The effect of melatonin application on the content of photosynthetic pigments and the activity of antioxidant enzymes in Cannabis sativa under excess copper exposure

In the last decade melatonin, an anti-oxidants compound with various effects on plant growth has known as a plant growth regulators. In this study, the effects of 100 μMmelatonin on photosynthetic pigment contents and antioxidant enzymes activity of Cannabis sativa under CuSo4 (0, 50 and 150 μM) treatments was assessed in greenhouse conditions on a randomized design with 3 replications. Copper treatment on both concentrations 50 and 150 μM significantly decreased chlorophyll a, b, total chlorophyll and carotenoids content, while the activity of catalase and guaiacol peroxidase increased by copper treatment. Melatonin 100 μM increased photosynthetic pigments in plant treated by excess Cu. Melatonin also caused a significant decrease in CAT and GPX comparing to the plants treated only by excess Cu. According to the results, it seems that in cannabis plants melatonin thereby improving effect on photosynthetic pigments might improve plant growth under excess Cu stress. Regarding the decrease in the activity of catalase and peroxidase as antioxidant enzymes, the role of this compound on the antioxidant system under copper stress conditions needs further investigation.

کلیدواژه ها:

Cannabis sativa ، Chlorophyll ، Catalase ، Peroxidase ، Melatonin