The mechanism underlying asymmetric bending of lateral petals in Delphinium (Ranunculaceae).

During the process of flower opening, most petals move downward in the direction of the pedicel (i.e., epinastic movement). In most Delphinium flowers, however, their two lateral petals display a very peculiar movement, the mirrored helical rotation, which requires the twist of the petal stalk. However, in some lineages, their lateral petals also exhibit asymmetric bending that increases the degree of mirrored helical rotation, facilitating the formation of a 3D final shape. Notably, petal asymmetric bending is a novel trait that has not been noticed yet, so its morphological nature, developmental process, and molecular mechanisms remain largely unknown. Here, by using D. anthriscifolium as a model, we determined that petal asymmetric bending was caused by the localized expansion of cell width, accompanied by the specialized array of cell wall nano-structure, on the adaxial epidermis. Digital gene analyses, gene expression, and functional studies revealed that a class I homeodomain-leucine zipper family transcription factor gene, DeanLATE MERISTEM IDENTITY1 (DeanLMI1), contributes to petal asymmetric bending; knockdown of it led to the formation of explanate 2D petals. Specifically, DeanLMI1 promotes cell expansion in width and influences the arrangement of cell wall nano-structure on the localized adaxial epidermis. These results not only provide a comprehensive portrait of petal asymmetric bending for the first time but also shed some new insights into the mechanisms of flower opening and helical movement in plants.

Nitric oxide effectively orchestrates postharvest flower senescence: a case study of Consolida ajacis.

Nitric oxide releasing compound sodium nitroprusside (SNP) is regarded as novel chemical to beat the daunting challenges of postharvest losses in cut flowers. In the recent years, it has yielded propitious results as postharvest vase preservative for cut flowers. Our study explicates the efficacy of SNP in mitigating postharvest senescence in Consolida ajacis (L.) Schur cut spikes. The freshly excised C. ajacis spikes were subjected to different SNP treatments viz , 20µM, 40µM, 60µM and 80µM. The control spikes were held in distilled water. The spikes held in test solutions showed a marked improvement in vase life and flower quality. Our results indicate a profound surge in sugars, phenols and soluble proteins in SNP-treated spikes over control. Moreover, the SNP treatments improved membrane stability as signposted by decreased lipoxygenase activity (LOX). The SNP treatments also upregulated different antioxidant enzymes viz , ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD). The current study recommends 40µM SNP as optimum concentration for preserving floral quality and extending display period of C. ajacis spikes. Together, these findings reveal that SNP at proper dosage can efficiently alleviate deteriorative postharvest changes by modulating physiological and biochemical mechanisms underlying senescence.

The diversity of elaborate petals in Isopyreae (Ranunculaceae): a special focus on nectary structure.

Elaborate petals are highly diverse in morphology, structure, and epidermal differentiation and play a key role in attracting pollinators. There have been few studies on the elaborate structure of petals in the tribe Isopyreae (Ranunculaceae). Seven genera in Isopyreae (Aquilegia, Semiaquilegia, Urophysa, Isopyrum, Paraquilegia, Dichocarpum, and Leptopyrum) have petals that vary in morphology, and two genera (Enemion and Thalictrum) have no petals. The petals of nine species belonged to 7 genera in the tribe were studied to reveal their nectary structure, epidermal micromorphology and ancestral traits. The petal nectaries of Isopyreae examined in this study were located at the tip of spurs (Aquilegia yabeana and A. rockii), or the bottom of shallow sacs (Semiaquilegia adoxoides, Urophysa henryi, Isopyrum manshuricum, and Paraquilegia microphylla), a cup-shaped structure (Dichocarpum fargesii) and a bilabiate structure (Leptopyrum fumarioides). The petal nectary of eight species in Isopyreae (except A. ecalcarata) was composed of secretory epidermis, nectary parenchyma, and vascular tissues, and some sieve tubes reached the secretory parenchyma cells. Among the eight species with nectaries examined in the present study, A. yabeana had the most developed nectaries, with 10-15 layers of secretory parenchyma cells. The epidermal cells of mature petals of the nine species were divided into 11 types. Among these 11 types, there were two types of secretory cells and two types of trichomes. Aquilegia yabeana and A. rockii had the highest number of cell types (eight types), and I. manshuricum and L. fumarioides had the lowest number of cell types (three types). Aquilegia ecalcarata had no secretory cells, and the papillose conical polygonal secretory cells of D. fargesii were different from those of the other seven species with nectaries. Trichomes were found only in Aquilegia, Semiaquilegia, Urophysa, and Paraquilegia. The ancestral mode of nectar presentation in Isopyreae was petals with hidden nectar (70.58%). The different modes of nectar presentation in petals may reflect adaptations to different pollinators in Isopyreae.

Immunosuppressive activity of a cycloartane triterpene glycoside from Beesia calthaefolia by inhibiting T cell proliferation.

