Auxin regulates aquaporin function to facilitate lateral root emergence [plus Supplementary information + supplementary note]

2012

Article référencé dans le Web of Science WOS:000309543800008

Péret B., Li G., Zhao J., Band L.R., Voß U., Postaire O., Luu D.T., Ines O.D., Casimiro I., Lucas Mikaël, Wells D.M., Lazzerini L., Nacry P., King J.R., Jensen O.E., Schäffner A.R., Maurel C., Bennett M.J.

Nature Cell Biology, 2012, 14 (10), 991-998 [+ 7 p. + 25 p.] ISSN 1465-7392

Aquaporins are membrane channels that facilitate water movement across cell membranes. In plants, aquaporins contribute to water relations. Here, we establish a new link between aquaporin-dependent tissue hydraulics and auxin-regulated root development in Arabidopsis thaliana. We report that most aquaporin genes are repressed during lateral root formation and by exogenous auxin treatment. Auxin reduces root hydraulic conductivity both at the cell and whole-organ levels. The highly expressed aquaporin PIP2;1 is progressively excluded from the site of the auxin response maximum in lateral root primordia (LRP) whilst being maintained at their base and underlying vascular tissues. Modelling predicts that the positive and negative perturbations of PIP2;1 expression alter water flow into LRP, thereby slowing lateral root emergence (LRE). Consistent with this mechanism, pip2;1 mutants and PIP2;1-overexpressing lines exhibit delayed LRE. We conclude that auxin promotes LRE by regulating the spatial and temporal distribution of aquaporin-dependent root tissue water transport.

Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du monde végétal [076]

Fonds IRD [F B010078752]

fdi:010078752