Recent release of whole genome draft sequences in legume species have led comparative genome studies among legume plants including Glycine max, G. soja, Cajanus cajan and Medicago truncatula. The majority of comparative genomic researches have been conducted based on synteny of coding sequences and coding sequence variations may be one of major forces for speciation and evolution. However, non-coding sequences have been also reported to be important phenotypic regulators. Especially, since short sequence motifs in the promoter regions are highly conserved, they are suggested to be another resources of interests in comparative studies. In this study, we predicted the conserved short sequence motifs by BLASTN algorithm using dicot promoter database from Softberry (http://www.softberry.com). A total of 37,396 conserved short sequence motifs were identified onto 2 kb upstreams of 46,367 high confident gene model of G. max (cv. Williams 82). Meanwhile, whole genome of 7 soybean landraces (G. max) and 7 wild soybean genotypes (G. soja) were sequenced at low depth of less than ten using Illumina Hiseq 2000. Among these genotypes, nucleotide variations were identified in predicted conserved regulatory motifs by mapping of short reads to the reference genome sequence using the Samtools program (http://samtools.sourceforge.net/). Fifteen and two genes, which have SNPs in regulatory motifs and no SNP in coding sequence, were identified by comparisons of inter-species and intra-species, respectively. qRT-PCR experiments are in progress for investigating differences of these 17 genes expressions at transcriptional level.

As soybean (Glycine max) is known for its high nutritional value of oil and protein, soybean has been domesticated and cultivated by one specific character trait based on human selection. Importantly, tracing back in time where G. max and G. soja, the undomesticated ancestor of G. max have diverged plays an important role in studying of genetic diversity and in investigating the common ancestor of soybean. In this study, we sequenced 6 G. max and 6 G. soja using Illumina’s Hiseq 2000 with a low coverage sequencing technology to estimate the divergence of times between genotypes and populations. A total of the 12 genotypes were sequenced at the average depth of 6.5 and resulted 892.5 Mb and 903.3 MB consensus sequences with the coverage of 91.54% and 92.65% for G. max and G. soja, respectively. The whole genome SNP analysis showed that G. max had lower frequency levels of polymorphism (~0.1%) than G. soja (~0.25%). And, a high number of SNPs located in introns were found among 6 G. soja genotypes as SNPs were approximately twice than those found in 6 G max. The number of SNPs in G. max intronic regions was 53,134, whereas a total of 133,329 SNPs were discovered in G. soja introns. Almost an equal number of SNPs were discovered in 5’ UTR and exon regions; however, different numbers of SNP in CDS and 3′ UTR were identified. By the rate of nonsynonymous change, divergence of time between G. soja and G. max would be investigated.

Phytic acid, myo-inositol (1, 2, 3, 4, 5, 6)-hexakisphosphate, is a material that plants store phosphorus in seeds. Phytic acid is classified as an antinutrient because of indigestibility. Non-ruminant animals, such as human and swine, excrete unavailable phytic acid. The unavailable phytic acid run off to ground water, river, sea, causing eutrophication as a factor. Accordingly, low-phytic acid crops draw the attention due to both nutritional and environmental reasons. Using more than 900 Glycine accessions including G. max, G. soja and G. gracillis, colormetric method was applied for detecting low-phytic acid mutant. Two hundred fifty accessions were screened by the colormetric method so far, but no mutant was identified. Screening of mutants with the rest 710 accessions is in progress. MIPS1 (D-myo-inositol 3-phosphate synthase) is considered as gene related to phytic acid content in soybean. Also, lpa1 (Zea mays low phytic acid 1) known as controlling phytic acid content in maize was recently reported that homologs of lpa1 were responsible for phytic acid content in soybean and located on linkage groups L and N (Chromosomes 19 and 3). After primers were designed from these three candidate genes for phytic acid content, identification of genes responsible for low phytic acid and investigation of genetic variation among 960 accessions will be performed as further study.