Microbial detoxification of eleven food and feed contaminating trichothecene mycotoxins.

BACKGROUND: Contamination of agricultural commodities with multiple trichothecene mycotoxins, produced by toxigenic Fusarium species, is a food safety issue, which greatly affects grain production and marketing worldwide. Importantly, exposure to multiple trichothecenes may increase toxicity in animals due to their synergistic and/or additive effects. To address the problem this study aimed to achieve a novel biological trait capable of detoxifying various food and feed contaminating trichothecenes under aerobic and anaerobic conditions and wide range of temperatures. RESULTS: A highly enriched microbial consortium (called DX100) capable of transforming eleven trichothecenes to significantly less toxic de-epoxy forms was achieved after prolonged incubation of soil microbial culture with 200 µg/mL deoxynivalenol (DON). DX100 demonstrated de-epoxidation activity under aerobic and anaerobic conditions, a greater range of temperatures and around neutral pH. The consortium contains 70% known and 30% unknown bacterial species, dominated by Stenotrophomonas species. Probably novel bacteria including strains of Stenotrophomonas and Alkaliphilus-Blautia species complex could be involved in aerobic and anaerobic de-epoxidation of trichothecenes, respectively. DX100 showed rapid and stable activity by de-epoxidizing 100% of 50 µg/mL deoxynivalenol at 48 h of incubation and retaining de-epoxidation ability after 100 subcultures in mineral salts broth (MSB). It was able to de-epoxidize high concentration of DON (500 µg/mL), and transformed ten more food contaminating trichothecenes into de-epoxy forms and/or other known/unknown compounds. Microbial de-epoxidation rate increased with increasing trichothecene concentrations in the broth media, suggesting that DX100 maintains a robust trichothecene detoxifying mechanism. Furthermore, the nature of microbial de-epoxidation reaction and inhibition of the reaction by sodium azide and the finding that bacterial cell culture lysate retained activity suggests that certain cytoplasmic reductases may be responsible for the de-epoxidation activity. CONCLUSIONS: This study reports the enrichment procedure for obtaining an effective and stable microbial consortium DX100 capable of de-epoxidizing several food contaminating trichothecene mycotoxins. DX100, which has de-epoxidation ability under wide range of conditions, represents a unique enzymatic source which has great industrial potential for reducing contamination of foods/feeds with multiple trichothecenes, and minimizing their synergistic/additive cytotoxic effects on consumer health.

Proanthocyanidin accumulation and transcriptional responses in the seed coat of cranberry beans (Phaseolus vulgaris L.) with different susceptibility to postharvest darkening.

BACKGROUND: Edible dry beans (Phaseolus vulgaris L.) that darken during postharvest storage are graded lower and are less marketable than their non-darkened counterparts. Seed coat darkening in susceptible genotypes is dependent upon the availability of proanthocyanidins, and their subsequent oxidation to reactive quinones. Mature cranberry beans lacking this postharvest darkening trait tend to be proanthocyanidin-deficient, although the underlying molecular and biochemical determinants for this metabolic phenomenon are unknown. RESULTS: Seed coat proanthocyanidin levels increased with plant maturation in a darkening-susceptible cranberry bean recombinant inbred line (RIL), whereas these metabolites were absent in seeds of the non-darkening RIL plants. RNA sequencing (RNA-seq) analysis was used to monitor changes in the seed coat transcriptome as a function of bean development, where transcript levels were measured as fragments per kilobase of exon per million fragments mapped. A total of 1336 genes were differentially expressed between darkening and non-darkening cranberry bean RILs. Structural and regulatory genes of the proanthocyanidin biosynthesis pathway were upregulated in seed coats of the darkening RIL. A principal component analysis determined that changes in transcript levels for two genes of unknown function and three proanthocyanidin biosynthesis genes, FLAVANONE 3-HYDROXYLASE 1, DIHYDROFLAVONOL 4-REDUCTASE 1 and ANTHOCYANIDIN REDUCTASE 1 (PvANR1) were highly correlated with proanthocyanidin accumulation in seed coats of the darkening-susceptible cranberry bean RIL. HPLC-DAD analysis revealed that in vitro activity of a recombinant PvANR1 was NADPH-dependent and assays containing cyanidin yielded epicatechin and catechin; high cyanidin substrate levels inhibited the formation of both of these products. CONCLUSION: Proanthocyanidin oxidation is a pre-requisite for postharvest-related seed coat darkening in dicotyledonous seeds. In model plant species, the accumulation of proanthocyanidins is dependent upon upregulation of biosynthetic genes. In this study, proanthocyanidin production in cranberry bean seed coats was strongly associated with an increase in PvANR1 transcripts during seed maturation. In the presence of NADPH, PvANR1 converted the physiologically relevant substrate cyanidin to epicatechin and catechin.

