Heavy metal-associated isoprenylated plant protein is a putative host target of AvrPto5 effector of kiwifruit pathogen Pseudomonas syringae pv. actinidiae
K. DHARMARAJ (1), W. CUI (2), M. YOON (2), E. RIKKERINK (2), M. TEMPLETON (1) (1) The University of Auckland & The New Zealand Institute for Plant & Food Research Limited, New Zealand; (2) The New Zealand Institute for Plant & Food Research Limited, New Zealand

Pseudomonas syringae pv. actinidiae (Psa) is responsible for bacterial canker in kiwifruit, severely affecting kiwifruit cultivation worldwide. Psa can be grouped into four biovars based on their genetic makeup and geographical origin. We chose to investigate the effector AvrPto5 because it is conserved across all biovars. This project aims to identify the AvrPto5 host targets in Actinidia chinensis. We have generated an Actinidia chinensis yeast two-hybrid cDNA library from young leaves and shoots by homologous recombination system of prey yeast cells. Yeast two-hybrid screening of the cDNA library as prey and AvrPto5 as a bait has revealed the interaction of AvrPto5 and heavy metal-associated isoprenylated plant protein (AcHIPP26) that functions as a metallochaperone in plants. It is interesting to note that rice has an R-gene with a fusion of an orthologue of one of AcHIPP26 domains. This suggest that the protein has a role in plant defense and is a putative target for pathogen effector. Swapping of these proteins in yeast two-hybrid assay has further confirmed as the positive interaction. Moreover to ascertain the specific regions in both proteins that are responsible for the interaction in yeast, we have performed yeast two-hybrid of partial version of AvrPto5 and AcHIPP26 proteins and identified interacting domains. To validate the above interaction in planta experiments are being carried out and results will be discussed. 

Abstract Number: P17-514
Session Type: Poster