Fatty alcohols, a minor component of the tree tobacco surface wax, are associated with defence against caterpillar herbivory

Despite decades of research resulting in a comprehensive understanding of epicuticular wax metabolism, the function of these almost ubiquitous metabolites in plant-herbivore interactions remains unresolved. In this study, we examined the effects of CRISPR-induced knockout mutations in four Nicotiana glauca (tree tobacco) wax metabolism genes. These mutations cause a wide range of changes in epicuticular wax composition, leading to altered interactions with insects and snails. Three interaction classes were examined: chewing herbivory by seven caterpillars and one snail species, phloem feeding by Myzus persicae (green peach aphid) and oviposition by Bemisia tabaci (whitefly). Although total wax load and alkane abundance did not affect caterpillar growth, a correlation across species, showed that fatty alcohols, a minor component of N. glauca surface waxes, negatively affected the growth of both a generalist caterpillar (Spodoptera littoralis) and a tobacco-feeding specialist (Manduca sexta). This negative correlation was overshadowed by the stronger effect of anabasine, a nicotine isomer, and was apparent when fatty alcohols were added to an artificial lepidopteran diet. By contrast, snails fed more on waxy leaves. Aphid reproduction and feeding activity were unaffected by wax composition but were potentially affected by altered cutin composition. Wax crystal morphology could explain the preference of B. tabaci to lay eggs on waxy wild-type plants relative to both alkane and fatty alcohol-deficient mutants. Together, our results suggest that the varied responses among herbivore classes and species are likely to be a consequence of the co-evolution that shaped the specific effects of different surface wax components in plant-herbivore interactions.

Tree tobacco (Nicotiana glauca) cuticular wax composition is essential for leaf retention during drought, facilitating a speedy recovery following rewatering

Despite decades of extensive study, the role of cuticular lipids in sustaining plant fitness is far from being understood. We utilized genome-edited tree tobacco (Nicotiana glauca) to investigate the significance of different classes of epicuticular wax in abiotic stress such as cuticular water loss, drought, and light response. We generated mutants displaying a range of wax compositions. Four wax mutants and one cutin mutant were extensively investigated for alterations in their response to abiotic factors. Although the mutations led to elevated cuticular water loss, the wax mutants did not display elevated transpiration or reduced growth under nonstressed conditions. However, under drought, plants lacking alkanes were unable to reduce their transpiration, leading to leaf death, impaired recovery, and stem cracking. By contrast, plants deficient in fatty alcohols exhibited elevated drought tolerance, which was part of a larger trend of plant phenotypes not clustering by a glossy/glaucous appearance in the parameters examined in this study. We conclude that although alkanes have little effect on whole N. glauca transpiration and biomass gain under normal, nonstressed conditions, they are essential during drought responses, since they enable plants to seal their cuticle upon stomatal closure, thereby reducing leaf death and facilitating a speedy recovery.

UPLC-HRESI-MS and GC-MS analysis of the leaves of Nicotiana glauca

The alkaloid-rich fraction obtained by fractionation of the crude methanolic extract of the leaves of wild tobacco tree Nicotiana glauca Graham (Solanaceae) was analyzed using UPLC-MS and GC-MS. Anabasine, a piperidine alkaloid, was identified as the major constituent with approximately 60 % (m/m) of the alkaloid-rich fraction. In addition to anabasine, six secondary metabolites were identified using high-resolution UPLC-MS. Anabasine was quantified in the leaves to be 1 mg g^-1 dry plant material. The GC-MS analysis revealed five compounds with anabasine as the major component, while nicotine was not detected. Moreover, GC-MS was used for the analysis of the volatile oil that was obtained by hydro-distillation from the leaves of N. glauca. The volatile plant oil was found to be rich in oxygenated sesquiterpenes (e.g., β-bisabolol) and carboxylic acids and esters (e.g., ethyl linoleate and hexadecanoic acid), whereas anabasine was not detected.

