A Rapid and Efficient Method for Isolating High Quality DNA from Leaves of Carnivorous Plants from the Drosera Genus

Drosera rotundifolia, Drosera capensis, and Drosera regia are carnivorous plants of the sundew family, characterized by the presence of stalked and sticky glands on the upper leaf surface, to attract, trap, and digest insects. These plants contain exceptionally high amounts of polysaccharides, polyphenols, and other secondary metabolites that interfere with DNA isolation and subsequent enzymatic reactions such as PCR amplification. We present here a protocol for quick isolation of Drosera DNA with high yield and a high level of purity, by combining a borate extraction buffer with a commercial DNA extraction kit, and a proteinase K treatment during extraction. The yield of genomic DNA is from 13.36 μg/g of fresh weight to 35.29 μg/g depending of the species of Drosera, with a A???/A??? ratio of 1.43-1.92. Moreover, the procedure is quick and can be completed in 2.5 h.     

The role of phenolic compounds and other plant constituents in feeding by Canada geese in a coastal marsh

Summary We have assessed the relative importance of phenolic compounds, other secondary metabolites, and gross nutrient levels as feeding cues to Canada geese. Phenolic content was the most significant constituent influencing feeding selection by geese. Nutrient content had little or no effect on feeding selection.Correlative data showing the negative influence of plant phenolics on food choices by wild geese were supported by feeding preference tests. Extracts of unpalatable plants inhibited feeding by captive geese relative to extracts of palatable plants. In high phenolic plants, the phenolic containing methanol extract was more inhibitory than extractions made with petroleum ether. In a relatively low phenolic, unpalatable plant, an inhibitory factor was extractable in petroleum ether, indicating that for this species, another class of deterrents was involved. Preference tests with individual secondary metabolites showed that tannic acid and quebracho tannin were very effective in inhibiting feeding by geese and phenolic acids were slightly inhibitory, but a sesquiterpene lactone was not deterrent. These results point out the primacy of some secondary metabolites in determining food choices by geese.     

Histolocalization of chemotaxonomic markers in Brazilian Vernonieae (Asteraceae)

Vernonieae are well represented in South America by subtribe Lychnophorinae, with 104 Brazilian species, some of them rare and endangered. Lychnophorinae are well known for producing metabolites of high pharmaceutical and chemotaxonomic value. Despite the importance of secondary metabolites in Lychnophorinae, there is still little evidence regarding the secretory structures responsible for producing these compounds. Therefore, in this study we investigated 15 species representative of the main lineages of Lychnophorinae, with the following objectives: to identify where the chemotaxonomic markers of Lychnophorinae are secreted and stored and in which developmental stage of the organ these metabolites are found. Samples of stems and leaves were processed according to the usual techniques in plant anatomy. It was found that the main sites of secondary metabolite biosynthesis are glandular trichomes, epidermal cells and parenchyma tissues. Metabolites from glandular trichomes, especially sesquiterpene lactones (STL), are prevalent in the early developmental stages of organs. The metabolite compounds stored in parenchyma tissues are mainly terpenoids, flavonoids and other phenolic compounds; young and expanded leaves are equally rich in metabolites. Thus, the information obtained in this study is essential for conducting chemotaxonomic studies in this group, helping to promote selective collection and conservation of species.     

Phylogeny of the sundews, Drosera (Droseraceae), based on chloroplast rbcL and nuclear 18S ribosomal DNA Sequences

The sundew genus Drosera consists of carnivorous plants with active flypaper traps and includes nearly 150 species distributed mainly in Australia, Africa, and South America, with some Northern Hemisphere species. In addition to confused intrageneric classification of Drosera, the intergeneric relationships among the Drosera and two other genera in the Droseraceae with snap traps, Dionaea and Aldrovanda, are problematic. We conducted phylogenetic analyses of DNA sequences of the chloroplast rbcL gene for 59 species of Drosera, covering all sections except one. These analyses revealed that five of 11 sections, including three monotypic sections, are polyphyletic. Combined rbcL and 18S rDNA sequence data were used to infer phylogenetic relationships among Drosera, Dionaea, and Aldrovanda. This analysis revealed that all Drosera species form a clade sister to a clade including Dionaea and Aldrovanda, suggesting that the snap traps of Aldrovanda and Dionaea are homologous despite their morphological differences. MacClade reconstructions indicated that multiple episodes of aneuploidy occurred in a clade that includes mainly Australian species, while the chromosome numbers in the other clades are not as variable. Drosera regia, which is native to South Africa, and most species native to Australia, were clustered basally, suggesting that Drosera originated in Africa or Australia. The rbcL tree indicates that Australian species expanded their distribution to South America and then to Africa. Expansion of distribution to the Northern Hemisphere from the Southern Hemispere occurred in a few different lineages.     

