Original Research ARTICLE
Temporal quantitative changes in the resistant and susceptible wheat leaf apoplastic proteome during infection by wheat leaf rust (Puccinia triticina).
- 1Morden Research and Development Centre, Agriculture and Agri-Food Canada, Canada
Wheat leaf rust caused by the pathogenic fungus Puccinia triticina, is a serious threat to bread wheat and durum production in many areas of the world. This plant-pathogen interaction has been studied extensively at the molecular genetics level, however proteomics data are still relatively scarce. The present study investigated temporal changes in the abundance of the apoplastic fluid proteome of wheat leaves infected with either virulent or avirulent races of P. triticina, using a label-free LC-MS-based approach. In general, there was very little difference between inoculated and control apoplastic proteomes in either host, until haustoria had become well established in the susceptible host, although the resistant host responds to pathogen challenge sooner. In the earlier samplings (up to 72 h after inoculation), there were just 46 host proteins with significantly changing abundance, and pathogen proteins were detected only rarely and not reproducibly. This is consistent with the biotrophic life-style of P. triticina, where the invading pathogen initially causes little tissue damage or host cell death, which occur only later during the infection cycle. The majority of the host proteins with altered abundance up to 72 h post-inoculation were pathogen-response-related, including peroxidases, chitinases, β-1-3-endo-glucanases and PR-proteins. Five days after inoculation with the susceptible apoplasm it was possible to detect 150 P. triticina proteins and 117 host proteins which had significantly increased in abundance as well as 33 host proteins which had significantly decreased in abundance. The latter represent potential targets of pathogen effectors and included enzymes which could damage the invader. The pathogen-expressed proteins – seen most abundantly in the incompatible interaction – were mostly uncharacterized proteins, however many of their functions could be inferred through homology-matching with pBLAST. Pathogen proteins also included several candidate effector proteins, some novel and some which have been reported previously. All MS data have been deposited in the PRIDE archive (www.ebi.ac.uk/pride/archive/) under Project PXD012586.
Keywords: Leaf rust (Puccinia triticina), Effector protein, apoplastic fluid, Proteomic analyses, Mass Spectrometry
Received: 26 Feb 2019;
Accepted: 17 Sep 2019.
Copyright: © 2019 Rampitsch, Huang, djuric-ciganovic, wang and fernando. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Christof Rampitsch, Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, R6M 1Y5, Manitoba, Canada, email@example.com