Pseudomonas palmensis sp. nov., a Novel Bacterium Isolated From Nicotiana glauca Microbiome: Draft Genome Analysis and Biological Potential for Agriculture

A novel Pseudomonas, designated strain BBB001T, an aerobic, rod-shaped bacterium, was isolated from the rhizosphere of Nicotiana glauca in Las Palmas Gran Canaria, Spain. Genomic analysis revealed that it could not be assigned to any known species of Pseudomonas, so the name Pseudomonas palmensis sp. nov. was proposed. A 16S rRNA gene phylogenetic analysis suggested affiliation to the Pseudomonas brassicae group, being P. brassicae MAFF212427 T the closest related type strain. Upon genomic comparisons of both strains, all values were below thresholds established for differentiation: average nucleotide identity (ANI, 88.29%), average amino acid identity (AAI, 84.53%), digital DNA-DNA hybridization (dDDH, 35.4%), and TETRA values (0.98). When comparing complete genomes, a total of 96 genes present exclusively in BBB001T were identified, 80 of which appear associated with specific subsystems. Phenotypic analysis has shown its ability to assimilate glucose, potassium gluconate, capric acid malate, trisodium citrate, and phenylacetic acid; it was oxidase positive. It is able to produce auxins and siderophores in vitro; its metabolic profile based on BIOLOG Eco has shown a high catabolic capacity. The major fatty acids accounting for 81.17% of the total fatty acids were as follows: C16:0 (33.29%), summed feature 3 (22.80%) comprising C16:1 ω7c and C16:1 ω6c, summed feature 8 (13.66%) comprising C18:1 ω7c, and C18:1ω6c and C17:0 cyclo (11.42%). The ability of this strain to improve plant fitness was tested on tomato and olive trees, demonstrating a great potential for agriculture as it is able to trigger herbaceous and woody species. First, it was able to improve iron nutrition and growth on iron-starved tomatoes, demonstrating its nutrient mobilization capacity; this effect is related to its unique genes related to iron metabolism. Second, it increased olive and oil yield up to 30% on intensive olive orchards under water-limiting conditions, demonstrating its capacity to improve adaptation to adverse conditions. Results from genomic analysis together with differences in phenotypic features and chemotaxonomic analysis support the proposal of strain BBB001T (=LMG 31775T = NCTC 14418T) as the type strain of a novel species for which the name P. palmensis sp. nov is proposed.

Direct Evidence That Sunbirds' Gut Microbiota Degrades Floral Nectar's Toxic Alkaloids

Orange-tufted sunbirds (Cinnyris osea) feed on the nectar of the tobacco tree (Nicotiana glauca) which contains toxic pyridine alkaloids characterized by high concentrations of anabasine and much lower concentrations of nicotine. We aimed at determining whether the gut microbiota of sunbirds harbors bacterial species that enable the birds to cope with these toxic alkaloids. An in vivo experiment that included 12 birds showed that inducing dysbiosis in sunbirds’ guts by the addition of sulfamethoxazole and trimethoprim, significantly reduced the birds’ ability to degrade anabasine (n = 3) compared to control birds (n = 3) with undisturbed microbiota. Sunbirds whose gut bacterial communities were altered by the antibacterial agents and who were fed with added nicotine, also showed a lower percentage of nicotine degradation (n = 3) in their excreta compared to the sunbirds with undisturbed microbiota (n = 3), though this difference was not significant. In an in vitro experiment, we studied the ability of Lactococcus lactis, Enterobacter hormaechei, Chryseobacterium gleum, Kocuria palustris, and Methylorubrum populi that were isolated from sunbirds’ excreta, to degrade anabasine and nicotine. By using gas chromatography-mass spectrometry (GC-MS) analysis, we successfully demonstrated, for the first time, the ability of these species to degrade the focal secondary metabolites. Our findings demonstrate the role of gut bacteria in detoxifying toxic secondary metabolites found in the N. glauca nectar. The degradation products may supply the birds with nitrogen which is scarce in nectar-rich diets. These findings support another role of bacteria in mediating the interactions between plants and their pollinators.

