Levels Of Glucosides Research Articles

Scorch processing of rhubarb (Rheum tanguticum Maxim. ex Balf.) pyrolyzed anthraquinone glucosides into aglycones and improved the therapeutic effects on thromboinflammation via regulating the complement and coagulation cascades pathway

Ethnopharmacological relevanceThe pathophysiological mechanism of thromboinflammation involves the intricate interplay between the inflammatory responses and coagulation cascades. Rhubarb is frequently used in traditional Chinese medicine to treat thromboinflammatory diseases. The scorched rhubarb (prepared by stir-baking the dried raw rhubarb till it partly turns to charcoal) is believed to possess enhanced blood-cooling and stasis-removing functions compared to the raw rhubarb, thereby augmenting the therapeutic effects on thromboinflammation. Aim of the studyThis study aimed to explore the chemical and pharmacological foundations of the scorch processing of rhubarb in order to ensure and enhance the efficacy and safety of the scorched rhubarb for treating thromboinflammatory diseases. Materials and methodsThe dried raw rhubarb pieces were subjected to stir-baking at 180 °C for 10∼80 min to obtain the rhubarbs with varying degrees of scorching. Typical ingredients present in rhubarb pieces and extracts were determined by high-performance liquid chromatography. The therapeutic effects of the raw and scorched rhubarb on thromboinflammation were evaluated using a rat model. Proteomics analysis was employed to screen potential biological pathways associated with thromboinflammation treatment by the raw and scorched rhubarb, which were further verified using a cell model. ResultsMorphological properties indicated that the rhubarb baked at 180 °C for 50 min in this research showed the optimal degree of scorching. Compared to the raw rhubarb, the properly scorched rhubarb exhibited lower levels of anthraquinone glucosides, higher levels of anthraquinone aglycones, superior anti-thromboinflammatory effects, and no purgative side effects. Proteomics analysis revealed that the complement and coagulation cascades pathway played a significant role in mediating the therapeutic effects of the raw and scorched rhubarb on thromboinflammation. Furthermore, it was found that anthraquinone aglycones were more effective than their glucoside counterparts in restoring the impaired vascular endothelial cells as well as regulating the complement and coagulation cascades pathway. ConclusionsProper scorch processing may augment the therapeutic effects of rhubarb on thromboinflammation via relieving inflammation and oxidative stress, repairing vascular endothelial cells, restoring coagulation cascades and blood rheology, and regulating some other biological processes. This may be partly caused by the scorch-induced thermolysis of anthraquinone glucosides into their aglycone counterparts that seemed to perform better in regulating the complement and coagulation cascades pathway.

Metabolomics analysis reveals the effect of fermentation on the chemical composition and antioxidant activity of Paeonia lactiflora Root

Fermentation is an effective means of enhancing the nutritional value of natural medicines, however, it is unclear how the metabolites changed during the fermentation of Paeonia lactiflora root (PLR). This study intends to elucidate how the active constituents and antioxidant activity of PLR change during fermentation. The study examined the levels of total glucosides of paeony (TGP), total flavonoids content (TFC), total phenols content (TPC), and antioxidant capability by high performance liquid chromatography (HPLC) and spectrophotometry. The chemical compositions before and after PLR fermentation were compared utilizing ultra-high performance liquid chromatography-mass spectrometry (UHPLC - MS). The findings from this study indicate that TGP, TFC and TPC peaked at Day 2 of fermentation, and the antioxidant capacity increased after fermentation. Of the 109 detected compounds, 18 were discrepant compounds. In summary, fermentation is an essential strategy for enhancing the functional activity of PLR. The current study could establish a scientific basis for future research on the fermentation of PLR, and provides new insights into the influence of fermentation on chemical composition as well as the antioxidant activity of drugs.