Molecular characterization of dihydroneopterin aldolase and aminodeoxychorismate synthase in common bean-genes coding for enzymes in the folate synthesis pathway.

Common beans (Phaseolus vulgaris) are excellent sources of dietary folates, but different varieties contain different amounts of these compounds. Genes coding for dihydroneopterin aldolase (DHNA) and aminodeoxychorismate synthase (ADCS) of the folate synthesis pathway were characterized by PCR amplification, BAC clone sequencing, and whole genome sequencing. All DHNA and ADCS genes in the Mesoamerican cultivar OAC Rex were isolated and compared with those genes in the genome of Andean genotype G19833. Both genotypes have two functional DHNA genes and one pseudo gene. PvDHNA1 and PvDHNA2 proteins have similar secondary structures and conserved residues as DHNA homologs in Staphylococcus aureus and Arabidopsis. Sequence analysis and synteny mapping indicated that PvDHNA1 might be a duplicated and transposed copy of PvDHNA2. There is only one ADCS gene (PvADCS) identified in the bean genome and it is identical in OAC Rex and G19833. PvADCS has the conserved motifs required for catalytic activity similar to other plant ADCS homologs. DHNA and ADCS gene-specific markers were developed, mapped, and compared to their physical locations on chromosomes 1 and 7, respectively. The gene-specific markers developed in this study should be useful for detection and selection of varieties with enhanced folate contents in bean breeding programs.

Cooked navy and black bean diets improve biomarkers of colon health and reduce inflammation during colitis.

Common beans contain non-digestible fermentable components (SCFA precursors) and phenolic compounds (phenolic acids, flavonoids and anthocyanins) with demonstrated antioxidant and anti-inflammatory potential. The objective of the present study was to assess the in vivo effect of cooked whole-bean flours, with differing phenolic compound levels and profiles, in a mouse model of acute colitis. C57BL/6 mice were fed a 20 % navy bean or black bean flour-containing diet or an isoenergetic basal diet (BD) for 2 weeks before the induction of experimental colitis via 7 d dextran sodium sulphate (DSS, 2 % (w/v) in the drinking-water) exposure. Compared with the BD, both bean diets increased caecal SCFA and faecal phenolic compound concentrations (P< 0·05), which coincided with both beneficial and adverse effects on colonic and systemic inflammation. On the one hand, bean diets reduced mRNA expression of colonic inflammatory cytokines (IL-6, IL-9, IFN-γ and IL-17A) and increased anti-inflammatory IL-10 (P< 0·05), while systemically reduced circulating cytokines (IL-1ß, TNFα, IFNγ, and IL-17A, P< 0·05) and DSS-induced oxidative stress. On the other hand, bean diets enhanced DSS-induced colonic damage as indicated by an increased histological injury score and apoptosis (cleaved caspase-3 and FasL mRNA expression) (P< 0·05). In conclusion, bean-containing diets exerted both beneficial and adverse effects during experimental colitis by reducing inflammatory biomarkers both locally and systemically while aggravating colonic mucosal damage. Further research is required to understand the mechanisms through which beans exert their effects on colonic inflammation and the impact on colitis severity in human subjects.

Agrobacterium tumefaciens-mediated transformation of corn (Zea mays L.) multiple shoots.

An Agrobacterium tumefaciens-mediated corn transformation method based on multiple shoot tissue cultures was developed, which is effective with a variety of corn inbred lines and standard binary vectors. Six factors that affected the success of corn transformation were tested, including A. tumefaciens strain, corn genotype, tissue culture growth stage, medium composition, co-culture temperature and surfactant treatment. Agropine-type bacteria (EHA 101 and AGL 1) were eightfold more effective than octopine-type strain for corn multi-shoot tissues transformation. The average frequency of Glucuronidase (GUS)-positive explants obtained from 14 corn genotypes ranged from 36% to 76%. L-proline (0.7 g L-1) in the co-culture medium apparently improved the frequency of transformation. The newly initiated multi-shoot tissues were most responsive to Agrobacterium infection. A positive correlation was found between multi-shoot tissue susceptibility to Agrobacterium and the proportion of cells in G1 phase. Transformants were identified by reverse transcription Polymerase Chain Reaction (PCR) and by southern blot hybridization assays. The frequency of transformants was approximately 2% based on the number of multi-shoot explants co-cultivated with Agrobacterium.