Phytoconstituents screening and antimicrobial activity of the invasive species Nicotiana glauca collected from Al-Baha region of Saudi Arabia

Nicotiana glauca belonging to the family Solanaceae is an exotic perinnial bushy species that recently has invaded the mountainous areas of Al-Baha region at the south-west of Saudi Arabia, causing degredation to soil and vegetation composition of those mountains. Accordingly, this plant must be either removed or exploited as a source of useful products such as medicines as it has been proven to contain many effective compounds with therapeutic properties. Thus, the current study aimd to screening N. glauca preliminary phytoconsitiuents and its anticmicrobial activity. Results showed that varying amounts of alkaloids, steroid, tannins, flavonoid, were present in the extracts of N. glauca leaves, stems and flowers. Saponins were present only in the flowers extract. However, all previuos bioactive compounds were absent in the roots except alkaloids, therefore, roots posses lesser amount of the phytoconstituents compared to the other parts of the plants. Leaves extracts inhibited the growth of E. coli (16.3 ± 0.71 mm) and also inhibited the growth of S. aureus (11.0 ± 0.23 mm), while, the flower extracts also inhibited the growth of E. coli (6.7 ± 0.65 mm), and also inhibited the growth of S. aureus (15.8 ± 0.52 mm). This result coincide with the previous results of the screening of N, glauca phytochemicals where the highest amounts found in leaves and flowers extracts. The inhibition zone of the antibiotic gentamycin (reference control) were 32 mm in S. aureus and 38 mm in E. coli. The inhibition zone of gentamycin (reference control) were 32 mm in S. aureus and 38 mm in E. coli. The minimum inhibitory concentration (MIC) of ethyl acetate was ranged (1.5–2 mg/ml). The lower MIC is an indication of high effectiveness of extract. Therefore, such bioactive property would support the idea that removing N. glauca from the mountainous areas of Al-Baha, Saudi Arabia, is not the only solution, but the plant can be exploited as a beneficial source of medicinal and economic purposes such as; antibacterial, antifungal and insecticidal, however, further comprehensive exploration is recommended to confirm such propreties.

Impact of the invasive plant species "Nicotiana glauca" toxins on the larvae of the invasive insect species "Rhynchophorus ferrugineus": A damaging pest of date palm trees in Saudi Arabia

The wild tree tobacco (Nicotiana glauca) is an alien species that invaded vast areas of the Southwestern region of Saudi Arabia. While, the Red Palm Weevil (RPW) (Rhynchophorus ferrugineus) is considered to be the most damaging invasive insect species of palm trees all over the kingdom of Saudi Arabia, causing major economic losses to farmers and the economy of the country. Using conventional insecticides to control harmful insects such as RPW has undesirable effects on the environment and human health. Alternatively, using biocontrol agents such as poisonous extracts from N. glauca might be a better approach in pest management and can be considered as an eco-friendly, cost-effective, and safe alternative. Therefore, the current study aimed to evaluate the larvicidal effect of N. glauca aqueous extracts against the red palm weevil larvae. The plant specimens were collected from Al-Baha region in the Southwest of Saudi Arabia. Each single test consisted of 20 larvae, and N. glauca preparations were; 1, 1.5, 2, 2.5, and 3 ml, besides the control test. Results obtained for the effect of botanical extracts; leaf, flower, stem and root against R. ferrugineus larvae for an exposure period of 24 hr. at the concentrations of 2.8, 4.2, 6.0, 7.0 and 8.0 ppm. The concentrations for N. glauca extracts reflected an LC₅₀ of 2.7 ppm for leave, 2.6 ppm for flower, 2.8 ppm for stem and 7.00 ppm for root. While, the same concentrations extracts reflected an LC₉₅of 11 ppm for leaf, 9.6 ppm for flower, 8.9 ppm for stem and 13.00 ppm for root. These results showed that N. glauca extracts have a remarkable potentiality as insecticidal substances that can be used as an ecofriendly integrated approach for the management of R. ferrugineus.

Geographic partitioning or environmental selection: What governs the global distribution of bacterial communities inhabiting floral nectar?

