Modelling the dynamics of polar auxin transport in inflorescence stems of Arabidopsis thaliana
| Autor: | Lambertus A. Peletier, Paulina C. van Spronsen, Kees J. M. Boot, Sander C. Hille, Kees R. Libbenga, Bert van Duijn, Remko Offringa |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Physiology Quantitative Biology::Tissues and Organs Mutant Arabidopsis Plant Science Biology Models Biological modelling 03 medical and health sciences Auxin Arabidopsis thaliana chemiosmotic theory Computer Simulation Inflorescence polar auxin transport mutants chemistry.chemical_classification Indoleacetic Acids Plant Stems IAA Wild type mathematical modeling Biological Transport biology.organism_classification 030104 developmental biology chemistry Biochemistry Biophysics Chromatography Thin Layer Plant hormone Polar auxin transport Flux (metabolism) Biomarkers Research Paper |
| Zdroj: | Journal of Experimental Botany Journal of Experimental Botany, 67(3), 649-666 |
| Popis: | Highlight An experimental and mathematical approach to polar auxin transport results in a model based on an extended general advection–diffusion equation including auxin immobilization and surrounding tissue exchange that accounts for crucial observations. The polar transport of the plant hormone auxin has been the subject of many studies, several involving mathematical modelling. Unfortunately, most of these models have not been experimentally verified. Here we present experimental measurements of long-distance polar auxin transport (PAT) in segments of inflorescence stems of Arabidopsis thaliana together with a descriptive mathematical model that was developed from these data. It is based on a general advection–diffusion equation for auxin density, as suggested by the chemiosmotic theory, but is extended to incorporate both immobilization of auxin and exchange with the surrounding tissue of cells involved in PAT, in order to account for crucial observations. We found that development of the present model assisted effectively in the analysis of experimental observations. As an example, we discuss the analysis of a quadruple mutant for all four AUX1/LAX1–LAX3 influx carriers genes. We found a drastic change in the parameters governing the exchange of PAT channels with the surrounding tissue, whereas the velocity was still of the order of magnitude of the wild type. In addition, the steady-state flux of auxin through the PAT system of the mutant did not exhibit a saturable component, as we found for the wild type, suggesting that the import carriers are responsible for the saturable component in the wild type. In the accompanying Supplementary data available at JXB online, we describe in more detail the data-driven development of the model, review and derive predictions from a mathematical model of the chemiosmotic theory, and explore relationships between parameters in our model and processes and parameters at the cellular level. |
| Databáze: | OpenAIRE |
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