Mapping yield and yield-related traits using diverse common bean germplasm.

Common bean (bean) is one of the most important legume crops, and mapping genes for yield and yield-related traits is essential for its improvement. However, yield is a complex trait that is typically controlled by many loci in crop genomes. The objective of this research was to identify regions in the bean genome associated with yield and a number of yield-related traits using a collection of 121 diverse bean genotypes with different yields. The beans were evaluated in replicated trials at two locations, over two years. Significant variation among genotypes was identified for all traits analyzed in the four environments. The collection was genotyped with the BARCBean6K_3 chip (5,398 SNPs), two yield/antiyield gene-based markers, and seven markers previously associated with resistance to common bacterial blight (CBB), including a Niemann-Pick polymorphism (NPP) gene-based marker. Over 90% of the single-nucleotide polymorphisms (SNPs) were polymorphic and separated the panel into two main groups of small-seeded and large-seeded beans, reflecting their Mesoamerican and Andean origins. Thirty-nine significant marker-trait associations (MTAs) were identified between 31 SNPs and 15 analyzed traits on all 11 bean chromosomes. Some of these MTAs confirmed genome regions previously associated with the yield and yield-related traits in bean, but a number of associations were not reported previously, especially those with derived traits. Over 600 candidate genes with different functional annotations were identified for the analyzed traits in the 200-Kb region centered on significant SNPs. Fourteen SNPs were identified within the gene model sequences, and five additional SNPs significantly associated with five different traits were located at less than 0.6 Kb from the candidate genes. The work confirmed associations between two yield/antiyield gene-based markers (AYD1m and AYD2m) on chromosome Pv09 with yield and identified their association with a number of yield-related traits, including seed weight. The results also confirmed the usefulness of the NPP marker in screening for CBB resistance. Since disease resistance and yield measurements are environmentally dependent and labor-intensive, the three gene-based markers (CBB- and two yield-related) and quantitative trait loci (QTL) that were validated in this work may be useful tools for simplifying and accelerating the selection of high-yielding and CBB-resistant bean cultivars.

Development of candidate gene markers associated to common bacterial blight resistance in common bean.

Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli (Xap), is a major yield-limiting factor of common bean (Phaseolus vulgaris L.) production around the world. Two major CBB-resistant quantitative trait loci (QTL), linked to the sequence characterized amplified region markers BC420 and SU91, are located at chromosomes 6 and 8, respectively. Using map-based cloning approach, four bacterial artificial chromosome (BAC) clones from the BC420-QTL locus and one BAC clone containing SU91 were sequenced by Roche 454 technique and subsequently assembled using merged assemblies from three different programs. Based on the quality of the assembly, only the sequences of BAC 32H6 and 4K7 were used for candidate gene marker (CGM) development and candidate gene (CG) selection. For the BC420-QTL locus, 21 novel genes were predicted in silico by FGENESH using Medicago gene model, whereas 16 genes were identified in the SU91-QTL locus. For each putative gene, one or more primer pairs were designed and tested in the contrasting near isogenic lines. Overall, six and nine polymorphic markers were found in the SU91- and BC420-QTL loci, respectively. Afterwards, association mapping was conducted in a breeding population of 395 dry bean lines to discover marker-trait associations. Two CGMs per each locus showed better association with CBB resistance than the BC420 and SU91 markers, which include BC420-CG10B and BC420-CG14 for BC420_QTL locus, and SU91-CG10 and SU91-CG11 for SU91_QTL locus. The strong associations between CBB resistance and the CGs 10 and 14 from BC420_QTL locus and the CGs 10 and 11 from SU91_QTL locus indicate that the genes 10 and 14 from the BC420 locus are potential CGs underlying the BC420_QTL locus, whereas the genes 10 and 11 from the SU91 locus are potential CGs underlying the SU91_QTL locus. The superiority of SU91-CG11 was further validated in a recombinant inbred line population Sanilac × OAC 09-3. Thus, co-dominant CGMs, BC420-CG14 and SU91-CG11, are recommended to replace BC420 and SU91 for marker-assisted selection of common bean with resistance to CBB.