Floral nectar harbors microbial communities which have significant impacts on its chemistry, volatiles, nutritional contents, and attractiveness for pollinators. Yet, fundamental knowledge regarding the structure and composition of nectar-associated microbiomes remains largely unknown. Especially elusive are the environmental factors and spatial effects that shape nectar-inhabiting microbial communities. The aim of this study was to explore and analyze the role of geographical and environmental factors affecting the composition and global distribution of floral nectar microbiota. We explored and compared the structure of bacterial communities inhabiting the floral nectar of the widely spread and invasive tobacco tree (Nicotiana glauca) in six continents: South and North America, Australia, Europe, Africa, and Asia, using 16S rRNA gene sequencing. Environmental abiotic data for each sampled plant was obtained from the Worldclim database and applied for inferring the effects of environmental conditions on bacterial community structure and diversity. Most abundant in the nectar were the Proteobacteria, Firmicutes, and Actinobacteria phyla, with Acinetobacter and Rosenbergiella (Proteobacteria) being the dominant bacterial genera that contributed most to the dissimilarities between sites. Acinetobacter and Rosenbergiella abundances were negatively correlated and significantly higher in the Mediterranean regions (Greece, Israel, and the Canary Islands) compared to Argentina and Australia. Temperature, site-elevation, rainfall, and density of vegetation were found to have significant effects on the structure and diversity of these bacterial communities in the nectar. Vegetation density was positively correlated with microbial diversity, while increased temperatures and elevation reduced the diversity and evenness of bacterial communities. Mantel's test showed that the similarity between the bacterial communities' composition significantly decreased as distances between them increased. We conclude that both geographical distance and local environmental abiotic conditions affect and shape the composition and diversity of nectar inhabiting bacterial communities.

An essay on ecosystem availability of Nicotiana glauca graham alkaloids: the honeybees case study

BACKGROUND

Invasive plant species pose a significant threat for fragile isolated ecosystems, occupying space, and consuming scarce local resources. Recently though, an additional adverse effect was recognized in the form of its secondary metabolites entering the food chain. The present study is elaborating on this subject with a specific focus on the Nicotiana glauca Graham (Solanaceae) alkaloids and their occurrence and food chain penetrability in Mediterranean ecosystems. For this purpose, a targeted liquid chromatography electrospray tandem mass spectrometric (LC-ESI-MS/MS) analytical method, encompassing six alkaloids and one coumarin derivative, utilizing hydrophilic interaction chromatography (HILIC) was developed and validated.

RESULTS

The method exhibited satisfactory recoveries, for all analytes, ranging from 75 to 93%, and acceptable repeatability and reproducibility. Four compounds (anabasine, anatabine, nornicotine, and scopoletin) were identified and quantified in 3 N. glauca flowers extracts, establishing them as potential sources of alien bio-molecules. The most abundant constituent was anabasine, determined at 3900 μg/g in the methanolic extract. These extracts were utilized as feeding treatments on Apis mellifera honeybees, resulting in mild toxicity documented by 16-18% mortality. A slightly increased effect was elicited by the methanolic extract containing anabasine at 20 μg/mL, where mortality approached 25%. Dead bees were screened for residues of the N. glauca flower extracts compounds and a significant mean concentration of anabasine was evidenced in both 10 and 20 μg/mL treatments, ranging from 51 to 92 ng/g per bee body weight. Scopoletin was also detected in trace amounts.

CONCLUSIONS

The mild toxicity of the extracts in conjunction with the alkaloid and coumarin residual detection in bees, suggest that these alien bio-molecules are transferred within the food chain, suggesting a chemical invasion phenomenon, never reported before.

