The Effects of Spermidine Physiological Activities of Wheat Seedlings under Osmotic Stress

The effects of osmotic stress on changes of some physiological indexes of wheat seedlings and the influences of spermidine(Spd) pretreatment on changes of corresponding indexes were investigated.Under 0.5 MPa polyethylene glycol(PEG)-6000 induced osmotic stress,relativewater content(RWC),levels of chl a,chl b,soluble and insoluble proteinsin leaves of wheat seedlings obviously decreased,and preliminary supply of Spdcould distinctly alleviate these declines.Contents of proline and malondialdehyde(MDA),and electrolyte leakage in control seedlings markedly increased during osmotic stress.Increased data of these parameters in Spd pretreatmeat seedlings were significantly retarded.These results suggested that Spd pretreatment could obviously alleviate the injuries of osmotic stress and enhance wheat seedlings' resistances to osmotic stress.