Wheat is one of the most strategically important cereals, which is significantly negatively affected by drought at all stages of crop development — starting from the moment of germination and ending with the grain filling stage. It is possible to increase significantly the tolerance to water deficit of this leading agricultural crop by using genetic engineering methods. Partial suppression of the expression of the proline dehydrogenase gene (ProDH) can lead to an increase in the content of free L-proline and, as a result, the level of resistance of wheat plants to water deficit. Since genetic transformation may cause changes in the metabolism of modified plants, the aim of the work was to perform a comparative analysis of the physiological and biochemical characteristics of transgenic winter bread wheat plants with partial suppression of the ProDH, and their original genotypes under normal growing conditions. It was shown that the content of free proline in the flag leaves of plants of transgenic lines was 1.7—1.8 times higher than that of the original genotype, and changed at different ontogenetic stages. Analysis of changes in the content of free proline showed that the effect of transformation was more significant than that of ontogenetic stage. No significant differences were found between transgenic and non-transformed plants in terms of such indices as the total chlorophyll (a+b) and total carotenoids content, the ratio of the total carotenoids to total chlorophyll content at different development stages; the amount of flavonoids and antioxidant activity; components of the grain productivity. At the same time, in terms of protein content, transgenic lines significantly exceeded the original genotypes — the protein content increased by 2.1—2.5 % (direct), gluten — by 4.6—5.7 % (direct).
Keywords: Triticum aestivum L., transgenic plants, proline content, photosynthetic pigments, flavonoids, antioxidant activity, grain quality, grain yield
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