Modelling and experimental analysis of hormonal crosstalk in Arabidopsis.
An important question in plant biology is how genes influence the crosstalk between hormones to regulate growth. In this study, we model POLARIS (PLS) gene function and crosstalk between auxin, ethylene and cytokinin in Arabidopsis. Experimental evidence suggests that PLS acts on or close to the ethylene receptor ETR1, and a mathematical model describing possible PLS-ethylene pathway interactions is developed, and used to make quantitative predictions about PLS-hormone interactions. Modelling correctly predicts experimental results for the effect of the pls gene mutation on endogenous cytokinin concentration. Modelling also reveals a role for PLS in auxin biosynthesis in addition to a role in auxin transport. The model reproduces available mutants, and with new experimental data provides new insights into how PLS regulates auxin concentration, by controlling the relative contribution of auxin transport and biosynthesis and by integrating auxin, ethylene and cytokinin signalling. Modelling further reveals that a bell-shaped dose-response relationship between endogenous auxin and root length is established via PLS. This combined modelling and experimental analysis provides new insights into the integration of hormonal signals in plants.
The Integrative Cell Biology Laboratory and The Biophysical Sciences Institute, School of Biological and Biomedical Sciences, Durham University, Durham, UK. junli.liu@durham.ac.uk
Junli
J
Liu
Saher
S
Mehdi
Jennifer
J
Topping
Petr
P
Tarkowski
Keith
K
Lindsey
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003583:Cytokinins / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000033:anatomy & histology / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D003583:Cytokinins; D005030:Ethylenes; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C469251:polaris protein, Arabidopsis; C036216:ethylene