The effects of an arbuscular mycorrhizal fungus (AMF) (Glomus constrictum Trappe) on the growth and
some physio-biochemical indexes of Zea mays L. seedlings under different levels of diesel stress were
investigated in a pot study. Generally, the symbiotic relationship between corn and AMF can be well
established under diesel stress. This was reflected by the better physio-biochemical index of the plants
inoculated with G. constrictum whose colonization rates were between 47.30% and 91.50%. Compared
with the non-inoculated ones, the heights and basal diameters of the inoculated seedlings increased by
0.08–47.20% and 6.74–35.71% respectively. The relative contents of chlorophyll and soluble proteins
increased by 1.88–38.79% and 3.87–77.27% respectively, while the contents of malondialdehyde and free
proline decreased by 2.74–52.74% and 24.69–32.86%. Three antioxidant enzymes reacted differently
under the diesel stress. The activities of superoxide dismutase (SOD) and catalase (CAT) increased at low
diesel concentration, but decreased at high concentration. In contrast, peroxidase (POD) had a decreased
activity at low diesel concentration, but an increased activity at high concentration. On the whole, the
activity of three antioxidant enzymes in the plants inoculated with AMF were higher than those without
AMF inoculation. Our results support the view that antioxidant enzymes have great influence on the
biomass of plants, and AMF can improve the capability of scavenging the reactive oxygen and alleviate Z.
mays seedlings from diesel stress.