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1.
J Ethnopharmacol ; 332: 118361, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-38763369

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: For the first time in two decades, a comprehensive, up-to-date overview of the medicinal and ritual plants of southern Africa is presented. This data is analysed and compared with a previous survey done in 2002. STUDY AIM: The main aim is to update the checklist of medicinal and ritual plants of southern Africa and to determine the number of new records since 2002. We also provide a high-level perspective on the selection of medicinal and ritual plant species in southern Africa, a taxonomic analysis of the new checklist as well as a chronological perspective on the citation of medicinal and ritual species before and after 2002. MATERIALS AND METHODS: The most recently published medicinal and ritual plants checklist for southern Africa was reviewed and updated. A wide range of ethnobotanical literature, including books, field guides and electronic journals, was used. All calculations were done by using formulas and functions in Microsoft Excel and R Studio. RESULTS: 4120 medicinal and ritual taxa and 3784 medicinal and ritual species have been recorded. Compared with the 2002 checklist, there are 1239 new taxa (1228 new species). A strong correlation between available taxa and selected medicinal taxa exists on order level, which corresponds with the results of an analysis done in 2008. The top 10 species-rich medicinal plant families of southern Africa are Asteraceae, Fabaceae, Apocynaceae, Euphorbiaceae, Asphodelaceae, Malvaceae, Lamiaceae, Poaceae, Rutaceae and Rubiaceae. Different patterns of plant family representation can be seen across certain cultural healing systems of southern Africa. The species popularity (number of citations) of Hypoxis hemerocallidea Fisch. & C.A.Mey. Has increased substantially after 2002. Other medicinal and ritual plant species have been consistently researched, such as Artemisia afra Jacq. ex Willd., Carpobrotus edulis (L.) L.Bolus, Aloe ferox Mill., Leonotis leonurus (L.) R.Br. and Gunnera perpensa L. CONCLUSIONS: The numerous new medicinal and ritual plant records that have been reported in the last two decades provide evidence of an incompletely documented ethnobotanical heritage that urgently requires documentation. Patterns of taxonomic diversity on family level indicate distinctive differences between cultural healing systems. Signs of the adaptability and dynamics of traditional healing systems in southern Africa can be seen in the changes in the citation of species over time.


Subject(s)
Ceremonial Behavior , Ethnobotany , Medicine, African Traditional , Plants, Medicinal , Plants, Medicinal/classification , Africa, Southern , Medicine, African Traditional/methods , Humans , Phytotherapy , Ethnopharmacology
2.
J Clin Med ; 13(3)2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38337359

ABSTRACT

Heterotopic ossification (HO) after elbow trauma can be responsible for significant motion restrictions. The study's primary aim was to develop a new X-ray-based classification for HO of the elbow. This retrospective study analyzed elbow injury radiographs from 138 patients aged 6-85 years (mean 45.9 ± 18) who underwent operative treatment. The new classification was applied at 6 weeks, 12 weeks, and 6 months postoperatively. The severity of HO was graded from 0 to 4 and localization was defined as r (radial), p (posterior), u (ulnar) or a (anterior) by two observers. The patients were categorized based on injury location and use of non-steroidal anti-inflammatory drugs (NSAIDs) for HO prophylaxis. The correlations between the generated data sets were analyzed using Chi-square tests (χ2) with a significance level of p < 0.05. The inter- and intraobserver reliability was assessed using Cohen's Kappa. In 50.7% of the evaluated X-rays, the formation of HO could be detected after 12 weeks, and in 60% after 6 months. The analysis showed a significant correlation between the injury's location and the HO's location after 12 weeks (p = 0.003). The use of an NSAID prophylaxis did not show a significant correlation with the severity of HO. The classification showed nearly perfect inter- (κ = 0.951, p < 0.001) and intrareliability (κ = 0.946, p < 0.001) according to the criteria of Landis and Koch. Based on the presented classification, the dimension and localization of HO in the X-ray image can be described in more detail compared to previously established classifications and, thus, can increase the comparability of results across studies.

