The effect of free proline accumulation on the content of photosynthetic pigments in transgenic wheat plants

Abstract

Aim. To analyze the effect of L-proline accumulation on chlorophyll content in transgenic wheat plants with a double-stranded RNA suppressor of the proline dehydrogenase gene under physiological and stress conditions. Methods. Agrobacterium-mediated transformation in planta; biochemical determination of free proline content; spectrophotometric determination of photosynthetic pigments content; of mathematical statistics. Results. It was shown that the content of free proline in the leaves of transgenic plants under physiological conditions was 1.7-1.9 times higher compared to the original genotype. Under conditions of drought, the content of this aminoacid increased in non-transformed plants of the original genotypes by 2.9-3.1 times, and in transgenic plants – by 4.5-4.9 times. The amount of chlorophyll in the flag leaves of plants of the original genotypes and their transgenic lines under physiological conditions did not differ significantly, while under drought conditions in the first of them it was 1.1-1.2 times less than in the second. Drought reduced the total chlorophyll content in plants of the original genotype to 85-90 %, compared to physiological conditions, while no significant changes were found in transgenic plants. Conclusions. It was established that under conditions of soil drought, the increase in proline content in genetically modified wheat plants compared to non-transgenic ones is accompanied by an increase in the amount of total chlorophyll (by 10-15 %), which indicates a better efficiency of their pigment apparatus under stressful conditions.