Изменение спектра фенольных соединений циннии при избытке ионов меди в субстрате

Abstract

Changes in the qualitative and quantitative composition of phenolic compounds in response to adverse environmental influences are actively studied, primarily in connection with the antioxidant function of these compounds. However, phenolic compounds such as phenylpropanoids are known to be involved in cell wall lignification. Lignin deposition is not only a natural process for the formation of secondary cell walls, but it is also often considered as a non-specific reaction of plants under stress conditions. However, changes in the content and composition of phenolic compounds during lignification in response to stressors have not been studied enough. Previously, we showed a decrease in the amount of phenolic compounds in response to the action of copper ions, but the question remained whether they are spent on the lignification process or on the quenching of reactive oxygen species. In this regard, the purpose of this work was to identify changes in the amount and composition of phenolic compounds of different polarity in the axial organs of zinnia when grown in a medium with an excess of copper ions. It was shown that under stress caused by copper ions (watering the substrate with a solution of 200 μM copper sulfate), in the roots of 40-day-old zinnia plants, the total content of phenolic compounds did not change significantly. At the same time, the content of fractions soluble in diethyl ether (hydroxycinnamic acids) and ethyl acetate (aglycones of flavonoids and coumarins) decreased, which may indicate the use of phenylpropanoids for additional synthesis of lignin, and flavonoids for antioxidant reactions under stress. In the hypocotyl, the content of hydroxycinnamic acids slightly increased, while in the first internode it did not change. The main part of phenolic compounds in all organs, both in control stressed plants, belonged to the fraction of glycosylated derivatives. At the same time, among this derivates the content of water-soluble phenols increased in the experimental plants in all organs. Thus, under the stress caused by copper ions, the composition and number of phenolic compounds changed.