Network flux analysis aims to
generate flux maps of the metabolic network and thus to provide a functional
description of the metabolic phenotype of the organism under study. Steady
state flux analysis, based on stable isotope labelling experiments, is one of
the principal experimental methods in network flux analysis and its application
to the plant metabolic network is increasing.
Postdoctoral Research: (Supervisors: Dr Lee Sweetlove and Prof. George
Ratcliffe)
Project: “EU-Smart Cell Project:
Rational design of plant systems for sustainable generation of value added
industrial products” see weblink http://www.smart-cell.org/
Specific aims: To establish flux
maps of primary and secondary metabolism in transgenic hairy root lines of Tobacco
and Catharanthus roseus. The focus is towards the sustainable
generation of value added industrial products.
D.Phil Research aims and achievements:
(Supervisors: Prof. George Ratcliffe
and Dr Nick Kruger)
Thesis title: Network flux analysis of central metabolism in plants
The aim of the project was to establish and validate robust techniques for
quantifying fluxes through the dominant pathways of carbohydrate oxidation in
plants. The subcellular compartmentation of these pathways between the cytosol
and plastid is a characteristic feature of the structure of the plant metabolic
network, and the project focused on the extent to which network flux analysis
is capable of distinguishing fluxes between and through the duplicated steps
and pathways. This lead to assessment of the response of the compartmented
network to nutritional perturbations of phosphate stress and nitrogen
sources.
Established in silico modeling strategies for 13C-based steady state
flux analysis using 13CFLUX® and quantified the fluxes in the compartmented
model of heterotrophic Arabidopsis
central carbon metabolism (published in Plant Physiology. 152: 602-619, 2010).
This study has physiological implications in establishing the fluxes through
the parallel reactions in the cytosol and plastid and explains the provision of
reducing power (NADPH) via oxidative steps of Pentose phosphate pathway.
The robust strategies developed were
applied to establish the response of Arabidopsis central network
to nutritional perturbations with relevance to phosphate stress and nitrogen
source(s). The results have established the metabolic phenotypes with
distinguishable response. The work was presented as talks and posters in
various international conferences (SEB Glasgow 2011-Pathways and fluxes
session July 2-4, International conference on Systems Biochemistry,
University of York, March 21-23, 2010 and Plant Systems Biology UK workshop,
Nottingham, June 1-3, 2010). The manuscripts for publication of the
Phosphate and Nitrogen work are under preparation.
Our research group at Oxford also
undertook a study related to the stability of the flux distribution of Arabidopsis suspension under different
oxygenation conditions (published in Plant Physiology. 148: 704-718, 2008).
More recently, we published a research review on the strategies for
investigating the plant metabolic network with steady-state metabolic flux
analysis (Journal of Experimental Botany, Special issue
on Pathways & Fluxes: Analysis of the Plant Metabolic Network
2012). In other collaborative projects with peers at John Innes
Center, UK and University of Oxford, we work on metabolic modeling of Rhizobium leguminosarum and Pseudomonas
syringae. The metabolic phenotypes obtained were presented as posters in
few international conferences in 2011.