat, we investigated role of eight different miRNAs viz. miR159, miR164, miR167, miR171, miR444, miR408, miR1129 and miR1138, involved in three different independent cellular defense response to infection. The result reveals that at the initiation of infection, accumulation of miRNAs might be playing a critical role in hypersensitive response (HR) from host, which diminishes at the advance stage of the disease. This suggests a possible host-fungal synergistic relation leading to susceptibility. Differential expression of these miRNAs in presence and absence of Sr24 gene provides a probable explanation of miRNA regulated Sr24 gene mediated independent pathways.