Effects of Pseudomonas fluorescens flagellin on physiological and biochemical characteristics in the suspension cells of Pinus thunbergii

In order to investigate the effects of flagellin secreted by bacteria associated with pine wood nematode (Bursaphelenchus xylophilus) on pine cells, suspension cells of Pinus thunbergii were treated with flagellin of Pseudomonas fluorescens GcM5-1A, and some physiological indices were determined. Superoxide anions radical (·O₂ ^?) in treated suspension cells increased with prolongation of treatment time, with maximum content of 1,282 μmol g^?1 FW at 30 h, but the content of H₂O₂ gradually decreased as compared with that in the control group. Maximum content of malondialdehyde (MDA) and free proline, which is 1.72 times and 1.49 times of that in the control, respectively, appeared when suspension cells were treated for 12 h, after that both of the contents decreased gradually. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalases (CAT) also increased at the primary stage of treatment and then decreased compared with those of the control.