3.
Sci Rep ; 13(1): 17351, 2023 10 13.
Article in English | MEDLINE | ID: mdl-37833272

ABSTRACT

Judo is an Olympic sport, and the way of its performing can lead to repetitive blunt injuries on head and ears. The chronic consequences of such traumata on the auricle are the formation of so-called cauliflower ear. This condition is painful, can lead to interruptions in the training process and long-term consequences for the athlete's health. There is limited knowledge of epidemiological data about cauliflower ear deformities in judo. Evaluation of the prevalence of cauliflower ear among judokas based on their profile pictures on the international judo federation was performed. A large cohort of judo athletes from around the world was studied. Two different classifications for the severity of ear deformities were used. Statistical calculations of the collected data and correlations to different parameters were performed. Images of 1632 top athletes were evaluated in the study. Ear deformities were found in 55.5% of the judokas. There was gender-specific differences. Male athletes were affected much more often than female athletes. In addition, ear deformities were more pronounced in male athletes. A correlation was found between the age of the athletes and the presence of an ear deformity. It has also been shown that judokas with a high world ranking are more likely to have an ear deformity. Ear deformities are a common consequence of injury among leading judo athletes. The current study represents the largest and high heterogeny cohort ever conducted on the prevalence of cauliflower ear in judoka. Knowledge of the prevalence of cauliflower ear in judoka based on reliable data from this study, may be important prerequisites for further studies on the impact of this traumatic consequence on training preparation and judoka health.


Subject(s)
Martial Arts , Humans , Male , Female , Prevalence , Martial Arts/injuries , Ear, External , Sex Factors , Athletes
4.
New Phytol ; 237(5): 1810-1825, 2023 03.
Article in English | MEDLINE | ID: mdl-36451537

ABSTRACT

Plant-specialized metabolism is complex, with frequent examples of highly branched biosynthetic pathways, and shared chemical intermediates. As such, many plant-specialized metabolic networks are poorly characterized. The N-methyl Δ1 -pyrrolinium cation is a simple pyrrolidine alkaloid and precursor of pharmacologically important tropane alkaloids. Silencing of pyrrolidine ketide synthase (AbPyKS) in the roots of Atropa belladonna (Deadly Nightshade) reduces tropane alkaloid abundance and causes high N-methyl Δ1 -pyrrolinium cation accumulation. The consequences of this metabolic shift on alkaloid metabolism are unknown. In this study, we utilized discovery metabolomics coupled with AbPyKS silencing to reveal major changes in the root alkaloid metabolome of A. belladonna. We discovered and annotated almost 40 pyrrolidine alkaloids that increase when AbPyKS activity is reduced. Suppression of phenyllactate biosynthesis, combined with metabolic engineering in planta, and chemical synthesis indicates several of these pyrrolidines share a core structure formed through the nonenzymatic Mannich-like decarboxylative condensation of the N-methyl Δ1 -pyrrolinium cation with 2-O-malonylphenyllactate. Decoration of this core scaffold through hydroxylation and glycosylation leads to mono- and dipyrrolidine alkaloid diversity. This study reveals the previously unknown complexity of the A. belladonna root metabolome and creates a foundation for future investigation into the biosynthesis, function, and potential utility of these novel alkaloids.


Subject(s)
Alkaloids , Atropa belladonna , Atropa belladonna/metabolism , Alkaloids/metabolism , Tropanes/chemistry , Tropanes/metabolism , Pyrrolidines/metabolism
5.
Nat Prod Rep ; 39(10): 1993-1994, 2022 Oct 19.
Article in English | MEDLINE | ID: mdl-36124957

ABSTRACT

Correction for 'Fruity, sticky, stinky, spicy, bitter, addictive, and deadly: evolutionary signatures of metabolic complexity in the Solanaceae' by Paul D. Fiesel et al., Nat. Prod. Rep., 2022, 39, 1438-1464, https://doi.org/10.1039/D2NP00003B.

