Effects of full-fat high-oleic soybean meal in layer diets on performance, egg quality and chemical composition.

The utilization of full-fat high-oleic soybean meal in layer diets could lead to value-added poultry products. To test this idea, 336 hens were randomly assigned to 4 isonitrogenous (18.5% CP) and isocaloric (2,927 kcal/kg) formulated diets and fed the following diets for eight weeks: conventional control solvent-extracted defatted soybean meal (CON); extruded-expelled defatted soybean meal (EENO); full fat normal-oleic soybean meal (FFNO); or full fat high-oleic soybean meal (FFHO). Body weights (BW) were collected at week 0 and week 8. Eggs were collected daily, and the totals counted each week. Feed consumption was measured weekly, and egg quality was measured bi-weekly. Eggs were collected at wk 0 and wk 8 for fatty acid analysis. There were no significant treatment differences in any of the production parameters measured, BW, feed consumption, feed conversion ratio or egg production (P > 0.05). Eggshell strength was significantly greater in eggs produced from the EENO group as compared to the control (P < 0.01), while egg yolk color was significantly darker in eggs of the control and EENO treatment groups relative to the FFNO and FFHO treatments (P < 0.0001). Eggs produced by hens fed the FFHO diet had a 52% increase in monounsaturated n-9 oleic acid content (P < 0.0001) and reduced palmitic (P < 0.01) and stearic (P < 0.0001) saturated fatty acid levels as compared to the conventional controls. These results validate the utilization of FFHO as a value-added poultry feed ingredient to enrich the eggs and/or poultry meat produced.

What Determines the Adoption of Conservation Agriculture? Evidence from Quebec.

Conservation agriculture (CA) is promoted by various organisations and scholars as alternative to conventional agriculture to meet growing food demand with minimal damage on environment; but its factors of adoption have not been well identified. The study uses the recent composite index of adoption of CA developed by Takam Fongang et al. (2023) to analyse the factors of adoption of conservation agriculture among maize and soybean farmers in Quebec. Using data from 93 maize and soybean producers and a Fractional logit model, the study shows that adoption of CA increases with farmer's favourable perceptions of yield and easiness of implementing CA, off-farm employment and higher education. The study therefore indicates that higher education, technical assistance and popularisation of performance of CA can play a significant role in boosting adoption of CA in Quebec.

Lactocaseibacillus-deglycosylated isoflavones prevent Aß 40-induced Alzheimer's disease in a rat model.

Alzheimer's disease (AD) is the most common neurodegenerative disease, with symptoms appearing in the cerebral cortex and hippocampus. amyloid ß peptide (Aß) has been shown to deposit in the brain, causing oxidative stress and inflammation, leading to impaired memory and learning. Lactocaseibacillus fermentation can produce deglycosylated isoflavones with high physiological activity, which can scavenge free radicals, enhance total antioxidant capacity and inhibit oxidative inflammatory responses. Therefore, in this study, Lactocaseibacillus paracasei subsp. paracasei NTU101 (NTU101) fermented soybean milk and its extracts were used as test substances, and AD model rats were established by infusion of Aß40 in the brain for 28 days, and the preventive and ameliorating effects of NTU 101 fermented soymilk were discussed. Effects of soymilk and unfermented soymilk on AD, and explore its effects on AD. Main functional ingredients. The results showed that deglycosylated isoflavones in NTU101 fermented soybean milk improved AD symptoms. Mechanisms of actions include the inhibition of oxidative inflammation; reduction in the expression of risk factors for tau protein and apo E protein production, the deposition of Aß40 around the hippocampus, and the expression of TLR-2 and RAGE proteins in astrocytes and microglia; and improvement in the memory and learning ability.

A fast and genotype-independent in planta Agrobacterium-mediated transformation method for soybean.

