Open AccessSystems level modelling of metabolism in fungal endophytes - implications for the symbiosis with ryegrass
Author(s) -
Rajiv Chaturvedi,
T. K. Soboleva,
Linda J. Johnson,
A. J. Parsons,
Susanne Rasmussen
Publication year - 2007
Publication title -
grassland research and practice series
Language(s) - English
Resource type - Journals
eISSN - 2463-4751
pISSN - 0110-8581
DOI - 10.33584/rps.13.2006.3049
Subject(s) - biology , metabolic network , symbiosis , flux balance analysis , metabolism , siderophore , mutant , lolium perenne , flux (metallurgy) , gene , epichloë , plant use of endophytic fungi in defense , microbiology and biotechnology , biochemistry , genetics , botany , poaceae , bacteria , chemistry , organic chemistry
We used constraint based stoichiometric modelling of metabolic fluxes in EpichloÑ' festucae (FL1), a targeted gene replacement of a non-ribosomal peptide synthetase (termed sidF) from E. festucae, and the symbiotic association of these endophytic fungi and their host Lolium perenne. SidF encodes an excreted ironchelating siderophore and the sidF knockouts (KO) are impaired in their ability to take up iron. After constructing the metabolic network at a genome scale, we applied constraints on enzymatic reactions that require iron as co-factor to study the variations in metabolic network capabilities of the siderophore mutant versus wildtype, in culture and in planta. We compared fluxes calculated for the production of amino acids with observed concentrations of these amino acids in planta. We report a counter-intuitive result from considering metabolism on a systems level in our models. Keywords: stoichiometric metabolic network modelling, flux balance analysis, symbiosis, Neotyphodium lolii, Lolium perenne, EpichloÑ' festucae.