6.
Nat Commun ; 13(1): 3832, 2022 07 02.
Article in English | MEDLINE | ID: mdl-35780230

ABSTRACT

Plant alkaloids constitute an important class of bioactive chemicals with applications in medicine and agriculture. However, the knowledge gap of the diversity and biosynthesis of phytoalkaloids prevents systematic advances in biotechnology for engineered production of these high-value compounds. In particular, the identification of cytochrome P450s driving the structural diversity of phytoalkaloids has remained challenging. Here, we use a combination of reverse genetics with discovery metabolomics and multivariate statistical analysis followed by in planta transient assays to investigate alkaloid diversity and functionally characterize two candidate cytochrome P450s genes from Atropa belladonna without a priori knowledge of their functions or information regarding the identities of key pathway intermediates. This approach uncovered a largely unexplored root localized alkaloid sub-network that relies on pseudotropine as precursor. The two cytochrome P450s catalyze N-demethylation and ring-hydroxylation reactions within the early steps in the biosynthesis of diverse N-demethylated modified tropane alkaloids.


Subject(s)
Alkaloids , Tropanes , Alkaloids/chemistry , Cytochrome P-450 Enzyme System/genetics , Metabolomics , Tropanes/metabolism
7.
In Vivo ; 36(3): 1077-1082, 2022.
Article in English | MEDLINE | ID: mdl-35478116

ABSTRACT

BACKGROUND/AIM: The typical insulin deficiency in type 1 diabetes mellitus has general effects on metabolism and also affects bone quality. MATERIALS AND METHODS: Two diabetic rat lines (BB/OK; BB.6KWR) and two non-diabetic rat strains (KWR and BB.14+18KWR), as control group, were included in the study. Bone mineral density, bone mineral content and body structure measurements were performed. The measurements took place before the onset of diabetes mellitus Results: A comparison of the groups showed increased bone density values of the diabetic rats in relation to the control groups. A new finding of increased bone density in the diabetic rats occurs. CONCLUSION: Diabetic rats showed no osteoporotic bone metabolism before the onset of clinically relevant type 1 diabetes mellitus, but rather increased bone metabolic activity.


Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 1 , Animals , Bone Density , Bone and Bones/metabolism , Diabetes Mellitus, Type 1/metabolism , Insulin , Rats
8.
Nat Prod Rep ; 39(7): 1438-1464, 2022 07 20.
Article in English | MEDLINE | ID: mdl-35332352

ABSTRACT

Covering: 2000-2022Plants collectively synthesize a huge repertoire of metabolites. General metabolites, also referred to as primary metabolites, are conserved across the plant kingdom and are required for processes essential to growth and development. These include amino acids, sugars, lipids, and organic acids. In contrast, specialized metabolites, historically termed secondary metabolites, are structurally diverse, exhibit lineage-specific distribution and provide selective advantage to host species to facilitate reproduction and environmental adaptation. Due to their potent bioactivities, plant specialized metabolites attract considerable attention for use as flavorings, fragrances, pharmaceuticals, and bio-pesticides. The Solanaceae (Nightshade family) consists of approximately 2700 species and includes crops of significant economic, cultural, and scientific importance: these include potato, tomato, pepper, eggplant, tobacco, and petunia. The Solanaceae has emerged as a model family for studying the biochemical evolution of plant specialized metabolism and multiple examples exist of lineage-specific metabolites that influence the senses and physiology of commensal and harmful organisms, including humans. These include, alcohols, phenylpropanoids, and carotenoids that contribute to fruit aroma and color in tomato (fruity), glandular trichome-derived terpenoids and acylsugars that contribute to plant defense (stinky & sticky, respectively), capsaicinoids in chilli-peppers that influence seed dispersal (spicy), and steroidal glycoalkaloids (bitter) from Solanum, nicotine (addictive) from tobacco, as well as tropane alkaloids (deadly) from Deadly Nightshade that deter herbivory. Advances in genomics and metabolomics, coupled with the adoption of comparative phylogenetic approaches, resulted in deeper knowledge of the biosynthesis and evolution of these metabolites. This review highlights recent progress in this area and outlines opportunities for - and challenges of-developing a more comprehensive understanding of Solanaceae metabolism.


