Wheat (Triticum aestivum) is considered anoxia intolerant but it shows variance in anoxia responses between genotypes and environmental treatments. We firstly examined 4 day old seedlings of five wheat genotypes in response to anoxia at 15 °C and 28 °C by assessing growth rate, tissue damage and changes in metabolite abundances. Significant genotypic variations in anoxia tolerance were observed, especially at 28 °C. Wheat seedlings grown at 15 °C appeared to be more anoxia tolerant and showed less genotypic variation than those at 28 °C. To minimize seedling size variations and define the temperature effects, we grew two contrasting genotypes at 15 °C for 3.5 d and adapted to 4 different temperatures for 0.5 d before exposing them to anoxia at each adapted temperature. Genotypic variation in abundance of anoxia induced metabolites occurred at 24 °C and 28 °C but not at 15 °C and 20 °C. Tissue-And temperature-dependent metabolic adaptations to anoxia were revealed. In roots, the ability to maintain sugar/sugar-phosphate and TCA cycle metabolite levels and the accumulation of amino acids when temperature was below 24 °C correlated with anoxia tolerance. Temperatures between 20 °C-24 °C are critical for metabolic adaptation and suggest that further assessment of waterlogging/flooding tolerance of wheat seedlings should consider the temperature-dependence of tolerance in evaluations.
|Publication status||Published - 1 Dec 2018|