Preparation Various Oligosaccharides Elicitors And Research On Disease Resistance Of Populus Tomentosa Callus Induced By Different Oligosaccharide Elicitors

Oligosaccharidesa are a kind of active molecules which can modulate the growth and development of plants. Because oligosaccharides are not toxic, the researches on them become more and more in recent years, especially in plant disease management. In this research, the Populus tomentosa callus was reduced by three elicitors, which were production of xdylooligosaccharides from corncobs, production of oligosaccharidesa from Dothiorella gregaria and oligochitosan Chitodigosaccharide from chitin.Chitin is the second most abundant natural biopolymer after cellose, and chitosan is obtained after alkaline deacetylation of the chitin. Chitin oligosaccharides possess special fuctional properties as elicitor to induce disease resistance of plants. Chitin oligosaccharides can be prepared by enzymic methods. This research reports the preparation of chitin oligoccharides from water-soluble chitin by unspecific enzyme hydrolysis with pectinase, The results show that the optimum conditions for depolymerizing water-soluble chitin by pectinase are as follows: pH 5.4,temperature 55℃,10 h, 15 g/L chitosan, and 4mg/L enzyme.Ethanol dissolution were used to separating the chitosan, different consistency of ethanol (90%,70%,50%) to offer different chotisan of narrow-range-molecule,and to mensurated the molecule by terminal analys had result as follows:C1(Mn=1124.64);C2(Mn=2168.25);C3(Mn=3208.38)。The infection index of callus after inoculation show that the disease resistance of populus tomentosa cell can induced by different Oligosaccharides Elicitors . The optimal elicitor was A, the second is C2, and the least induction effect is B .Chitinase, PAL, chlorogenic acid, SOD, CAT, and PPO could be induced by the three elicitors. Induced by the three elicitors, the maximum of CAT ,SOD, and PPO appeared at 2 hour later.Chitinase reached the maximum at 2~4 hour later, PAL and chlorogenic acid reached the maximum at 32 hour later.