Abstract
Water-soluble protein content (WSPC) is a critical factor in both soybean protein quality and functionality. However, the underlying genetic determinants are unclear. Here, we used 219 soybean accessions and 152 recombinant inbred lines genotyped with high-density markers and phenotyped in multi-environments to dissect the genetic architectures of WSPC and protein content (PC) using single- and multi-locus genome-wide association studies. In the result, a total of 32 significant loci, including 10 novel loci, significantly associated with WSPC and PC across multi-environments were identified, which were subsequently validated by linkage mapping. Among these loci, only four exhibited pleiotropic effects for PC and WSPC, explaining the low correlation coefficient between the two traits. The largest-effect WSPC-specific loci, GqWSPC8, was stably identified across all six environments and tagged to a linkage disequilibrium block comprising two promising candidate genes AAP8 and 2 S albumin, which might contribute to the high level of WSPC in some soybean varieties. In addition, two genes, Glyma.13G123500 and Glyma.13G194400 with relatively high expression levels at seed development stage compared with other tissues were regarded as promising candidates associated with the PC and WSPC, respectively. Our results provide new insights into the genetic basis of WSPC affecting soybean protein quality and yield.
Highlights
Soybean is an important legume because of high protein with a nutritionally balanced amino acid profile in seeds, soybean seeds are commonly used as a prime source of vegetable protein worldwide[1]
A great level of genetic variation in water-soluble protein content (WSPC) and protein content (PC) were observed in its expanded panel (219 accessions) that was used in the present study (Table S1, Fig. 1 and Figure S1)
We identified a total of 32 additive loci and 51 epistatic interactions associated with soybean PC and WSPC at various environments by applying the high-resolution Genome-wide association studies (GWAS) mapping, demonstrating that epistatic effects are a substantial complement to additive effects in contributing to soybean protein
Summary
Soybean is an important legume because of high protein with a nutritionally balanced amino acid profile in seeds, soybean seeds are commonly used as a prime source of vegetable protein worldwide[1]. Soybean WSPC and total protein content (PC) are complex quantitative traits controlled by multiple genes, some might have small effects[7]. Despite a preliminary understanding of the soybean WSPC obtained, the molecular basis of natural variation in WSPC biosynthesis has not been fully elucidated because the QTL resolution is limited by the low density of molecular markers used in these studies. Genome-wide association studies (GWAS) using high-density DNA markers offer an opportunity to dissect the genetic architecture of complex traits in soybean. Compared with the QTL linkage mapping approach, GWAS can greatly increase the range of detection of natural variation, the number of genome-wide significant loci, and even QTL resolution for complex agronomic traits. A soybean collection containing 367 diverse accessions has been genotyped using a high-throughput NJAU 355 K SoySNP array, which provides a high-resolution of genome-wide markers facilitating GWAS of complex traits in soybean[16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