Subject(s)
Fruit , Solanum lycopersicum , Herbivory , Humans , Solanum lycopersicum/metabolism , Phylogeny , Trichomes/metabolism
9.
Physiol Mol Biol Plants ; 27(5): 907-921, 2021 May.
Article in English | MEDLINE | ID: mdl-34092944

ABSTRACT

Drought is a key environmental factor that restricts crop growth and productivity. Plant responses to water-deficit stress at the whole plant level are mediated by stress-response gene expression through the action of transcription factors (TF). The NAC (NAM/ATAF/CUC) transcription factor family has been well documented in its role in improving plant abiotic stress tolerance. In the present study we evaluated the effects of overexpression of SlNAC2 TF on the photosynthetic machinery, relative water content (RWC), reactive oxygen species, antioxidants and proline levels in tobacco plants exposed to a water-deficit treatment. Shoot growth and seed formation were also evaluated before, during and following water-deficit to determine any morphological consequences of transgene expression. The transgenic plants maintained higher RWC and chlorophyll levels over 21 days after withholding water and stomatal conductance until the 16th day of water-deficit. Overexpression of SlNAC2 in tobacco increased proline levels, improved seed setting and delayed leaf senescence of the transgenic plants. Reactive oxygen species accumulated at lower levels in the dehydrated transgenic plants but no significant difference in superoxide dismutase and catalase content were seen between the genotypes. The conversion of glutathione to oxidized glutathione was significantly higher in the transgenic plants, supported by increased glutathione reductase transcript levels. Our results indicate that overexpression of SlNAC2 in tobacco improved survival during and recovery from water-deficit stress, without an associated biomass penalty under irrigation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-00996-2.

10.
New Phytol ; 231(1): 475-489, 2021 07.
Article in English | MEDLINE | ID: mdl-33749860

ABSTRACT

Plant metabolites from diverse pathways are important for plant survival, human nutrition and medicine. The pathway memberships of most plant enzyme genes are unknown. While co-expression is useful for assigning genes to pathways, expression correlation may exist only under specific spatiotemporal and conditional contexts. Utilising > 600 tomato (Solanum lycopersicum) expression data combinations, three strategies for predicting memberships in 85 pathways were explored. Optimal predictions for different pathways require distinct data combinations indicative of pathway functions. Naive prediction (i.e. identifying pathways with the most similarly expressed genes) is error prone. In 52 pathways, unsupervised learning performed better than supervised approaches, possibly due to limited training data availability. Using gene-to-pathway expression similarities led to prediction models that outperformed those based simply on expression levels. Using 36 experimental validated genes, the pathway-best model prediction accuracy is 58.3%, significantly better compared with that for predicting annotated genes without experimental evidence (37.0%) or random guess (1.2%), demonstrating the importance of data quality. Our study highlights the need to extensively explore expression-based features and prediction strategies to maximise the accuracy of metabolic pathway membership assignment. The prediction framework outlined here can be applied to other species and serves as a baseline model for future comparisons.


