Sutka M. auteur aut IRD Li G. W. auteur aut IRD Boudet J. auteur aut IRD Boursiac Y. auteur aut IRD Doumas Patrick auteur aut IRD Maurel C. auteur aut IRD text journalArticle eng text/pdf born digital access To gain insights into the natural variation of root hydraulics and its molecular components, genotypic differences related to root water transport and plasma membrane intrinsic protein (PIP) aquaporin expression were investigated in 13 natural accessions of Arabidopsis (Arabidopsis thaliana). The hydraulic conductivity of excised root systems (Lp(r)) showed a 2-fold variation among accessions. The contribution of aquaporins to water uptake was characterized using as inhibitors mercury, propionic acid, and azide. The aquaporin-dependent and -independent paths of water transport made variable contributions to the total hydraulic conductivity in the different accessions. The distinct suberization patterns observed among accessions were not correlated with their root hydraulic properties. Real-time reverse transcription-polymerase chain reaction revealed, by contrast, a positive overall correlation between Lp(r) and certain highly expressed PIP transcripts. Root hydraulic responses to salt stress were characterized in a subset of five accessions (Bulhary-1, Catania-1, Columbia-0, Dijon-M, and Monte-Tosso-0 [Mr-0]). Lp(r) was down-regulated in all accessions except Mr-0. In Mr-0 and Catania-1, cortical cell hydraulic conductivity was unresponsive to salt, whereas it was down-regulated in the three other accessions. By contrast, the five accessions showed qualitatively similar aquaporin transcriptional profiles in response to salt. The overall work provides clues on how hydraulic regulation allows plant adaptation to salt stress. It also shows that a wide range of root hydraulic profiles, as previously reported in various species, can be observed in a single model species. This work paves the way for a quantitative genetics analysis of root hydraulics. specialized 076 155 3 1264-1276 2011 0032-0889 https://www.documentation.ird.fr/hor/fdi:010053175 10.1104/pp.110.163113 0032-0889 [F B010053175] https://www.documentation.ird.fr/hor/fdi:010053175 https://www.documentation.ird.fr/intranet/publi/2011/03/010053175.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2011-04-07 2024-04-29 fdi:010053175 fre