title: Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods.
abstract: Floods and salinization of agricultural land adversely impact global rice production. We investigated whether gas films on leaves of submerged rice delay salt entry during saline submergence. Two-week-old plants with leaf gas films (+GF) or with gas films experimentally removed (-GF) were submerged in artificial floodwater with 0 or 50 mm NaCl for up to 16 d. Gas films were present >9 d on GF plants after which gas films were diminished. Tissue ion analysis (Na+, Cl-and K+) showed that gas films caused some delay of Na+entry, as leaf Na+concentration was 36-42% higher in -GF leaves than +GF leaves on days 1-5. However, significant net uptakes of Na+and Cl-, and K+net loss, occurred despite the presence of gas films, indicating the likely presence of some leaf-to-floodwater contact, so that the gas layer must not have completely separated the leaf surfaces from the water. Natural loss and removal of gas films resulted in severe declines in growth, underwater photosynthesis, chlorophyllaand tissue porosity. Submergence was more detrimental to leaf PNand growth than the additional effect of 50 mm NaCl, as salt did not significantly affect underwater PNat 200 μm CO2nor growth.
authors.affiliation: Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, 2100, Copenhagen, Denmark.|School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.
authors.forename: Max
authors.initials: M
authors.lastname: Herzog
authors.affiliation: Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, 2100, Copenhagen, Denmark.|School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.
authors.forename: Dennis
authors.initials: D
authors.lastname: Konnerup
authors.affiliation: Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, 2100, Copenhagen, Denmark.|School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.|Institute of Advanced Studies, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.
authors.forename: Ole
authors.initials: O
authors.lastname: Pedersen
authors.affiliation: Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, 2100, Copenhagen, Denmark.|School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.
authors.forename: Anders
authors.initials: A
authors.lastname: Winkel
authors.affiliation: School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.|Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia.
authors.forename: Timothy David
authors.initials: TD
authors.lastname: Colmer
mesh_terms: D001692:Biological Transport; D002734:Chlorophyll / Q000378:metabolism; D055868:Floods; D005740:Gases / Q000378:metabolism; D012275:Oryza / Q000502:physiology*; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism*; D013312:Stress, Physiological; D014867:Water / Q000502:physiology*
chemical_list: D005740:Gases; D014867:Water; D002734:Chlorophyll; D012965:Sodium Chloride; D011188:Potassium
keywords: flooding; leaf Cl−; leaf K+; leaf Na+; plant submergence tolerance; salinity; salt intrusion