Yield Improvement of Oilseed Rape Through
Genetic Manipulation of Rhizosphere Exudation
Gary Bendinga, Graham Teakleb, Paul Huntera, Sally Hiltona,
Hendrik Schafera, Jonathan Moorea, Dave Pinkc, Mark Barrowd
a; School of Life Sciences, University of Warwick, b; Warwick Crop Centre, c; Harper
Adams University, d; Department of Chemistry, University of Warwick
A. Healthy plants roots exude organic carbon compounds
(rhizodeposition), which can influence the structure, function and
microbial community of the soil close to the root.
The ability to manipulate rhizodeposition could:
increase yield
B. Plants are grown in sterile hydroponic systems (1)
Exudates are analysed using Mass Spectrometry (MS)
(2) & Nuclear Magnetic Resonance Spectrometry (NMR)
(3) by collaborators at Rothamsted Research.
Selected lines are used for high resolution profiling by
Fourier Transform Ion Cyclotron Resonance MS
(FTICR) (4) in Warwick Chemistry Department.
increase natural protection v. pests and pathogens
reduce agricultural input by improving;
N & P availability
soil structure & water retention
This project will focus on Brassicas (well studied major UK crops),
and will:
(2) ESI Mass Spectrometer
assess variation in Brassica exudates
identify the underlying genes
assess the impact of specific compounds on rhizosphere
microbial diversity & function, plant nutrition & yield.
(1) Sterile
hydroponic
systems
r-1-nin-9/03/bj-3102-11rpA/2371
1_03_bj-3102-11rpA
r-3-pat-8/06/bj-3102-11rpA/2371
1_06_bj-3102-11rpA
r-1-nin-9/03/bj-3102-11rpA/2371
1_03_bj-3102-11rpA
r-3-pat-8/06/bj-3102-11rpA/2371
1_06_bj-3102-11rpA
Compound
Nin
P.
Average
µmol/g
root
Carboxylic acids
53.3
Malate
0.049*
26.4
Succinate
0.009**
3.2
Citrate
<0.001***
<0.1
0.002**
<0.1
Tap
00.5
52.5
00.005.5
00.157.5
00.2
00.3
(5) Two regions of the NMR
profiles of two oilseed rape lines
showing contrasting profiles
00.4
Fumarate
Sugars
Sucrose
4.1
0.003**
0.4
(3) +H-NMR
Spectrometer
(4) FTICR Mass
Spectrometer
C. MS & NMR profiles (5) and multivariate analysis (6)
showed significant differences between lines.
NMR quantification also indicated which compounds were
different between the lines (7).
The most informative segregating population (6 - red dots)
was further assessed for exuded malate (associated with P
uptake) & sucrose (a microbial energy source) levels.
Lines with high & low levels of each compound have been
sown in field trials, using a bulked segregant approach
Other Compounds
Choline
(6) MDS plot of multivariate
analysis of NMR exudate
profiles
0.031*
0.8
(7) NMR quantification of exudate
components showing significant
differences (by ANOVA) between
plant lines and average
concentrations
Associated publications: Hunter et al.,(2014) doi: 10.3389/fpls.2014.00027
Website: http://www2.warwick.ac.uk/fac/sci/lifesci/research/rhizodeposition//
Contact: Gary Bending: 02476 575057,Gary.Bending@warwick.ac.uk
We would like to thank Prof. Mike Beale and Dr. Jane Ward at Rothamsted
Research for the metabolomics, Mark Nightingale at Elsoms Seeds for the
field trials and BBSRC for funding (BBSRC CIRC Grant BB/J019690/1)
D. Next generation sequencing will provide rhizosphere
microbial community profiles from all the Brassica lines.
The field trial will provide:
seed yield, oil yield & plant nutrition data
rhizosphere microbial community composition
plant & microbial function (meta-transcriptomics)
Transcription profile differences in the field lines will be
identified and compared to QTL associated with exudation.
14C
carbon budgets & FTICR-MS will identify differences in
the amount and composition of exudates from selected lines.
Warwick Crop Centre
www.warwick.ac.uk/go/wcc