Search Results (28)

Soybean (Glycine max) is a critically important crop for oil, protein, feed, and food security in China. Expanding soybean cultivation into high-latitude regions represents one of the most direct and effective strategies to increase total production. In the present study, we employed KASP (Kompetitive Allele-Specific PCR) marker technology to systematically analyze 18 variant loci across 14 flowering-time genes in 443 soybean germplasm accessions adapted to high-latitude conditions in Arctic Village (Beiji Cun), Mohe City (>53° N), northeastern China. Our results revealed clear functional-tier-dependent selection gradients: key mutation sites (frequency > 96%) in upstream photoreceptors and core circadian clock genes, such as E2 and GmPRR3a, were nearly fixed in the population, whereas downstream flowering genes such as GmFT5b and GmFT2b remained under dynamic selection. Combinatorial analysis of early-maturity allelic variants identified 178 distinct genotype combinations, including six dominant types (n ≥ 10). Field phenotypic analysis demonstrated that the cumulative number of early-maturity alleles was significantly negatively correlated with flowering time, with specific allele combinations such as FT5a^A + FKF1b-hap3^T exhibiting particularly strong flower-promoting effects. A set of 80 highly enriched super-early-maturity accessions, including extreme materials such as MHL22002, were identified, providing valuable genetic resources and a theoretical framework for elucidating the flowering regulatory mechanisms of high-latitude soybean and for breeding super-early-maturing varieties. Full article

Soybean mosaic virus (SMV) is a major constraint on global soybean (Glycine max (L.) Merr.) production, causing substantial economic losses worldwide. Despite these losses, the potential of resistance genes as a solution remains largely unexplored. In this study, the COPPER CHAPERONE FOR SUPEROXIDE DISMUTASE (GmCCS) was initially employed as a bait to screen the soybean cDNA library, leading to the identification of a protein homologous to Arabidopsis thaliana COP9 signalosome complex subunit 5B (AtCSN5B), designated as GmCSN5B. Quantitative real-time PCR (qRT-PCR) analysis revealed differential expression of GmCSN5B in the SMV-resistant (Qihuang No.1, QH) and susceptible (Nannong 1138-2, NN) variety following SMV-SC3 strain inoculation. Knockdown of GmCSN5B via Bean pod mottle virus (BPMV)-induced gene silencing (VIGS) significantly enhanced SMV resistance compared to control plants. This work further demonstrated that GmCSN5B can interact with the downstream GmVTC1 protein, which was potentially associated with ascorbic acid (AsA; Vitamin C) synthesis. Moreover, GmVTC1 also responded to SMV infection, and its knockdown led to a reduction in endogenous AsA levels within the host, thereby compromising the plant’s resistance to SMV. Together, these findings suggest that the GmCCS-GmCSN5B-GmVTC1 pathway in soybean modulates host resistance to SMV through the regulation of AsA synthesis. Full article

The coordinated development of stems and branches, together with optimal strip spacing, is crucial for improving soybean yield in the soybean–maize relay strip intercropping system. Shading during the seedling stage often causes excessive stem elongation and reduced branching; however, the physiological mechanisms underlying stem–branch responses to changing light environments remain unclear. This study aimed to clarify how early-stage shading and subsequent light recovery regulate stem and branch development through changes in canopy light environment, phytohormones, and the expression of related genes. Shade-tolerant Nandou12 and shade-sensitive Nannong99-6 were used as experimental soybean cultivars. Six treatments were implemented: a non-shaded control with uniform strip spacing (T0: 40 cm); seedling shading (40% PAR-transmission nets for 35 days after emergence) combined with variable strip spacing (T1: 40 cm; T2: 70 cm; T3: 100 cm; T4: 130 cm; T5: 160 cm). Canopy light environment, main stem and branch traits, photosynthetic characteristics, phytohormones, related gene expression, and yield components were measured. The results indicated that shade at the seedling stage significantly upregulated auxin (IAA) biosynthesis gene GmYUCC and downregulated phytochrome gene GmPhyB in the main stem tips, corresponding to increased IAA and cytokinins (CKs). In branch tips, shading significantly downregulated GmYUCC and GmPhyB while upregulated GmMAX3B, which is consistent with reduced levels of IAA, CKs, and brassinosteroid (BR), and increased strigolactones (SLs). After light recovery, GmPhyB and GmYUCC were upregulated whereas GmMAX3B was downregulated, accompanied by higher IAA, GA, CKs, and BRs, lower SLs, and improved chlorophyll content, Rubisco content, photosynthesis, and the accumulation of soluble sugar and starch in branches. Nandou12 achieved up to 10% higher yield under shading, and a 100 cm strip spacing maintained 74–111% yield of the non-shaded soybean. These findings demonstrate that cultivars with strong shade tolerance and high branching potential, combined with a 100-cm strip spacing, effectively sustain yield in relay-intercropped soybean by enabling favorable physiological responses to early shading and subsequent light recovery. Full article

