Roles of Morphology, Anatomy, and Aquaporins in Determining Contrasting Hydraulic Behavior of Roots

• DOI: 10.1104/pp.108.134098
• Publication Date: 2009-03-26T01:46:11Z
• Authors: Helen Bramley; Neil C. Turner; David W. Turner; Stephen D. Tyerman
• Keywords: Endodermis; Lupinus angustifolius; Water Transport; Root system; Hydraulics; Lupinus

Abstract The contrasting hydraulic properties of wheat (Triticum aestivum), narrow-leafed lupin (Lupinus angustifolius), and yellow luteus) roots were identified by integrating measurements water flow across different structural levels organization with anatomy modeling. Anatomy played a major role in root hydraulics, influencing axial conductance (L ax) the distribution uptake along root, more localized for aquaporins (AQPs). Lupin had greater L ax than roots, due to xylem development. r) related each other, such that both variables increased distance from tip roots. r constant Despite these behaviors, conductivity cells (Lp c) was similar all species surface toward endodermis. Lp c largely controlled AQPs, as demonstrated dramatic reductions AQP blocker mercury. Modeling series concentric, cylindrical membranes, inhibition activity at level, indicated occurred primarily through apoplast, without crossing membranes involvement AQPs. In contrast, crossed mercury-sensitive AQPs endodermis, which significantly influenced r. This study demonstrates importance examining morphology assessing hydraulics.