title: Bundle-sheath aquaporins play a role in controlling Arabidopsis leaf hydraulic conductivity.
abstract: The role of molecular mechanisms in the regulation of leaf hydraulics (K(leaf)) is still not well understood. We hypothesized that aquaporins (AQPs) in the bundle sheath may regulate K(leaf). To examine this hypothesis, AQP genes were constitutively silenced using artificial microRNAs and recovery was achieved by targeting the expression of the tobacco AQP (NtAQP1) to bundle-sheath cells in the silenced plants. Constitutively silenced PIP1 plants exhibited decreased PIP1 transcript levels and decreased K(leaf). However, once the plants were recovered with NtAQP1, their K(leaf) values were almost the same as those of WT plants. We also demonstrate the important role of ABA, acting via AQP, in that recovery and K(leaf) regulation. These results support our previously raised hypothesis concerning the role of bundle-sheath AQPs in the regulation of leaf hydraulics.
authors.affiliation: a Institute of Plant Sciences and Genetics in Agriculture; Robert H. Smith Faculty of Agriculture, Food, and Environment; Hebrew University of Jerusalem ; Rehovot , Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Sade
authors.forename: Arava
authors.initials: A
authors.lastname: Shatil-Cohen
authors.forename: Menachem
authors.initials: M
authors.lastname: Moshelion
mesh_terms: D000040:Abscisic Acid / Q000502:physiology; D020346:Aquaporins / Q000378:metabolism*; D017360:Arabidopsis / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology*; D014867:Water / Q000502:physiology*
chemical_list: D020346:Aquaporins; D014867:Water; D000040:Abscisic Acid
keywords: abscisic acid (ABA); aquaporins (AQPs); artificial microRNA (amiRNA); bundle sheath; leaf hydraulic conductivity (Kleaf); plasma membrane intrinsic proteins (PIPs)