Effect of Colchicum ritchii derived nanoparticles on apple ring rot disease without changing the taste through the prevented metabolites changes and increased sialic acid synthesis

ObjectiveIn this current study, we were planned to produce Colchicum ritchii flower extract associated calcium chloride nanoparticle (CRNPs) in a simple organic method and evaluate their apple fruit pathogenic resistance as well as their shelf-life extension properties during storage. MethodsThis CRNPs was confirmed by analysis of various established physical and chemical methods. Moreover, the apple fruit pathogenic resistance as well as their shelf-life extension properties during storage were evaluated by standardizing methods. ResultsOur results showed that the CRNPs were contrived and proven by physical and chemical evaluations. Moreover, the biological observation of CRNPs indicates that they have good pathogenic resistance properties against the Botryosphaeria dothidea without changing the taste through the prevented metabolites changes and increased sialic acid synthesis. The effective dose of pathogenic resistance in CRNPs was 40 µg/mL. The levels of defensive enzymes such as chitinase (CHI), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), and β-1,3-glucanase (GLU) significantly increased in CRNPs treated fruits. The increasing antioxidant enzymes activities including superoxide dismutase (SOD) and catalase (CAT) were shown in CRNPs treated apple fruit. The CRNPs-treated apple fruit was found to increase in salicylic acid (SA) and SA glucoside (SAG) levels, owing to increased SA synthesis. Moreover, shelf-life extension studies of fresh cut apples were conducted by immersing them in 20 and 40 µg/mL CRNPs as well as a standard solution of 2% calcium chloride for 5 mins. The standard solution of calcium chloride as well the CRNPs were proved as a good preservative and they were preserved the apple fruits shelf-life up to 25 days. ConclusionIn this study, we have concluded that the CRNPs were produced by fusion with Colchicum ritchii flower extract and calcium chloride in a superlative natural method. Our results recommended that the CRNPs is acted as a best source for apple ring rot resistance without changing the taste through the prevented metabolites changes and increased sialic acid synthesis as well as the antioxidant properties. In addition, the CRNPs is superlative source for apple shelf-life extension up to 25 days without any toxicology nature.

AtBBX29 integrates photomorphogenesis and defense responses in Arabidopsis

Light is an environmental signal that modulates plant defenses against attackers. Recent research has focused on the effects of light on defense hormone signaling; however, the connections between light signaling pathways and the biosynthesis of specialized metabolites involved in plant defense have been relatively unexplored. Here, we show that Arabidopsis BBX29, a protein that belongs to the B-Box transcription factor (TF) family, integrates photomorphogenic signaling with defense responses by promoting flavonoid, sinapate and glucosinolate accumulation in Arabidopsis leaves. AtBBX29 transcript levels were up regulated by light, through photoreceptor signaling pathways. Genetic evidence indicated that AtBBX29 up-regulates MYB12 gene expression, a TF known to induce genes related to flavonoid biosynthesis in a light-dependent manner, and MYB34 and MYB51, which encode TFs involved in the regulation of glucosinolate biosynthesis. Thus, bbx29 knockout mutants displayed low expression levels of key genes of the flavonoid biosynthetic pathway, and the opposite was true in BBX29 overexpression lines. In agreement with the transcriptomic data, bbx29 mutant plants accumulated lower levels of kaempferol glucosides, sinapoyl malate, indol-3-ylmethyl glucosinolate (I3M), 4-methylsulfinylbutyl glucosinolate (4MSOB) and 3-methylthiopropyl glucosinolate (3MSP) in rosette leaves compared to the wild-type, and showed increased susceptibility to the necrotrophic fungus Botrytis cinerea and to the herbivore Spodoptera frugiperda. In contrast, BBX29 overexpressing plants displayed increased resistance to both attackers. In addition, we found that AtBBX29 plays an important role in mediating the effects of ultraviolet-B (UV-B) radiation on plant defense against B. cinerea. Taken together, these results suggest that AtBBX29 orchestrates the accumulation of specific light-induced metabolites and regulates Arabidopsis resistance against pathogens and herbivores.Graphical

Probiotic and Cyanide Degrading Potentials of Pediococcus Pentosaceus and Pichia Exigua Isolated from Cassava Products Effluent

ABSTRACT Cassava tubers contain high levels of cyanogenic glucosides that are toxic when consumed. Lactic acid bacteria and yeast from the effluent generated during the processing of cassava products were assessed for cyanide degradation and probiotic potentials. Pediococcus sp. OG08 and Pichia sp. OG4 had higher bile salt tolerance (p < 0.05) in 0.3 % bile salts (82.5 %,77.7 %) and 0.5 % bile salts (69.3 %, 71.2 %) respectively. They displayed high potassium cyanide tolerance (Pediococcus sp. OG08, 45.7 % and Pichia sp. OG4, 44.7 %). Pediococcus pentosaceus OG08 and Pichia exigua OG4 resulted in the lowest residual cyanide content of 2.75 and 2.80 mg/kg respectively. The unfermented cassava flour had a residual cyanide content of 19.78 mg/kg. Pediococcus pentosaceus OG08 and Pichia exigua OG4 passed safety assessments, were valuable as probiotics due to their beneficial attributes. Cassava effluent possess valuable resource for potential probiotics.

