Disease Resistance Of Populus Tomentosa Cell Induced By Oligosaccharide Elicitors

The phenomena that a plant shows partial or systemic resistance to some organic, physical or chemical factors calls induction resistance. The factor causing the induction resistance in plants calls elicitor. Induction resistance is an immunization in organism. Oligosaccharide is a kind of biological active molecular that can modulate the growth and development of plants. Albersheim, an American researcher, discovered that oligosaccharides could induce resistance in plants at middle of 1970's. Since then, it becomes a hot point in biological research field. The Populus tomentosa callus was reduced by three elicitors, which were produced by Dothiorella gregaria and chitin. In order to obtain the best elictor, the changes of PAL, chitinase, β-N-acetyle-D-glucosaminidase, SOD, POD, CAT, PPO, HRGP and chlorogenic acid were tested. The reason that causes the induction resistance in plant was also discussed.The optimal concentration of the elicitor I, which was produced by Dothiorella gregaria, corresponding to 21μg/ml saccharide. The most suitable method for producing elicitor II was hydrolyzing the elicitorⅠin 10%(v/v)1mol/L HCl for 30min. The elicitorⅢ was made from chito-chitin by dissolving the chitin in 1:30(w/v)2% acetic acid and hydrolyzing the solution in 1:0.3(v/v) 3% H2O2 75℃ for 3h.SOD, POD, CAT, and PPO could be induced by the three elicitors. Induced by the three elicitors, the maximum of CAT appeared at 2 hour later, SOD at the 2.5 hour later, PPO at the 3.5 hour later, and POD at the 6～12 hour later.Chitinase, β-N-acetyle-D-glucosaminidase, HRGP, PAL and chlorogenic acid could be induced by the three elicitors. Chitinase and β-N-acetyle-D-glucosaminidase reached the maximum at 4 hour later, PAL and chlorogenic acid reached the maximum at 48 hour later, and the content of HRGP was increasing after inducing.