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Objective The objectives of these experiments were to evaluate (1) if inclusion of inedible tallow containing ractopamine (RAC) in the cattle diet influences feedlot performance, carcass characteristics, and results in detectable RAC in tissues and (2) the effect of withdrawal time on RAC residues in the gastrointestinal-tract digesta of cattle. Materials and Methods In Exp. 1, beef steers (n = 28) were assigned to dietary treatments formulated with feed tallow ranging from 100% inedible tallow to 100% technical tallow. After 91 d, steers were transported to a commercial abattoir and slaughtered, and tissues were collected for RAC analysis. In Exp. 2, steers fitted with ruminal and duodenal cannulas were assigned to the control group (no RAC) or a group in which RAC was supplemented at 400 mg of RAC∙animal−1∙d−1 for 28 d. On d 29, RAC supplementation was withdrawn. Daily ruminal, duodenal, and fecal samples were obtained for RAC analysis beginning 3 d before RAC withdrawal and continuing to d 13 after withdrawal. Results and Discussion No treatment effects of dietary inedible tallow inclusion was observed for final BW (P Implications and Applications The results indicate that RAC residue in feed tallow does not affect animal performance or carcass characteristics. Detectable RAC in sampled tissues and gastrointestinal digesta suggests a need for further investigation of RAC residues to maintain compliance for exported beef products.

Root exudation is one of the primary processes that mediate interactions between plant roots, microorganisms, and the soil matrix. Previous research has shown that plant root exudate profiles vary between species and genotypes which can likely support different microbial associations. Here, utilizing distinct sorghum genotypes as a model system, we characterized the chemical heterogeneity between root exudates and the effects of that variability on soil microbial membership and metabolisms. Distinct exudate chemical profiles were quantified and used to formulate synthetic root exudate treatments, a High Organic acid Treatment (HOT) and a High Sugar Treatment (HST). Root exudate treatments were added to laboratory soil reactors and 16S rRNA gene profiling illustrated distinct microbial membership in response to HST or HOT amendments. Alpha and beta diversity metrics were significantly different between treatments, (Shannon’s, p < 0.0001, mrpp = 0.01, respectively). Exometabolite production was highest in the HST, with increased production of key organic acids, non-proteinogenic amino acids, and three plant growth-promoting phytohormones (benzoic acid, salicylic acid, indole-3-acetic acid), suggesting plant-derived sugars fuel microbial carbon metabolism and contribute to phytohormone production. Linking the metabolic capacity of metagenome-assembled genomes in the HST to the exometabolite patterns, we identified potential plant growth-promoting microorganisms that could produce these phytohormones. Our findings emphasize the tractability of high-resolution multi-omics tools to investigate soil microbiomes, opening the possibility of manipulating native microbial communities to improve specific soil microbial functions and enhance crop production.ImportanceUnderstanding interactions between plant root exudates and the soil microbiome provides an avenue for a more comprehensive appreciation for how plant roots modulate their microbial counterparts to promote an environment favorable to plant fitness. Although these dynamics are appreciated as indispensable, mechanisms controlling specific rhizobiome membership and complexity are not fully understood. In this study, we investigate how variability in root exudation, modeled after differences observed between distinct sorghum genotypes, contributes to altered microbial membership and metabolisms. The results demonstrate how microbial diversity is influenced by root exudates of differing chemical composition and how changes in microbial membership correspond to modifications in carbon utilization and enhance production of plant-relevant metabolites. Our findings suggest carbon substrate preferences among bacteria in semi-arid climate soils and mechanisms for root exudate utilization. These findings provide new information on plant-soil environments useful for the development of efficient and precise microbiota management strategies in agricultural systems.