Variation in production of cyanogenic glucosides during early plant development: A comparison of wild and domesticated sorghum

Domestication has narrowed the genetic diversity found in crop wild relatives, potentially reducing plasticity to cope with a changing climate. The tissues of domesticated sorghum (Sorghum bicolor), especially in younger plants, are cyanogenic and potentially toxic. Species of wild sorghum produce lower levels of the cyanogenic glucoside (CNglc) dhurrin than S. bicolor at maturity, but it is not known if this is also the case during germination and early growth. CNglcs play multiple roles in primary and specialised metabolism in domesticated sorghum and other crop plants. In this study, the temporal and spatial distribution of dhurrin in wild and domesticated sorghum at different growth stages was monitored in leaf, sheath and root tissues up to 35 days post germination using S. bicolor and the wild species S. brachypodum and S. macrospermum as the experimental systems. Growth parameters were also measured and allocation of plant total nitrogen (N%) to both dhurrin and nitrate (NO3−) was calculated. Negligible amounts of dhurrin were produced in the leaves of the two wild species compared to S. bicolor. The morphology of the two wild sorghums also differed from S. bicolor, with the greatest differences observed for the more distantly related S. brachypodum. S. bicolor had the highest leaf N% whilst the wild species had significantly higher root N%. Allocation of nitrogen to dhurrin in aboveground tissue was significantly higher in S. bicolor compared to the wild species but did not differ in the roots across the three species. The differences in plant morphology, dhurrin content and re-mobilisation, and nitrate/nitrogen allocation suggest that domestication has affected the functional roles of dhurrin in sorghum.

Anti-oxidant and Anti-inflammatory Effects of the Fermented Rhododendron weyrichii Flower Extracts in Shindari, a Traditional Jeju Fermented Drink

The aim of this study was to investigate the anti-oxidant and anti-inflammatory activities of the Rhododendron weyrichii flower extract fermented using Shindari, a traditional Jeju barley Nuruk-based fermentation. In this study, we examined the antioxidant potential of R. weyrichii flower extracts (RF) and R. weyrichii flower extracts fermented with Nuruk or Shindari (RFFN or RFFS, respectively) using various in vitro antioxidant assays including DPPH and ABTS radical scavenging assays, total phenol content and FRAP assays. We also evaluated the anti-inflammatory activity of the RF and RFFS on murine RAW 264.7 cells. The anti-inflammatory activity was evaluated by treating the RAW 264.7 cells with various concentrations (6.25, 12.5, 25, and 50 μg/ml) of RF or RFFS. As a result, we observed that the ABTS radical scavenging activity and total phenol content of RFFS was higher than that of RF and RFFN. Additionally, lipopolysaccharide- induced nitric oxide (NO) production was significantly lower in RFFS-treated cells when compared to the LPS-treated control. In addition, RFFS-treated cells exhibited decreased expression of inducible NO synthase (iNOS) proteins and high-performance liquid chromatography (HPLC) fingerprinting showed that both the quercetin and quercetin glucoside (quercitrin and isoquercitrin) levels were affected by the fermentation process. In conclusion, our data suggests that traditional fermentation could be an important strategy in improving the biological properties of raw materials including their antioxidant and antiinflammatory activities. Finally, RFFS may be a candidate for developing topical antioxidant and antiinflammatory agents.

Dwarfism of high-monolignol Arabidopsis plants is rescued by ectopic LACCASE overexpression.

