Effects of cadmium stress on seed germination,seedling growth and antioxidative enzymes in Achnatherum inebrians plants infected with a Neotyphodium endophyte

The effects of cadmium (Cd) on germination, and antioxidative enzyme activity (AEA) involving superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase, and on amounts of malondialdehyde and proline present within Achnatherum inebrians, were determined for specimens infected (E+) vs. non-infected (E−) by Neotyphodium gansuense, and cultivated in the presence of various concentrations of CdCl₂ (0, 50, 100, 200 and 300 μmol/l). Under high Cd concentrations (100, 200 and 300 μM), E+ (vs. E−) specimens exhibited a higher germination rate and index, and higher values for shoot length, root length and dry biomass, but there was no significant difference (P > 0.05) under low Cd concentrations (0 and 50 μM). AEA and the proline content increased, but malondialdehyde content declined in the E+ (vs. E−) specimens under high Cd concentrations (100, 200 and 300 μM). There was no significant difference (P > 0.05) under low Cd concentrations (0 and 50 μM). Endophyte infection was concluded to be of benefit to the germination and anti-oxidative mechanisms within A. inebrians under plant exposures to high CdCl₂ concentrations.