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Polyamine oxidases (PAOs) are flavin adenine dinucleotide-dependent enzymes that are involved in polyamine catabolism and play an essential role in growth and developmental processes as well as the response to abiotic stresses. Although the PAO gene families have been intensively studied in many plants, the soybean ( Glycine max (L.) Merr.) PAO gene family has not been systematically identified. Here, we identified six PAO genes in the soybean genome and named them GmPAO1– GmPAO6. The phylogenetic analysis revealed that plant PAO proteins are divided into four classes. GmPAO1 and GmPAO4 belong to class I; GmPAO2, GmPAO5, and GmPAO6 belong to class IV. Similar to most dicotyledonous plants, soybeans do not contain class II. Interestingly, we identified an additional SWIRM-domain PAO gene GmPAO3, which exists between classes III and IV . GmPAO3 had a different gene structure and expression. To determine the individual roles of GmPAOs, we analyzed their expression levels in various tissues and under abiotic stress. Each GmPAO gene can respond in a specific tissue under specific abiotic stress. The data can help to clarify the role of GmPAOs in abiotic stress responses in soybean and provide a breeding basis for enhancing soybean tolerance to abiotic stresses.

To maximize the benefits of wire arc additive manufacturing (WAAM) processes, the effect of post-deposition heat treatment on the microstructure and mechanical properties of WAAM AZ80M magnesium (Mg) alloy was investigated. Three different heat treatment procedures (T4, T5 and T6) were performed. According to the results, after T4 heat treatment, the microsegregation of alloying elements was improved with the eutectic structure dissolved. Samples after T5 heat treatment inherited the net-like distribution of secondary phases similar to the as-deposited sample, where the eutectic structure covering the interdendritic regions and the β-phase precipitated around the eutectic structure. After T6 heat treatment, the tiny β-phases re-precipitated from the matrix and distributed in inner and outer of the grains. The hardness distribution of the samples went through T4 and T6 heat treatment was more uniform in comparison to that of T5 heat treated samples. The tensile test showed that the T6 heat treatment improved the strength and ductility, and the anisotropy between horizontal and vertical can be eliminated. Moreover, T4 treated samples exhibited highest ductility.

Context Soybean cyst nematode is the most important pest of soybean (Glycine max (L.) Merr.) worldwide, causing serious yield losses. Lignin is a vital component of the cell wall that can provide resistance to cyst nematode. O-Methyltransferase (OMT) is a key enzyme involved in lignin metabolism in the phenylalanine pathway. Aims In this study, the soybean OMT gene family was systematically identified, and the expression response of GmOMT to abiotic and cyst nematode stresses was investigated. Methods In total, 67 OMT genes were obtained from the soybean genome through conserved structural domain alignment. GmOMT expression under abiotic stress of soybean was examined based on next-generation RNA sequencing (RNA-Seq). Comprehensive analysis of the genes was conducted, including gene structure, conserved structure, affinity, chromosomal localisation, functional prediction, Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, promoter analysis, and expression pattern analysis. Key results The 67 GmOMT genes were identified and distributed among the 19 chromosomes. The GmOMT genes were classified into two categories: CCOMT subfamily and COMT subfamily. GmOMT genes from the same family shared similar gene structures and conserved structural domains, which have undergone strong purifying selection during evolution. The presence of multiple cis-responsive elements in the promoters of GmOMT genes suggested that members of the soybean OMT family may be involved in growth and developmental activities and resistance to stress in soybean. Conclusions GmOMT expression under abiotic stress showed that some of the genes may play a role in abiotic stress. Of them, GmCCOMT3 and GmCCOMT7 were closely associated with lignin synthesis based on both RNA-Seq and quantitative real-time PCR analysis. Implications These findings are valuable for elucidating the function of GmOMT in lignin metabolism and the relationship with SCN resistance.

Frogeye leaf spot (FLS) causes severe yield loss in soybean and has been found in several countries worldwide. Therefore, it is necessary to select and utilize FLS-resistant varieties for the management of FLS. In the present study, 335 representative soybean materials were assessed for partial resistance to FLS race 7. Quantitative trait nucleotide (QTN) and FLS race 7 candidate genes were identified using genome-wide association analysis (GWAS) based on a site-specific amplified fragment sequencing (SLAF-seq) approach. A total of 23,156 single nucleotide polymorphisms (SNPs) were used to evaluate the level of linkage disequilibrium with a minor allele frequency ≥ 5 and deletion data < 3%. These SNPs covered about 947.01 MBP, nearly 86.09% of the entire soybean genome. In addition, a compressed mixed linear model was utilized to identify association signals for partial resistance to FLS race 7. A total of 15 QTNs associated with resistance were found to be novel for FLS race 7 resistance. A total of 217 candidate genes located in the 200 kb genomic region of these peak SNPs were identified. Based on gene association analysis, qRT-PCR, haplotype analysis and virus-induced gene silencing (VIGS) systems were used to further verify candidate genes Glyma.16G176800, Glyma.16G177300, Glyma.16G177400 and Glyma.16G182300. This indicates that these four candidate genes may participate in FLS race 7 resistance responses.