Application of image analysis in studies of quantitative disease resistance, exemplified using common bacterial blight-common bean pathosystem.

The effectiveness of image analysis (IA) compared with an ordinal visual scale, for quantitative measurement of disease severity, its application in quantitative genetic studies, and its effect on the estimates of genetic parameters were investigated. Studies were performed using eight backcross-derived families of common bean (Phaseolus vulgaris) (n = 172) segregating for the molecular marker SU91, known to be associated with a quantitative trait locus (QTL) for resistance to common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. fuscans subsp. fuscans. Even though both IA and visual assessments were highly repeatable, IA was more sensitive in detecting quantitative differences between bean genotypes. The CBB phenotypic difference between the two SU91 genotypic groups was consistently more than fivefold for IA assessments but generally only two- to threefold for visual assessments. Results suggest that the visual assessment results in overestimation of the effect of QTL in genetic studies. This may have been caused by lack of additivity and uneven intervals of the visual scale. Although visual assessment of disease severity is a useful tool for general selection in breeding programs, assessments using IA may be more suitable for phenotypic evaluations in quantitative genetic studies involving CBB resistance as well as other foliar diseases.

Aerobic and anaerobic de-epoxydation of mycotoxin deoxynivalenol by bacteria originating from agricultural soil.

One hundred and fifty soil samples collected from different crop fields in southern Ontario, Canada were screened to obtain microorganisms capable of transforming deoxynivalenol (DON) to de-epoxy DON (dE-DON). Microbial DON to dE-DON transformation (i.e. de-epoxydation) was monitored by using liquid chromatography-ultraviolet-mass spectrometry (LC-UV-MS). The effects of growth substrates, temperature, pH, incubation time and aerobic versus anaerobic conditions on the ability of the microbes to de-epoxydize DON were evaluated. A mixed microbial culture from one composite soil sample showed 100% DON to dE-DON biotransformation in mineral salts broth (MSB) after 144 h of incubation. Treatments of the culture with selective antibiotics followed an elevated temperature (50°C) for 1.5 h considerably reduced the microbial diversity. Partial 16S-rRNA gene sequence analysis of the bacteria in the enriched culture indicated the presence of at least six bacterial genera, namely Serratia, Clostridium, Citrobacter, Enterococcus, Stenotrophomonas and Streptomyces. The enriched culture completely de-epoxydized DON after 60 h of incubation. Bacterial de-epoxydation of DON occurred at pH 6.0-7.5, and a wide array of temperatures (12-40°C). The culture showed rapid de-epoxydation activity under aerobic conditions compared to anaerobic conditions. This is the first report on microbial DON to dE-DON transformation under aerobic conditions and moderate temperatures. The culture could be used to detoxify DON contaminated feed and might be a potential source for gene(s) for DON de-epoxydation.

Characterization of seed coat post harvest darkening in common bean (Phaseolus vulgaris L.).

Seed coat post harvest darkening (PHD) represents a problem for producers and consumers of several market classes of dry bean. There are three PHD phenotypes: (1) non-darkening (ND), (2) slow darkening (SD) and (3) regular darkening (RD). The inheritance of PHD was elucidated by evaluating populations derived from crosses among multiple RD, SD and ND genotypes. Results indicate that at least two unlinked major genes control the PHD trait in common bean. Recessive epistasis with three phenotypic classes explains the segregation ratios of populations from crosses between SD and ND parents. One gene, J, is responsible for whether a bean will darken as seeds from plants that are jj do not darken at all. Another gene, sd, influences how quickly a seed coat will darken with sdsd individuals darkening more slowly than those with the dominant Sd allele.

Navy Bean Supplementation in Established High-Fat Diet-Induced Obesity Attenuates the Severity of the Obese Inflammatory Phenotype.

