The ethylene response factors SNORKEL1 and SNORKEL2 allow rice to adapt to deep water

Abstract

Living organisms must acquire new biological functions to adapt to changing and hostile environments. Deepwater rice has evolved and adapted to flooding by acquiring the ability to significantly elongate its internodes, which have hollow structures and function as snorkels to allow gas exchange with the atmosphere, and thus prevent drowning. Many physiological studies have shown that the phytohormones ethylene, gibberellin and abscisic acid are involved in this response, but the gene(s) responsible for this trait has not been identified. Here we show the molecular mechanism of deepwater response through the identification of the genes SNORKEL1 and SNORKEL2, which trigger deepwater response by encoding ethylene response factors involved in ethylene signalling. Under deepwater conditions, ethylene accumulates in the plant and induces expression of these two genes. The products of SNORKEL1 and SNORKEL2 then trigger remarkable internode elongation via gibberellin. We also demonstrate that the introduction of three quantitative trait loci from deepwater rice into non-deepwater rice enabled the latter to become deepwater rice. This discovery will contribute to rice breeding in lowland areas that are frequently flooded during the rainy season.

QTL for chlorophyll fluorescence of barley plants grown at low oxygen concentration in hydroponics to simulate waterlogging

“…Tolerant plants seem to be able to maintain or conserve energy, but also escape mechanisms are common (Hattori et al 2009;van Veen et al 2013). Chlorophyll fluorescence is widely accepted as an indicator of the activity of PSII, which is involved in electron transport in plant photosynthesis and is particularly sensitive to stresses (Fracheboud et al 2004;Guo et al 2008;Gu et al 2012).…”

Differential Control of Ethylene Responses byGREEN-RIPEandGREEN-RIPE LIKE1Provides Evidence for Distinct Ethylene Signaling Modules in Tomato

“…Impaired ethylene biosynthesis and responsiveness can lead to altered cell expansion, cell elongation, senescence, abscission, cell death, fruit ripening, root hair formation, lateral root development, nodulation, and sex determination (Bleecker et al, 1988;Guzmán and Ecker, 1990;Oeller et al, 1991;Lanahan et al, 1994;Tanimoto et al, 1995;Wilkinson et al, 1997;O'Donnell et al, 2001;Xu et al, 2006;Boualem et al, 2008;Penmetsa et al, 2008;Hattori et al, 2009;Wang et al, 2010;Lewis et al, 2011). A framework of the ethylene signaling pathway has been assembled using a combination of genetic and biochemical analyses in Arabidopsis (Arabidopsis thaliana; Kendrick and Chang, 2008;Stepanova and Alonso, 2009;Zhao and Guo, 2011).…”

Nitrogen metabolism in plants under low oxygen stress

“…Another escape strategy observed in species like Rumex acetosa naturally adapted to progressive and long-term partial submergence consists in a SUB1A-independent enhanced stem internode or petiole elongation to allow at least part of the shoot to be above the surface of water. Shoot elongation under submergence condition is triggered by ethylene signaling pathway and two ERFs of the sub-group VII, SNORKEL1 and SNORKEL2 (SK1 and SK2) (Hattori et al 2009). The increase in the active form of gibberellin (GA1) in the internodes following submergence suggested GA biosynthesis as a target of SK signaling in the process of internode elongation.…”

“…The increase in the active form of gibberellin (GA1) in the internodes following submergence suggested GA biosynthesis as a target of SK signaling in the process of internode elongation. Sugar degradation, glycolysis and fermentation were increased in consequence to enable germination and growth under low oxygen condition (Hattori et al 2009). In coleoptiles of rice growing under low oxygen the abundance of SUS4, enzymes involved in several steps of glycolysis, e.g., pyrophosphate (PPi)-Fru-6-P 1-phosphotransferase, Fructose-bisP aldolase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase and enzymes of ethanolic fermentation, ADH1 and PDC1 increased significantly compared to aerobic condition (Shingaki-Wells et al 2011).…”