Efficient genotype-independent transformation and genome editing is highly desirable for plant biotechnology research and product development efforts. We have developed a novel approach to enable fast, high-throughput and genotype-flexible Agrobacterium-mediated transformation using the important soybean crop as a test system. This new method is called GiFT (Genotype-independent Fast Transformation) and involves only a few simple steps. The method uses germinated seeds as explants and DNA delivery is achieved through Agrobacterium infection of wounded explants as in conventional in vitro-based method. Following infection, the wounded explants are incubated in liquid medium with sublethal level of selection and then directly transplanted to soil. The transplanted seedlings are then selected with herbicide spray for three weeks. The time required from initiation to fully established healthy T0 transgenic events is about 35 days. The GiFT method requires minimal in vitro manipulation or use of tissue culture media. Since the regeneration is in planta, the GiFT method is thus highly genotype flexible, which we have demonstrated via successful transformation of elite germplasms from diverse genetic backgrounds. We also show that the soybean GiFT method can be applied to both conventional binary vectors and CRISPR-Cas12a vectors for genome editing applications. T1 progeny analyses demonstrated that the events had a high inheritance rate and could be used for genome engineering applications. By minimizing the need for tissue culture, the described novel approach significantly improves operational efficiency while greatly reducing personnel and supply cost. It is the first industry-scale transformation method utilizing in planta selection in a major field crop.

Effects of isotretinoin on tooth movement, orthodontically induced and non-orthodontic root resorption: A micro-CT and study.

OBJECTIVES: This study aims to investigate whether cumulative dose-dependent isotretinoin (Roaccutane®) could affect orthodontic tooth movement (OTM) and root resorption. MATERIALS AND METHODS: Ninety male Wistar Albino rats were divided into 4 groups. While, the control (SALINE), solvent (SOYBEAN) and orthodontic drug (ISOTM) groups underwent orthodontic force, the non-orthodontic drug group (ISO) did not. The rats were administrated saline, soybean oil (SBO) and isotretinoin diluted in SBO (ISOTM, ISO) for 30 days, respectively. Six rats were euthanized in each orthodontic group. Fifty grams of orthodontic force was applied to the remaining rats' first molars using the incisors as anchorage. Six more rats in each group were euthanized on the 7th, 14th and 21st days of the force application. In the ISO group, six rats were euthanized on the 37th, 44th and 51st days of administration. Six rats that were euthanized for ISOTM on the 30th day were also used for ISO to reduce the number of rats used. Micro-computed tomography (micro-CT) and histological analysis were performed. RESULTS: Independent of orthodontic force, isotretinoin caused root resorption in the apical region. However, there was no statistically significant influence of isotretinoin on OTM and orthodontically induced root resorption (OIRR). CONCLUSIONS: Despite the lack of strong evidence supporting the orthodontically induced resorptive effect of isotretinoin, this study provided findings regarding the resorptive effects of isotretinoin on non-orthodontic root resorption. Therefore, the present results underscore the importance of close monitoring during orthodontic treatment to mitigate potential root resorption in patients who use isotretinoin because of acne complaints.

Rhizobia cystathionine γ-lyase-derived H2S delays nodule senescence in soybean.

Hydrogen sulphide (H2S) is required for optimal establishment of soybean (Glycine max)-Sinorhizobium fredii symbiotic interaction, yet its role in regulating the nitrogen fixation-senescence transition remains poorly understood. A S. fredii cystathionine γ-lyase (CSE) mutant deficient in H2S synthesis showed early nodule senescence characterized by reduced nitrogenase activity, structural changes in nodule cells, and accelerated bacteroid death. In parallel, the CSE mutant facilitated the generation of reactive oxygen species (ROS) and elicited antioxidant responses. We observed that H2S-mediated persulfidation of cysteine C31/C80 in ascorbate peroxidase (APX) and C32 in APX2 modulated enzyme activity, thereby participating in hydrogen peroxide (H2O2) detoxification and delaying nodule senescence. Comparative transcriptomic analysis revealed a significant up-regulation of GmMYB128, an MYB transcription factor (TF), in the CSE mutant nodules. Functional analysis through overexpression and RNAi lines of GmMYB128 demonstrated its role as a positive regulator in nodule senescence. MYB128-OE inoculated with the CSE mutant strain exhibited a reduction in nitrogenase activity and a significant increase in DD15 expression, both of which were mitigated by NaHS addition. Changes at the protein level encompassed the activation of plant defenses alongside turnover in carbohydrates and amino acids. Our results suggest that H2S plays an important role in maintaining efficient symbiosis and preventing premature senescence of soybean nodules.

