Aquaporin function and exogenous application of abscisic acid (ABA) to barley roots

Using an immunochemical approach to reveal the link between changes in abscisic acid (ABA) levels, aquaporin function and changes in root cell hydraulic conductivity (LpCell), Sharipova et al. compared the abundance of AQPs and ABA by means of immunolocalization in the tissue of barley (Hordeum vulgare) roots, and related it to LpCell.

Immunolocalization of AQPs in roots (3–5 mm from the root tip) of ‘Steptoe’ plants using antibodies against HvPIP2;1 (A), HvPIP2;2 (B) and HvPIP2;5 (C). (D) Sections treated with non-immune serum. Scale bars = 50 µm.

Shortly after (< 2 hours) ABA application to the roots of ABA-deficient barley, increased tissue ABA concentrations and AQP abundance (especially the plasma-membrane localised isoforms HvPIP2;1 and HvPIP2;2) were spatially correlated in root epidermal cells and the cortical cell layer located beneath, in conjunction with increased LpCell of the cortical cells.

This paper is part of the Root Biology Special Issue.