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, chlorophyll and tissue porosity. Submergence was more detrimental to leaf P and growth than the additional effect of 50 mm NaCl, as salt did not significantly affect underwater P at 200 μm CO nor growth.

Climate resilient crops for improving global food security and safety

“…Drought stress alone is expected to limit the productivity of more than half of the earth's arable land in the next 50 years, competition for water between urban and agricultural areas compounding the problem. Several papers in this volume (Herzog, Konnerup, Pedersen, Winkel, & Colmer, ; Kerr et al, ; Pérez‐Jiménez, Hernández‐Munuera, Piñero, López‐Ortega, & Amor, ) describe the physiological, molecular, and biochemical responses of plants to drought and flooding. Although the use of brackish and saline water could help alleviate the world's water problems, this option is only possible with the development of salt‐tolerant crops (Figure ) or management practices that alleviate salt stress.…”

Hypoxia and the group VII ethylene response transcription factor HRE2 promote adventitious root elongation inArabidopsis

“…), adventitious roots (Lorbiecke & Sauter ) and gas films (Herzog et al . ), or induce hyponastic growth (Millenaar et al . ; Pierik et al .…”

“…In flooding-tolerant species several traits have evolved that improve O 2 supply and metabolic adjustments to compensate for limited oxidative ATP synthesis through substrate-level ATP synthesis and NAD + recovery in fermentation (Mustroph et al 2014). To improve gas exchange, flooding-tolerant plants form aerenchyma (Steffens et al 2011;Yamauchi et al 2013), adventitious roots (Lorbiecke & Sauter 1999) and gas films (Herzog et al 2018), or induce hyponastic growth Pierik et al 2005) and stem or petiole elongation (Kende et al 1998;Millenaar et al 2005) to raise leaves above the water surface.…”

The Effect of Climate Change on Abiotic Plant Stress: A Review

“…According to Dhankher [15], drought as an abiotic stress factor is being projected to hinder productivity in more than 50% of the arable lands in the world by the next 50 years. But the availability of saline water might lighten the world's water problem if plants that are salt tolerant are being developed [15,[19][20][21][22]. However, in response to this kind of plant stress, the need for drought tolerant plant is a necessity to boycott or reduce its negative impacts on food security.…”