Dynamics of accumulation of phenolic compounds, anthocyanins, and photosynthetic pigments in the vegetative organs of the wheat plants under continuous drought stress

Abstract

Phenolic compounds play an important role in photosynthesis and respiration processes, growth and development, reproduction, and immunity of plants. Although progress is gained in the research of the chemical composition and biosynthesis of phenolic compounds and their intracellular localization, the role of phenolic compounds in the protection of plants from adverse environmental factors, including drought, has not been fully studied. This problem is still relevant today, as a number of important crops, including durum wheat (Triticum durum Desf.), are exposed to soil and atmospheric drought during their development. The main purpose of the research was to determine the role of phenolic compounds, anthocyanins, and photosynthetıc pigments in the protection of wheat from drought. For analysis, plant samples (Barakatli 95 (drought-tolerant) and Garagylchyg 2 (drought-sensitive)) were taken during the generative development of the plant -flowering, milk ripeness, and wax ripeness.Root and leaf samples were crushed in liquid nitrogen, then the amount of dissolved phenolic compounds was determined based on the interaction of phenols with the Folin-Ciocalteu reagent. The amount of anthocyanins and photosynthetic pigments decreased, the phenolic compounds reached the maximum at the end of the milk ripeness phase and then decreased relatively, while this parameter remained higher than in the watered variant. The amount of phenolic compounds in the leaves of both genotypes was found to increase under drought. In this case, more phenolic compounds were synthesized in the tolerant genotype compared to the sensitive genotype. Besides, under drought conditions, wheat leaves were found to be able to synthesize more phenolic compounds than roots.