Background/Objectives: Alfalfa is a widely cultivated high-quality forage crop, and salinity tolerance is one of the most important breeding goals. Glycine max SALT INDUCED NAC 1 (GmSIN1) was found to enhance salinity tolerance in soybean plants. The phylogenetic analysis showed there were two homologs of GmSIN1 in Medicago truncatula, MtSIN1a and MtSIN1b. This raised questions regarding the roles of MtSIN1s in alfalfa under salinity stress. Methods: From a Tnt1 mutant collection, we identified the mutants of MtSIN1a. We recorded the survival rate and plant height of mtsin1a-1 and mtsin1a-2 after 100 mM NaCl treatment. Subsequently, we generated 35S:MtSIN1a-GFP transgenic alfalfa lines via genetic transformation. Two lines with relatively high MtSIN1a expression, 35S:MtSIN1a-GFP#3 and 35S:MtSIN1a-GFP#4, were selected for gradient NaCl treatments. In addition, DAB and NBT staining were performed, and the H₂O₂ content and catalase (CAT) activity were determined. Then, we used RNA-seq analysis and RT-qPCR to study the mechanism of its tolerance. Results: This study found that after salt treatment, the survival rate and plant height of mtsin1a-1 and mtsin1a-2 were significantly lower than those of the WT. The mutants of MtSIN1a were sensitive to salinity stress. The transgenic alfalfa plants exhibited higher plant height, weaker DAB staining, stronger NBT staining, less H₂O₂ content, and enhanced CAT activity. The transgenic alfalfa constructed by transforming MtSIN1a showed enhanced salinity tolerance with elevated ROS scavenging. We identified MsSOD1 showing elevated expression levels in transcriptomic analysis. Conclusions: MtSIN1a is a positive regulator for enhancing salinity tolerance in alfalfa with activated ROS scavenging. Full article

Soybean (Glycine max (L.) Merr.) is a vital crop for the global supply of protein and oil, with its growth and development being regulated by genetic, hormonal, and environmental factors, particularly light and hormone signaling. The Small Auxin-Up RNA (SAUR) gene family plays a crucial role in plant growth regulation; however, the molecular mechanisms by which GmSAUR46 integrates photosynthesis and hormonal networks in soybean remain unclear. In this study, we focused on GmSAUR46b (Glyma.19G182600.1) and employed CRISPR/Cas9-mediated knockout and 35S-driven overexpression lines, alongside wild-type soybean (cv. Williams 82), to investigate its function. RNA sequencing (RNA-Seq) was conducted on shoot apical meristems, stems, and leaves at three developmental stages (V1, V2, V3), followed by transcriptomic analyses, including differential gene expression (DEG) identification and functional enrichment (GO, KEGG, KOG). Anatomical studies using paraffin sectioning and scanning electron microscopy (SEM) assessed the leaf midrib thickness and stem trichome density under varying light conditions. The transcriptomic results revealed DEGs enriched in pathways related to cell wall metabolism, hormone response, and photosynthesis. Anatomical analyses demonstrated that GmSAUR46b specifically regulates the leaf midrib thickness and stem trichome density in a light-dependent manner: under shade, the overexpression lines exhibited increased midrib thickness and trichome density, whereas the knockout lines showed reduced trichome density. Additionally, novel transcripts associated with stress resistance, hormone metabolism, and photosynthesis were identified, expanding the known soybean gene repertoire. Collectively, GmSAUR46b functions as a central hub integrating light signals with hormone and cell wall pathways to modulate soybean growth, particularly leaf and stem traits. This study advances understanding of SAUR gene function in soybean and provides valuable insights for molecular breeding aimed at improving adaptability and yield under diverse environmental conditions. Full article

