Effects of alginate cerium complexes on ascorbate-glutathione cycle in spinach leaves under chlorpyrifos stress
海藻酸铈配合物对毒死蜱胁迫下菠菜叶片抗坏血酸-谷胱甘肽循环的影响

Pesticides have played an important role in protecting vegetable crops from diseases and insect pests, and reducing yield loss. However, due to its improper use, the residues of pesticides cause severe food safety accidents, which has the serious influence on people's physical and mental health. In recent years, more attentions have been paid to the chemical pesticide application and its influences on crops in international trade of agricultural products. Spinach(Spinacia oleracea L.)is an important variety of vegetable export in China, so its food safety is increasingly concerned. The experiment mainly studied alleviative effects of spraying alginate /cerium complexes on ascorbate-glutathione cycle in spinach leaves under chlorpyrifos stress, which in order to discuss the feasibility of cerium complexes as the degradation preparation applied in leafy vegetables to degrade chlorpyrifos in the safety production process.Under the stress of chlorpyrifos,the effects of alginate cerium complexes on the ascorbate-glutathione circulation system in spinach were investigated at open-field condition. The activities of antioxidant enzymes and H2O2 content were determined under the stress of chlorpyrifos during 0,1,3,5,7,14 days after spraying different concentrations of alginate cerium complexes on the spinach leaves. The results showed that, under the stress of chlorpyrifos, there had obviously increased content of H2O2 and decreased contents of ascorbic acid(AsA) and glutathione(GSH), and also increased activities of ascorbate peroxidase(APX), glutathione reductase(GR), dehydroascorbate reductase(DHAR) and monodehydroascorbate reductase (MDAR) in the spinach leaves, but it would recover after a period of time. The content of H2O2 was decreased, and contents of AsA and GSH, and the activities of APX,GR,DHAR and MDAR were increased after spraying different concentrations of alginate cerium complexes on the spinach leaves. To some extent, spraying alginate cerium complexes on the spinach leaves had alleviated changes of antioxidant metabolites contents and antioxidant enzymes activities caused by the chlorpyrifos stress, which could make spinach leaves be recovered more earlier from the chlorpyrifos stress to the control level. The experimental results showed that spraying appropriate concentrations of alginate cerium complexes had an alleviation effects on spinach under chlorpyrifos stress. The effects of spraying alginate cerium complexes on the contents of H2O2, AsA and GSH in spinach leaves were more effectively than on the activities of APX,GR,DHAR and MDAR. So finding a method about degradatin of chlorpyrifos residues to alleviate effects on spinach under chlorpyrifos stress to improve safety of spinach is meaningful. And further study whether alginate cerium complexes as signal material promoted related activities of antioxidant enzymes and the antioxidants content in spinach under the chlorpyrifos stress, or cerium complexes hydrolyzing phosphate key