Adverse Effects in Skeletal Muscle Following the Medicinal Use of Nicotiana glauca

Nicotiana glauca is a cosmopolitan shrub, used in medicine to treat swellings, wounds, sores and cancer. However, its users lack of knowledge of the adverse effects. We seek to evaluate the effects of lipid extracts from N. glauca on myoblasts, identifying the compounds which cause undesirable effects. Myoblasts are important in muscle homeostasis, thus a high death rate of them cause myopathies. We performed an ethanolic extraction from leaves of N. glauca and the extract was successively partitioned with hexane, chloroform and ethyl acetate. The effects of extracts in C2C12 cells were analysed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), Mitotracker and 4',6-diamidino-2-phenylindole (DAPI) staining, Western blotting, real-time PCR and immunofluorescence assays. Caspase activity was studied. The fraction with the highest apoptotic effects was analysed by chromatography, NMR and GC-MS spectrometry were used to identify the apoptotic agent, after which its biological activity was evaluated. The extracts from N. glauca induced apoptosis in C2C12 cells involving caspase-3/7. We found that the extracts trigger a defence response in muscle through Akt and heat shock protein 27 (HSP27). We identified an apoptotic agent as palmitic acid. These data suggest that the use of N. glauca in hormone replacement therapy, or in other therapies affects skeletal muscle homeostasis, worsening the negative effects of the menopause. Thus, the relevance of this work lies in the fact that it is the first time that a report about the molecular mechanism responsible for the side effects of medicinal use of N. glauca, has been shown. Moreover the compound responsible for these effects has been identified.

Nicotiana glauca whole-genome investigation for cT-DNA study

OBJECTIVE

Nicotiana glauca (tree tobacco) is a naturally transgenic plant, containing sequences acquired from Agrobacterium rhizogenes by horizontal gene transfer. Besides, N. glauca contains a wide profile of alkaloids of medical interest.

DATA DESCRIPTION

We report a high-depth sequencing and de novo assembly of N. glauca full genome and analysis of genome elements with bacterial origin. The draft genome assembly is 3.2 Gb, with N50 size of 31.1 kbp. Comparative analysis confirmed the presence of single, previously described gT insertion. No evidence was acquired to support idea of multiple T-DNA insertions in the N. glauca genome. Our data is the first comprehensive de novo assembly of tree tobacco and provide valuable information for researches in pharmacological and in phylogenetic fields.

Horizontal Transfer of a Synthetic Metabolic Pathway between Plant Species

Transgene expression from the plastid (chloroplast) genome provides unique advantages, including high levels of foreign protein accumulation, convenient transgene stacking in operons, and increased biosafety due to exclusion of plastids from pollen transmission [1, 2]. However, applications in biotechnology and synthetic biology are severely restricted by the very small number of plant species whose plastid genomes currently can be transformed [3, 4]. Here we report a simple method for the introduction of useful plastid transgenes into non-transformable species. The transgenes tested comprised a synthetic operon encoding three components of a biosynthetic pathway for producing the high-value ketocarotenoid astaxanthin in the plastids of the cigarette tobacco, Nicotiana tabacum. Transplastomic N. tabacum plants accumulated astaxanthin to up to 1% of the plants' dry weight. We then used grafting, a procedure recently shown to facilitate horizontal genome transfer between plants [5-7], to let the transgenic chloroplast genome move across the graft junction from N. tabacum plants into plants of the nicotine-free tree species Nicotiana glauca. Transplastomic N. glauca trees expressing the synthetic pathway were recovered at high frequency, thus providing a straightforward method for extension of the transplastomic technology to new species.

From Microhabitat of Floral Nectar Up to Biogeographic Scale: Novel Insights on Neutral and Niche Bacterial Assemblies

Microbial model systems are very useful in addressing macro-ecological questions. Two major theories exist to date, to explain the community structure of organisms: (1) the dispersal (neutral) assembly theory which predicts that community similarity decreases with increasing geographic distance, independent of any environmental variables, and (2) the niche assembly theory which predicts that the communities' compositions are more homogeneous among sites characterized by similar environmental conditions. Our study system offered a unique opportunity to investigate the relative role of environmental conditions and spatial factors in shaping community composition. We explored the bacterial community composition (BCC) of Nicotiana glauca floral nectar using the Illumina MiSeq technique at three spatial scales (plants, site, and region) and two taxonomic levels. Floral nectar samples were collected from 69 N. glauca plants at 11 different sites along a 200-km transect in Israel, along three biogeographic regions. A distance decay of BCC was found among all plants throughout Israel, but such pattern was not found among either sites or biogeographical regions. The BCC was also governed by environmental conditions in all examined scales (from the plant up to the biogeographical region). We also found that taxonomic resolution (89 and 97% sequence identity for clustering operational taxonomic units) affected the results of these BCC analyses. Hence, our study revealed that the BCC in N. glauca floral nectar is shaped by both the environmental conditions and the distance between plants, depending on the sampling scale under examination as well as by taxonomic resolution.

