Effect of atmospheric cold plasma and cadmium stress on biochemical properties and activity of antioxidant enzymes in wheat plant

Heavy metals are one of the most important environmental problems and have caused many concerns due to their carcinogenic properties, non-renewability and biological accumulation. Considering the expansion of lands contaminated with heavy metals and the inevitable cultivation of strategic grains such as wheat in these lands and the fact that according to research wheat accumulates more cadmium than other grains, therefore the purpose of this research is to investigate the effect of plasma Atmospheric cold and cadmium were on the activity levels of antioxidant enzymes, proline and the amount of protein and soluble sugars on two cultivars Karim and Gonbad. This experiment was carried out in a factorial form in a completely randomized design with four replications in the greenhouse of Mohaghegh Ardabili University. Factors included wheat cultivars (susceptible cultivar Gombad and resistant cultivar Karim), atmospheric cold plasma at three levels (control, 60 and 120 seconds) and treatment with cadmium metal at four levels (control, 50, 100 and 150 µM). The results showed that the amount of soluble sugar, protein, methionine amino acid concentration, catalase and superoxide dismutase enzymes, and root length were affected by the cultivar × plasma × cadmium interaction. The results of the comparison of three-way effects showed that Gombad wheat cultivar had the highest amount of methionine amino acid in plasma 60 and cadmium 150 with an average of 0.22 (nanmol/g). In general, it can be concluded from the results that the stress caused by the increase of cadmium and plasma concentration on the physiological processes of wheat is different and both cultivars use different mechanisms to deal with cadmium stress. Kareem and Gonbad wheat cultivars spend all their energy in the synthesis of factors involved in the defense mechanism in order to adapt and bear more in order to deal with the development and accumulation of toxic concentrations of this heavy metal in stress conditions. The results of the evaluation of cultivars showed that with the increase in the concentration of cadmium chloride, the amount of catalase, polyphenol oxidase, superoxide dismutase and ascorbate peroxidase decreased and the amount of soluble sugar, total protein, lysine and methionine increased. Also, in Gonbad variety, with the increase in the concentration of cadmium chloride, the amount of total protein, polyphenol oxidase enzyme, superoxide dismutase enzyme and ascorbate-peroxidase decreased, which shows the effects of cadmium toxicity and the production of oxygen free radicals. As a result, it follows oxidative damage and growth reduction, and the amount of soluble sugar of catalase enzyme, the amount of lysine and methionine increased. Also, Karim cultivar is more tolerant to cadmium stress than Gonbad cultivar. Therefore, this research showed that cadmium treatment at 150 micromolar in the presence of cold plasma was able to stimulate the defense mechanisms of the plant and make the plant bear the stress.