Lignin is a key secondary cell wall chemical constituent, and is both a barrier to biomass utilization and a potential source of bioproducts. The Arabidopsis transcription factors MYB58 and MYB63 have been shown to upregulate gene expression of the general phenylpropanoid and monolignol biosynthetic pathways. The overexpression of these genes also results in dwarfism. The vascular integrity, soluble phenolic profiles, cell wall lignin, and transcriptomes associated with these MYB‐overexpressing lines were characterized. Plants with high expression of MYB58 and MYB63 had increased ectopic lignin and the xylem vessels were regular and open, suggesting that the stunted growth is not associated with loss of vascular conductivity. MYB58 and MYB63 overexpression lines had characteristic soluble phenolic profiles with large amounts of monolignol glucosides and sinapoyl esters, but decreased flavonoids. Because loss of function lac4 lac17 mutants also accumulate monolignol glucosides, we hypothesized that LACCASE overexpression might decrease monolignol glucoside levels in the MYB‐overexpressing plant lines. When laccases related to lignification (LAC4 or LAC17) were co‐overexpressed with MYB63 or MYB58, the dwarf phenotype was rescued. Moreover, the overexpression of either LAC4 or LAC17 led to wild‐type monolignol glucoside levels, as well as wild‐type lignin levels in the rescued plants. Transcriptomes of the rescued double MYB63‐OX/LAC17‐OX overexpression lines showed elevated, but attenuated, expression of the MYB63 gene itself and the direct transcriptional targets of MYB63. Contrasting the dwarfism from overabundant monolignol production with dwarfism from lignin mutants provides insight into some of the proposed mechanisms of lignin modification‐induced dwarfism.

Hop (Humulus lupulus L.) terroir has large effect on a glycosylated green leaf volatile but not on other aroma glycosides

Genetics and environment both influence the content of hop (Humulus lupulus L.) aroma compounds. The effects of these two factors on aroma glycosides, which can change the aroma profile of beer over time, were examined in a preliminary study. Twenty-three hop cultivars were grown in the northwestern United States in two locations with distinct terroirs. UPLC–MS/MS analysis of hop cone extracts revealed that growing location had a large effect on hexyl glucoside levels but only a negligible effect on levels of linalyl, raspberry ketone, and 2-phenylethyl glucoside, which were mostly affected by genetic differences. The large terroir effect on hexyl glucoside, which releases a green leaf volatile with a grassy aroma when hydrolyzed, but not on the other aroma glucosides, which have more desirable aromas when hydrolyzed, could have an impact on beer aroma profiles.

Cyanide in Cassava Varieties and People’s Perception on Cyanide Poisoning in Selected Regions of Tanzania

Cassava, an important food crop in the tropical regions of the world, is known to carry varying levels of cyanogenic glucosides that are potential poison to humans. In Tanzania, cases of cyanide poisoning have been reported in many cassava producing areas. This study was launched to quantify cyanide in fresh tubers of so called “sweet” cassava varieties and to gauge peoples’ perception on cyanide poisoning in Kagera and Morogoro regions. The study employed a questionnaire survey and a cross-sectional research design to identify different cassava varieties and their cyanide content using alkaline titration method. Findings showed that cyanide content in all of the analyzed tubers were above the internationally accepted levels in human consumables. Some sweet varieties were found to be wrongly classified as sweet because their cyanide content was above acceptable limits. For the same variety tubers sampled from a lowland area had significantly higher (P &lt; 0.01) cyanide content than those from a highland point. It was also found that the upper (slippery) parenchymal tissue had more cyanide content (P &lt; 0.05) than the inner tissue. Nearly 80% of the studied population was unaware of cyanide poisoning, its health effects and how to reduce cyanide content prior to consumption. It is concluded that consumption of raw cassava tubers can lead to undesirable health effects despite of some of them being categorized as sweet. The public should be sensitized on the issues of cyanide in cassava and should avoid consuming raw cassava tubers as preventive measures against cyanide poisoning.

Plant tissue analysis as a tool for predicting fertiliser needs for low cyanogenic glucoside levels in cassava roots: An assessment of its possible use.