Profiling and Elucidation of the Phenolic Compounds in the Aerial Parts of Gynura bicolor and G. divaricata Collected from Different Chinese Origins

Gynura bicolor and G. divaricata are not only known to be nutritive as cultured vegetables, but also beneficial as folk medicines in East Asia. As demonstrated by the current phytochemical knowledge, the genus Gynura is a promising source of phenolics with multiple medicinal activities. To expand this phytochemical knowledge, the phenolic secondary metabolites of G. bicolor and G. divaricata were studied. From the aerial parts of these two species, collected in five different Chinese locations, two fractions of phenolic compounds with different polarity were obtained by extraction and chromatographic separation. Using UPLC/MS/MS analysis, a total of 53 phenolics were either identified by comparison with respective reference compounds or tentatively characterized by their chromatographic behavior, UV‐absorption patterns, and MS fragmentations. Some naturally existing positional isomers of O‐caffeoylquinic acid, O‐p‐coumaroylquinic acid, O‐feruloylquinic acid, and dicaffeoylquinic acid as well as their methyl esters were qualitatively characterized by their specific fragmentation patterns in targeted MS/MS. In addition, the aerial parts of the two Gynura species contained kaempferol, quercetin oligoglycosides, and a variety of derivatives of benzoic acid, hydroxycinnamic acid, and caffeic acid. Furthermore, the distribution of phenolic compounds in the two species from different Chinese origins was discussed. Finally, an investigation of the total phenolic content and in vitro antioxidant activity of the various phenolic fractions was completed, to evaluate the potential of the extracts of these species for medicinal development. The free‐radical‐scavenging activities of the extracts derived from plants originating from Nanjing were proven to be higher than those of the other extracts, which correlated well with their total phenolic content.     

Phytochemical analysis and biological evaluation of the aerial parts from Symphytum anatolicum Boiss. and Cynoglottis barrelieri (All.) Vural & Kit Tan (Boraginaceae)

The present study is focused on the phytochemical analysis of the aerial parts of Symphytum anatolicum and Cynoglottis barrelieri (Boraginaceae). Their methanol extracts were subjected to qualitative LC-MS analysis, sixteen secondary metabolites have been identified from S. anatolicum and eighteen from C. barrelieri, respectively. Sixteen among all are phenolic derivatives (phenolic acids and flavonoids) and six belong to pyrrolizidine alkaloids (PAs) in the form of bases and/or N-oxides (PANOs). The observed chemical profiles are discussed chemotaxonomically as both species share the same tribe Boragineae. Caffeic acid and its derivatives together with quercetin- and kaempferol-glucosides were among the common metabolites, as they were identified in both studied plant species. Furthermore, their total phenolic and flavonoid contents were determined. Antioxidant capacity was evaluated by different chemical assays, together with their in vitro enzyme inhibitory properties towards cholinesterases (AChE and BChE), α-amylase and α-glucosidase. The results showed that C. barrelieri exhibited strong antioxidant activity, while S. anatolicum displayed good enzyme inhibitory effects contributing to a very interesting profile for further applications.     

Antimicrobial activity and chemical investigation of Brazilian Drosera

The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa.     

Antibacterial Activity of Phenolic Compounds Against the Phytopathogen Xylella fastidiosa

Xylella fastidiosa is a pathogenic bacterium that causes diseases in many crop species, which leads to considerable economic loss. Phenolic compounds (a group of secondary metabolites) are widely distributed in plants and have shown to possess antimicrobial properties. The anti-Xylella activity of 12 phenolic compounds, representing phenolic acid, coumarin, stilbene and flavonoid, was evaluated using an in vitro agar dilution assay. Overall, these phenolic compounds were effective in inhibiting X. fastidiosa growth, as indicated by low minimum inhibitory concentrations (MICs). In addition, phenolic compounds with different structural features exhibited different anti-Xylella capacities. Particularly, catechol, caffeic acid and resveratrol showed strong anti-Xylella activities. Differential response to phenolic compounds was observed among X. fastidiosa strains isolated from grape and almond. Elucidation of secondary metabolite-based host resistance to X. fastidiosa will have broad implication in combating X. fastidiosa-caused plant diseases. It will facilitate future production of plants with improved disease resistance properties through genetic engineering or traditional breeding approaches and will significantly improve crop yield.     

