|ZHANG, JIAOPING - South Dakota State University|
|LU, YAMING - South Dakota State University|
|BHUSSA, SIDDHI - South Dakota State University|
|YEN, YANG - South Dakota State University|
|BROWN, MICHAEL - South Dakota State University|
|JIANG, GUO-LIANG - Virginia State University|
Submitted to: Molecular Plant
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2017
Publication Date: 1/2/2018
Citation: Zhang, J., Lu, Y., Bhussa, S.J., Song, Q., Yen, Y., Brown, M., Jiang, G. 2018. Genome-wide scan for seed composition provides insights into the improvement of soybean quality and the impacts of domestication and modern breeding. Molecular Plant. https://doi.org/10.1016/j.molp.2017.12.016.
Interpretive Summary: Soybean has been widely used in food, feed and fuel industries. The diverse needs for soybean require varieties with different profiles of seed proteins, oil, amino acids and fatty acids. The soybean genes that control the composition of amino acids and fatty acids in seeds are not completely known, and this has resulted in a lack of trait improvement. So we evaluated the whole genomes of several soybean varieties and used DNA markers to follow genes linked to traits for seed composition, including protein, oil, abd five fatty acids, as well as to follow genes that produce 18 amino acids. We identified a number of genomic regions and genes that are associated with one or more of the traits for seed composition. Interestingly, we discovered that some genes had changed during the course of 100 years of breeding soybeans in North America. This study extends our knowledge about the genetic control of seed composition in soybean. The discovered genes and the markers for the genes that control seed composition can be used by breeders at universities, government agencies, and private businesses to improve seed quality of soybean.
Technical Abstract: Soybean (Glycine max (L.) Merrill) is a world-widely grown major crop rich in both protein and oil. Improvement of seed nutrients has long been one of the most important breeding objectives in soybean. To better understand the genetic architecture of the traits for improvement, we conducted genome-wide association studies for the concentration of seed protein, oil, fatty acids and amino acids through single-locus mixed linear model (MLM) and multi-locus MLM (MLMM) analyses using 313 diverse soybean germplasm accessions genotyped with the SoySNP50K array. A total of 135 quantitative trait loci (QTL) were identified, explaining 8-89% of genetic variances. The GmSAT1, GmAK-HSDH, GmFAD3A, and putative FATB and steroid-5-a-reductase, involved in N2 fixation, amino acid biosynthesis and lipid metabolism, were found in the genomic region harboring the major-effect QTL. Further analysis indicated that these loci were subject to soybean domestication or breeding selection in North America. This study uncovers the underlying genetic mechanism of the relationships among the seed compositions, especially the negative correlation between protein and oil, and the genetic basis of soybean quality alteration during domestication and modern breeding selection. It also provides insights into the genetic improvement of soybean nutrients through molecular breeding.