Soybean (Glycine max (L.) Merr.) flowering time and plant height are critical agronomic traits that significantly influence yield and environmental adaptability. To clarify the regulatory mechanisms of flowering-related genes and their associations with plant height, a genome-wide identification of such genes in soybean were performed. This analysis used Arabidopsis thaliana flowering genes as references, employing BLASTP searches and pathway classification. All of the identified flowering-related genes were classified into eight regulatory pathways, with the photoperiod pathway (Ph) being the most prominent. Evolutionary and expression analyses revealed that core regulators (e.g., GmFTs, GmSOC1s) are conserved across pathways and are preferentially expressed in shoot apical meristems (SAMs). Additionally, both flowering-related genes and key hormones (e.g., IAA, GA, ABA) exhibited rhythmic responses to light signals. CRISPR-Cas9-mediated validation confirmed that genes GmSAUR46b regulates both flowering time and plant height, as mutants of this gene showed early flowering and reduced height. Notably, a large proportion of previously mapped flowering genes overlapped with our identified ones, while some remained undetected, likely due to whole-genome duplication and adaptive evolution, which generate new regulatory networks. Most of the identified flowering-related genes, however, have not been mapped, which highlights substantial uncharacterized potential in soybean flowering and plant height regulation. This provides a valuable molecular framework to guide soybean molecular breeding for enhanced yield and environmental adaptability. Full article

Soybean (Glycine max) seeds are rich in amino acids, offering key nutritional and physiological benefits. In this study, 290 soybean accessions from the USDA Germplasm Collection based in Urbana, IL Information Network (GRIN) were analyzed. Four Genome-Wide Association Study (GWAS) models—Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK), Mixed Linear Model (MLM), Fixed and Random Model Circulating Probability Unification (FarmCPU), and Multi-Locus Mixed Model (MLMM)—identified two significant Single Nucleotide Polymorphisms (SNPs) associated with arginine content: Gm06_19014194_ss715593808 (LOD = 9.91, 3.91% variation) at 19,014,194 bp on chromosome 6 and Gm11_2054710_ss715609614 (LOD = 9.05, 19% variation) at 2,054,710 bp on chromosome 11. Two candidate genes, Glyma.06g203200 and Glyma.11G028600, were found in the two SNP marker regions, respectively. Genomic Prediction (GP) was performed for arginine content using several models: Bayes A (BA), Bayes B (BB), Bayesian LASSO (BL), Bayesian Ridge Regression (BRR), Ridge Regression Best Linear Unbiased Prediction (rrBLUP), Random Forest (RF), and Support Vector Machine (SVM). A high GP accuracy was observed in both across- and cross-populations, supporting Genomic Selection (GS) for breeding high-arginine soybean cultivars. This study holds significant commercial potential by providing valuable genetic resources and molecular tools for improving the nutritional quality and market value of soybean cultivars. Through the identification of SNP markers associated with high arginine content and the demonstration of high prediction accuracy using genomic selection, this research supports the development of soybean accessions with enhanced protein profiles. These advancements can better meet the demands of health-conscious consumers and serve high-value food and feed markets. Full article

As a globally important leguminous crop, soybean (Glycine max L.) serves as a vital source of edible oils and proteins for humans and livestock. Oils in leaves can help crops combat fungal infections, adapt to temperature changes via fatty acid modulation, and support resource recycling during leaf senescence. However, accumulating oils in leaves is a fundamental challenge due to the need to balance the inherently competing photosynthesis and fatty acid biosynthesis processes within chloroplasts. RETICULATA-RELATED (RER), known to regulate chloroplast function and plastid metabolism in Arabidopsis, plays an essential role in leaf development. Here, 14 non-redundant GmRER genes were identified in soybean and phylogenetically classified into four subclades. Most Arabidopsis RER genes were evolutionarily preserved as gene duplicates in soybean, except for GmRER5 and GmRER6. RNA secondary structures spanning the coding sequences (CDSs), the 5′- and 3′- untranslated regions (UTRs) of GmRERs, displayed exceptional structural plasticity in CDSs, while exhibiting limited conservation in UTRs. In contrast, protein structures retained conserved folds, underscoring evolutionary constraints on functional domains despite transcriptional plasticity. Notably, GmRER4a and GmRER4b represented an exceptional case of high similarity in both protein and RNA structures. Expression profiling across fourteen tissues and three abiotic stress conditions revealed a dynamic shift in expression levels between leaf-predominant and root-enriched GmRER paralogs after stress treatments. A comparative transcriptome analysis of six soybean landraces further revealed transcriptional polymorphism in the GmRER family, which was associated with the expression patterns of lipid biosynthesis regulators. Our comprehensive characterization of GmRERs may offer potential targets for soybean breeding optimization in overall plant oil production. Full article

