Epsilon Archive for Student Projects

Abstract

Peptidase inhibitors are released by fungal pathogens in order to inhibit peptidase activity against fungal effectors or metabolites during infection. VL3320 is a putative peptidase inhibitor found in V. longisporum belonging to the I78 family of peptidase inhibitors. VD3424 is a homolog of VL3320 found in V. dahliae which present very similar functions and induction patterns. Through phylogenetic analysis, the I78 signal peptide domain as well as the potential catalytic region appeared to be conserved among all homologs identified. Both VD3424 and VL3320 showed low signs of upregulation until 5 days post inoculation, from which the genes were then downregulated until very low levels of expression at 8 days post inoculation. The homolog VD3424 is shown to interact with the pathosystem of Nicotiana benthiamiana, upregulating PR proteins and transcription factor PR1, PTI5, and WRKY7. Conversely, there appears to be a suppression of HIN1 and MAPKKKa, and further analysis could determine whether VL3320 is able to suppress proteins or transcription factors involved in the hypersensitive response and programmed cell death molecular pathways. In conclusion, VL3320 is involved in infection and elicits plant immune responses upon infection of V. longisporum, further analytical steps will highlight specific mechanisms of VL3320 in infection.