Identification of host proteins targeted by the flax rust effector protein AvrL567
type: CreativeWork
description: The flax rust fungus (Melampsora lini) and its flax host (Linum usitatissimum) have served as a successful model system for rust infection for many years. The experiments described in this thesis aim to identify cellular targets of the two M. lini effector proteins AvrL567 and AvrM and elucidate the function of these targets. To identify targets of the effector proteins, Yeast-2-Hybrid (Y2H) screens were performed with cDNA from rust infected flax leaves. This approach allowed for the identification of plant targets as well as potential fungal cofactors. Eight putative interactors (iA1 to iA8) were isolated for AvrL567, none could be identified for AvrM. The candidates identified in the Y2H screen were truncated proteins. Two of them showed low sequence homology to fungal proteins, three putative interactors had low sequence homology to plant proteins and three had no sequence homology to any known protein. At the time of this project, neither the flax nor the flax rust genome had been sequenced and thus additional experiments were conducted to obtain full length sequence information of the putative interactors. Using a lambda phage assay and Rapid Amplification of cDNA-Ends (RACE) full length sequence information was obtained for five putative interactors (iA1, iA2, iA3, iA4 and iA8). They were successfully tested for interaction with AvrL567 in Y2H assays and computational analysis revealed homology to known proteins and protein domains. Based on this analysis three interactors (iA1, iA2 and iA3) of AvrL567 were chosen for further investigation. iA1 is a plant protein that shows high sequence homology to the Arabidopsis thaliana cytokinin oxidase/dehydrogenase enzyme AtCKX7 and was termed L. usitatissimum CKX1. AtCKX7 is involved in plant hormone metabolism and two isoforms of the LuCKX1 were identified in flax. Both show interaction with AvrL567 in Bimolecular Fluorescent Complementation (BiFC) assays but differ in their enzymatic activity. Addition of purified A…
abstract: The flax rust fungus (Melampsora lini) and its flax host (Linum usitatissimum) have served as a successful model system for rust infection for many years. The experiments described in this thesis aim to identify cellular targets of the two M. lini effector proteins AvrL567 and AvrM and elucidate the function of these targets. To identify targets of the effector proteins, Yeast-2-Hybrid (Y2H) screens were performed with cDNA from rust infected flax leaves. This approach allowed for the identification of plant targets as well as potential fungal cofactors. Eight putative interactors (iA1 to iA8) were isolated for AvrL567, none could be identified for AvrM. The candidates identified in the Y2H screen were truncated proteins. Two of them showed low sequence homology to fungal proteins, three putative interactors had low sequence homology to plant proteins and three had no sequence homology to any known protein. At the time of this project, neither the flax nor the flax rust genome had been sequenced and thus additional experiments were conducted to obtain full length sequence information of the putative interactors. Using a lambda phage assay and Rapid Amplification of cDNA-Ends (RACE) full length sequence information was obtained for five putative interactors (iA1, iA2, iA3, iA4 and iA8). They were successfully tested for interaction with AvrL567 in Y2H assays and computational analysis revealed homology to known proteins and protein domains. Based on this analysis three interactors (iA1, iA2 and iA3) of AvrL567 were chosen for further investigation. iA1 is a plant protein that shows high sequence homology to the Arabidopsis thaliana cytokinin oxidase/dehydrogenase enzyme AtCKX7 and was termed L. usitatissimum CKX1. AtCKX7 is involved in plant hormone metabolism and two isoforms of the LuCKX1 were identified in flax. Both show interaction with AvrL567 in Bimolecular Fluorescent Complementation (BiFC) assays but differ in their enzymatic activity. Addition of purified A…
author: Koeck, Markus
language: en_AU
date published: 2012
date modified: 2026-07-24T00:54:33Z
provider: Australian National University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Australian National University

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property ID: Handle
value: http://hdl.handle.net/1885/151772