Stay-green syndrome (SGS) is an important factor that causes soybean (Glycine max) yield reduction. Despite progress being made, the regulatory mechanism remains largely unclear. Therefore, in this study, an SGS-sensitive soybean variety, “HD0702”, was employed to investigate the underlying mechanism. Transcriptomic analyses were performed in a tissue-specific manner to investigate differentially expressed genes (DEGs) in soybeans impacted by SGS and in those without SGS. A total of 1858 DEGs were identified in the pods, and 2814 DEGs were identified in the leaves. Further investigation revealed that SGS mainly affected the expression levels of key genes involved in the regulation of photosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. To support this finding, the chlorophyll content of the pods was to be found increased by 320% for chlorophyll a and 260% for chlorophyll b. In leaves, soluble sugar levels significantly increased, whereas phytohormones IAA and ABA decreased in SGS pods. DEGs were classified using gene ontology (GO) terms, and photosynthesis-related genes α-glucosidase, β-mannosidase, β-amylase 5 (GmBAM5), and starch synthase 2 (GmSS2) were up-regulated. This study demonstrates a molecular and physiological basis for SGS that merits further investigation to allow for SGS management. Full article

Soybean (Glycine max (L.) Merr) is one of the most important crops worldwide, but its yield is vulnerable to abiotic stresses. In Arabidopsis, the AlkB homologue (ALKBH) family genes plays a crucial role in plant development and stress response. However, the identification and functions of its homologous genes in soybean remain obscured. Here, we identified a total of 22 ALKBH genes in soybean and classified them into seven subfamilies according to phylogenetic analysis. Gene duplication events among the family members and gene structure, conserved domains, and motifs of all candidate genes were analyzed. By comparing the changes in the m⁶A levels on mRNA from hair roots between soybean seedlings harboring the empty vector and those harboring the GmALKBH10B protein, we demonstrated that all four GmALKBH10B proteins are bona fide m⁶A RNA demethylases in vivo. Subcellular localization and expression patterns of the GmALKBH10B revealed that they might be functionally redundant. Furthermore, an analysis of cis-elements coupled with gene expression data demonstrated that GmALKBH10B subfamily genes, including GmALKBH10B1, GmALKBH10B2, GmALKBH10B3, and GmALKBH10B4, are likely involved in the cis-elements’ response to various environmental stimuli. In summary, our study is the first to report the genome-wide identification of GmALKBH family genes in soybean and to determine the function of GmALKBH10B proteins as m⁶A RNA demethylases, providing insights into GmALKBH10B genes in response to abiotic stresses. Full article

While it is well known that plants interpret UV-B as an environmental cue and a potential stressor influencing their growth and development, the specific effects of UV-B-induced oxidative stress on the dynamics of membrane lipids and proteins remain underexplored. Here, we demonstrate that UV-B exposure notably increases the formation of ordered lipid domains on the plasma membrane (PM) and significantly alters the behavior of the Glycine max nodule autoregulation receptor kinase (GmNARK) protein in Arabidopsis leaves. The GmNARK protein was located on the PM and accumulated as small particles in the cytoplasm. We found that UV-B irradiation interrupted the lateral diffusion of GmNARK proteins on the PM. Furthermore, UV-B light decreases the efficiency of surface molecule internalization by clathrin-mediated endocytosis (CME). In brief, UV-B irradiation increased the proportion of the ordered lipid phase and disrupted clathrin-dependent endocytosis; thus, the endocytic trafficking and lateral mobility of GmNARK protein on the plasma membrane are crucial for nodule formation tuning. Our results revealed a novel role of low-intensity UV-B stress in altering the organization of the plasma membrane and the dynamics of membrane-associated proteins. Full article

Soybean [Glycine max (L.) Merr.] is a short-day (SD) plant that is sensitive to photoperiod, which influences flowering, maturity, and even adaptation. TEOSINTE-BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors have been shown to regulate photoperiodic flowering. However, the roles of TCPs in SD plants such as soybean, rice, and maize remain largely unknown. In this study, we cloned the GmTCP40 gene from soybean and investigated its expression pattern and function. Compared with wild-type (WT) plants, GmTCP40-overexpression plants flowered earlier under long-day (LD) conditions but not under SD conditions. Consistent with this, the overexpression lines showed upregulation of the flowering-related genes GmFT2a, GmFT2b, GmFT5a, GmFT6, GmAP1a, GmAP1b, GmAP1c, GmSOC1a, GmSOC1b, GmFULa, and GmAG under LD conditions. Further investigation revealed that GmTCP40 binds to the GmAP1a promoter and promotes its expression. Analysis of the GmTCP40 haplotypes and phenotypes of soybean accessions demonstrated that one GmTCP40 haplotype (Hap6) may contribute to delayed flowering at low latitudes. Taken together, our findings provide preliminary insights into the regulation of flowering time by GmTCP40 while laying a foundation for future research on other members of the GmTCP family and for efforts to enhance soybean adaptability. Full article

