Xyooligosaccharide And Harpin On Growth And Resistance To SMV In Soybean

Elicitor is a kind of special compound which can induce defense response in the host plant, according to the source which can be divided into two categories, biotic and abiotic. biotic elicitor including oligosaccharides and protein, but a biotic elicitor including heavy metal ions. When the pathogen contracts with host, elicitors induce host plants occur many biochemical changes, causing plants to produce multiple defense responses, for example, phytoalexins bioactivities and acculation, proteinase inhibirors bioactivities and deposition et al., which limit disease development.Treated soybean with different concentrations of xylooligosaccharide in order to study the effect of xylooligosaccharide on growth and resistance to soybean mosaic virus (SMV) in soybean. The results of greenhouse experiment shows that18days after the xylooligosaccharide solution dealt with the seed of soybean6h, xylooligosaccharide promotes the height, the fresh weight, and the length of the main root of the soybean seedling obviously. Concentration30mg/L of xylooligosaccharide obviously increased the germination percentage, but concentration50mg/L of xylooligosaccharide obviously increased the height, the fresh weight, and the length of the main root of the soybean seedling, they had been increasd by49.63%,29.76%,20.96%. Inoculated with SMV after18hours of pre-atomized the soybean leaves with xylooligosaccharide, compared with the water treatment, the disease index of soybean mosaic virus was obviously reduced, The disease index of100mg/L xylooligosaccharide is34.59%. Using Quantitative RT-PCR to test the expression of the defense-related gene of the soybean leaves dealt by xylooligosaccharide, comparing with the water treatment, the defense-related gene PR2, PR10, PR12and LOX2has the highest related expression quantity at the time of12hours, upregulsted expression of multiple are21.56,7.19,7.95and8.56, PR3at18hours, is2.73, while PR1, PAL, PPO and CHS obviously upregulate at24h, is7.75,1.99,3.98and2.56. It shows that xylooligosaccharide can active salicylic acid (SA) and jasmonic acid (JA) signaling pathways of soybean, and enhances its resistance against SMV.Treated soybean seeds with HrpZpsgs1of Bacterial Blight of soybean P. syringae pv. phaseolicola. Compared with the expression product of empty vector, hrpzpsgs1can obiviously promote the growth of soybean, the heights, the fresh weights are enhanced by11.62%and8.67%. The results showed that harpinpsgs1can promote soybean growth.18hours after harpinpsgs1and harpinPET atomized the soybean leaves and then inoculated with SMV, the disease index of soybean mosaic virus obviously reduced, comparing with the water treatment, and there is no difference between them. Using Quantitative RT-PCR to test the expression of mRNA of the defense-related genes PR1, PR2, PR3, PR10, PR12, PAL, PPO, CHS and LOX2. The results showed both harpinpsgs1and harpinpET can induce expression of defense-related genes upregulsted, but there were difference between them. Compared with harpinpET, harpinpsgs1can obviously active express of the SA responsive gene PR1and JA responsive genes PR12and LOX2. It shows that harpinpsgs1can active salicylic acid (SA) and jasmonic acid (JA) signaling pathways of soybean, and enhances its resistance against SMV.