The last two decades have seen a dramatic shift in cannabis legislation around the world. Cannabis products are now widely available and commercial production and use of phytocannabinoid products is rapidly growing. However, this growth is outpacing the research needed to elucidate the therapeutic efficacy of the myriad of chemical compounds found primarily in the flower of the female cannabis plant. This lack of research and corresponding regulation has resulted in processing methods, products, and terminology that are variable and confusing for consumers. Importantly, the impact of processing methods on the resulting chemical profile of full spectrum cannabis extracts is not well understood. As a first step in addressing this knowledge gap we have utilized a combination of analytical approaches to characterize the broad chemical composition of a single cannabis cultivar that was processed using previously optimized and commonly used commercial extraction protocols including alcoholic solvents and super critical carbon dioxide. Significant variation in the bioactive chemical profile was observed in the extracts resulting from the different protocols demonstrating the need for further research regarding the influence of processing on therapeutic efficacy as well as the importance of labeling in the marketing of multi-component cannabis products.

Ractopamine hydrochloride (RAC) is a beta-agonist approved by the U.S. Food and Drug Administration (FDA) as a medicated feed ingredient for cattle during the final days of finishing to improve feed efficiency and growth. Maximum residue limits and U.S. FDA residue tolerances for target tissues have defined management practices around RAC usage in the U.S. However, many countries have adopted zero tolerance policies and testing of off-target tissues, presenting a major challenge for international export. Therefore, the objective this study was to determine the necessary withdrawal time among cattle group-fed RAC to achieve residue concentrations below tolerance levels in muscle and off-target tissues. Specifically, both total and parent RAC residues were quantified in muscle, adipose tissue, rendered tallow, and large intestines from animals group-fed RAC and subjected to withdrawal 2, 4, or 7 days before harvest. Ractopamine (parent and total) residues were below the assay limit of detection (< 0.12 ng/g) in all muscle and adipose tissue samples from animals in control groups (no RAC). However, RAC residues were detectable, but below the limit of quantitation, in 40% of tallow and 17% of large intestine samples from control animals. As expected, mean RAC residue concentrations in muscle, adipose tissue, and large intestine samples decreased (P< 0.05) as the RAC withdrawal duration (days) was extended. Irrespective of RAC withdrawal duration, mean parent RAC residue concentrations in muscle, adipose tissue, and large intestine ranged from 0.33 to 0.76 ng/g, 0.16 to 0.26 ng/g, 3.97 to 7.44 ng/g, respectively and all tallow samples were > 0.14 ng/g (detectable but below the limit of quantitation). Results of this study provide a baseline for the development of management protocol recommendations associated with withdrawal following group-feeding of RAC to beef cattle in countries that allow RAC use and intend to export to global markets which may be subject to zero tolerance policies and off-target tissue testing.

Background Microgreens are the young leafy greens of many vegetables, herbs, grains, and flowers with potential to promote human health and sustainably diversify the global food system. For successful further integration into the global food system and evaluation of their health impacts, it is critical to elucidate and optimize their nutritional quality. Objectives We aimed to comprehensively evaluate the metabolite and mineral contents of 6 microgreen species, and the influence of maturity on their contents. Methods Plant species evaluated were from the Brassicaceae (arugula, broccoli, and red cabbage), Amaranthaceae (red beet and red amaranth), and Fabaceae (pea) plant families. Nontargeted metabolomics and ionomics analyses were performed to examine the metabolites and minerals, respectively, in each microgreen species and its mature counterpart. Results Nontargeted metabolomics analysis detected 3321 compounds, 1263 of which were annotated and included nutrients and bioactive compounds. Ionomics analysis detected and quantified 26 minerals including macrominerals, trace minerals, ultratrace minerals, and other metals. Principal component analysis indicated that microgreens have distinct metabolite and mineral profiles compared with one another and with their mature counterparts. Several compounds were higher (P, The 6 microgreen species evaluated had an extensive and diverse range of metabolites and minerals, providing evidence for their nutritional quality and potential to promote human health.

