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Phosphorus (P) deficiency seriously affects plant growth and development and ultimately limits the quality and yield of crops. Here, a new P efficiency‐related major quantitative trait locus gene, GmEIL4 (encoding an ethylene‐insensitive 3‐like 1 protein), was cloned at qP2, which was identified by linkage analysis and genome‐wide association study across four environments. Overexpressing GmEIL4 significantly improved the P uptake efficiency by increasing the number, length and surface area of lateral roots of hairy roots in transgenic soybeans, while interfering with GmEIL4 resulted in poor root phenotypic characteristics compared with the control plants under low P conditions. Interestingly, we found that GmEIL4 interacted with EIN3‐binding F box protein 1 (GmEBF1), which may regulate the root response to low P stress. We conclude that the expression of GmEIL4 was induced by low‐P stress and that overexpressing GmEIL4 improved P accumulation by regulating root elongation and architecture. Analysis of allele variation of GmEIL4 in 894 soybean accessions suggested that GmEIL4 is undergoing artificial selection during soybean evolution, which will benefit soybean production. Together, this study further elucidates how plants respond to low P stress by modifying root structure and provides insight into the great potential of GmEIL4 in crop P‐efficient breeding. Significance Statement: GmEIL4 regulates soybean phosphorus efficiency. [ABSTRACT FROM AUTHOR]

Photosynthesis plays an extremely important role throughout the life cycle of plants. Improving the photosynthetic rate is a major target for increasing crop productivity. This study was conducted to identify single nucleotide polymorphisms (SNPs) associated with the net photosynthetic rate (Pn), stomatal conductance (Cond), intercellular carbon dioxide concentration (Ci) and transpiration rate (Trmmol) through genome-wide association study (GWAS) and to inspect the relationships among these traits in soybean (Glycine max (L.) Merr.). A population of 219 soybean accessions was used in this research. A total of 12 quantitative trait loci (QTLs) associated with Pn, Cond, Ci and Trmmol were detected and distributed on chromosomes 1, 2, 6, 7, 9, 11, 12, 13, 15, 16, 18, and 19, and some of these QTL overlapped with previously reported QTLs. Furthermore, four candidate genes were identified, and there were significantly different expression levels between the high-light-efficiency accessions and low-light-efficiency accessions. These putative genes may participate in the regulation of photosynthesis through different metabolic pathways. Therefore, the associated novel QTLs and candidate genes detected in this study will provide a theoretical basis for genetic studies of photosynthesis and provide new avenues for crop improvement. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is essential for the growth and development of plants, playing crucial roles in energy acquisition, storage and utilization, regulation of enzyme activities, and yield formation. Therefore, P deficiency in soil is a main factor restricting crop production. The main reason is that crop yields depend on photosynthesis which is vulnerable to low P stress. Thus, it is important to study the relationship between photosynthesis and P efficiency. In this study, we evaluated the P efficiency by using the photosynthesis-related traits in 219 diverse soybean accessions across three different environments and dissected the underlying mechanism using a high-resolution genome-wide association study (GWAS). In total, 30 significant SNPs distributed in 14 genomic regions were identified to be associated with three photosynthesis-related traits under different P levels. Among the 14 associated regions, two regions (qP13 and qP19) were both found in two environments and explained 14.01% and 16.75% of the phenotypic variation, respectively. Furthermore, seven candidate genes underlying qP13 and qP19 were considered promising candidates involved in both soybean photosynthetic and low P tolerance. In all, we uncover two novel environmentally stable major genomic regions of P efficiency by using photosynthesis-related traits, which may provide more information for marker-assisted breeding in soybean and laying the foundation for simultaneously improving P efficiency and photosynthetic capacity. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is essential for plant growth, especially for soybean. P deficiency results in a severe decline of soybean productivity worldwide. Biomass is an important index to measure the tolerance of plants to low P. In this study, SNPs significantly associated with four P deficiency tolerance‐related traits were identified by genome‐wide association study (GWAS) using a natural population comprised of 272 soybean accessions from a wide geographic range and a high‐density NJAU 355K SoySNP array. As a result, four SNPs associated with RPDW (ratio of root dry weight under normal P condition and low P condition) with similar positions on chromosome 18 were identified and explained 24.71% to 30.89% of the phenotypic variation. One of these SNPs was identified in two environments and with two traits. Two genes were chosen as candidate genes responding to low P stress, one of which was annotated as a copper transporter and the other was annotated as a lipid transfer protein. In brief, these findings will be helpful for improving P efficiency and the marker‐assisted selection breeding in soybean. [ABSTRACT FROM AUTHOR]

Background: Phosphorus (P) is an essential element in maintaining high biomass and yield in crops. Soybean [Glycine max (L.) Merr.] requires a large amount of P during growth and development. Improvement of P efficiency and identification of P efficiency genes are important strategies for increasing soybean yield. Results: Genome-wide association analysis (GWAS) with NJAU 355 K SoySNP array was performed to identify single nucleotide polymorphisms (SNPs) significantly associated with three shoot P efficiency-related traits of a natural population of 211 cultivated soybeans and relative values of these traits under normal P (+P) condition and P deficiency (−P) condition. A total of 155 SNPs were identified significantly associated with P efficiency-related traits. SNPs that were significantly associated with shoot dry weight formed a SNP cluster on chromosome 11, while SNPs that were significantly associated with shoot P concentration formed a SNP cluster on chromosome 10. Thirteen haplotypes were identified based on 12 SNPs, and Hap9 was considered as the optimal haplotype. Four SNPs (AX-93636685, AX-93636692, AX-93932863, and AX-93932874) located on chromosome 10 were identified to be significantly associated with shoot P concentration under +P condition in two hydroponic experiments. Among these four SNPs, two of them (AX-93636685 and AX-93932874) were also significantly associated with the relative values of shoot P concentration under two P conditions. One SNP AX-93932874 was detected within 5′-untranslated region of Glyma.10 g018800, which contained SPX and RING domains and was named as GmSPX-RING1. Furthermore, the function research of GmSPX-RING1 was carried out in soybean hairy root transformation. Compared with their respective controls, P concentration in GmSPX-RING1 overexpressing transgenic hairy roots was significantly reduced by 32.75% under +P condition; In contrast, P concentration in RNA interference of GmSPX-RING1 transgenic hairy roots was increased by 38.90 and 14.51% under +P and -P conditions, respectively. Conclusions: This study shows that the candidate gene GmSPX-RING1 affects soybean phosphorus efficiency by negatively regulating soybean phosphorus concentration in soybean hairy roots. The SNPs and candidate genes identified should be potential for improvement of P efficiency in future soybean breeding programs. [ABSTRACT FROM AUTHOR]