title: Enzyme-driven metabolomic screening: a proof-of-principle method for discovery of plant defence compounds targeted by pathogens.
abstract: Plants produce a variety of secondary metabolites to defend themselves from pathogen attack, while pathogens have evolved to overcome plant defences by producing enzymes that degrade or modify these defence compounds. However, many compounds targeted by pathogen enzymes currently remain enigmatic. Identifying host compounds targeted by pathogen enzymes would enable us to understand the potential importance of such compounds in plant defence and modify them to make them insensitive to pathogen enzymes. Here, a proof of concept metabolomics-based method was developed to discover plant defence compounds modified by pathogens using two pathogen enzymes with known targets in wheat and tomato. Plant extracts treated with purified pathogen enzymes were subjected to LC-MS, and the relative abundance of metabolites before and after treatment were comparatively analysed. Using two enzymes from different pathogens the in planta targets could be found by combining relatively simple enzymology with the power of untargeted metabolomics. Key to the method is dataset simplification based on natural isotope occurrence and statistical filtering, which can be scripted. The method presented here will aid in our understanding of plant-pathogen interactions and may lead to the development of new plant protection strategies.
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia. Jason.Carere@csiro.au.
authors.forename: Jason
authors.initials: J
authors.lastname: Carere
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Colgrave
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia.
authors.forename: Jiri
authors.initials: J
authors.lastname: Stiller
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia.
authors.forename: Chunji
authors.initials: C
authors.lastname: Liu
authors.affiliation: CSIRO Agriculture, Black Mountain, Canberra, ACT, 2601, Australia.
authors.forename: John M
authors.initials: JM
authors.lastname: Manners
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia.
authors.forename: Kemal
authors.initials: K
authors.lastname: Kazan
authors.affiliation: Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Queensland Bioscience Precinct, Brisbane, Qld, 4067, Australia.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Gardiner
mesh_terms: D004798:Enzymes / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000276:immunology* / Q000382:microbiology*; D013058:Mass Spectrometry; D055432:Metabolomics / Q000379:methods*; D064209:Phytochemicals / Q000737:chemistry / Q000378:metabolism*; D014053:Tomatine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D014908:Triticum / Q000276:immunology* / Q000382:microbiology*
chemical_list: D004798:Enzymes; D005656:Fungal Proteins; D064209:Phytochemicals; C003677:tomatidine; D014053:Tomatine
keywords: defence compounds; mass spectrometry (MS); metabolomic screening; phytoalexin; phytoanticipin; secondary metabolites