Lodging is an important agronomic trait related to crop yield and is easily susceptible to environmental influences. In this study, a recombinant inbred line population from soybean (Glycine max (L.) Merr.) Hefeng 25 × Dongnong L28 including 109 lines was used to identify quantitative trait loci (QTLs) related to soybean lodging. Seven QTLs were identified in the three environments (Harbin in 2017, 2018 and 2019), and these could explain 2.21–20.17% of the phenotypic variation. Among these QTLs, qLDG-I-1 (Chr20_24146101–Chr20_24297321) was stable for multiple environments. A residue heterozygous line, which was heterozygous at the qLDG-I-1 locus, was used to verify qLDG-I-1, and the results showed that this QTL could significantly improve lodging resistance of soybean. Meanwhile, 13 pairs of epistatic QTLs were detected, which could explain 3.26–18.24% of the phenotypic variation. QTL × environment interaction mapping was also used, and it detected 31 QTLs, which could explain 1.61–7.94% of the phenotypic variation. In total, 122 pairs of epistatic QTLs were detected, and they could explain 5.39–27.81% of the phenotypic variation. Additionally, candidate genes related to soybean lodging in the qLDG-I-1 interval were predicted, and Glyma.20g068000 was mined as a candidate gene based on quantitative real-time PCR analysis. The QTLs and candidate genes identified in this study are of great significance to position cloning, and could accelerate the progress of breeding resistance to lodging in soybean.

Genome-wide association studies (GWAS) is an efficient method to detect quantitative trait locus (QTL), and has dissected many complex traits in soybean [Glycine max (L.) Merr.]. Although these results have undoubtedly played a far-reaching role in the study of soybean biology, environmental interactions for complex traits in traditional GWAS models are frequently overlooked. Recently, a new GWAS model, 3VmrMLM, was established to identify QTLs and QTL-by-environment interactions (QEIs) for complex traits. In this study, the GLM, MLM, CMLM, FarmCPU, BLINK, and 3VmrMLM models were used to identify QTLs and QEIs for tocopherol (Toc) content in soybean seed, including δ‐Tocotrienol (δ‐Toc) content, γ‐Tocotrienol (γ‐Toc) content, α‐Tocopherol (α‐Toc) content, and total Tocopherol (T-Toc) content. As a result, 101 QTLs were detected by the above methods in single-environment analysis, and 57 QTLs and 13 QEIs were detected by 3VmrMLM in multi-environment analysis. Among these QTLs, some QTLs (Group I) were repeatedly detected three times or by at least two models, and some QTLs (Group II) were repeatedly detected only by 3VmrMLM. In the two Groups, 3VmrMLM was able to correctly detect all known QTLs in group I, while good results were achieved in Group II, for example, 8 novel QTLs were detected in Group II. In addition, comparative genomic analysis revealed that the proportion of Glyma_max specific genes near QEIs was higher, in other words, these QEIs nearby genes are more susceptible to environmental influences. Finally, around the 8 novel QTLs, 11 important candidate genes were identified using haplotype, and validated by RNA-Seq data and qRT-PCR analysis. In summary, we used phenotypic data of Toc content in soybean, and tested the accuracy and reliability of 3VmrMLM, and then revealed novel QTLs, QEIs and candidate genes for these traits. Hence, the 3VmrMLM model has broad prospects and potential for analyzing the genetic structure of complex quantitative traits in soybean.

Lodging is an important agronomic trait that affects soybean seed yield. In this study, a recombinant inbred line (RIL) population derived from ‘Zhongdou 27’ × ‘Jiunong 20’ (including 112 lines) was used to identify quantitative trait loci (QTL) associated with lodging of soybean. A genetic map of 2050.27 cM was previously constructed using 4412 single nucleotide polymorphism (SNP) bins in this population. Three major QTL were identified in the single environment for 3 years, accounting for 12.38–16.5% of the phenotypic variation. Among these QTL, qldg-1 was stable for 3 years and qldg-2 was stable for 2 years. QTL by environment interactions (QEI) mapping was also used to detect QTL. A total of 14 QTL were detected, which could explain 2.62–11.28% of the phenotypic variation. The constructed residual heterozygous lines (RHL) were used for the verification of qldg-1 and qldg-2, and the results showed that these two QTL could significantly improve lodging resistance. In addition, genes in the confidence interval of qldg-1 and qldg-2 were designed to predict the candidates. The results of quantitative real-time PCR (qRT-PCR) verification of five genes revealed that two genes (Glyma.17G048100 and Glyma.09G239000) were expressed differentially during the dynamic stages between the parents, demonstrating that these two were the candidates associated with soybean lodging. The QTL and candidate genes related to soybean lodging identified in this study will be of great significance to the future soybean molecular-assisted breeding for lodging resistance.