The use of plant tissue analysis as a tool for attaining low cyanogenic glucoside levels in cassava roots, has hardly been investigated. Just as the quality of crops is improved through the use of plant tissue analysis, the same can probably be done to consistently attain the lowest possible cyanogenic glucoside levels in cassava roots. High levels of cyanogenic glucosides in consumed fresh cassava roots or in their products have the potential of causing cyanide intoxication, hence the need to lower them. An experiment was thus conducted to assess the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production in cassava roots. Total hydrogen cyanide (HCN) levels in cassava roots were used to assess cyanogenic glucoside production. Using NPK fertiliser application to induce changes in plant nutritional status, the main objective of the study was investigated using the following sub-objectives; (1) to determine the effects of increased NPK fertiliser application on cassava root HCN levels; (2) and to show the occurrence of relationships between changes in nutrient levels in plant 'indicator tissue' and HCN levels in cassava roots. The study was a field experiment laid out as a split-plot in a randomized complete block design with three replicates. It was repeated in two consecutive years, with soil nutrient deficiencies only being corrected in the second year. The varieties Salanga, Kalinda, Supa and Kiroba were used in the experiment, while the NPK fertiliser treatments included; a control with no fertiliser applied; a moderate NPK treatment (50 kg N + 10 kg P + 50 kg K /ha); and a high NPK treatment (100 kg N + 25 kg P + 100 kg K /ha). A potassium only treatment (50 kg K/ha) was also included, but mainly for comparison. The root HCN levels of Salanga, Kalinda and Kiroba were significantly influenced by NPK fertiliser application in at least one of the two field experiments, while those of Supa remained uninfluenced. Changes in plant nutritional status in response to fertiliser application were thus shown to influence cyanogenic glucoside production. The results of the multiple linear regression analysis for the first field experiment, generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by decreasing concentrations of nitrogen, potassium and magnesium in plants, or by improving plant calcium concentrations along with NPK fertiliser application. However, in the second field experiment (with corrected soil nutrient deficiencies) the regression analysis generally showed that the root HCN levels of some cassava varieties could have been 'reduced' by improving either one or a combination of the nutrients phosphorous, zinc and potassium in plants along with NPK fertiliser application. Although the results obtained in the two experiments had been contradicting due to slight differences in how they were conducted, the study had nonetheless demonstrated the occurrence of meaningful relationships between plant nutritional status and cyanogenic glucoside production; confirming the possible use of plant tissue analysis in predicting fertiliser needs for the consistent attainment of low cyanogenic glucosides in cassava roots.

Molecular identification and functional characterization of a cyanogenic glucosyltransferase from flax (Linum unsitatissimum).

Flax seed has become consumers’ choice for not only polyunsaturated alpha-linolenic fatty acid but also nutraceuticals such as lignans and soluble fiber. There is, however, a major drawback of flax as a source of functional food since the seeds contain significant level of cyanogenic glucosides. The final step of cyanogenic glucoside biosynthesis is mediated by UDP-glucose dependent glucosyltransferase. To date, no flax cyanogenic glucosyl transferase genes have been reported with verified biochemical functionality. Here we present a study on the identification and enzymatic characterization of a first flax cyanogenic glucosyltransferase, LuCGT1. We show that LuCGT1 was highly active towards both aliphatic and aromatic substrates. The LuCGT1 gene is expressed in leaf tissues as well as in developing seeds, and its expression level was drastically reduced in flax mutant lines low in cyanogenic glucosides. Identification of LuCGT1 provides a molecular handle for developing gene specific markers for targeted breeding of low cyanogenic glucosides in flax.

Yeast–Bacterial Interactions during Malolactic Inoculations Affecting Anthocyanin Adsorption and Content in Shiraz Wine

Wine color is an important sensory attribute originating from anthocyanins present in grape skin. The present study investigated the involvement or interference of bacterial cells (Oenococcus oeni and Lactobacillus plantarum mixed culture) on the adsorption of Shiraz anthocyanins during co-inoculation with yeast. The yeast-bacterial interactions during co-malolactic fermentation resulted in higher levels of glucosides and vitisin B and lower levels of coumaryl and caffeyl anthocyanins compared to wines produced via sequential malolactic fermentation and alcoholic fermentation. However, a detailed profiling of the sediments (lees) revealed no significant differences in the anthocyanin adsorption patterns between alcoholic- and malolactic-fermentation inoculations, even though significant differences were observed in the wines. The lees primarily contained acylated anthocyanins of peonidin and malvidin, indicating hydrophobic interactions involved in adsorption. Overall, yeast-bacterial interaction during malolactic fermentation showed a drastic influence on the final wine composition, and adsorption was a minor variable governing the anthocyanin changes. The incorporation of the L. plantarum strain for co-inoculation resulted in high pyranoanthocyanin levels and could therefore be a strategy to prevent loss of color during co-inoculation.

