Search

Flowering time and active accumulated temperature (AAT) are two key factors that limit the expanded production especially for soybean across different regions. Wild soybean provides an important germplasm for functional genomics study in cultivar soybean. However, the studies on genetic basis underlying flowering time in response to AAT especially in wild soybean were rarely reported. In this study, we used 294 wild soybean accessions derived from major soybean production region characterized by different AAT in Northeast of China. Based on genome-wide association study (GWAS), we identified 96 SNPs corresponded to 342 candidate genes that significantly associated with flowering time recorded in two-year experiments. Gene Ontology enrichment analysis suggests that the pathways of photosynthesis light reaction and actin filament binding were significantly enriched. We found three lead SNPs with -log10(p-value) > 32 across the two-year experiments, i.e., Chr02:9490318, Chr04:8545910 and Chr09:49553555. Linkage disequilibrium block analysis shows 28 candidate genes within the genomic region centered on the lead SNPs. Among them, expression levels of three genes (aspartic peptidase 1, serine/threonine-protein kinase and protein SCAR2-like) were significantly differed between two subgroups possessing contrasting flowering time distributed at chromosome 2, 4 and 9, respectively. There are 6, 7 and 3 haplotypes classified on the coding regions of the three genes, respectively. Collectively, accessions with late flowering time phenotype are typically derived from AAT zone 1, which is associated with the haplotypic distribution and expression levels of the three genes. This study provides an insight into a potential mechanism responsible for flowering time in response to AAT in wild soybean, which could promote the understanding of genetic basis for other major crops. [ABSTRACT FROM AUTHOR]

Background: Thoracic aortic dissection (TAD) is the most common life-threatening disorder, and MMP-2 is involved in TAD pathogenesis. Our purpose is to systematically evaluate the association of the MMP-2 gene with TAD risk in Chinese Han population.Methods: In our case-control study, we recruited 755 unrelated participants: 315 case participants with TAD and 440 controls. Twenty-two tag SNPs were selected from MMP-2 gene and were genotyped. Genotype data were analyzed by logistic regression.Results: Although we did not find any significant association for MMP-2 SNPs using single-marker analysis, we identified many windows with haplotype frequencies significantly different between case participants and control participants using a variable-sized sliding-window strategy. In particular, the most significant association was shown by a 2-SNP window consisting of rs2241145 and rs9928731 (omnibus test: asymptotic Pasym = 7.48 × 10 (-5) and empirical Pemp = 0.001867). There were two protective haplotypes: CT (Pasym = 0.00303; odds ratio [OR], 0.403) and GC (Pasym = 0.000976; OR, 0.448).Conclusions: MMP-2 haplotypes are associated with genetic susceptibility to thoracic aortic dissection in Chinese Han population. [ABSTRACT FROM AUTHOR]