Subject(s)
Metabolic Networks and Pathways , Solanum lycopersicum , Gene Expression , Genes, Plant , Solanum lycopersicum/genetics , Metabolic Networks and Pathways/genetics
11.
In Silico Plants ; 2(1): diaa005, 2020.
Article in English | MEDLINE | ID: mdl-33344884

ABSTRACT

Plant specialized metabolites mediate interactions between plants and the environment and have significant agronomical/pharmaceutical value. Most genes involved in specialized metabolism (SM) are unknown because of the large number of metabolites and the challenge in differentiating SM genes from general metabolism (GM) genes. Plant models like Arabidopsis thaliana have extensive, experimentally derived annotations, whereas many non-model species do not. Here we employed a machine learning strategy, transfer learning, where knowledge from A. thaliana is transferred to predict gene functions in cultivated tomato with fewer experimentally annotated genes. The first tomato SM/GM prediction model using only tomato data performs well (F-measure = 0.74, compared with 0.5 for random and 1.0 for perfect predictions), but from manually curating 88 SM/GM genes, we found many mis-predicted entries were likely mis-annotated. When the SM/GM prediction models built with A. thaliana data were used to filter out genes where the A. thaliana-based model predictions disagreed with tomato annotations, the new tomato model trained with filtered data improved significantly (F-measure = 0.92). Our study demonstrates that SM/GM genes can be better predicted by leveraging cross-species information. Additionally, our findings provide an example for transfer learning in genomics where knowledge can be transferred from an information-rich species to an information-poor one.

12.
Acta Orthop ; 91(1): 53-57, 2020 02.
Article in English | MEDLINE | ID: mdl-31735107

ABSTRACT

Background and purpose - The neck-shaft angle (NSA) is valuable for diagnostics and therapy of the hip, but current reference values derive mostly from studies on anatomic specimens, small cohorts, or are hospital-based. Moreover, associated factors such as age, sex, or anthropometric data have rarely been considered. Therefore, we determined associated factors for NSA and reassessed the historical reference values in a general adult population.Methods - NSAs on both sides of 3,226 volunteers from the population-based Study of Health in Pomerania (SHIP) were measured with MRI. SHIP drew a representative sample of the population of Pomerania (northeastern Germany). NSAs were compared with sex, age, and anthropometric data by bivariable linear regression models. Reference values were assessed by quantile regressions for 2.5th and 97.5th percentiles.Results - The mean NSA was 127° (SD 7), while men had a lower NSA than women (95% confidence interval [CI] 0.4°-1.4°). The reference range was 114°-140°. Age was inversely associated with NSA (CI -0.2 to -0.1). Body height was positively associated with the NSA, while BMI and waist circumference showed a negative association. There was no association between body weight and NSA.Interpretation - The historical lower limit of 120° might be too high, so the radiological prevalence of hip pathology might have been overestimated. The previously reported influence of age, sex, and body height on the NSA has been confirmed.


Subject(s)
Femur Head/diagnostic imaging , Femur Neck/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Femur Head/anatomy & histology , Femur Neck/anatomy & histology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Reference Values , Young Adult
13.
Front Plant Sci ; 10: 1536, 2019.
Article in English | MEDLINE | ID: mdl-31827480

ABSTRACT

The fruit surface is a unique tissue with multiple roles influencing fruit development, post-harvest storage and quality, and consumer acceptability. Serving as the first line of protection against herbivores, pathogens, and abiotic stress, the surface can vary markedly among species, cultivars within species, and developmental stage. In this study we explore developmental changes and natural variation of cucumber (Cucumis sativus L.) fruit surface properties using two cucumber lines which vary greatly for these traits and for which draft genomes and a single nucleotide polymorphism (SNP) array are available: Chinese fresh market type, Chinese Long '9930' (CL9930), and pickling type, 'Gy14'. Thin-section samples were prepared from the mid-region of fruit harvested at 0, 4, 8, 12, 16, 20, 24 and 30 days post pollination (dpp), stained with Sudan IV and evaluated for cuticle thickness, depth of wax intercalation between epidermal cells, epidermal cell size and shape, and number and size of lipid droplets. 'Gy14' is characterized by columnar shaped epidermal cells, a 2-3 fold thicker cuticular layer than CL9930, increased cuticular intercalations between cells and a larger number and larger sized lipid droplets. In both lines maximal deposition of cuticle and increase in epidermal size coincided with exponential fruit growth and was largely completed by approximately 16 dpp. Phenotyping and quantitative trait locus mapping (QTL) of fruit sampled from an F7:F8 Gy14 × CL9930 recombinant inbred line (RIL) population identified QTL regions on chromosomes 1, 4 and 5. Strong QTL for epidermal cell height, cuticle thickness, intercalation depth, and diameter of lipid droplets co-localized on chromosome 1. SSR markers on chromosome 1 were used to screen for recombinants in an extended RIL population to refine the QTL region. Further fine mapping by KASP assay combined with gene expression profiling suggested a small number of candidate genes. Tissue specificity, developmental analysis of expression, allelic diversity and gene function implicate the regulatory factor CsSHINE1/WIN1 as a source of natural variation for cucumber fruit epidermal traits.