Precultivation of young seedlings under different color shades modifies the accumulation of phenolic compounds in Cichorium leaves in later growth phases

Manipulation of spectral composition has been found to be an efficient way to influence the growth and quality of plant production in protected or controlled environments. The aim of this study was to compare the short- and long-term effects of early pretreatment with different color shades on the composition of phenolic compounds and photosynthetic pigments in Cichorium leaves. The analyses conducted immediately after color shade pretreatments at ˜40 μmol m−²s−1 (blue, red orange, white) indicated lower values of chlorophyll, anthocyanin and flavonoid indices, as well as of the majority of flavonoids, compared to those in the same plants subsequently grown for 4 weeks under higher white light with an intensity of ˜320 μmol m−²s−1. However, we observed significant differences in the contents of phenolics and pigments depending on previous color shade pretreatment in plants grown for 4 weeks in the same environment and in leaves grown during this period. The most significant effect was observed in plants pretreated with orange light, in which levels of isorhamnetin, its derivatives and feruloyl malate were increased, and kaempferol-3-(6”-acetyl)-glucoside levels were significantly decreased. Blue light pretreatment led to lower values of chlorogenic acid, caftaric acid and isorhamnetin-3-(6”-acetyl)-glucoside but a higher content of isorhamnetin-3-glucoside. Red light led to an increase in quercetin derivatives. Compared to plants grown under constant conditions, low light in the early growth phases led to the upregulation of feruloyl malate, caffeoyl malate and kaempferol derivatives. Nondestructive measurements enabled the identification of significant effects of light pretreatment on the chlorophyll contents, as well as the accumulation of flavonoids and anthocyanins in the epidermal leaf layer. The induction of specific metabolites influenced by the acclimation of plants to colored light environments may emphasize the environment‐induced biochemical responses associated with the remarkable plasticity of phenylpropanoid metabolism.

Soil nutrient adequacy for optimal cassava growth, implications on cyanogenic glucoside production: A case of konzo-affected Mtwara region, Tanzania.

Soils in areas affected by konzo (a cassava cyanide intoxication paralytic disorder) are predominantly infertile and probably unable to supply cultivated cassava with the nutrients it needs to achieve optimal growth. Soil nutrient supply in these areas could also be influencing cyanogenic glucoside production in cassava, however there is hardly any knowledge on this. An assessment of soil nutrient levels on crop fields in konzo-affected areas was therefore carried out to determine their adequacy for optimal cassava growth. Konzo-affected Mtwara region of Tanzania, was used as a case study. Whether soil nutrient supply influences cyanogenic glucoside production in cassava cultivated in konzo-affected areas and how it could be doing this, was additionally investigated. To investigate this, correlations between total hydrogen cyanide (HCN) levels (a measure of cyanogenic glucoside content) in cassava roots and various soil nutrient levels on crops fields were carried out. This was followed by an investigation of relationships between cases of cassava cyanide intoxication and soil nutrient levels on crop fields from which the consumed toxic cassava roots had been harvested. Cases of cassava cyanide intoxication were used as a proxy for high cyanogenic glucoside levels in cassava roots. Logistic regression analysis was used in the latter investigation. Other important non-nutrient soil chemical characteristics, like pH and soil organic carbon, were also included in all analysis performed. The results revealed that most soil nutrients known to have reducing effects on cassava cyanogenic glucosides, like potassium (mean = 0.09 cmol/kg, SD = 0.05 cmol/kg), magnesium (mean = 0.26 cmol/kg, SD = 0.14 cmol/kg) and zinc (mean = 1.34 mg/kg, SD = 0.26 mg/kg) were deficient on several crop fields. The results also showed that cyanogenic glucosides in cassava roots could be increased with the increased supply of sulphur in soils in bitter cassava varieties (rs = 0.593, p = 0.032), and with the increased supply of P in soils in all cassava varieties (rs = 0.486, p = 0.026). The risk of cassava cyanide intoxication occurring (and thus high cyanogenic glucoside levels in cassava) was found to be likely increased by cultivating cassava on soils with high pH (X2 = 8.124, p = 0.004) and high iron (X2 = 5.740, p = 0.017). The study managed to establish that cassava grows under conditions of severe nutrient stress and that soil nutrient supply influences cyanogenic glucoside production in cassava cultivated in konzo-affected areas of Mtwara region. Despite the multiple soil nutrient deficiencies on crop fields, low soil fertility was however not the only probable cause of increased cyanogenic glucosides in cassava, as high soil nutrient levels were also found to be potential contributors.

Farmers' perceptions on the causes of cassava root bitterness: A case of konzo-affected Mtwara region, Tanzania.