Cooked common beans (Phaseolus vulgaris) improve intestinal health in lean mice and attenuate intestinal dysbiosis and inflammation when consumed concurrent with obesity development. We determined the effects of a high-fat (HF) bean supplemented diet in mice with established obesity (induced by 12 weeks of HF diet (60% fat as kcal)) compared to obese mice consuming a HF or low-fat (LF) weight loss control diet. Obese C57BL/6 male mice remained consuming HF for eight weeks or were randomly switched from HF to an isocaloric HF with 15.7% cooked navy bean powder diet (HFàHFB) or LF (11% fat as kcal; HFàLF) (n = 12/group). HFàHFB improved the obese phenotype, including (i) fecal microbiome (increased Prevotella, Akkermansia muciniphila, and short-chain fatty acid levels), (ii) intestinal health (increased ZO-1, claudin-2, Muc2, Relmß, and Reg3γ expression), and (iii) reduced adipose tissue (AT) inflammatory proteins (NFκBp65, STAT3, IL-6, MCP-1, and MIP-1α), versus HF (p < 0.05). Conversely, HFàLF reduced body weight and circulating hormones (leptin, resistin, and PAI-1) versus HF and HFàHFB (p < 0.05); however, AT inflammation and intestinal health markers were not improved to the same degree as HFàHFB (p < 0.05). Despite remaining on a HF obesogenic diet, introducing beans in established obesity improved the obese phenotype (intestinal health and adipose inflammation) more substantially than weight loss alone.

Identification, Gene Structure, and Expression of BnMicEmUP: A Gene Upregulated in Embryogenic Brassica napus Microspores.

Microspores of Brassica napus can be diverted from normal pollen development into embryogenesis by treating them with a mild heat shock. As microspore embryogenesis closely resembles zygotic embryogenesis, it is used as model for studying the molecular mechanisms controlling embryo formation. A previous study comparing the transcriptomes of three-day-old sorted embryogenic and pollen-like (non-embryogenic) microspores identified a gene homologous to AT1G74730 of unknown function that was upregulated 8-fold in the embryogenic cells. In the current study, the gene was isolated and sequenced from B. napus and named BnMicEmUP (B. napus microspore embryogenesis upregulated gene). Four forms of BnMicEmUP mRNA and three forms of genomic DNA were identified. BnMicEmUP2,3 was upregulated more than 7-fold by day 3 in embryogenic microspore cultures compared to non-induced cultures. BnMicEmUP1,4 was highly expressed in leaves. Transient expression studies of BnMicEmUP3::GFP fusion protein in Nicotiana benthamiana and in stable Arabidopsis transgenics showed that it accumulates in chloroplasts. The features of the BnMicEmUP protein, which include a chloroplast targeting region, a basic region, and a large region containing 11 complete leucine-rich repeats, suggest that it is similar to a bZIP PEND (plastid envelope DNA-binding protein) protein, a DNA binding protein found in the inner envelope membrane of developing chloroplasts. Here, we report that the BnMicEmUP3 overexpression in Arabidopsis increases the sensitivity of seedlings to exogenous abscisic acid (ABA). The BnMicEmUP proteins appear to be transcription factors that are localized in plastids and are involved in plant responses to biotic and abiotic environmental stresses; as well as the results obtained from this study can be used to improve crop yield.

Postharvest seed coat darkening in pinto bean (Phaseolus vulgaris) is regulated by Psd , an allele of the basic helix-loop-helix transcription factor P.

Pinto bean (Phaseolus vulgaris) is one of the leading market classes of dry beans that is most affected by postharvest seed coat darkening. The process of seed darkening poses a challenge for bean producers and vendors as they encounter significant losses in crop value due to decreased consumer preference for darker beans. Here, we identified a novel allele of the P gene, Psd , responsible for the slow darkening seed coat in pintos, and identified trait-specific sequence polymorphisms which are utilized for the development of new gene-specific molecular markers for breeding. These tools can be deployed to help tackle this economically important issue for bean producers. SUMMARY: Postharvest seed coat darkening in pinto bean is an undesirable trait that reduces the market value of the stored crop. Regular darkening (RD) pintos darken faster after harvest and accumulate higher level of proanthocyanidins (PAs) compared to slow darkening (SD) cultivars. Although the markers cosegregating with the SD trait have been known for some time, the SLOW DARKENING (Sd) gene identity had not been proven.Here, we identified Psd as a candidate for controlling the trait. Genetic complementation, transcript abundance, metabolite analysis, and inheritance study confirmed that Psd is the Sd gene. Psd is another allele of the P (Pigment) gene, whose loss-of-function alleles result in a white seed coat. Psd encodes a bHLH transcription factor with two transcript variants but only one is involved in PA biosynthesis. An additional glutamate residue in the activation domain, and/or an arginine to histidine substitution in the bHLH domain of the Psd-1 transcript in the SD cultivar is likely responsible for the reduced activity of this allele compared to the allele in a RD cultivar, leading to reduced PA accumulation.Overall, we demonstrate that a novel allele of P, Psd , is responsible for the SD phenotype, and describe the development of new, gene-specific, markers that could be utilized in breeding to resolve an economically important issue for bean producers.