Crop load management is an important preharvest factor to balance yield, quality, and maturation in peach. However, few studies have addressed how preharvest factors impact metabolism on fruit of equal maturity. An experiment was conducted to understand how carbon competition impacts fruit internal quality and metabolism in ‘Cresthaven’ peach trees by imposing distinct thinning severities. Fruit quality was evaluated at three developmental stages (S2, S3, S4), while controlling for equal maturity using non-destructive near-infrared spectroscopy. Non-targeted metabolite profiling was used to characterize fruit at each developmental stage from trees that were unthinned (carbon starvation) or thinned (carbon sufficiency). Carbon sufficiency resulted in significantly higher fruit dry matter content and soluble solids concentration at harvest when compared to the carbon starved, underscoring the true impact of carbon manipulation on fruit quality. Significant differences in the fruit metabolome between treatments were observed at S2 when phenotypes were similar, while less differences were observed at S4 when the carbon sufficient fruit exhibited a superior phenotype. This suggests a potential metabolic priming effect on fruit quality when carbon is sufficiently supplied during early fruit growth and development. In particular, elevated levels of catechin may suggest a link between secondary/primary metabolism and fruit quality development.HighlightAn investigation of variable carbon supply conditions in peach fruit reveals that early metabolic priming is associated with quality development

Beverage quality in the brewing industry is heavily influenced by ingredient properties. The contribution of raw ingredients such as yeast and hops to beer flavor is well understood. However, the influence of barley genotype and/or environment on flavor (the malt 'source') is largely unexplored. Here, a study was performed to determine (i) if there are metabolite differences among six commercial malt sources, (ii) if differences in malt chemistry are reflected in the chemistry of the beer, and (iii) if the differences in the beer chemistry impact sensory attributes of beer, through flavor and flavor stability. Six distinct sources of malts (six varieties from three maltsters) were brewed into six beers using a recipe designed to evaluate differences in flavor. Metabolomics and ionomics was used to characterize chemical variation among the six malts and beers using UHPLC- and HILIC-MS (non-volatile metabolites), HS-SPME/GC–MS (beer volatiles), and ICP-MS (malt metals). These analyses detected a total of 5042 compounds in malt, of which 217 were annotated and included amines, amino acids, fatty acids/lipids/fatty acyls, saccharides/glucosides/sugar acids/sugar alcohols, carboxylic acid derivatives, organic acids, phenolics/benzenoids, purines, pyrimidines/pyridines, terpenes, and organosulfurs. A total of 4568 compounds were detected in beer, of which 246 were annotated and included esters, aldehydes, and alcohols. Statistical analysis revealed chemical variation among the six malts (50/217 malt metabolites varied) and beers (150/246). The six beers were evaluated for flavor using a modified descriptive analysis for 45 sensory traits at 0, 4, and 8 weeks of storage at 4 °C. Principal component analysis of the sensory data revealed flavor differences among the six beers at 8 weeks, and the malt-type Full Pint was described as fruity and Meredith as corn chip. The metabolite and sensory data were integrated and revealed associations between flavor profiles in beer and the annotated malt and beer. The fruity or corn chip flavor profiles in beer were associated beer purines/pyrimidines, volatile ketones, amines, and phenolics, and malt lipids, saccharides, phenols, amines, and alkaloids. Taken together, these data support a role of malt source in beer flavor and flavor stability. As a raw ingredient, malting barley genotypes can be evaluated for a contribution to flavor, and this may be a future target for plant breeding, agronomy, and malting efforts to selectively improve flavor, flavor stability, and quality in beer.

Fruit developing in different canopy positions are exposed to distinct light environments that can influence their maturation process and internal quality development. Maturation, a highly regulated process at the molecular level, significantly impacts fruit quality. Our understanding of the true effect of various pre-harvest factors on fruit quality is limited due to poor control of maturity among comparisons in previous studies. Here, an experiment was conducted to assess the true impact of canopy vigor and position (bottom: 0.3–1.2 m and top: 2.1–3.0 m) on ‘Sierra Rich’ (low vigor, LV) and ‘Cresthaven’ (high vigor, HV) peach fruit internal quality. Given the lower vigor of ‘Sierra Rich,’ it was recorded that light was more evenly distributed throughout the canopy thus, hypothesized that this could be leading to fruit of uniform quality across the different positions. Fruit from the different canopy positions were assessed at the commercial harvest stage for size, dry matter content (DMC) and physiological maturity (index of absorbance difference, IAD), using non-destructive visible (Vis) to near-infrared spectroscopy (NIRS). Fruit maturity and DMC advanced/increased with the elevated height of canopy in both cultivars. However, when controlling for equal maturity, only fruit coming from the vigorous ‘Cresthaven’ trees showed a significant (P ≤ 0.05) ΔDMC of 2.1 % between extreme canopy positions. Non-targeted metabolite profiling was carried out using gas chromatography mass spectrometry (GC–MS) on the mesocarp and exocarp of equally mature peach fruit samples. Mesocarp metabolite profiling of equally mature fruit coming from the different canopy positions demonstrated minimal metabolic variation. However, significant metabolite variation across canopy positions was observed in the exocarp of the HV cultivar. In general, sucrose, sorbitol and catechin were more abundant in higher quality, exposed to high-light environment fruit, while increased aspartic acid, asparagine, threonine, citric acid, monosaccharides (sorbose and fructose), butanoic acid and shikimic acid were associated with inferior quality, exposed to low-light environment fruit. Overall, this combined physiological and metabolomic analysis provides insight into the true impact of canopy position and underscores the light environment-related metabolic regulations that facilitate peach fruit quality development.

