title: Physiological mechanisms in plant growth models: do we need a supra-cellular systems biology approach?
abstract: In the first part of this paper, we review the extent to which various types of plant growth models incorporate ecophysiological mechanisms. Many growth models have a central role for the process of photosynthesis; and often implicitly assume C-gain to be the rate-limiting step for biomass accumulation. We subsequently explore the extent to which this assumption actually holds and under what condition constraints on growth due to a limited sink strength are likely to occur. By using generalized dose-response curves for growth with respect to light and CO₂, models can be tested against a benchmark for their overall performance. In the final part, a call for a systems approach at the supra-cellular level is made. This will enable a better understanding of feedbacks and trade-offs acting on plant growth and its component processes. Mechanistic growth models form an indispensable element of such an approach and will, in the end, provide the link with the (sub-)cellular approaches that are yet developing. Improved insight will be gained if model output for the various physiological processes and morphological variables ('virtual profiling') is compared with measured correlation networks among these processes and variables. Two examples of these correlation networks are presented.
authors.affiliation: IBG-2 Plant Sciences, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany. h.poorter@fz-juelich.de
authors.forename: Hendrik
authors.initials: H
authors.lastname: Poorter
authors.forename: Niels P R
authors.initials: NP
authors.lastname: Anten
authors.forename: Leo F M
authors.initials: LF
authors.lastname: Marcelis
mesh_terms: D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology; D063245:Plant Development / Q000502:physiology*; D049490:Systems Biology
keywords: dose-response curves; evolutionary stable strategy; photosynthesis; plant growth; simulation; source-sink interaction