Active accumulated temperature (AAT) serves as a pivotal metric for assessing soybean adaptation across diverse climatic conditions, particularly in the northeastern regions of China. This study embarked on a genome-wide association analysis (GWAS) to elucidate the genetic determinants influencing AAT and its impact on flowering time among soybean varieties. Leveraging a panel of 140 elite soybean varieties encompassing both Chinese and European early-maturity groups and employing high-density genotyping, significant associations were identified on chromosome 6. Notably, a key gene, Glyma.06g204500, emerged as a central component, exhibiting strong linkage to the well-established E1 locus, alongside three distinct haplotypes. This investigation underscores Glyma.06g204500’s potential role in mediating soybean’s response to temperature fluctuations, offering novel insights into the genetic mechanisms underpinning soybean adaptation to local environmental conditions.

Understanding the genetic basis of leaf sucrose content can provide a novel way in improving soybean yields. To identify the related QTLs, 190 materials of chromosome fragment substitution lines (CSSLs) were used in this study. The CSSLs were developed from the cross between the cultivated soybean Suinong 14 (SN14) and wild soybean ZYD00006. Only one QTL with a high logarithm of odds (LOD) score was detected in 2021 and 2022 among 3780 bin markers (combined by 580,524 SNPs) distributed in 20 chromosomes. Nine candidate genes were screened and Glyma.14G029100 was considered as the hub gene. A promoter difference and CDS mutant was found among the parents and the reference genome, which lead to the relative transcriptional level difference.. Our results lay the groundwork for further research into its genetic mechanism.

Soybean (Glycine max L.), an important oilseed, food, and feed crop, has its yield and quality regulated by complex genetic networks. Shikimate O-hydroxycinnamoyltransferase (HCT) is a key enzyme in the phenylpropanoid metabolic pathway and plays important roles in plant secondary metabolism and growth and development. However, whether HCT is involved in regulating oil accumulation in soybean remains unclear. Here, we identified 39 GmHCT members in the soybean genome. Phylogenetic analysis classified these genes into three subgroups, revealing distinct variations in their conserved motifs and gene architectures. The analysis of cis-elements revealed that GmHCT promoters contain abundant motifs associated with hormonal regulation, abiotic stress, and developmental processes. The GmHCT members were widely distributed across 18 soybean chromosomes. Transcriptomic analysis indicated that the majority of GmHCT genes exhibited elevated expression levels during reproductive development, while specific members displayed particularly high expression in roots and nodules. By comparing materials with different quality phenotypes (high-protein high-oil (HPHO), high-protein low-oil (HPLO), low-protein high-oil (LPHO), and low-protein low-oil (LPLO)) and between wild and cultivated soybean (ZYD06 and SN14), six differentially expressed genes were screened, and four genes associated with oil accumulation were identified through haplotype analysis. Combining transcriptomic, RT-qPCR, and haplotype analyses, Glyma.04G040000 and Glyma.06G041400 were ultimately determined as key candidate genes linked to soybean oil accumulation. Further hairy-root transformation and gas chromatography analyses showed that upregulation of Glyma.04G040000 and Glyma.06G041400 increased fatty acid content in soybean hairy roots. Overall, this research presents a comprehensive genome-wide identification and characterization of the GmHCT gene family in soybean, and these identified candidate genes offer valuable references for the molecular breeding of oil-related and other quality traits in soybean.