Partial replacement of soybean with alternative protein sources: Effects on meat quality, sensory attributes, and fatty acids and amino acids content of breast meat of a local chicken strain.

The environmental sustainability of soybean cultivation has been questioned as it has been linked to deforestation, eutrophication, pesticide use, and carbon dioxide footprint. Agri-industrial byproducts and black soldier fly (BSF) larvae meal are promising alternative protein sources that can be used to partly replace soybean in broiler diets. The present study aimed to investigate the effect of partial replacement of soybeans with agro-industrial by-products with or without the addition of BSF dried larvae meal on the meat quality, fatty acid and amino acid content, and sensory traits of breast meat of local chickens. A total of 252 one-day-old mixed-sex chicks from the Anadolu-T pure dam line were randomly assigned to 1 of 3 diets; a soybean-based Control diet, a diet in which soybean meal was partly replaced (SPR) with brewers' dried grain, sunflower seed meal, and wheat middlings and an SPR + BSF diet in which 5% of BSF dried larva meal was added to the SPR diet. All birds were slaughtered at a commercial slaughterhouse at 55 days and breast and drumstick muscles were sampled for meat quality analysis from 18 chickens/dietary treatments. No significant effects of diets were observed for the pH24 and lightness, redness, and yellowness of breast and leg meats. Thawing loss significantly decreased and cooking loss increased in the breast meat of chickens fed the SPR + BSF compared with those fed Control and SPR diets. Diets did not affect either texture profile or consumer sensory properties of breast meat. The chickens fed the SPR + BSF had the highest total saturated fatty acid and lower polyunsaturated fatty acid content in breast meat than those fed the Control and SPR diets. The essential and nonessential amino acid content of breast meat decreased by the SPR diet compared with the SPR + BSF diet. The chickens fed SPR + BSF diet had higher values of tasty, aromatic, and umami-related amino acids than those fed SPR and Control diets. In conclusion, the results of the present study indicated that agri-industrial byproducts with or without BSF larvae meal could be used to partially replace soybean meal in broiler diets without affecting technological meat quality traits. The addition of BSF larvae meal to the diet along with agri-industrial by-products improved the amino acid content of the breast meat of chickens but reduced polyunsaturated fatty acid levels.

MS2/GmAMS1 encodes a bHLH transcription factor important for tapetum degeneration in soybean.

KEY MESSAGE: GmAMS1 is the only functional AMS and works with GmTDF1-1 and GmMS3 to orchestrate the tapetum degeneration in soybean. Heterosis could significantly increase the production of major crops as well as soybean [Glycine max (L.) Merr.]. Stable male-sterile/female-fertile mutants including ms2 are useful resources to apply in soybean hybrid production. Here, we identified the detailed mutated sites of two classic mutants ms2 (Eldorado) and ms2 (Ames) in MS2/GmAMS1 via the high-throughput sequencing method. Subsequently, we verified that GmAMS1, a bHLH transcription factor, is the only functional AMS member in soybean through the complementary experiment in Arabidopsis; and elucidated the dysfunction of its homolog GmAMS2 is caused by the premature stop codon in the gene's coding sequence. Further qRT-PCR analysis and protein-protein interaction assays indicated GmAMS1 is required for expressing downstream members in the putative DYT1-TDF1-AMS-MYB80/MYB103/MS188-MS1 cascade module, and might regulate the upstream members in a feedback mechanism. GmAMS1 could interact with GmTDF1-1 and GmMS3 via different region, which contributes to dissect the mechanism in the tapetum degeneration process. Additionally, as a core member in the conserved cascade module controlling the tapetum development and degeneration, AMS is conservatively present in all land plant lineages, implying that AMS-mediated signaling pathway has been established before land plants diverged, which provides further insight into the tapetal evolution.

