TY - JOUR
T1 - Phosphate availability alters lateral root development in Arabidopsis by modulating auxin sensitivity via a mechanism involving the TIR1 auxin receptor
AU - Pérez-Torres, Claudia Anahí
AU - López-Bucio, José
AU - Cruz-Ramírez, Alfredo
AU - Ibarra-Laclette, Enrique
AU - Dharmasiri, Sunethra
AU - Estelle, Mark
AU - Herrera-Estrella, Luis
PY - 2008/12
Y1 - 2008/12
N2 - The survival of plants, as sessile organisms, depends on a series of postembryonic developmental events that determine the final architecture of plants and allow them to contend with a continuously changing environment. Modulation of cell differentiation and organ formation by environmental signals has not been studied in detail. Here, we report that alterations in the pattern of lateral root (LR) formation and emergence in response to phosphate (Pi) availability is mediated by changes in auxin sensitivity in Arabidopsis thaliana roots. These changes alter the expression of auxin-responsive genes and stimulate pericycle cells to proliferate. Modulation of auxin sensitivity by Pi was found to depend on the auxin receptor TRANSPORT INHIBITOR RESPONSE1 (TIR1) and the transcription factor AUXIN RESPONSE FACTOR19 (ARF19). We determined that Pi deprivation increases the expression of TIR1 in Arabidopsis seedlings and causes AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) auxin response repressors to be degraded. Based on our results, we propose a model in which auxin sensitivity is enhanced in Pi-deprived plants by an increased expression of TIR1, which accelerates the degradation of AUX/IAA proteins, thereby unshackling ARF transcription factors that activate/repress genes involved in LR formation and emergence.
AB - The survival of plants, as sessile organisms, depends on a series of postembryonic developmental events that determine the final architecture of plants and allow them to contend with a continuously changing environment. Modulation of cell differentiation and organ formation by environmental signals has not been studied in detail. Here, we report that alterations in the pattern of lateral root (LR) formation and emergence in response to phosphate (Pi) availability is mediated by changes in auxin sensitivity in Arabidopsis thaliana roots. These changes alter the expression of auxin-responsive genes and stimulate pericycle cells to proliferate. Modulation of auxin sensitivity by Pi was found to depend on the auxin receptor TRANSPORT INHIBITOR RESPONSE1 (TIR1) and the transcription factor AUXIN RESPONSE FACTOR19 (ARF19). We determined that Pi deprivation increases the expression of TIR1 in Arabidopsis seedlings and causes AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) auxin response repressors to be degraded. Based on our results, we propose a model in which auxin sensitivity is enhanced in Pi-deprived plants by an increased expression of TIR1, which accelerates the degradation of AUX/IAA proteins, thereby unshackling ARF transcription factors that activate/repress genes involved in LR formation and emergence.
UR - http://www.scopus.com/inward/record.url?scp=62549165835&partnerID=8YFLogxK
U2 - 10.1105/tpc.108.058719
DO - 10.1105/tpc.108.058719
M3 - Article
C2 - 19106375
AN - SCOPUS:62549165835
SN - 1040-4651
VL - 20
SP - 3258
EP - 3272
JO - Plant Cell
JF - Plant Cell
IS - 12
ER -