Auxin plays a central role in the root system architecture changes induced by phosphate starvation in Arabidopsis thaliana

摘要

Although large insights have been made in biochemical knowledge of the response to Pi starvation, very little is known about the hormonal control or the molecular events underlying the morphological responses. To address these questions, we combined two complementary approaches. On one hand, we described a fine analysis of the root system architecture changes induced by P starvation either on hormonal mutants (axr4, aux1, eir1, eto1, etr1) or on wild type plants grown on medium containing various phytohormones (effectors and inhibitors). On the basis of this extensive study, we propose that the root adaptive response to P starvation can mainly be explained by a global auxin reallocation from the primary to the lateral roots. On the other hand, morphological characterisation and transcriptome analysis were combined to identify genes displaying altered expression during the morphological changes by Pi depletion. Then, we focused on transcription factors and T-DNA mutants of the selected genes were analysed for root architecture phenotypes.