Constructing in-situ and real-time monitoring methods during soy sauce production by miniature fiber NIR spectrometers.

The digestion rate of steamed soybean (DRSS), protease activity of koji (PAK) and formaldehyde nitrogen content of moromi (FNCM) are key indicators to monitor soy sauce production. Currently, monitoring these indicators relies on workers' experience, which can sometimes lead to low material utilization rates and even fermentation failures. Near-infrared spectra were collected during soybean steaming, as well as koji and moromi fermentation, using miniature fiber spectrometers. These spectra were optimized using four pretreatment methods, and regression models were constructed using PLS, iPLS, and Si-PLS. The evaluation of models in prediction sets was based on the correlation coefficient (Rp) and root mean square error (RMSEP). Results indicated that Rp = 0.9327, RMSEP = 4.37% for DRSS, Rp = 0.9364, RMSEP = 228 U/g for PAK, and Rp = 0.9237, RMSEP =0.148 g/100 mL for FNCM were obtained. The above results coupling with validation experiments demonstrated that the developed in-situ and real-time spectroscopy system could ensure high-quality soy sauce production.

Potential prebiotic effects of soy by-products as novel dietary fibre: Structure, function, in vitro simulation of digestion and fermentation properties.

This study aimed to prepare soybean dregs dietary fibre (DF) using physically assisted chemical (KHMSO) modification and study its structure, function and vitro simulation experiments. The soluble dietary fibre (SDF) content in KHMSO increased and insoluble dietary fibre (IDF) content decreased. The modified DF surface becomes irregular and rough, and the results of XPS fitting indicated that the DF structure had different peak-splitting groups. The KHMSO-treated group had the lowest digestion rate in gastric fluid and the highest digestibility in intestine fluid. The OD600 of fecal cultures was increased to 0.915, and the increased abundance of microbiota was associated with the metabolism of SCFAs, such as Lachnospiraceae, as well as the higher n-butyric acid in the KHMSO-treated group compared to the other groups and lower than the inulin, suggesting KHMSO might enhance the production of functional foods aimed at promoting intestinal health.

Regulating the pore structure and heteroatom doping of soybean straw carbon based on a bifunctional template method for the high-performance carbon supercapacitor.

The previous research addressed the waste problem of agriculture and forestry residues by exploring the efficient utilization of liquefied soybean straw in supercapacitor. The structures of the liquefied soybean straw were controlled by coupling microwave hydrothermal treatment with carbonization under the influence of a C3N4 bifunctional template. What's more, C3N4 could effectively regulate the pore structures and provide an effective N active site of carbon materials C3N4. The obtained N-SLR Carbon-700 possess a specific surface area of up to 1593.7 m2 g-1, and the pore size is mainly concentrated in the range of 1.8-2.5 nm, providing efficient ions transmission channels and storage space. Its specific capacitance is up to 261.5F g-1 (current density of 0.5A g-1), and the capacity retention is 74.04% when the current density is expanded by 20 times. In the two-electrode system, the energy density of N-SLR Carbon-700 could reach to 31.3 W h kg-1 at a power density of 360 W kg-1, as well as the energy surface density is maintained at 69% when the power density is increased by a factor of 20. This work enhances effectively the charging and discharging stability and capacitance value of carbon-based supercapacitor.

Alleviation of drought stress damages by melatonin and Bacillus thuringiensis associated with adjusting photosynthetic efficiency, antioxidative system, and anatomical structure of Glycine max (L.).