Plant phenolics in allelopathy

Phenolics are one of the many secondary metabolites implicated in allelopathy. To establish that allelopathy functions in a natural ecosystem, the allelopathic bioassay must be ecologically realistic so that responses of appropriate bioassay species are determined at relevant concentrations. It is important to isolate, identify, and characterize phenolic compounds from the soil. However, since it is essentially impossible to simulate exact field conditions, experiments must be designed with conditions resembling those found in natural systems. It is argued that allelopathic potential of phenolics can be appreciated only when we have a good understanding of 1) species responses to phenolic allelochemicals, 2) methods for extraction and isolation of phenolic allelochemicals, and 3) how abiotic and biotic factors affect phenolic toxicity.     

Phenolic compounds accumulation in <Emphasis Type="Italic">Hypericum ternum</Emphasis> propagated in vitro and during plant development acclimatization

The phenolic compound content of Hypericum ternum was investigated after micropropagation establishment and during acclimatization over the phenological development of the plant. Plantlets cultured in vitro on full Murashige and Skoog medium without growth regulators displayed higher phenolic compound yields, were acclimatized, and field grown. Production of total phenolic compounds as well as hyperoside, chlorogenic acid, quercitrin, guaijaverin, isoquercitrin, and uliginosin B were quantified at vegetative, flowering and fructification stages, and different plant organs (roots, stems, leaves and reproductive parts) showing that reproductive parts at flowering stage and the leaves at fructification stage were the main repository site of secondary metabolites, except for uliginosin B. The stems were the least accumulative organ, while the roots accumulated only hyperoside and uliginosin B. Moreover, the accumulation of most of the flavonoids and uliginosin B in acclimatized plants surpassed the levels found in the wild plant, warranting further research with the species.     

Chemical evidence for hybridity in Drosera (Droseraceae)

Naphthoquinone patterns found in Drosera hybrids between quinone-heterogenous parent species are reported here for the first time. Quinone patterns are constant in and characteristic for all taxa investigated. Each investigated parent species contains only one quinone isomer (either plumbagin or 7-methyljuglone), whereas all investigated hybrids between quinone-heterogenous parent species contain both isomers at almost equal concentrations, which indicates co-dominant heredity resulting from expression of both parental loci affecting regioselectivity in the biosynthesis of these acetogenic metabolites. This allows predictions on hybridity (and possibly on parentage) in some taxa of the genus.     

Anatomical structure and distribution of secondary metabolites as a peripheral defence strategy in Aloe hereroensis leaves

Eight leaves from four different plants of Aloe hereroensis and 18 leaf parts of each leaf were tested by anatomic, fluorescence microscopy and TLC methods. Four phenolic secondary metabolites, homonataloin and three isomers of aloeresin, were found in the leaves. The highest content of these metabolites was found in the top third of a leaf and along the leaf margins. In the margins, the content of the four secondary metabolites in the adaxial was higher than in the abaxial direction. In the centre parts of the leaves, the metabolic content of the abaxial parts was higher than in the adaxial parts. The results indicate that homonataloin mainly accumulates in the inner bundle sheath cells (IBSC). The three isomers of aloeresin appear in the outer bundle sheath and in the boundary cells between the chlorenchyma and water-storage tissues. The density of the vascular bundles, the area ratio of the chlorenchyma to the tested counterpart, and the area ratio of the IBSC to a whole bundle are important structural factors to determine the differences in the content of these four secondary metabolites in all the leaf parts. The distribution according to the rosette leaf arrangement and the existence of the 'cocktail' of four phenolic secondary metabolites indicate a peripheral defence strategy of this plant. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 107–116.     

Phenolic compounds in berries and flowers of a natural hybrid between bilberry and lingonberry (Vaccinium × intermedium Ruthe)

Hybridization between species plays an important role in the evolution of secondary metabolites and in the formation of combinations of existing secondary metabolites in plants. We have investigated the content of phenolic compounds in berries and flowers of Vaccinium × intermedium Ruthe, which is a rare natural hybrid between bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.). The berries and flowers of the hybrid showed characteristics inherited from both parent species in the distribution and contents of phenolic compounds. Bilberry is known as one of the richest sources of anthocyanins and to have a profile of 15 major forms combining cyanidin, delphinidin, petunidin, peonidin and malvidin with galactose, glucose and arabinose. Lingonberry contains only cyanidin glycosides. Hybrid berries contained all bilberry anthocyanins with pronounced cyanidin content. With regard to proanthocyanidins and flavonol glycosides, the hybrid inherited diverse profiles combining those of both parental species. The distribution of hydroxycinnamic acids was quite uniform in all studied berries. Of the identified compounds, 30 were detected in lingonberry, 46 in bilberry, 53 in hybrid berries and 38 in hybrid flowers. Hence, compared with the parent species, hybrid berries possess a more diverse profile of phenolic compounds and, therefore, can offer interesting material for breeding purposes.     