In areas where konzo (a cassava cyanide related paralytic disorder) persists, the agronomic factors causing increased cyanogenic glucoside levels in cassava, during periods without water stress, are hardly known. However, through their assessment of cassava root toxicity, using its bitter taste, farmers may have noticed factors unrelated to water stress that additionally influence the cyanogenic glucoside content of cassava cultivated in these areas. Increased cassava root bitterness is often associated with an increase in cyanogenic glucoside levels, making it a good indicator of changes in root cyanogenic glucoside content. Bitter cassava varieties that are preferentially planted by people living in most konzo-affected areas, are an additional known contributor to high cyanogenic glucosides. It is water stress that further increases the inherent toxicity of the planted bitter cassava varieties. Using konzo-affected Mtwara region in Tanzania as a case study, a household survey was carried out to identify the overlooked agronomic factors that additionally influence cyanogenic glucoside levels in cassava cultivated in konzo-affected areas. A total of 120 farmers were interviewed and they mentioned a number of factors unrelated to water stress, as agronomic factors that influenced cassava root bitterness and hence cyanogenic glucoside production in cassava. The mentioned factors included; certain soil characteristics (14.2%), plant age at harvest (7.5%), poor weeding (0.8%), piecemeal harvesting (0.8%), and branch pruning (0.8%). The revealed factors constitute permanent environmental characteristics and crop management practices commonly used by farmers living in konzo-affected Mtwara region in Tanzania. The revealed factors could be contributing to increased cyanogenic glucoside levels in cassava, during periods without water stress in areas where konzo persists.

Deletion of biosynthetic genes, specific SNP patterns and differences in transcript accumulation cause variation in hydroxynitrile glucoside content in barley cultivars

Barley (Hordeum vulgare L.) produces five leucine-derived hydroxynitrile glucosides, potentially involved in alleviating pathogen and environmental stresses. These compounds include the cyanogenic glucoside epiheterodendrin. The biosynthetic genes are clustered. Total hydroxynitrile glucoside contents were previously shown to vary from zero to more than 10,000 nmoles g−1 in different barley lines. To elucidate the cause of this variation, the biosynthetic genes from the high-level producer cv. Mentor, the medium-level producer cv. Pallas, and the zero-level producer cv. Emir were investigated. In cv. Emir, a major deletion in the genome spanning most of the hydroxynitrile glucoside biosynthetic gene cluster was identified and explains the complete absence of hydroxynitrile glucosides in this cultivar. The transcript levels of the biosynthetic genes were significantly higher in the high-level producer cv. Mentor compared to the medium-level producer cv. Pallas, indicating transcriptional regulation as a contributor to the variation in hydroxynitrile glucoside levels. A correlation between distinct single nucleotide polymorphism (SNP) patterns in the biosynthetic gene cluster and the hydroxynitrile glucoside levels in 227 barley lines was identified. It is remarkable that in spite of the demonstrated presence of a multitude of SNPs and differences in transcript levels, the ratio between the five hydroxynitrile glucosides is maintained across all the analysed barley lines. This implies the involvement of a stably assembled multienzyme complex.

Determination of the species status of Fallopia multiflora, Fallopia multiflora var. angulata and Fallopia multiflora var. ciliinervis based on morphology, molecular phylogeny, and chemical analysis

