Research On The Pathogenicity And Molecular Basis For The Different Races Of Heterodera Glycines

The researches on the pathogenic differences of different races of Heterodera glycines were systematically conducted to the relationship between pathogenic differences and the soybean’s membrane lipid peroxidation, photosynthetic capacity, material metabolism, oxidases system. Proteomics and SSH were used in research on different races of SCN to study different proteomics and different genes. It was important for fundamentally revelation pathogenic differences of different races of Heterodera glycines. The main results of this study were as follows:1. Four Heterodera glycines samples from different areas were collected, race tests were conducted on this population. The sample collected from Kangping is race 1; the sample S2 collected from Shenyang is race 3; the sample collected from Hefei is race 4; the sample collected from Anda is race 14. Employ by HG type appraisal results as follows:The sample collected from Kangping is 2,5,7; the sample S2 collected from Shenyang is 5,7; the sample collected from Hefei is 1,2,3,5,7; the sample collected from Anda is 1,3,7.2. Three soybean varieties’Liaodou 10’,’PI88788’and’PI90763’were inoculated with different races of Heterodera glycines (race 1, race 3, race 4 and race 14) in the same time. The three physiological indices of MDA contents, Electronic efflux percentage and Chlorophyll contents were analyzed. Results showed that the three physiological indices of soybean cultivars’PI88788’colonized by H.glycines race 1、race 4and ’PI90763’ colonized by H.glycines race 4、race 14 were both higher than those in control soybean cultivars. But this three physiological indices of soybean cultivars’PI88788’colonized by H.glycines race 3 and race 14 were a little higher than those in control roots; three physiological indices of soybean cultivars’PI90763’colonized by H.glycines race 1 and race 3 were a little higher than those in control Soybean cultivars. It is concluded that the activities of this three physiological indices had closely related to pathogenicity of different races of H.glycines.3. The study on the relationships between the metabolism and resistance to H.glycines indicated that the soluble sugar content of resistant varieties root was increased in different degree after inoculating by the same race of SCN, the soluble sugar content of susceptible varieties root was relatively lower than CK. Host plants need carbohydrate to resist SCN. Low sugar content in soybean roots was beneficial to nematode invasion. Moreover, the soluble protein content in the roots of soybean cultivars’PI88788’colonized by H.glycines race 3 and race 14 and soybean cultivars’PI90763’colonized by H.glycines race 1 and race 3 were obviously increased, maybe soybean infected by SCN were induced to express resistant protein4. Defensive enzymes were stimulated after infected by different races of SCN. The dynamic changes of defensive enzymes, include phenylalanine ammonialyase (PAL), polyphenoloxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) were studied. The results showed that the change of enzymes had closely related to pathogenicity of different races of H.glycines.5. Differential proteomics were studied of different races of SCN(race 3 and race 4 as a control group; race 1 and race 14 as a control group). Two-dimensional gel electrophoresis (2-DE) were adopted to identify proteins from different races of SCN. Nearly 500 protein spots were detected. Furthermore, analysis with MALDI-TOF-MASS identification Peptide Mass Fingerprinting of 30 protein spots. The 17 protein spots were obtained by Mascot database searching and intercomparison preliminary identification Mascot, The proteins were respectively nebulin-related-anchoring protein isoform 1(80,114); myosin heavy chain(240); CRE- UGT- 56 protein(119); cornified envelope precursor protein(136); similar to Rho-associated kinase (352); GG18879(206a); GF17954(206b); golgi antigen gcp372(253, 389); Rp49(405); predicted protein(274); hypothetical protein(127,128,209,296).6. Forward and reverse suppressive subtractive hybridization (SSH) libraries were constructed by using RNA prepared from different races of H.glycines(race 3 and race 4 as a control group; race 1 and race 14 as a control group). Had more than 2000 clones. The both subtraction libraries with the inserted fragments between 200bp and 900bp. All these results indicated that both SSH libraries were qualified for further studies.7. Plasmids with 500bp inserted fragment were selected from each of the two forward and reverse suppressive subtractive hybridization libraries for dot blotting hybridization in which DIG was used to label probes from SSH PCR products, respectively. A total of 972 genes were found. To confirm further the differential expressions of the genes,20 genes were chosen for RT-PCR analysis. The results indicated that:LFSSH-875, LFSSH-950, LFSSH-963, LFSSH-1000, LFSSH-1103 were expressed mainly in race 4; LRSSH-1209 was expressed mainly in race 3; XFSSH-938 was expressed mainly in race 14; XRSSH-1018、 XRSSH-1250、XRSSH-1258 were expressed mainly in race 1.