14.
ACS Synth Biol ; 8(3): 474-481, 2019 03 15.
Article in English | MEDLINE | ID: mdl-30721031

ABSTRACT

Enzymes are the ultimate entities responsible for chemical transformations in natural and engineered biosynthetic pathways. However, many natural enzymes suffer from suboptimal functional expression due to poor intrinsic protein stability. Further, stability enhancing mutations often come at the cost of impaired function. Here we demonstrate an automated protein engineering strategy for stabilizing enzymes while retaining catalytic function using deep mutational scanning coupled to multiple-filter based screening and combinatorial mutagenesis. We validated this strategy by improving the functional expression of a Type III polyketide synthase from the Atropa belladonna biosynthetic pathway for tropane alkaloids. The best variant had a total of 8 mutations with over 25-fold improved activity over wild-type in E. coli cell lysates, an improved melting temperature of 11.5 ± 0.6 °C, and only minimal reduction in catalytic efficiency. We show that the multiple-filter approach maintains acceptable sensitivity with homology modeling structures up to 4 Å RMS. Our results highlight an automated protein engineering tool for improving the stability and solubility of difficult to express enzymes, which has impact for biotechnological applications.


Subject(s)
Acyltransferases/chemistry , Acyltransferases/genetics , Atropa belladonna/enzymology , Biotechnology/methods , Data Science/methods , Protein Engineering/methods , Acyltransferases/metabolism , Belladonna Alkaloids/metabolism , Biosynthetic Pathways , Codon, Nonsense , Enzyme Stability/genetics , Escherichia coli/metabolism , Green Fluorescent Proteins/chemistry , Green Fluorescent Proteins/metabolism , Luminescent Agents/chemistry , Luminescent Agents/metabolism , Mutagenesis , Mutation, Missense , Saccharomyces cerevisiae/metabolism , Solubility , Transition Temperature
15.
Nat Commun ; 9(1): 5281, 2018 12 11.
Article in English | MEDLINE | ID: mdl-30538251

ABSTRACT

Tropinone is the first intermediate in the biosynthesis of the pharmacologically important tropane alkaloids that possesses the 8-azabicyclo[3.2.1]octane core bicyclic structure that defines this alkaloid class. Chemical synthesis of tropinone was achieved in 1901 but the mechanism of tropinone biosynthesis has remained elusive. In this study, we identify a root-expressed type III polyketide synthase from Atropa belladonna (AbPYKS) that catalyzes the formation of 4-(1-methyl-2-pyrrolidinyl)-3-oxobutanoic acid. This catalysis proceeds through a non-canonical mechanism that directly utilizes an unconjugated N-methyl-Δ1-pyrrolinium cation as the starter substrate for two rounds of malonyl-Coenzyme A mediated decarboxylative condensation. Subsequent formation of tropinone from 4-(1-methyl-2-pyrrolidinyl)-3-oxobutanoic acid is achieved through cytochrome P450-mediated catalysis by AbCYP82M3. Silencing of AbPYKS and AbCYP82M3 reduces tropane levels in A. belladonna. This study reveals the mechanism of tropinone biosynthesis, explains the in planta co-occurrence of pyrrolidines and tropanes, and demonstrates the feasibility of tropane engineering in a non-tropane producing plant.