Sequencing and characterization of leaf transcriptomes of six diploid Nicotiana species

BACKGROUND

Nicotiana belongs to the Solanaceae family that includes important crops such as tomato, potato, eggplant, and pepper. Nicotiana species are of worldwide economic importance and are important model plants for scientific research. Here we present the comparative analysis of the transcriptomes of six wild diploid Nicotiana species. Wild relatives provide an excellent study system for the analysis of the genetic basis for various traits, especially disease resistance.

RESULTS

Whole transcriptome sequencing (RNA-seq) was performed for leaves of six diploid Nicotiana species, i.e. Nicotiana glauca, Nicotiana noctiflora, Nicotiana cordifolia, Nicotiana knightiana, Nicotiana setchellii and Nicotiana tomentosiformis. For each species, 9.0-22.3 Gb high-quality clean data were generated, and 67,073-182,046 transcripts were assembled with lengths greater than 100 bp. Over 90 % of the ORFs in each species had significant similarity with proteins in the NCBI non-redundant protein sequence (NR) database. A total of 2491 homologs were identified and used to construct a phylogenetic tree from the respective transcriptomes in Nicotiana. Bioinformatic analysis identified resistance gene analogs, major transcription factor families, and alkaloid transporter genes linked to plant defense.

CONCLUSIONS

This is the first report on the leaf transcriptomes of six wild Nicotiana species by Illumina paired-end sequencing and de novo assembly without a reference genome. These sequence resources hopefully will provide an opportunity for identifying genes involved in plant defense and several important quality traits in wild Nicotiana and will accelerate functional genomic studies and genetic improvement efforts of Nicotiana or other important Solanaceae crops in the future.

Scopoletin, an active principle of tree tobacco (Nicotiana glauca) inhibits human tumor vascularization in xenograft models and modulates ERK1, VEGF-A, and FGF-2 in computer model

We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06μM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2.

A direction-selective local-thresholding method, DSLT, in combination with a dye-based method for automated three-dimensional segmentation of cells and airspaces in developing leaves

Quantifying the anatomical data acquired from three-dimensional (3D) images has become increasingly important in recent years. Visualization and image segmentation are essential for acquiring accurate and detailed anatomical data from images; however, plant tissues such as leaves are difficult to image by confocal or multi-photon laser scanning microscopy because their airspaces generate optical aberrations. To overcome this problem, we established a staining method based on Nile Red in silicone-oil solution. Our staining method enables color differentiation between lipid bilayer membranes and airspaces, while minimizing any damage to leaf development. By repeated applications of our staining method we performed time-lapse imaging of a leaf over 5 days. To counteract the drastic decline in signal-to-noise ratio at greater tissue depths, we also developed a local thresholding method (direction-selective local thresholding, DSLT) and an automated iterative segmentation algorithm. The segmentation algorithm uses the DSLT to extract the anatomical structures. Using the proposed methods, we accurately segmented 3D images of intact leaves to single-cell resolution, and measured the airspace volumes in intact leaves.