Molecular signaling in the tumor microenvironment (TME) is complex, and crosstalk among various cell compartments in supporting metastasis remains poorly understood. In particular, the role of vascular pericytes, a critical cellular component in the TME, in cancer invasion and metastasis warrants further investigation. Here, we report that an elevation of FGF-2 signaling in samples from patients with nasopharyngeal carcinoma (NPC) and xenograft mouse models promoted NPC metastasis. Mechanistically, tumor cell-derived FGF-2 strongly promoted pericyte proliferation and pericyte-specific expression of an orphan chemokine (C-X-C motif) ligand 14 (CXCL14) via FGFR1/AHR signaling. Gain- and loss-of-function experiments validated that pericyte-derived CXCL14 promoted macrophage recruitment and polarization toward an M2-like phenotype. Genetic knockdown of FGF2 or genetic depletion of tumoral pericytes blocked CXCL14 expression and tumor-associated macrophage (TAM) infiltration. Pharmacological inhibition of TAMs by clodronate liposome treatment resulted in a reduction of FGF-2-induced pulmonary metastasis. Together, these findings shed light on the inflammatory role of tumoral pericytes in promoting TAM-mediated metastasis. We provide mechanistic insight into an FGF-2/FGFR1/pericyte/CXCL14/TAM stromal communication axis in NPC and propose an effective antimetastasis therapy concept by targeting a pericyte-derived inflammation for NPC or FGF-2hi tumors.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma, with the combination of rituximab and chemotherapy being the standard treatment for it. Although rituximab monotherapy has a remarkable response rate, drug resistance with unclear mechanisms and lack of effective second-line therapy limit the survival benefits of patients with lymphoma. Here, we report that MORTALIN is highly expressed and correlates with resistance to rituximab-based therapy and poor survival in patients with DLBCL. Mechanistically, gain- and loss-of-function experiments revealed that the voltage-dependent anion channel 1-binding protein, MORTALIN, regulated Ca

Isoflavones, one of the most important secondary metabolites produced by soybeans (Glycine max (L.) Merr.), are important for a variety of biological processes, and are beneficial for human health. To identify genetic loci underlying soybean isoflavone content, a mapping population containing 119 F5:18 recombinant inbred lines, derived by crossing soybean cultivar “Zhongdou27” with “Dongong8004,” was used. We identified 15 QTLs associated with isoflavone contents. A novel loci, qISO19-1, was mapped onto soybean chromosome 19 and was fine-mapped to a 62.8 kb region using a BC2F2 population. We considered GmMT1 as a candidate gene for the qISO19-1 locus due to the significant positive correlation recovered between its expression level and isoflavone content in the seeds of 43 soybean germplasms. Overexpression of GmMT1 in Arabidopsis and soybean cultivars increased isoflavone contents. Transgenic soybeans overexpressing GmMT1 also exhibited improved resistance to pathogenic infection, while transgenic Arabidopsis resisted salt and drought stress.

Tocopherol (Toc) occurs in soybean seeds and is extracted together with the soybean oil. Toc is utilized as an antioxidant in food and an additive in animal feed. A total of 180 representative accessions and 144 recombinant inbred lines (RILs) from the cross of ‘Hefeng 25’ and ‘OAC Bayfield’ were selected to evaluate individuals and total Toc concentrations in soybean seeds. The 180 soybean samples were sequenced by the approach of Specific Locus Amplified Fragment Sequencing (SLAF-seq). A total of 22,611 single nucleotide polymorphisms (SNPs) were developed. Nineteen quantitative trait nucleotides (QTNs) were identified associated with individual or total-Toc based on genome-wide association analysis (GWAS). Among them, three QTNs located near known QTLs, and 16 were novel. Eighteen QTLs and nine eQTLs were also detected by linkage mapping. The QTN rs9337368 on Chr.02 was colocalized according to the linkage mapping of the RILs and genome-wide association analysis and regarded as a stable locus for mining the candidate genes in association with Toc. A total of 42 candidate genes near the 200 kbp flanking region of this identified locus were found. Upon a gene-based association, 11 SNPs from five genes out of the 42 candidates were detected. Expression level analysis of five candidate genes revealed that two genes were significantly related to Toc content. The identified loci, along with the candidate genes, might be valuable for increasing the Toc concentration in soybean seeds and improving the nutritional value of soybean oil.