Chalcone isomerase (CHI) is an important enzyme involved in the biosynthesis of flavonoids, one that is crucial in both plant defense and human health. Although many CHI genes have been previously identified, the function of CHI-like genes in soybean remains unclear. In this study, we cloned the CHI-like genes GmCHI4A and GmCHI4B (GmCHI4s) in soybean. The real-time quantitative polymerase chain reaction showed that GmCHI4s were expressed primarily in soybean root, but were also present in other tissues, including the stem, leaf, and seed with a low expression level. Overexpression of GmCHI4s was able to significantly improve some beneficial traits of the transformed hair roots of cotyledon or composite plants under salt stress conditions. Root length, root wet weight, and the underground biomass was increased, and the elevation of MDA content was inhibited under 100 mmol L⁻¹ or 150 mmol L⁻¹ NaCl treatment. Leaf chlorophyll content was elevated in overexpressed GmCHI4A composite plants under 150 mmol L⁻¹ NaCl treatment. The expression levels of salt-stress-related genes GmSOD1, GmAPX1, GmSOS1, and GmNHX1 were significantly upregulated in overexpressed GmCHI4 hairy roots compared to that in empty-vector-expressed hairy roots. The above results indicated GmCHI4s’ potential action against salt stress. Furthermore, overexpression of GmCHI4A and GmCHI4B increased the total isoflavone content by six times and three times, respectively. Glycitin and glycitein levels were significantly elevated in the overexpressed GmCHI4A hairy roots, while glycitin, genistin, daidzein, and genistein were significantly increased in overexpressed GmCHI4B hairy roots. This study identified a new function of the CHI-like gene, as well as providing a new selected gene for salt tolerance and isoflavone improvement using biotechnological approaches in soybean. Full article

The plant architecture of higher plants is regulated through environmental and genetic factors, as well as phytohormones. Phytohormones play a critical role in regulating shoot branching. We determined the branching phenotype of D16 and N99-6, the content of strigolactones, the genetic expression level, and the interaction between auxin and strigolactones. We found that the branching development of the two soybean varieties under shading was significantly slower than that under normal light. The average branch length of N99-6 decreased by 40.9% after shading; however, the branch length of D16 was not significantly affected. Meanwhile, the branch formation rate in D16 was significantly higher than in N99-6. In addition, after shading treatment, the content of strigolactones in D16 and N99-6 axillary buds increased significantly, and the expression of phytochrome genes, PhyA and PhyB, showed opposite changes. However, strigolactone synthesis gene GmMAX4 and signal transduction gene GmMAX2 expression levels of D16 were lower than those of N99-6 after 24 h of shading. In addition, the application of strigolactone inhibitor TIS108 and auxin inhibitor NPA to soybean had no significant effect on the branch phenotype. The expression of the GmMAX2 gene was significantly up-regulated after the external application of the auxin analog, and the expression of auxin transporter gene GmPINI was significantly down-regulated after external application of the strigolactone analog under shade. In this study, we investigated the adverse effect of shade on soybean branching development, which may be due to the interaction of strigolactones with auxins. Full article

Plants respond to heat stress by producing heat-shock proteins. These are regulated by heat-shock promoters containing regulatory elements, which can be harnessed to control protein expression both temporally and spatially. In this study, we designed heat-inducible promoters to produce the diterpene casbene in Nicotiana benthamiana, through a multi-step metabolic pathway. To potentially increase gene transcription, we coupled heat-shock elements from Arabidopsis thaliana Hsp101 or Glycine max GmHsp17.3-B promoters, CAAT and TATA boxes from CaMV 35S, and the 5′UTR from the tobacco mosaic virus. The resulting four chimeric promoters fused to a green fluorescent protein (GFP) reporter showed that the variant Ara2 had the strongest fluorescent signal after heat shock. We next created a 4-gene cassette driven by the Ara2 promoter to allow for exogenous synthesis of casbene and transformed this multigene construct along with a selectable marker gene into Nicotiana benthamiana. Metabolic analysis on the transgenic lines revealed that continuous heat outperforms heat shock, with up to 1 μg/mg DW of casbene detected after 32 h of uninterrupted 40 °C heat. These results demonstrate the potential of heat-inducible promoters as synthetic biology tools for metabolite production in plants. Full article