title: Role of aquaporins in determining transpiration and photosynthesis in water-stressed plants: crop water-use efficiency, growth and yield.
abstract: The global shortage of fresh water is one of our most severe agricultural problems, leading to dry and saline lands that reduce plant growth and crop yield. Here we review recent work highlighting the molecular mechanisms allowing some plant species and genotypes to maintain productivity under water stress conditions, and suggest molecular modifications to equip plants for greater production in water-limited environments. Aquaporins (AQPs) are thought to be the main transporters of water, small and uncharged solutes, and CO2 through plant cell membranes, thus linking leaf CO2 uptake from the intercellular airspaces to the chloroplast with water loss pathways. AQPs appear to play a role in regulating dynamic changes of root, stem and leaf hydraulic conductivity, especially in response to environmental changes, opening the door to using AQP expression to regulate plant water-use efficiency. We highlight the role of vascular AQPs in regulating leaf hydraulic conductivity and raise questions regarding their role (as well as tonoplast AQPs) in determining the plant isohydric threshold, growth rate, fruit yield production and harvest index. The tissue- or cell-specific expression of AQPs is discussed as a tool to increase yield relative to control plants under both normal and water-stressed conditions.
authors.affiliation: The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot, 76100, Israel.
authors.forename: Menachem
authors.initials: M
authors.lastname: Moshelion
authors.affiliation: Department of Soil and Water Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel.
authors.forename: Ofer
authors.initials: O
authors.lastname: Halperin
authors.affiliation: Department of Soil and Water Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel.
authors.forename: Rony
authors.initials: R
authors.lastname: Wallach
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.|Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), SE-901 83, Umeå, Sweden.
authors.forename: Ram
authors.initials: R
authors.lastname: Oren
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.|Department of Biology, Western University, London, ON, Canada, N6A5B7.
authors.forename: Danielle A
authors.initials: DA
authors.lastname: Way
mesh_terms: D020346:Aquaporins / Q000502:physiology*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000378:metabolism; D003681:Dehydration; D010788:Photosynthesis / Q000502:physiology*; D063245:Plant Development; D018515:Plant Leaves / Q000502:physiology; D018517:Plant Roots / Q000033:anatomy & histology / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D018526:Plant Transpiration / Q000502:physiology*; D010944:Plants / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D020346:Aquaporins; D014867:Water; D002245:Carbon Dioxide
keywords: anisohydric; drought stress; isohydric; risk-taking