These experiments were performed to study the effect of exogenous treatment with melatonin at 100 µM and seed treatment with Bacillus thuringiensis (106-8 CFU/cm3) on growth, physio-biochemical characters, antioxidant enzymes, and anatomical features of soybean plants cv. Giza 111 under drought conditions. The findings showed that leaves number, nodules number, branches number, relative water content (RWC), chlorophyll content, and maximum quantum efficiency of PSII (Fv/Fm) were significantly reduced in soybean under drought stress. In addition, anatomical structure of stems and leaves were negatively affected in stressed plants. Moreover, proline, electrolyte leakage (EL%) lipid peroxidation (MDA), superoxide (O2 ·-), hydrogen peroxide (H2O2), and antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), were significantly increased under drought stress. However, application of melatonin or Bacillus caused an improvement in growth characters, such as branches number, and increased chlorophyll a and b content, RWC as well as Fv/Fm in drought stressed soybean plants. Furthermore, melatonin and Bacillus treatments showed a significant decrease in EL%, MDA, O2 ·- and H2O2, besides regulating the activity of antioxidant enzymes under drought stress. The stems and leaves anatomical structure, such as lamina thickness, lower and upper epidermis thickness, number of xylem vessels/bundle, stem diameter, xylem vessels diameter, and phloem thickness, were improved under drought conditions with melatonin and Bacillus treatments. Therefore, the outcomes of this investigation recommended the use of melatonin as foliar spray and Bacillus thuringiensis as seed treatment, which could regulate a number of stress-responsive mechanisms to protect the stressed soybean plants, improve their growth under drought stress.

Fermentative metabolic features of doenjang-meju as revealed by genome-centered metatranscriptomics.

Fermentative features of doenjang-meju, a traditional Korean soybean brick, were investigated over 45 days via genome-centered metatranscriptomics. The pH value rapidly decreased within 10 days and successively increased after 20 days, along with an initial bacterial growth, including lactic acid bacteria, and subsequent fungal growth, suggesting their association. Polysaccharides and lipids underwent degradation, and amino acids, free sugars, and organic acids increased during the early stage. Metagenome analysis identified Aspergillus, Bacillus, Enterococcus, Staphylococcus, and Leuconostoc as major microbes, which were isolated and genome-sequenced. Metatranscriptomic analysis revealed the major roles of Bacillus and Enterococcus during the early period, shifting to Aspergillus dominance after 10 days. Metabolic pathway reconstruction and transcriptional analysis reveal that Aspergillus primarily decomposed polysaccharides to free sugars; Aspergillus and Bacillus metabolized lipids, free sugars, and organic acids generated by Enterococcus; and Aspergillus and Bacillus were instrumental in amino acid metabolism: their contributions varied by compounds and pathways.

DNA methylation analysis reveals local changes in resistant and susceptible soybean lines in response to Phytophthora sansomeana.

Phytophthora sansomeana is an emerging oomycete pathogen causing root rot in many agricultural species including soybean. However, as of now, only one potential resistance gene has been identified in soybean, and our understanding of how genetic and epigenetic regulation in soybean contributes to responses against this pathogen remains largely unknown. In this study, we performed whole genome bisulfite sequencing (WGBS) on two soybean lines, Colfax (resistant) and Williams 82 (susceptible) in response to P. sansomeana at two time points: 4 and 16 hours post inoculation to compare their methylation changes. Our findings revealed that there were no significant changes in genome-wide CG, CHG (H = A, T, or C), and CHH methylation. However, we observed local methylation changes, specially an increase in CHH methylation around genes and transposable elements (TEs) after inoculation, which occurred earlier in the susceptible line and later in the resistant line. After inoculation, we identified differentially methylated regions (DMRs) in both Colfax and Williams 82, with a predominant presence in TEs. Notably, our data also indicated that more TEs exhibited changes in their methylomes in the susceptible line compared to the resistant line. Furthermore, we discovered 837 DMRs within or flanking 772 differentially expressed genes (DEGs) in Colfax and 166 DMRs within or flanking 138 DEGs in Williams 82. These DEGs had diverse functions, with Colfax primarily showing involvement in metabolic process, defense response, plant and pathogen interaction, anion and nucleotide binding, and catalytic activity, while Williams 82 exhibited a significant association with photosynthesis. These findings suggest distinct molecular responses to P. sansomeana infection in the resistant and susceptible soybean lines.

Soil application of graphitic carbon nitride nanosheets alleviate cadmium toxicity by altering subcellular distribution, chemical forms of cadmium and improving nitrogen availability in soybean (Glycine max L.).