Although it is well known that diet is one of the major modulators of the gut microbiome, how the major components of diet shape the gut microbial community is not well understood. Here, we developed a simple system that allows the investigation of the impact of given compounds as supplements of the diet on the termite gut microbiome. The 16S rRNA pyrosequencing analysis revealed that feeding termites different blends of sugars and amino acids did not majorly impact gut community composition; however, ingestion of blends of secondary metabolites caused shifts in gut bacterial community composition. The supplementation of sugars and amino acids reduced the richness significantly, and sugars alone increased the evenness of the gut bacterial community significantly. Secondary metabolites created the most dramatic effects on the microbial community, potentially overriding the effect of other types of compounds. Furthermore, some microbial groups were stimulated specifically by particular groups of compounds. For instance, termites fed with secondary metabolites contained more Firmicutes and Spirochaetes compared to the other treatments. In conclusion, our results suggest that the termite (Reticulitermes flavipes) can be used as a simple and effective system to test the effects of particular chemical compounds in modulating the gut microbiome.

Produced water (PW), a wastewater resulting from hydraulic fracturing and oil and gas production, has been utilized in arid regions for irrigation purposes and potentially presents a new water source for crop irrigation in areas of increasing water scarcity. However, there is a potential for both synthetic and geogenic contaminants in these waters to accumulate in irrigated food crops. This study assessed how water treatment technologies targeted at removal of salinity (i.e., total dissolved solids) and organic chemical content (i.e., dissolved organic carbon) from PW to achieve agricultural irrigation standards altered the impact of inorganic contaminants and nutrient uptake on two salt-tolerant food crops, sunflower (Helianthus annuus) and wheat (Triticum aestivum). The impacts of the treatment technologies on inorganic contaminant loadings in the irrigated soils were also assessed. Treatment technologies to improve PW quality decreased the adverse impacts on plant health; however, plant health was more affected by dilutions of PW than by the treatment technologies employed. Phenotypically, plants irrigated with 90% dilution (low) treatment groups, regardless of treatment technology, were comparable to controls; however, plants watered with high proportions (50%) of raw or treated PW displayed stunted growth, with reduced height and leaf area, and sunflower seed saw 100% yield loss. Although phenotypically similar, plants of the low treatment groups exhibited changes in the ionome, illustrating the influence of PW on plant uptake, translocation, and accumulation of metals, salts, and micronutrients. In addition, bioavailability of metals and nutrients was impacted by the unique and complex PW matrix: bioconcentration factors traditionally used to evaluate risk may therefore over or underestimate accumulation.

Plant growth-promoting rhizobacteria (PGPR) have garnered interest in agriculture due to their ability to influence the growth and production of host plants. ATP-binding cassette (ABC) transporters play important roles in plant-microbe interactions by modulating plant root exudation. The present study aimed to provide a more precise understanding of the mechanism and specificity of the interaction between PGPR and host plants. In the present study, the effects of interactions between a PGPR strain, Bacillus cereus AR156, and Arabidopsis thaliana wild type (Col-0) or its ABC transporter mutants on plant growth have been studied. B. cereus AR156 promoted the shoot growth of Col-0 and Atabcg30 but repressed the growth of Atabcc5. Bacterial volatiles and secretion promoted the shoot growth of Col-0 and Atabcg30 but had no effect on Atabcc5. We also found that root exudates of Col-0 induced the expression of B. cereus AR156 genes related to siderophore and chitinase production; while root exudates of Atabcc5 inhibited the expression level of those genes. Further analysis of root exudates revealed that amino acids, organic acids, and sugars were significantly less abundant in Atabcc5 when compared to Col-0. Our findings highlight that both host plant and PGPR play active roles in the outcome of the plant-microbe interaction.