A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae)

KONDO, K. & LAVARACK, P. S., 1984. A cytotaxonomic study of some Australian species of Drosera L. (Droseraceae). Karyomorphological comparisons of 15 species of Australian Drosera are presented along with 11 new chromosome counts. In Australia the genus forms an extensive aneuploid series. The species which have chromosome numbers from n =10 to n = 19 show large chromosomes, while those which have chromosome numbers more than 20 show small chromosomes. Drosera paleacca shows the lowest chromosome number in the genus, 2 n = 10, with 10 large chromosomes, indicating a new basic number, x = 5. The non-staining gap between the chromatids of each chromosome is rather wide and their centromeric region is not seen throughout prophase, prometaphase, and metaphase. The C-banding and silver-staining analyses in Drosera petiolaris chromosomes suggest that Drosera chromosomes could have diffuse centromeres and simplified C-segments. Some taxonomic implications are considered, notably the possible removal of Drosera banksii from Drosera section Ergaleium to Drosera section Lasiocephala and the reduction to synonymy of Drosera section Prolifera .     

Metabolite specific effects of solar UV-A and UV-B on alder and birch leaf phenolics

We measured the concentrations of ultraviolet (UV)‐absorbing phenolics varying in response to exclusion of either solar UV‐B or both solar UV‐A and UV‐B radiations in leaves of grey alder (Alnus incana) and white birch (Betula pubescens) trees under field conditions. In alder leaves 20 and in birch leaves 13 different phenolic metabolites were identified. The response to UV exclusion varied between and within groups of phenolics in both tree species. The changes in concentration for some metabolites suggest effects of only UV‐A or UV‐B, which band being effective depending on the metabolite. For some other metabolites, the results indicate that UV‐A and UV‐B affect concentrations in the same direction, while for a few compounds there was evidence suggesting opposite effects of UV‐A and UV‐B radiation. Finally, the concentration of some phenolics did not significantly respond to solar UV. We observed only minor effects on the summed concentration of all determined phenolic metabolites in alder and birch leaves, thus indicating that measuring only total phenolics concentration may not reveal the effects of radiation. Here, we show that the appropriate biological spectral weighting functions for plant‐protective responses against solar UV radiation extend in most cases – but not always – into the UV‐A region and more importantly that accumulation of different phenolic metabolites follows different action spectra. This demonstrates under field conditions that some of the implicit assumptions of earlier research simulating ozone depletion and studying the effects of UV radiation on plant secondary metabolites need to be reassessed.     

Metabolomic analysis reveals reliance on secondary plant metabolites to facilitate carnivory in the Cape sundew,Drosera capensis

Background and AimsSecondary metabolites are integral to multiple key plant processes (growth regulation, pollinator attraction and interactions with conspecifics, competitors and symbionts) yet their role in plant adaptation remains an underexplored area of research. Carnivorous plants use secondary metabolites to acquire nutrients from prey, but the extent of the role of secondary metabolites in plant carnivory is not known. We aimed to determine the extent of the role of secondary metabolites in facilitating carnivory of the Cape sundew, Drosera capensis.MethodsWe conducted metabolomic analysis of 72 plants in a time-series experiment before and after simulated prey capture. We used ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) and the retention time index to identify compounds in the leaf trap tissue that changed up to 72 h following simulated prey capture. We identified associated metabolic pathways, and cross-compared these compounds with metabolites previously known to be involved in carnivorous plants across taxa.Key ResultsFor the first time in a carnivorous plant, we have profiled the whole-leaf metabolome response to prey capture. Reliance on secondary plant metabolites was higher than previously thought – 2383 out of 3257 compounds in fed leaves had statistically significant concentration changes in comparison with unfed controls. Of these, ~34 compounds are also associated with carnivory in other species; 11 are unique to Nepenthales. At least 20 compounds had 10-fold changes in concentration, 12 of which had 30-fold changes and are typically associated with defence or attraction in non-carnivorous plants.ConclusionsSecondary plant metabolites are utilized in plant carnivory to an extent greater than previously thought – we found a whole-metabolome response to prey capture. Plant carnivory, at the metabolic level, likely evolved from at least two distinct functions: attraction and defence. Findings of this study support the hypothesis that secondary metabolites play an important role in plant diversification and adaptation to new environments.     

