Molecular mapping and genomics of soybean seed protein: a review and perspective for the future

Abstract

Key message Genetic improvement of soybean protein meal is a complex process because of negative correlation with oil, yield, and temperature. This review describes the progress in mapping and genomics, identifies knowledge gaps, and highlights the need of integrated approaches. AbstractMeal protein derived from soybean [Glycine max (L) Merr.] seed is the primary source of protein in poultry and livestock feed. Protein is a key factor that determines the nutritional and economical value of soybean. Genetic improvement of soybean seed protein content is highly desirable, and major quantitative trait loci (QTL) for soybean protein have been detected and repeatedly mapped on chromosomes (Chr.) 20 (LG-I), and 15 (LG-E). However, practical breeding progress is challenging because of seed protein content’s negative genetic correlation with seed yield, other seed components such as oil and sucrose, and interaction with environmental effects such as temperature during seed development. In this review, we discuss rate-limiting factors related to soybean protein content and nutritional quality, and potential control factors regulating seed storage protein. In addition, we describe advances in next-generation sequencing technologies for precise detection of natural variants and their integration with conventional and high-throughput genotyping technologies. A syntenic analysis of QTL on Chr. 15 and 20 was performed. Finally, we discuss comprehensive approaches for integrating protein and amino acid QTL, genome-wide association studies, whole-genome resequencing, and transcriptome data to accelerate identification of genomic hot spots for allele introgression and soybean meal protein improvement.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-017-2955-8) contains supplementary material, which is available to authorized users.

Dissecting genomic hotspots underlying seed protein, oil, and sucrose content in an interspecific mapping population of soybean using high‐density linkage mapping

“…When the elite genotypes from South Korea (44.06 ± 1.8%) compared with the USA (41.12 ± 1.3%) and China (42.10 ± 1.4%), Korean elite lines showed a significantly higher protein. It has been reported that geographical origin and maturity groups are the principal determinants of population structure and phenotypic variation and accessions from Korea form a unique population structure compared with Chinese and US accessions (Patil et al ., ). Furthermore, GWAS for protein content based on geographical origin identified the strongest association on Chr.…”

“…The heritability of measured traits was calculated based on the analysis of variance of family means (Table S1). It is well studied that seed protein content is negatively correlated to seed oil and sucrose content in soybean (Nichols et al ., ; Patil et al ., ; Sonah et al ., ) Based on the phenotypic correlation among traits estimated for protein, oil, and sucrose across four environments, a similar trend was observed in this population (Figure ). Moreover, the phenotypic data presented in this study supported the fact that soybean seed composition is significantly affected by environmental conditions (Bandillo et al ., ; Chaudhary et al ., ; Thomas et al ., ).…”

“…The advanced breeding strategies mostly rely on a precise understanding of different aspects involved in the trait development. In soybean, the complex molecular and physiological mechanisms controlling yield, seed protein, and oil content are largely unknown (Patil et al ., ,). Soybean seed composition is considered a complex and tightly regulated trait that is affected by the environment and environment × genotype interaction.…”

Environmental Stability and Correlation of Soybean Seed Starch with Protein and Oil Contents

“…is an important legume crop in the world, domesticated mainly for its high oil and protein contents (Patil et al 2017). Major constituents of soybean seeds are protein (∼40%), carbohydrate (∼34%), oil (∼21%), and ash (∼5%) (Burton 1997).…”

Trends in Soybean Trait Improvement over Generations of Selective Breeding

“…This may be due to specialty cultivars with trait‐specific breeding objectives, such as high protein, rather than solely yield improvement. As the genetic basis of the oil and protein relationship is complex and still poorly understood, a number of questions remain to be addressed (Patil et al, 2017).…”