Award details

13 ERA-CAPS: Biosynthesis, transport and exudation of 1,4-benzoxazin-3-ones as determinants of plant biotic interactions

Reference	BB/L027925/1
Principal Investigator / Supervisor	Professor Jurriaan Ton
Co-Investigators / Co-Supervisors	Professor Duncan Cameron, Professor Stephen Rolfe
Institution	University of Sheffield
Department	Animal and Plant Sciences
Funding type	Research
Value (£)	300,495
Status	Completed
Type	Research Grant
Start date	30/06/2014
End date	29/06/2017
Duration	36 months

Abstract

This technical summary concerns work package 4 of the consortium project, which addresses the role of benzoxazinoids in biotic interactions at the root-soil interface: I. Targeted approach: we will investigate how BXs influence the plant's interaction with 1) the plant growth promoting rhizobacterial (PGPR) strain Pseudomonas putida KT2440, which is a competitive colonizer of the maize rhizosphere, 2) the arbuscular mycorrhizal fungi (AMF) of the family Glomeraceae, and 3) the specialist root herbivore and important invasive pest Diabrotica virgifera. Both D. virgifera and P. putida KT2440 are attracted to BX-producing roots, while G. intraradices has been shown to boost BX production. Different sets of experiments will be conducted to study the role of BXs in interactions with the above rhizoshere organisms. involving chemical profiling of benzoxazinoids and corresponding breakdown products in the (mycor)rhizosphere, transcirptional profiling of BX biosynhtesis genes, and tripartite root colonization assays using transgenic maize lines affected in different steps of the BX biosynhtesis pathway. II. Global approach: we will determine the global impact of BXs on the microbial composition of the (mycor)rhizosphere. Using a deep-sequencing approach of operational taxonomic units (OTUs) from 16S rRNA sequences, we will compare dominant microbial OTUs present in the rhizosphere of mycorrhizal and non-mycorrhizal roots of BX-producing maize and BX-deficient maize lines.

Summary

The establishment of a suitable biotic niche is essential for plant survival and agricultural productivity. One important mechanism by which plants shape their environment is the release of phytochemicals. Low molecular weight compounds in particular can initiate the interaction with beneficial microbes in the soil and ward off herbivores. However, the same signalling molecules may also be exploited by specialized pests and pathogens. A detailed understanding of their biosynthesis, transport and release will be essential to disentangle these seemingly contradicting effects and to harness the full potential of secondary metabolite exudation in sustainable cropping systems. Yet to date, no secondary metabolite exporters have been identified in crop model systems. Here we propose to unite the expertise of different research groups across Europe to study the molecular basis of 1,4-benzoxazin-3-one (BX) exudation in maize. Previous work by the consortium members has identified BXs as important resistance factors in maize and other grasses and has elucidated their biosynthesis in detail. We have also shown that BXs are the dominant secondary metabolites in maize root exudates and the leaf-apoplast and that they are important recruitment signals for beneficial microbes as well as for one of the most damaging pests of maize, the western corn rootworm Diabrotica virgifera. Given their obvious importance for crop productivity and their strong involvement in extracellular signalling, BXs are an ideal and relevant model to study the molecular ecology of secondary metabolite exudation. The overall aim of BENZEX is to create the most advanced molecular toolkit in extracellular plant-environment interactions to date. First, a comprehensive population of maize genotypes that are altered in BX biosynthesis will be established by interrupting or enhancing the expression of three important biosynthetic enzymes. Second targeted and untargeted reference methods to identify and quantifyBX production, storage, exudation and transformation will be established using HPLC-MS and 13C-labelled BX precursors. Third, BX transporters will be identified by a combination of proteomics, quantitative PCR and phytochemically guided QTL-mapping. Fourth, the generated resources will be used to analyse the role of extracellular BXs in the interaction with the soil microbiome, plant growth promoting bacteria, arbuscular mycorrhizal fungi, root herbivores and leaf-feeding aphids. Taken together, our project will substantially increase knowledge about the biological relevance of secondary metabolite exudation. It will furthermore enhance the competitiveness of European molecular plant sciences by providing an array of new tools and resources, including transgenic plants and mutants, analytical methods as well as molecular and microbial markers for maize as an important agricultural model system.

Impact Summary

The project will achieve impact via the following pathways: 1. Peer reviewed publication and presentation: Given the nature of the proposed research, the most efficient way of communicating the findings of BENZEX will be through i) the presentation at scientific conferences (including for instance the Gordon Research Conference on Plant-Herbivore Interactions 2016; the 57th Maize Genetics Conference 2015; and the XVI International Congress of Molecular Plant-Microbe Interactions 2014) and ii) the publication in major peer-reviewed journals. Preference will be given to journals that support an open access option (e.g. Plant Physiology, Plant Cell, PLoS Biology). All group members who have made significant research contributions will be included as authors, with the order of authorship according to the relative contributions. Publications will include detailed methods sections that allow other researchers to reproduce the experiments. 2. Deposition of materials in repositories, databases and germplasm banks: The resources generated by BENZEX will be made freely available to the scientific community, except in the case of patented material (see below), which will require a Material Transfer Agreement. The following existing data repositories will be employed for this purpose: - Gene expression data: SRA (Short Read Archive; http://www.ncbi.nlm.nih.gov/sra) and GEO (Gene Expression Omnibus; http://www.ncbi.nlm.nih.gov/geo/) - 16sRNA sequences: European Nucleotide Archive (ENA) (http://www.ebi.ac.uk/ena/about/submit_and_update) - Metabolite and metabolomics data: METLIN (http://metlin.scripps.edu/) and Fiehn Lib (http://fiehnlab.ucdavis.edu/projects/FiehnLib/index_html ) - Seed stocks: Maize genetics cooperation stock centre (http://maizecoop.cropsci.uiuc.edu/). T1-seeds of transgenic plants will be made available directly from MPI-CE upon request. - Cloned DNA in bacterial vectors: Plasmid DNA or stocks of Escherichia coli and Agrobacterium tumefaciens carrying the cloned DNA will be made available to other researchers by the consortium partners. 3. Communication through public media: To reach a wider audience, the findings of BENZEX will be communicated using the following media: - Concerted press releases on outstanding papers and publications of BENZEX by the MPI-CE's press information officer (PIO) Angela Overmeyer M.A., and distributed to more than 18.000 journalists and subscribers e.g. via "Informationsdienst Wissenschaft (idw)" for Germany, Switzerland and Austria and EurekAlert, the idw's equivalent in the USA. - Launching of all relevant information and the outcome of BENZEX projects via the Max Planck Societies "Sci. & Corp. Com." and "Research Marketing, Events& Exhibition" Depts. - Articles in the bi-annual open access PULS/CE ("Public Understanding of Life Science/Chemical Ecology") newsletter of the MPI-CE (Edited by Angela Overmeyer and Jan Kellman) - Public lectures, including the "German Talks" and the "Ernst-Stahl Seminars" at the MPI-CE

Committee	Research Committee B (Plants, microbes, food & sustainability)
Research Topics	Crop Science, Microbiology, Plant Science, Soil Science
Research Priority	X – Research Priority information not available
Research Initiative	ERA-NET on Coordinating Action in Plant Sciences (ERA-CAPS) [2013-2014]
Funding Scheme	X – not Funded via a specific Funding Scheme

I accept the terms and conditions of use (opens in new window)

export PDF file

back to list new search