Genetic Diversity, Nitrogen Fixation, and Water Use Efficiency in a Panel of Honduran Common Bean (Phaseolus vulgaris L.) Landraces and Modern Genotypes.

Common bean (Phaseolus vulgaris L.) provides critical nutrition and a livelihood for millions of smallholder farmers worldwide. Beans engage in symbiotic nitrogen fixation (SNF) with Rhizobia. Honduran hillside farmers farm marginal land and utilize few production inputs; therefore, bean varieties with high SNF capacity and environmental resiliency would be of benefit to them. We explored the diversity for SNF, agronomic traits, and water use efficiency (WUE) among 70 Honduran landrace, participatory bred (PPB), and conventionally bred bean varieties (HON panel) and 6 North American check varieties in 3 low-N field trials in Ontario, Canada and Honduras. Genetic diversity was measured with a 6K single nucleotide polymorphism (SNP) array, and phenotyping for agronomic, SNF, and WUE traits was carried out. STRUCTURE analysis revealed two subpopulations with admixture between the subpopulations. Nucleotide diversity was greater in the landraces than the PPB varieties across the genome, and multiple genomic regions were identified where population genetic differentiation between the landraces and PPB varieties was evident. Significant differences were found between varieties and breeding categories for agronomic traits, SNF, and WUE. Landraces had above average SNF capacity, conventional varieties showed higher yields, and PPB varieties performed well for WUE. Varieties with the best SNF capacity could be used in further participatory breeding efforts.

Agronomic Performance and Nitrogen Fixation of Heirloom and Conventional Dry Bean Varieties Under Low-Nitrogen Field Conditions.

Common beans (Phaseolus vulgaris) form a relationship with nitrogen-fixing rhizobia and through a process termed symbiotic nitrogen fixation (SNF) which provides them with a source of nitrogen. However, beans are considered poor nitrogen fixers, and modern production practices involve routine use of N fertilizer, which leads to the down-regulation of SNF. High-yielding, conventionally bred bean varieties are developed using conventional production practices and selection criteria, typically not including SNF efficiency, and may have lost this trait over decades of modern breeding. In contrast, heirloom bean genotypes were developed before the advent of modern production practices and may represent an underutilized pool of genetics which could be used to improve SNF. This study compared the SNF capacity under low-N field conditions, of collections of heirloom varieties with and conventionally bred dry bean varieties. The heirloom-conventional panel (HCP) consisted of 42 genotypes from various online seed retailers or from the University of Guelph Bean Breeding program seedbank. The HCP was genotyped using a single nucleotide polymorphism (SNP) array to investigate genetic relatedness within the panel. Field trials were conducted at three locations in ON, Canada from 2014 to 2015 and various agronomic and seed composition traits were measured, including capacity for nitrogen fixation (using the natural abundance method to measure seed N isotope ratios). Significant variation for SNF was found in the panel. However, on average, heirloom genotypes did not fix significantly more nitrogen than conventionally bred varieties. However, five heirloom genotypes fixed >60% of their nitrogen from the atmosphere. Yield (kg ha-1) was not significantly different between heirloom and conventional genotypes, suggesting that incorporating heirloom genotypes into a modern breeding program would not negatively impact yield. Nitrogen fixation was significantly higher among Middle American genotypes than among Andean genotypes, confirming previous findings. The best nitrogen fixing line was Coco Sophie, a European heirloom white bean whose genetic makeup is admixed between the Andean and Middle American genepools. Heirloom genotypes represent a useful source of genetics to improve SNF in modern bean breeding.

Navy bean supplemented high-fat diet improves intestinal health, epithelial barrier integrity and critical aspects of the obese inflammatory phenotype.

