Sequence Diversity And Functional Analysis Of SHMT Gene Of Small Black Soybean Cyst Nematode

Soybean serine hydroxymethyltransferase gene(SHMT)is the soybean cyst nematode resistance gene on Rhg4 locus.The coding region of SHMT of 30 soybeans were sequenced,their sequence diversity and qRT-PCR was analysed.To study the genetic diversity and its relationship with the resistance to soybean cyst nematode,in order to further explore the mechanism of resistant varieties.The cloning result showed that the CDS of SHMT gene is 1416 bp or 1417 bp.A total of 8 SNPs were identified,the DNA variations formed 6 haplotypes,haplotype diversity was 0.447,3 neutrality tests(Tajima's D,Fu and Li's F,and Fisher's test)were not significant for the gene in these 30 small black soybean genotypes,suggesting there was different selection pressure on different soybeans.X2 text for distribution of alleles in resistant and susceptible accessions indicated that SHMT 389G/C and 1072T/A locus have correlation with small black soybean resistance to soybean cyst nematode.30 small black soybeans were grouped into 3 clusters using UPGME methood,relationship was found between their origin and their genetic relationship.Real time fluorescence quantitative PCR showed that SHMT gene in resistant and susceptible varieties were both expressed,the SHMT expression was significantly different in soybean varieties,after SCN3 infected 12 days,the expression of SHMT gene was significantly up-reg ?Lated,it is specullated that the gene may be related to the development of SCN3,further validation of SHMT gene have different metabolism paths in resistant and susceptible soybean.