Short-Term Pretreatment with Melatonin Increases the Resistance of Barley Plants to the Subsequent Action of Cadmium

Abstract

The effect of short-term and long-term root treatment with melatonin on growth parameters, photochemical activity of PSII, content of basic photosynthetic pigments, lipid peroxidation, and accumulation of inorganic ions in barley plants under the action of cadmium chloride was studied. It was shown for the first time that the protective effect of phytomelatonin during short-term treatment is manifested in a decrease in the toxic effect of cadmium on the content of photosynthetic pigments and the accumulation of cadmium ions in the shoots and roots of barley plants. The protective effect of melatonin is based on its ability to reduce the intensity of oxidative stress by maintaining the level of carotenoids and increasing the activity of antioxidant enzymes. The effectiveness of short-term use of melatonin in a number of indicators exceeds its protective effect from long-term exposure. The data obtained indicate the possibility of using melatonin as a substance that induces the state of plant priming upon subsequent exposure to cadmium.