Osmotic adjustment and activity of stress-related genes in wheats of different origin exposed to water stress

Resumo

Plant traits involved in drought tolerance include ability to sustain plant hydration through osmotic adjustment and also the accumulation of certain specific protective proteins. The objective of this work was to evaluate the differences in water stress reaction in several lines of winter wheat (Triticum aestivum L.) of Czech, Hungarian and Syrian origin. The stress response was evaluated in young plants exposed to continuous drying using following parameters: relative water content in leaves, osmotic potential, concentration of proline, and on the molecular level the relative expression of genes from the LEA group (Late Emryogenesis Abundant) (WDHN13 and WRAB17) and genes coding transcription factors (TF) WABI5 and WDREB2γ. Czech varieties showed high expression of WDHN13 and TF WABI5 genes, and to some extent of WDREB2γ, than the other lines. Particularly Meritto variety retained a high level of tissue hydration. Relatively more drought tolerant Syrian lines had higher accumulation of proline and also high activity of the TF WDREB2γ gene. According to the results, the expression of WRAB17 was more associated to the desiccation-induced damages.