The effect of intermittent dosing of Nicotiana glauca on teratogenesis in goats

Sustained inhibition of fetal movement in livestock species, induced by several poisonous plants, can result in numerous skeletal-contracture malformations. Lupines are responsible for a condition in cattle referred to as "crooked calf syndrome" that occurs when pregnant cattle graze teratogenic lupines. Similar malformations are also seen in animals poisoned by Conium maculatum (coniine) and Nicotiana glauca (anabasine). A proposed management strategy to limit these types of birth defects includes utilizing an intermittent grazing schedule to allow short durations of grazing lupine-infested areas interrupted by movement to a lupine-free pasture. The objective of this study was to use a goat model to determine if an intermittent schedule of five continuous days on treatment followed by two days off treatment would be sufficient to decrease, or prevent, the incidence of anabasine-induced malformations. The data from this study suggest that, for N. glauca in goats, the intermittent grazing program of five days exposure with two days of non-exposure is insufficient to prevent significant skeletal malformations from occurring. However, this study did demonstrate an inverse relationship between the amount of serum anabasine in the dam and the extent of fetal movement.

A study on embryonic death in goats due to Nicotiana glauca ingestion

Numerous plants are known to be teratogenic in livestock. In addition to causing malformations, several plants can also cause embryonic death. These losses decrease the reproductive efficiency of animals exposed to these plants. The aim of this study was to determine if teratogenic plants such as lupines or tobaccos cause embryonic losses. A goat model using the plant Nicotiana glauca was used in this study, as this model has been used to characterize the mechanism of Lupinus, Conium, and Nicotiana-induced terata. Four groups of goats were dosed from gestational day 1-10, 11-20, 21-30, and 31-40. Goats were evaluated via ultrasound imaging for pregnancy after completion of the dosing regimen and kids were evaluated for malformations at the time of parturition. Overall, there was no evidence from this study that N. glauca (anabasine) at this dose (2 g/kg/day) would cause embryonic losses in goats. However, the dose of N. glauca used in this study was at the lower threshold that would be expected to produce terata. Therefore it is possible that higher doses of anabasine could cause embryonic loss. Further work is also needed to characterize the kinetic profile of anabasine, and other teratogenic alkaloids, in the fetal compartments.

Acute respiratory failure due to Nicotiana glauca ingestion

BACKGROUND

A variety of organisms produce potent toxins that impact human health through compromising respiratory function.

CASE REPORT

We describe a rare case of abrupt respiratory failure afterNicotiana glaucaingestion in a previously healthy sixty years old female patient. She presented complaining for gait instability and malaise after ingestion of cooked leaves of the wild plant and two hours after the onset she developed respiratory failurefor which she was intubated and mechanically ventilated for two days. The patient fully recovered and was discharged from the hospital.

CONCLUSION

Anabasine, the plant's main active ingredient, can cause severe systemic intoxication due to its nicotinic receptor agonist action with respiratory muscle paralysis being the main effect.

Autotoxicity and chemical defense: nicotine accumulation and carbon gain in solanaceous plants

We quantified the accumulation of and tolerance to exogenously-fed nicotine by monitoring photosynthetic capacity and growth in two nicotine producing species of Solanaceous plants (Nicotiana sylvestris andN. glauca) as well as two Solanaceous species (Datura stramonium andLycopersicon esculentum) that do not produce nicotine to examine the relationship between tolerence and the ability to produce nicotine in defensive quantities. SinceN. sylvestris uses nicotine as an inducible defense, we examined whether nicotine tolerance is induced by damage to examine further the relationship between nicotine tolerence and synthesis. All species were grown in a 1 mM nicotine-containing hydroponic solution. Reductions in the photosynthetic capacity of nicotine-fed plants were found in all species tested. Nicotine-producing species showed no greater tolerance as measured by photosynthetic capacity than the two non-producing species. Leaf damage marginally increased the tolerence ofN. sylvestris to exogeneouslyfed nicotine suggesting that photosynthetic tolerance is coordinated with nicotine production in this nicotine-producing species.N. glauca plants regained photosynthetic capacity after their accumulated nicotine was demethylated to form nornicotine. Leaf nicotine pools in the other three species did not decrease, suggesting that for these species alkaloid metabolism does not play a major role in tolerance. Tolerance, as measured by biomass gained, was higher in the two non-producing species than in the nicotine-producing species suggesting that nicotine may also be functioning as a growth regulator. These results do not support the hypothesis that tolerance is as important as biosynthetic ability in determining which species accumulate defensively significant quantities of nicotine.