Obesity is associated with impaired intestinal epithelial barrier function and an altered microbiota community structure, which contribute to host systemic inflammation and metabolic dysfunction. Fiber-rich common beans (Phaseolus vulgaris) promote intestinal health (microbiota and host epithelial barrier integrity) in lean mice. The objective was to assess the intestinal health promoting effects of navy bean supplementation during high-fat (HF)diet-induced obesity. Male C57BL/6 mice were fed either a high-fat (HF) diet (60% of kcal from fat) or an isocaloric HF diet supplemented with 15.7% (by weight) cooked navy bean powder (HF+B) for 12 weeks. Compared to HF, the HF+B diet altered the fecal microbiota community structure (16S rRNA gene sequencing), most notably increasing abundance of Akkermansia muciniphila (+19-fold), whose abundance typically decreases in obese humans and rodents. Additionally, HF+B fecal abundance of carbohydrate fermenting, short chain fatty acid (SCFA) producing Prevotella (+332-fold) and S24-7 (+1.6-fold) and fecal SCFA levels were increased. HF+B improved intestinal health and epithelial barrier integrity versus HF, evidenced by reduced serum fluorescein isothiocyanate (FITC)-dextran concentration in an in vivo gut permeability test, and increased intestinal mRNA expression of tight junction components (ZO-1, occludin), anti-microbial defenses (Reg3γ, IgA, Defα5, Defß2) and mucins (Muc2). Additionally, HF+B improved the systemic obese phenotype via reduced serum HOMA-IR and leptin:adiponectin ratio, and locally via attenuation of epididymal adipose tissue crown-like structure formation, adipocyte size, and inflammatory transcription factor (NFκBp65 and STAT3) activation. Therefore, navy bean supplementation improved obese intestinal health (microbiota and epithelial barrier integrity) and attenuated the severity of the obese phenotype.

Draft Genome Sequence of Enterobacter cloacae 3D9 (Phylum Proteobacteria).

Presented here is the draft genome sequence of Enterobacter cloacae 3D9. This candidate seed endophyte was isolated from Zea nicaraguensis. The genome contains 4,653,375 bp in 28 contigs.

Draft Genome Sequence of Enterobacter cloacae 3F11 (Phylum Proteobacteria).

Presented here is the draft genome sequence of Enterobacter cloacae 3F11. This seed endophyte solubilizes rock phosphate and was isolated from Zea nicaraguensis. The genome contains 4,579,108 bp in 264 contigs.

Quantification and persistence of recombinant DNA of Roundup Ready corn and soybean in rotation.

The presence of the recombinant cp4 epsps gene from Roundup Ready (RR) corn and RR soybean was quantified using real-time PCR in soil samples from a field experiment growing RR and conventional corn and soybean in rotation. RR corn and RR soybean cp4 epsps persisted in soil for up to 1 year after seeding. The concentration of recombinant DNA in soil peaked in July and August in RR corn and RR soybean plots, respectively. A small fraction of soil samples from plots seeded with conventional crops contained recombinant DNA, suggesting transgene dispersal by means of natural process or agricultural practices. This research will aid in the understanding of the persistence of recombinant DNA in agricultural cropping systems.

Navy and black bean supplementation primes the colonic mucosal microenvironment to improve gut health.

Common beans (Phaseolus vulgaris L.) are enriched in non-digestible fermentable carbohydrates and phenolic compounds that can modulate the colonic microenvironment (microbiota and host epithelial barrier) to improve gut health. In a comprehensive assessment of the impact of two commonly consumed bean varieties (differing in levels and types of phenolic compounds) within the colonic microenvironment, C57Bl/6 mice were fed diets supplemented with 20% cooked navy bean (NB) or black bean (BB) flours or an isocaloric basal diet control (BD) for 3 weeks. NB and BB similarly altered the fecal microbiota community structure (16S rRNA sequencing) notably by increasing the abundance of carbohydrate fermenting bacteria such as Prevotella, S24-7 and Ruminococcus flavefaciens, which coincided with enhanced short chain fatty acid (SCFA) production (microbial-derived carbohydrate fermentation products) and colonic expression of the SCFA receptors GPR-41/-43/-109a. Both NB and BB enhanced multiple aspects of mucus and epithelial barrier integrity vs. BD including: (i) goblet cell number, crypt mucus content and mucin mRNA expression, (ii) anti-microbial defenses (Reg3γ), (iii) crypt length and epithelial cell proliferation, (iv) apical junctional complex components (occludin, JAM-A, ZO-1 and E-cadherin) mRNA expression and (v) reduced serum endotoxin concentrations. Interestingly, biomarkers of colon barrier integrity (crypt height, mucus content, cell proliferation and goblet cell number) were enhanced in BB vs. NB-fed mice, suggesting added benefits attributable to unique BB components (e.g., phenolics). Overall, NB and BB improved baseline colonic microenvironment function by altering the microbial community structure and activity and promoting colon barrier integrity and function; effects which may prove beneficial in attenuating gut-associated diseases.