Subject(s)
Atropa belladonna/enzymology , Atropa belladonna/metabolism , Cytochrome P-450 Enzyme System/metabolism , Plant Proteins/metabolism , Polyketide Synthases/metabolism , Tropanes/chemistry , Tropanes/metabolism , Atropa belladonna/genetics , Cyclization , Cytochrome P-450 Enzyme System/genetics , Molecular Structure , Plant Proteins/genetics , Plant Roots/chemistry , Plant Roots/enzymology , Plant Roots/genetics , Plant Roots/metabolism , Polyketide Synthases/genetics
16.
Langmuir ; 34(4): 1528-1534, 2018 01 30.
Article in English | MEDLINE | ID: mdl-29261324

ABSTRACT

Here we present a designer's approach to building cellular neuronal networks based on a biocompatible negative photoresist with embedded coaxial feedthroughs made of semiconductor microtubes. The diameter of the microtubes is tailored and adjusted to the diameter of cerebellum axons having a diameter of 2-3 µm. The microtubes as well as the SU-8 layer serve as a topographical cue to the axons. Apart from the topographical guidance, we also employ chemical guidance cues enhancing neuron growth at designed spots. Therefore, the amino acid poly-l-lysine is printed in droplets of pl volume in the front of the tube entrances. Our artificial neuronal network has an extremely high yield of 85% of the somas settled at the desired locations. We complete this by basic patch-clamp measurements on single cells within the neuronal network.

17.
Plant Physiol ; 176(1): 524-537, 2018 01.
Article in English | MEDLINE | ID: mdl-29122986

ABSTRACT

Flowers of Tanacetum cinerariifolium produce a set of compounds known collectively as pyrethrins, which are commercially important pesticides that are strongly toxic to flying insects but not to most vertebrates. A pyrethrin molecule is an ester consisting of either trans-chrysanthemic acid or its modified form, pyrethric acid, and one of three alcohols, jasmolone, pyrethrolone, and cinerolone, that appear to be derived from jasmonic acid. Chrysanthemyl diphosphate synthase (CDS), the first enzyme involved in the synthesis of trans-chrysanthemic acid, was characterized previously and its gene isolated. TcCDS produces free trans-chrysanthemol in addition to trans-chrysanthemyl diphosphate, but the enzymes responsible for the conversion of trans-chrysanthemol to the corresponding aldehyde and then to the acid have not been reported. We used an RNA sequencing-based approach and coexpression correlation analysis to identify several candidate genes encoding putative trans-chrysanthemol and trans-chrysanthemal dehydrogenases. We functionally characterized the proteins encoded by these genes using a combination of in vitro biochemical assays and heterologous expression in planta to demonstrate that TcADH2 encodes an enzyme that oxidizes trans-chrysanthemol to trans-chrysanthemal, while TcALDH1 encodes an enzyme that oxidizes trans-chrysanthemal into trans-chrysanthemic acid. Transient coexpression of TcADH2 and TcALDH1 together with TcCDS in Nicotiana benthamiana leaves results in the production of trans-chrysanthemic acid as well as several other side products. The majority (58%) of trans-chrysanthemic acid was glycosylated or otherwise modified. Overall, these data identify key steps in the biosynthesis of pyrethrins and demonstrate the feasibility of metabolic engineering to produce components of these defense compounds in a heterologous host.