Soil microbes live in close association with plants and are crucial for plant health and fitness. Recent literature revealed that specific microbes were cultured at distinct developmental stages of Arabidopsis. It is not clear how fast the roots, depending on their developmental stage, can alter the root-associated microbiome. In this study, Arabidopsis, grown under sterile conditions at precisely distinct developmental stages were supplied with a soil microbial slurry. Within four days, roots selected specific microorganisms depending on plant development, and Proteobacteria among other bacterial groups were found to colonize the roots irrespective of developmental stage. Moreover, exposure to a microbiome resulted in modulation of phytohormone levels at different stages of Arabidopsis.

It has frequently been shown that plants interact with soils to shape rhizosphere microbiomes. However, previous work has not distinguished between effects of soil properties per se, and effects attributable to the resident microbial communities of those soils. We aimed to test whether differences in the structure of bulk soil microbial communities, within a given soil type, would carry over to impact the structure of the rhizosphere microbial community. We used repeated chemical amendments to develop divergent bulk soil microbial community starting points from which rhizosphere development proceeded. Additionally, we contrasted rhizosphere microbiomes associated with two different cultivars of corn (Zea mays). A wide range of bacterial and archaeal taxa responded to chemical resource amendments, which reduced bulk soil microbiome diversities. Corn genotypes P9714XR and 35F40 had largely similar impacts on rhizosphere microbiome development, although significant differences were evident in select treatments. Notably, in cases where resource amendments altered bulk soil microbial community composition, legacy effects persisted into the rhizosphere. Our results suggest that rhizosphere microbial communities may develop into different states depending on site history and prior selective events. This work advances our understanding of soil microbiome dynamics and responsiveness to change in the form of simple resource amendments and the development of the rhizosphere.

There is a concerted understanding of the ability of root exudates to influence the structure of rhizosphere microbial communities. However, our knowledge of the connection between plant development, root exudation and microbiome assemblage is limited. Here, we analyzed the structure of the rhizospheric bacterial community associated with Arabidopsis at four time points corresponding to distinct stages of plant development: seedling, vegetative, bolting and flowering. Overall, there were no significant differences in bacterial community structure, but we observed that the microbial community at the seedling stage was distinct from the other developmental time points. At a closer level, phylum such as Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and specific genera within those phyla followed distinct patterns associated with plant development and root exudation. These results suggested that the plant can select a subset of microbes at different stages of development, presumably for specific functions. Accordingly, metatranscriptomics analysis of the rhizosphere microbiome revealed that 81 unique transcripts were significantly (P

The roots of plants have the ability to influence its surrounding microbiology, the so-called rhizosphere microbiome, through the creation of specific chemical niches in the soil mediated by the release of phytochemicals. Here we report how these phytochemicals could modulate the microbial composition of a soil in the absence of the plant. For this purpose, root exudates of Arabidopsis were collected and fractionated to obtain natural blends of phytochemicals at various relative concentrations that were characterized by GC-MS and applied repeatedly to a soil. Soil bacterial changes were monitored by amplifying and pyrosequencing the 16 S ribosomal small subunit region. Our analyses reveal that one phytochemical can culture different operational taxonomic units (OTUs), mixtures of phytochemicals synergistically culture groups of OTUs, and the same phytochemical can act as a stimulator or deterrent to different groups of OTUs. Furthermore, phenolic-related compounds showed positive correlation with a higher number of unique OTUs compared with other groups of compounds (i.e. sugars, sugar alcohols, and amino acids). For instance, salicylic acid showed positive correlations with species of Corynebacterineae, Pseudonocardineae and Streptomycineae, and GABA correlated with species of Sphingomonas, Methylobacterium, Frankineae, Variovorax, Micromonosporineae, and Skermanella. These results imply that phenolic compounds act as specific substrates or signaling molecules for a large group of microbial species in the soil.

