Activities of protective enzymes的用法和样例：
- The study focused on the dynamics of MDA contents and the activities of protective enzymes in the leaves of alfalfa varieties with various resistance to Aphis medicaginis Koch.
- The relationship between leaf senescence and the activities of protective enzymes was studied through comparion of a xanthan rice mutant HuangyuB with its wild type parent LongtefuB.
- Under the circumstances of high temperature and high light，soil water stess decreased the activities of protecteive enzymes SOD，POD and CAT.
- CCC with 2500 mg/L was most effective in improving activities of protective enzyme.