When exposed to water stress induced by PEG, the activity of SOD in the maize seedlings with different drought-resistance lowered at the beginning and then increased and then lowered again; the activity of CAT went up (or almost did not change) at the beginning and then lowered in the strong drought-resistance genotypes but lowered straight in the weak droughtresistance genotypes; the activity of POD lowered apparently in all genotypes. At the sametime, the permeability of plasma membrane increased; the super-microstructures of chloroplasts and mitochondria in the leaves were damaged, and the damaged degree was lighter in the strong drought-resistance genotypes than that in the weak drought-resistance genotypes. The activities of SOD and CAT were negatively related to the damaged degree of plasmalemrna and chloroplasts and mitochondria membrane systems, but positively related to the drought-resistant properties of the genotypes, thus may be used as the biochernical appraisal indexes of drought-resistance of matte. However, the correlation between POD activity and the damaged degree of the membrane systems and the correlation between POD activity and the drought-resistant properties of the genotypes were not apparent.
Acta Agriculturae Boreali-Sinica
Protective enzyme system