Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

TY - JOUR

T1 - Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

AU - Herzog, Max

AU - Konnerup, Dennis

AU - Pedersen, Ole

AU - Winkel, Anders

AU - Colmer, Timothy David

N1 - © 2016 John Wiley & Sons Ltd.

PY - 2018/5

Y1 - 2018/5

N2 - 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, chlorophylla and tissue porosity. Submergence was more detrimental to leaf PN and growth than the additional effect of 50 mm NaCl, as salt did not significantly affect underwater PN at 200 μm CO2 nor growth.

AB - 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, chlorophylla and tissue porosity. Submergence was more detrimental to leaf PN and growth than the additional effect of 50 mm NaCl, as salt did not significantly affect underwater PN at 200 μm CO2 nor growth.

KW - Journal Article

U2 - 10.1111/pce.12873

DO - 10.1111/pce.12873

M3 - Journal article

C2 - 27925226

SN - 0140-7791

VL - 41

SP - 885

EP - 897

JO - Plant, Cell and Environment

JF - Plant, Cell and Environment

IS - 5

ER -