Subject(s)
Biosynthetic Pathways/genetics , Chrysanthemum cinerariifolium/enzymology , Chrysanthemum cinerariifolium/growth & development , Gene Expression Regulation, Plant , Insecticides/chemistry , Monoterpenes/metabolism , Oxidoreductases/metabolism , Pyrethrins/chemistry , Chrysanthemum cinerariifolium/genetics , Flowers/metabolism , Genes, Plant , Genetic Association Studies , Kinetics , Oxidoreductases/genetics , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Pyrethrins/metabolism , Recombinant Proteins/metabolism , Substrate Specificity , Terpenes/chemistry , Terpenes/metabolism
18.
Science ; 358(6366): 1042-1046, 2017 11 24.
Article in English | MEDLINE | ID: mdl-29170233

ABSTRACT

Most networked systems of scientific interest are characterized by temporal links, meaning the network's structure changes over time. Link temporality has been shown to hinder many dynamical processes, from information spreading to accessibility, by disrupting network paths. Considering the ubiquity of temporal networks in nature, we ask: Are there any advantages of the networks' temporality? We use an analytical framework to show that temporal networks can, compared to their static counterparts, reach controllability faster, demand orders of magnitude less control energy, and have control trajectories, that are considerably more compact than those characterizing static networks. Thus, temporality ensures a degree of flexibility that would be unattainable in static networks, enhancing our ability to control them.


Subject(s)
Community Networks/trends , Humans , Time Factors
19.
Plant Physiol ; 175(1): 36-50, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28701351

ABSTRACT

Acylsugars are synthesized in the glandular trichomes of the Solanaceae family and are implicated in protection against abiotic and biotic stress. Acylsugars are composed of either sucrose or glucose esterified with varying numbers of acyl chains of differing length. In tomato (Solanum lycopersicum), acylsugar assembly requires four acylsugar acyltransferases (ASATs) of the BAHD superfamily. Tomato ASATs catalyze the sequential esterification of acyl-coenzyme A thioesters to the R4, R3, R3', and R2 positions of sucrose, yielding a tetra-acylsucrose. Petunia spp. synthesize acylsugars that are structurally distinct from those of tomato. To explore the mechanisms underlying this chemical diversity, a Petuniaaxillaris transcriptome was mined for trichome preferentially expressed BAHDs. A combination of phylogenetic analyses, gene silencing, and biochemical analyses coupled with structural elucidation of metabolites revealed that acylsugar assembly is not conserved between tomato and petunia. In P. axillaris, tetra-acylsucrose assembly occurs through the action of four ASATs, which catalyze sequential addition of acyl groups to the R2, R4, R3, and R6 positions. Notably, in P. axillaris, PaxASAT1 and PaxASAT4 catalyze the acylation of the R2 and R6 positions of sucrose, respectively, and no clear orthologs exist in tomato. Similarly, petunia acylsugars lack an acyl group at the R3' position, and congruently, an ortholog of SlASAT3, which catalyzes acylation at the R3' position in tomato, is absent in P. axillaris Furthermore, where putative orthologous relationships of ASATs are predicted between tomato and petunia, these are not supported by biochemical assays. Overall, these data demonstrate the considerable evolutionary plasticity of acylsugar biosynthesis.


Subject(s)
Acyltransferases/metabolism , Carbohydrate Metabolism , Petunia/enzymology , Trichomes/metabolism , Solanum lycopersicum/enzymology , Plant Proteins/metabolism
20.
Sci Rep ; 7: 41584, 2017 01 30.
Article in English | MEDLINE | ID: mdl-28134293

ABSTRACT

We present a radio-frequency impedance-based biosensor embedded inside a semiconductor microtube for the in-flow detection of single cells. An impedance-matched tank circuit and a tight wrapping of the electrodes around the sensing region, which creates a close, leakage current-free contact between cells and electrodes, yields a high signal-to-noise ratio. We experimentally show a twofold improved sensitivity of our three-dimensional electrode structure to conventional planar electrodes and support these findings by finite element simulations. Finally, we report on the differentiation of polystyrene beads, primary mouse T lymphocytes and Jurkat T lymphocytes using our device.


Subject(s)
Biosensing Techniques , Electric Impedance , Flow Cytometry , Semiconductors , Flow Cytometry/instrumentation , Flow Cytometry/methods , Humans , Models, Theoretical , T-Lymphocytes/metabolism
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