Relationships among Fallopia multiflora (Thunb.) Haraldson., F. multiflora var. angulata (S. Y. Liu) H. J. Yan, Z. J. Fang & Shi Xiao Yu., and F. multiflora var. ciliinervis (Nakai) Yonekura & H. Ohashi. were determined based on macroscopic and microscopic morphology, molecular phylogeny, and chemical analysis. The macroscopic and microscopic morphologies of root tubers or rhizomes, stems, and leaves were compared among the three taxa. The content of 11 chemical components (catechin, polydatin, stilbene glucoside, emodin, emodin-8-O-β-D-glucopyranoside, rhein, chrysophanol, aloe-emodin, quercetin, physcion, and resveratrol) in the three taxa was determined by HPLC, and the chemical diversity was further evaluated by principal component and hierarchical cluster analyses. Molecular phylogenies were mapped using two chloroplast markers (matK and the psbA-trnH intergenic region) and a nuclear ribosomal marker [internal transcribed spacer 2 (ITS2) region]. Analyses of macroscopic and microscopic morphological characteristics revealed that the subterranean organs of F. multiflora and F. multiflora var. angulata are root tubers, whereas those of F. multiflora var. ciliinervis are rhizomes. In the phylogenetic trees, F. multiflora and F. multiflora var. angulata were clustered into a clade based on the combine matK + psbA-trnH sequence, with neighbour-joining, maximum likelihood, and Bayesian inference bootstrap support values of 99, 85, and 0.99, respectively. In addition, there were obvious differences in the chemical compositions of F. multiflora, F. multiflora var. angulata and F. multiflora var. ciliinervis. The root tubers of F. multiflora contain higher levels of stilbene glucoside and catechin, but lower levels of polydatin and anthraquinone compounds. In contrast to F. multiflora, the rhizomes of F. multiflora var. ciliinervis contain higher levels of polydatin and anthraquinone compounds, but lack stilbene glucoside. The content of all 11 assessed components was lower in F. multiflora var. angulata than in F. multiflora and F. multiflora var. cillinervis. Principal component and hierarchical cluster analyses revealed that F. multiflora and F. multiflora var. angulata individuals were clustered into a single clade, whereas F. multiflora var. ciliinervis individuals were clustered into a single clade separate from that containing F. multiflora and F. multiflora var. angulata individuals. On the basis of the results of our morphological, molecular phylogeny, and chemical analyses, we tentatively conclude that F. multiflora var. ciliinervis is an independent species, whereas F. multiflora var. angulata should be considered as a variety of F. multiflora.

Sex differences but no evidence of quantitative honesty in the warning signals of six-spot burnet moths (Zygaena filipendulae L.).

The distinctive black and red wing pattern of six‐spot burnet moths (Zygaena filipendulae, L.) is a classic example of aposematism, advertising their potent cyanide‐based defences. While such warning signals provide a qualitatively honest signal of unprofitability, the evidence for quantitative honesty, whereby variation in visual traits could provide accurate estimates of individual toxicity, is more equivocal. Combining measures of cyanogenic glucoside content and wing color from the perspective of avian predators, we investigate the relationship between coloration and defences in Z. filipendulae, to test signal honesty both within and across populations. There were no significant relationships between mean cyanogenic glucoside concentration and metrics of wing coloration across populations in males, yet in females higher cyanogenic glucoside levels were associated with smaller and lighter red forewing markings. Trends within populations were similarly inconsistent with quantitative honesty, and persistent differences between the sexes were apparent: larger females, carrying a greater total cyanogenic glucoside load, displayed larger but less conspicuous markings than smaller males, according to several color metrics. The overall high aversiveness of cyanogenic glucosides and fluctuations in color and toxin levels during an individual's lifetime may contribute to these results, highlighting generally important reasons why signal honesty should not always be expected in aposematic species.

Demonstration of monolignol β-glucosidase activity of rice Os4BGlu14, Os4BGlu16 and Os4BGlu18 in Arabidopsis thaliana bglu45 mutant

The glycoside hydrolase family 1 members Os4BGlu14, Os4BGlu16, and Os4BGlu18 were proposed to be rice monolignol β-glucosidases. In vitro studies demonstrated that the Os4BGlu16 and Os4BGlu18 hydrolyze the monolignol glucosides coniferin and syringin with high efficiency compared to other substrates. The replacement of the conserved catalytic acid/base glutamate residue by a nonionizable glutamine residue in Os4BGlu14 suggested that it may be inactive as a β-glucosidase. Here, we investigated the activities of Os4BGlu14, Os4BGlu16, and Os4BGlu18 in planta by recombinant expression of their genes in the Arabidopsis bglu45-2 (monolignol β-glucosidase) mutant and analysis of monolignol glucosides by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MSMS). The bglu45-2 line exhibits elevated monolignol glucoside levels, but lower amounts of coniferin, syringin, and p-coumaryl alcohol glucoside were seen in Arabidopsis bglu45-2 rescued lines complemented by the Os4BGlu14, Os4BGlu16, and Os4BGlu18 genes. These data suggest that the bglu45-2 mutant has a broader effect on monolignols than previously reported and that the Os4BGlu14, Os4BGlu16 and Os4BGlu18 proteins act as monolignol β-glucosidases to complement the defect. An OsBGlu16-GFP fusion protein localized to the cell wall. This apoplastic localization and the effect of these enzymes on monolignol glucoside levels suggest monolignol glucosides from the vacuole may meet the monolignol β-glucosidases, despite their different localization.