Effect of secondary metabolites associated with anaerobic soil conditions on ion fluxes and electrophysiology in barley roots

The effects of secondary metabolites produced by waterlogged soils on net K(+), H(+), and Ca(2+) fluxes were studied in the mature zone of roots of two barley (Hordeum vulgare) cultivars contrasting in their waterlogging (WL) tolerance using the noninvasive microelectrode ion flux measuring technique. In WL-sensitive variety 'Naso Nijo', all three lower monocarboxylic acids (formic, acetic, and propionic acids) and three phenolic acids (benzoic, 2-hydroxybenzoic, 4-hydroxybenzoic acids) caused a substantial shift toward steady K(+) efflux, accompanied by an immediate net influx of H(+). Detrimental effects of secondary metabolites on K(+) homeostasis in root cells were absent in WL-tolerant 'TX' variety. Root treatment with Mn(2+) caused only a temporary K(+) loss that returned to the initial level 10 min after treatment. Phenolic acids slightly increased Ca(2+) influx immediately after treatment, while other metabolites tested resulted in transient Ca(2+) efflux from the root. In the long-term (24 h) treatment, all metabolites tested significantly reduced K(+) uptake and the adverse effects of phenolic acids were smaller than for monocarboxylic acids and Mn(2+). Treatment with monocarboxylic acids for 24 h shifted H(+) from net efflux to net influx, while all three phenolic acids did not cause significant effects compared with the control. Based on results of pharmacological experiments and membrane potential measurements, a model explaining the effects of secondary metabolites on membrane transport activity is proposed. We also suggest that plant tolerance to these secondary metabolites could be considered a useful trait in breeding programs.     

The distribution of the phenolic metabolites barbaloin, aloeresin and aloenin as a peripheral defense strategy in the succulent leaf parts of Aloe arborescens

Aloe arborescens is a large, multi-stemmed shrub. It is used as hedge plants to protect agricultural fields or stock and as horticultural plants in gardens. In natural habitats it is one of the very common Aloe species along the Indian Ocean coast of southern Africa, from the Cape, in the south, to Zimbabwe and Malawi in the north. Secondary phenolic metabolites such as barbaloin (Rf 0.31-0.35), aloeresin (Rf 0.25-0.3) and aloenin (Rf 0.51-0.55) have been found to be distributed in the succulent leaves of Aloe arborescens in a peripheral defense strategy. The youngest leaves have the highest content. The terminal third of each leaf has the highest content and the basal third, the lowest. Along the leaf margins, on the top third and adaxial side, the content is the highest and in the base third, the lowest along the leaf center on the abaxial side. Similar relative amounts of these three secondary phenolic metabolites were found in the different leaf locations. The leaf orientation may affect the total content of these three phenols but not their relative amounts in the different parts of the leaves. It is possible that the more often the plant parts are damaged by consumption by animals such as elephants, kudu or insects, the greater the increase of their phenolic metabolites. This increase may reduce or prevent further consumption when the content of the metabolites reaches a certain level. The plants then have a chance to renew themselves.     

柞蚕蛹培养蛹虫草不同时间后的代谢组分析

为了解柞蚕蛹培养蛹虫草(简称柞蚕蛹虫草)不同时间后的代谢物变化规律,利用广泛靶向代谢组学技术,比较不同培养时期的柞蚕蛹虫草代谢产物成分,找出差异代谢物并进行代谢通路分析.在柞蚕蛹虫草的5个生长时期共检测到10类421种化合物,主要包括:氨基酸及其衍生物、核苷酸及其衍生物、萜类、酚酸、有机酸、糖及醇类、甾体、脂类、生物碱...     

松突圆蚧为害对马尾松针叶主要次生物质的影响

对受松突圆蚧不同程度为害的马尾松针叶主要次生物质的测定表明,不同受害程度的马尾松与其针叶内的次生物质含量呈显著的相关性。黄酮、单宁和总酚含量随着为害程度的加重而发生变化,先增加,后降低,这说明了受害程度的强弱对马尾松诱导化学物质变化有影响,次生代谢物质的合成需要消耗能量和物质,影响主要代谢。这是被害松树针叶枯黄、枝干枯死直至植株枯死的原因之一。