Cadmium (Cd)-contamination impairs biological nitrogen fixation in legumes (BNF), threatening global food security. Innovative strategies to enhance BNF and improve plant resistance to Cd are therefore crucial. This study investigates the effects of graphitic carbon nitride nanosheets (g-C3N4 NSs) on soybean (Glycine max L.) in Cd contaminated soil, focusing on Cd distribution, chemical forms and nitrogen (N) fixation. Soybean plants were treated with 100 mg kg-1 g-C3N4 NSs, with or without 10 mg kg-1 Cd for 4 weeks. Soil addition of g-C3N4 NSs alleviated Cd toxicity and promote soybean growth via scavenging Cd-mediated oxidative stress and improving photosynthesis. Compared to Cd treatment, g-C3N4 NSs increased shoot and root dry weights under Cd toxicity by 49.5% and 63.4%, respectively. g-C3N4 NSs lowered Cd content by 35.7%-54.1%, redistributed Cd subcellularly by increasing its proportion in the cell wall and decreasing it in soluble fractions and organelles, and converted Cd from high-toxicity to low-toxicity forms. Additionally, g-C3N4 NSs improved the soil N cycle, stimulated nodulation, and increased the N-fixing capacity of nodules, thus increasing N content in shoots and roots by 12.4% and 43.2%, respectively. Mechanistic analysis revealed that g-C3N4 NSs mitigated Cd-induced loss of endogenous nitric oxide in nodules, restoring nodule development. This study highlights the potential of g-C3N4 NSs for remediating Cd-contaminated soil, reducing Cd accumulation, and enhancing plant growth and N fixation, offering new insights into the use of carbon nanomaterials for soil improvement and legume productivity under metal(loid)s stress.

UV-B Radiation Exhibited Tissue-Specific Regulation of Isoflavone Biosynthesis in Soybean Cell Suspension Cultures.

Isoflavones, a class of substances with high biological activity, are abundant in soybeans. This study investigated isoflavone biosynthesis in soybean cell suspension cultures under UV-B radiation. UV-B radiation enhanced the transcription level and activity of key enzymes involved in isoflavone synthesis in cell suspension cultures. As a result, the isoflavone contents significantly increased by 19.80% and 91.21% in hypocotyl and cotyledon suspension cultures compared with the control, respectively. Meanwhile, a significant difference was observed in the composition of isoflavones between soybean hypocotyl and cotyledon suspension cultures. Genistin was only detected in hypocotyl suspension cultures, whereas glycitin, daidzein, and genistein accumulated in cotyledon suspension cultures. Therefore, UV-B radiation exhibited tissue-specific regulation of isoflavone biosynthesis in soybean cell suspension cultures. The combination of suspension cultures and abiotic stress provides a novel technological approach to isoflavone accumulation.

A Sustainable Approach for Degradation of Alternariol by Peroxidase Extracted from Soybean Hulls: Performance, Pathway, and Toxicity Evaluation.

Alternariol (AOH), an emerging mycotoxin, inevitably exists widely in various food and feed commodities with cereals and fruits being particularly susceptible, raising global concerns over its harm to human and livestock health. The development of eco-friendly and efficient strategies to decontaminate AOH has been an urgent task. This study provided insight into the utilization of crude soybean hull peroxidase as a powerful biocatalyst for degrading AOH. The results confirmed that crude soybean hull peroxidase (SHP) could catalyze the oxidation of AOH by use of H2O2 as a co-substrate. The optimum reaction conditions for SHP-catalyzed AOH degradation were recorded at pH 4.0-8.0, at 42-57 °C, and at H2O2 concentration of 100-500 µM. Mass analysis elucidated the degradation of AOH through hydroxylation and methylation by crude SHP. Moreover, toxicological analysis indicated that crude SHP-catalyzed AOH degradation detoxified the hepatotoxicity of this mycotoxin. The performance of crude SHP to degrade AOH in food matrices was further evaluated, and it was found that the enzyme agent could achieve AOH degradation by 77% in wheat flour, 84% in corn flour, 34% in grape juice, and 26% in apple juice. Collectively, these findings establish crude SHP as a promising candidate for effective AOH degradation, with potential applications in the food and feed industry.