Isoflavone, a secondary metabolite produced by Glycine max (L.) Merr. (soybean), is valuable for human and plant health. The genetic architecture of soybean isoflavone content remains unclear, however, despite several mapping studies. We generated genomic data for 200 soybean cultivars and 150 recombinant inbred lines (RILs) to localize putative loci associated with soybean seed isoflavone content. Using a genome-wide association study (GWAS), we identified 87 single-nucleotide polymorphisms (SNPs) that were significantly associated with isoflavone concentration. Using linkage mapping, we identified 37 quantitative trait loci (QTLs) underlying the content of four isoflavones found in the RILs. A major locus on chromosome 8 (qISO8-1) was co-located by both the GWAS and linkage mapping. qISO8-1 was fine mapped to a 99.5-kb region, flanked by SSR_08_1651 and SSR_08_1656, in a BC2 F5 population. GmMPK1, encoding a mitogen-activated protein kinase, was identified as the causal gene in qISO8-1, and two natural GmMPK1 polymorphisms were significantly associated with isoflavone content. Overexpression of GmMPK1 in soybean hairy roots resulted in increased isoflavone concentrations. Overexpressing GmMPK1 in transgenic soybeans had greater resistance to Phytophthora root rot, suggesting that GmMPK1 might increase soybean resistance to biotic stress by influencing isoflavone content. Our results not only increase our understanding of the genetic architecture of soybean seed isoflavone content, but also provide a framework for the future marker-assisted breeding of high isoflavone content in soybean cultivars.

Soybean seed oil was valued in foods, animal feed and some industrial applications. Molecular marker-assisted selection (MAS) for high-oil-content cultivars was an important method for soybean breeders. The objective of this study was to identify quantitative trait loci (QTL) and epistatic QTL underlying the seed oil content of soybeans across two backcross (BC) populations (with one common male parent ‘Dongnong47’) and two different environments. Two molecular genetic maps were constructed. They encompassed 1046.8 cM [with an average distance of 6.75 cM in the ‘Dongnong47’ × ‘Jiyu89’ (DJ) population] and 846.10 cM [with an average distance of 5.76 cM in the ‘Dongnong47’ × ‘Zaoshu18’ (DZ) population]. Nine and seven QTL were identified to be associated with oil content in the DJ and DZ populations, respectively. The phenotypic variation explained by most of the QTL was usually less than 10%. Among the identified QTL, those stable ones across multiple environments and populations often had stronger additive effects. In addition, three stable QTL in the DZ populations were identified in the similar genomic region of the three QTL in the DJ population [qDJE and qDZE-1 were located near Satt151 of Chromosome 15 (Chr15), qDJA1 and qDZA1 were located near Satt200 of Chr15 (LG A1), and qDJD2-1 and qDZD2-1 were located near Sat365 of Chr17]. In conclusion, MAS will be able more effectively to combine beneficial alleles of the different donors to design new genotypes with higher soybean seed oil content using the BC populations.

Tocopherol (Toc) in soybean seeds has value for foods, medicines, cosmetics, and animal husbandry. Soybean breeders and soybean-derived food industries have thus focused on breeding new soybean cultivars with higher seed Toc content. In this study, an association panel consisting of 180 diverse soybean accessions were used to detect quantitative trait nucleotides (QTNs) and scan possible candidate genes based on genome-wide association analysis (GWAS) and high-throughput single-nucleotide polymorphisms (SNP). Approximately 22,611 SNPs were identified using the specific locus amplified fragment sequencing (SLAF-seq) approach and based on minor allele frequencies (MAFs) > 5 %, which spanned 84.10 % of the soybean whole genome. For the three individuals including α-tocopherol (α-Toc), γ- tocopherol (γ-Toc), δ- tocopherol (δ-Toc), and total tocopherol (total Toc) levels, a total of 18 quantitative trait nucleotides (QTNs) distributed on the 18 genomic regions of 10 chromosomes were verified via GWAS. Seven QTNs (rs55811336, rs7975863, rs37094897, rs7097743, rs17125409, rs330000, and rs4730199) could be identified in more than three environments, and the other eleven could be identified in least two environments. A total of 6, 8, 4, and 10 QTNs were novel loci for α-Toc, γ-Toc, δ-Toc, and total Toc, respectively. Nine QTNs (rs37505279, rs37686178, rs36359429, rs6898494, rs7097743, rs17125409, rs10200201, rs21080726, and rs5680781) were associated with more than one Toc component. A total of 216 candidate genes near the 200-kb flanking region of these identified QTNs were identified as potential candidate genes associated with soybean seed Toc levels. Of these genes, Glyma.17G061900 (located near QTN rs4730199 on Chr.17), a homogentisate phytyltransferase 1 that catalytic homogentisate to 2-methyl-6-phyl-1,4-benzoquinol in Toc biosynthesis, was detected through association analysis, haplotype analysis, and expression pattern analysis. The identified QTNs with beneficial alleles and the candidate genes would be valuable for improving Toc levels in soybean seeds and improving the nutritional value of soybean oil.