To what extent may changes in the root system architecture of Arabidopsis thaliana grown under contrasted homogenous nitrogen regimes be explained by changes in carbon supply? A modelling approach.
Root system architecture adapts to low nitrogen (N) nutrition. Some adaptations may be mediated by modifications of carbon (C) fluxes. The objective of this study was to test the hypothesis that changes in root system architecture under different N regimes may be accounted for by using simple hypotheses of C allocation within the root system of Arabidopsis thaliana. With that purpose, a model during vegetative growth was developed that predicted the main traits of root system architecture (total root length, lateral root number, and specific root length). Different experimental data sets crossing three C levels and two N homogenous nutrition levels were generated. Parameters were estimated from an experiment carried out under medium C and high N conditions. They were then checked under other CxN conditions. It was found that the model was able to simulate correctly C effects on root architecture in both high and low N nutrition conditions, with the same parameter values. It was concluded that C flux modifications explained the major part of root system adaptation to N supply, even if they were not sufficient to simulate some changes, such as specific root length.
Brun
François
F
AgroParisTech, UMR1091 INRA AgroParisTech Environnement et Grandes Cultures, F-78850 Thiverval-Grignon, France.
Richard-Molard
Céline
C
Pagès
Loïc
L
Chelle
Michaël
M
Ney
Bertrand
B
D017360:Arabidopsis / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D009584:Nitrogen / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism
D002244:Carbon; D009584:Nitrogen