Densification of Genetic Map and Stable Quantitative Trait Locus Analysis for Amino Acid Content of Seed in Soybean (Glycine max L.).

Soybean, a primary vegetable protein source, boasts favorable amino acid profiles; however, its composition still falls short of meeting human nutritional demands. The soybean amino acid content is a quantitative trait controlled by multiple genes. In this study, an F2 population of 186 individual plants derived from the cross between ChangJiangChun2 and JiYu166 served as the mapping population. Based on the previously published genetic map of our lab, we increased the density of the genetic map and constructed a new genetic map containing 518 SSR (simple sequence repeats) markers and 64 InDel (insertion-deletion) markers, with an average distance of 5.27 cm and a total length of 2881.2 cm. The content of eight essential amino acids was evaluated in the F2:5, F2:6, and BLUP (best linear unbiased prediction). A total of 52 QTLs (quantitative trait loci) were identified, and 13 QTL clusters were identified, among which loci02.1 and loci11.1 emerged as stable QTL clusters, exploring candidate genes within these regions. Through GO enrichment and gene annotation, 16 candidate genes associated with soybean essential amino acid content were predicted. This study would lay the foundation for elucidating the regulatory mechanisms of essential amino acid content and contribute to germplasm innovation in soybeans.

Nitrate Inhibits Nodule Nitrogen Fixation by Accumulating Ureide in Soybean Plants.

The mechanism by which nitrate inhibits nitrogen fixation in soybean (Glycine max L.) is not fully understood. Accumulation of ureide in soybean plant tissues may regulate the nitrogen fixation capacity through a feedback pathway. In this study, unilaterally nodulated dual-root soybeans prepared by grafting were grown in sand culture. They were subjected to the removal of the nodulated side roots, and were given either nitrate supply or no supply to the non-nodulated side roots for 3 days (experiment I). Additionally, they received nitrate supply to the non-nodulated side roots for 1-14 days (experiment II). The results showed that nitrate supply increased the levels of asparagine and ureide in soybean shoots (Experiment I). In Experiment II, nodule dry weight, nodule number, nodule nitrogenase activity, and nodule urate oxidase activity decreased significantly after 3, 7, and 14 days of nitrate supply. Ureide content in the shoots and nodules increased after 1, 3, and 7 days of nitrate supply, but decreased after 14 days of nitrate supply. There was a significant positive correlation between urate oxidase activity and nitrogenase activity. Hence, we deduced that nitrate supply increased the asparagine content in soybean shoots, likely inhibiting ureide degradation, which induced the accumulation of ureide in soybean shoots and nodules, and, in turn, feedback inhibited the nodule nitrogen fixation. In addition, urate oxidase activity can be used to assess the nitrogen fixation capacity of nodules.

GmHs1-1 and GmqHS1 Simultaneously Contribute to the Domestication of Soybean Hard-Seededness.

Seed physical dormancy (hard-seededness) is an interesting ecological phenomenon and important agronomic trait. The loss of seed coat impermeability/hard-seededness is a key target trait during the domestication of leguminous crops which allows seeds to germinate rapidly and uniformly. In this study, we examined the mutation of quantitative trait locus (QTL) genes, GmHs1-1 and GmqHS1, in 18 wild soybean (G. soja) and 23 cultivated soybean (G. max) accessions. The sequencing results indicate that a G-to-T substitution in GmqHS1 and a C-to-T substitution in GmHs1-1 occurred in all 23 cultivated soybean accessions but not in any of the 18 wild soybean accessions. The mutations in the two genes led to increased seed coat permeability in cultivated soybean. Therefore, we provide evidence that two genes, GmHs1-1 and GmqHS1, simultaneously contribute to the domestication of hard-seededness in soybeans. This finding is of great significance for genetic analysis and improved utilization of the soybean hard-seededness trait.