A variety of soil factors are known to increase nutrient availability and plant productivity. The most influential might be the organisms comprising the soil microbial community of the rhizosphere, which is the soil surrounding the roots of plants where complex interactions occur between the roots, soil, and microorganisms. Root exudates act as substrates and signaling molecules for microbes creating a complex and interwoven relationship between plants and the microbiome. While individual microorganisms such as endophytes, symbionts, pathogens, and plant growth promoting rhizobacteria are increasingly featured in the literature, the larger community of soil microorganisms, or soil microbiome, may have more far-reaching effects. Each microorganism functions in coordination with the overall soil microbiome to influence plant health and crop productivity. Increasing evidence indicates that plants can shape the soil microbiome through the secretion of root exudates. The molecular communication fluctuates according to the plant development stage, proximity to neighboring species, management techniques, and many other factors. This review seeks to summarize the current knowledge on this topic.

The complexes (cnt)2[Fe(nta)Cl2], where nta = nitrilotriacetate and cnt = Et4N+ or PyH+, catalyze the air oxidation of thiols to disulfides under ambient conditions. Dithiols are converted to linear and cyclic oligomers that differ in their terminal groups as a function of the counterion, cnt. Cysteine ethyl ester was converted to the corresponding cystine diethylester in high yield.

(Abstract) Next generation sequencing has allowed for the analysis and ability to identify the microbial communities present in the environment. While DNA extraction from environments (such as soil) have provided a wealth of knowledge regarding microbial communities there are drawbacks that one encounters when using DNA as opposed to RNA. RNA allows for the determination of the identity of the microbes that are active and present at a particular time point and thus gives a clear picture of what these microbes are actually doing at a specific point in time and under a set of conditions. Extracting RNA from soil is challenging due to the inherent inhibitors present in the soil such as humic acids. Here we describe modifications to the MoBio RNA PowerSoil TM total RNA isolation kit to reproducively extract total RNA from the soil.

The roots of plants secrete compounds as a way to exchange information with organisms living in the soil. Here, we report the involvement of seven root-expressed ATP-binding cassette (ABC) transporters corresponding to both full and half-size molecules (Atabcg36, Atabcg37, Atabcc5, Atabcf1, Atabcf3, Atnap5, and Atath10) in root exudation processes using Arabidopsis thaliana. Root exuded phytochemicals were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS), and it was determined that some of the root exudates from the corresponding ABC transporter mutants were significantly different compared to the wild type. For example, Atabcg37 and Atabcc5 secreted higher levels of the phytoalexin camalexin, and Atabcg36 secreted higher levels of organic acids, specifically salicylic acid (SA). Furthermore, we analyzed the root tissue metabolites of these seven ABC transporter mutants and found that the levels of SA, quercetin, and kaempferol glucosides were higher in Atabcg36, which was correlated with higher expression levels of defense genes in the root tissues compared with the wild type. We did not observe significant changes in the root exudates of the half-size transporters except for Atabcf1 that showed lower levels of few organic acids. In summary, full-size transporters are involved in root secretion of phytochemicals.

Plant roots constantly secrete compounds into the soil to interact with neighboring organisms presumably to gain certain functional advantages at different stages of development. Accordingly, it has been hypothesized that the phytochemical composition present in the root exudates changes over the course of the lifespan of a plant. Here, root exudates of in vitro grown Arabidopsis plants were collected at different developmental stages and analyzed using GC-MS. Principle component analysis revealed that the composition of root exudates varied at each developmental stage. Cumulative secretion levels of sugars and sugar alcohols were higher in early time points and decreased through development. In contrast, the cumulative secretion levels of amino acids and phenolics increased over time. The expression in roots of genes involved in biosynthesis and transportation of compounds represented in the root exudates were consistent with patterns of root exudation. Correlation analyses were performed of the in vitro root exudation patterns with the functional capacity of the rhizosphere microbiome to metabolize these compounds at different developmental stages of Arabidopsis grown in natural soils. Pyrosequencing of rhizosphere mRNA revealed strong correlations (p