BC-1 is a cycloartane triterpene glycoside isolated from the whole plant of Beesia calthaefolia. Our recent studies proved that BC-1 inhibited proliferation of splenic lymphocyte and phagocytosis of macrophages, and inhibited the increased production of TNF-α and IL-1ß. However, it lacks of study about the immunomodulatory effect of BC-1 on purified T lymphocytes. Therefore, in the present study, we evaluated the suppressive potentials of BC-1 on immune responses in vitro. BC-1 markedly suppressed anti-CD3/CD28 mAbs (mAbs) induced murine T lymphocytes proliferation, the expression levels of CD69 and CD25 of CD3+ T cells. BC-1 could strongly decrease ratio of CD4+/CD8+, decrease the Th1/Th2 cytokines production (IL-2, IFN-γ, IL-4, and IL-10) of CD4+ T-cells. In addition, we studied signal transduction pathways about T-cell activation on puried murine CD4+ T lymphocytes by western-blot assay. The data revealed that BC-1 could inhibit the activation of JNK, ERK and PI3K/AKT signal transduction pathways. These results indicated that BC-1 possesses potential downregulating effect on the immune system and might be developed as an immunosuppressive agent in treatment of CD4+ T cell-mediated inflammatory and undesired immune responses.

Metabolite Profiling Based on UPLC-Q-TOF-MS/MS and the Biological Evaluation of Medicinal Plants of Chinese Dichocarpum (Ranunculaceae).

The genus Dichocarpum is endemic to East Asia, and many species have been used to treat various diseases. However, phytochemical researches of this genus have been limited to date. In the present study, a metabolomic approach based on UPLC-Q-TOF-MS/MS was used to explore the phytochemical profiles of 10 Chinese Dichocarpum species, and cannabinoid receptor (CB1/CB2) agonistic activities evaluation of these plants was performed. A total of 128 features were putatively annotated, belonging to alkaloids, flavonoids, triterpenes saponins, phenolic acids, and others. Semi-quantitative statistics demonstrated that alkaloids and flavonoids were widely distributed, with the former the most abundant, whereas triterpenes saponins were mainly distributed in D. fargesii and D. wuchuanense. The phylogenetic results obtained from DNA sequencing assigned the 10 species to three groups. Further results of in silico annotation revealed three chemical families and helped determine the characteristic features of the three groups. In addition, the plant extracts of nine species from this genus showed agonistic activity on CB2 receptors. This comprehensive analysis revealed the chemotype distribution and pharmacophylogenetic relationship, to provide clues for the prospective resource utilization of the medicinal plants from the genus Dichocarpum.

Root exudate composition of grass and forb species in natural grasslands.

Plants exude a diverse cocktail of metabolites into the soil as response to exogenous and endogenous factors. So far, root exudates have mainly been studied under artificial conditions due to methodological difficulties. In this study, each five perennial grass and forb species were investigated for polar and semi-polar metabolites in exudates under field conditions. Metabolite collection and untargeted profiling approaches combined with a novel classification method allowed the designation of 182 metabolites. The composition of exuded polar metabolites depended mainly on the local environment, especially soil conditions, whereas the pattern of semi-polar metabolites was primarily affected by the species identity. The profiles of both polar and semi-polar metabolites differed between growth forms, with grass species being generally more similar to each other and more responsive to the abiotic environment than forb species. This study demonstrated the feasibility of investigating exudates under field conditions and to identify the driving factors of exudate composition.

The morphology, molecular development and ecological function of pseudonectaries on Nigella damascena (Ranunculaceae) petals.

Pseudonectaries, or false nectaries, the glistening structures that resemble nectaries or nectar droplets but do not secrete nectar, show considerable diversity and play important roles in plant-animal interactions. The morphological nature, optical features, molecular underpinnings and ecological functions of pseudonectaries, however, remain largely unclear. Here, we show that pseudonectaries of Nigella damascena (Ranunculaceae) are tiny, regional protrusions covered by tightly arranged, non-secretory polygonal epidermal cells with flat, smooth and reflective surface, and are clearly visible even under ultraviolet light and bee vision. We also show that genes associated with cell division, chloroplast development and wax formation are preferably expressed in pseudonectaries. Specifically, NidaYABBY5, an abaxial gene with ectopic expression in pseudonectaries, is indispensable for pseudonectary development: knockdown of it led to complete losses of pseudonectaries. Notably, when flowers without pseudonectaries were arrayed beside those with pseudonectaries, clear differences were observed in the visiting frequency, probing time and visiting behavior of pollinators (i.e., honey bees), suggesting that pseudonectaries serve as both visual attractants and nectar guides.

Cycloartane and Oleanane Glycosides from the Tubers of Eranthis cilicica.

Phytochemical analysis of the tubers of Eranthis cilicica was performed as part of our continuous study on the plants of the family Ranunculaceae, which resulted in the isolation of eleven new cycloartane glycosides (1⁻11) and one new oleanane glycoside (13), together with one known oleanane glycoside (12). The structures of the new compounds were determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR, and enzymatic hydrolysis followed by either X-ray crystallographic or chromatographic analysis. The aglycone (1a) of 2 and its C-23 epimer (8a), and the oleanane glycosides (12 and 13) showed cytotoxic activity against HL-60 leukemia cells with IC50 values ranging from 10.6 µM to 101.6 µM. HL-60 cells were much more sensitive to 8a (IC50 14.8 µM) than 1a (IC50 101.1 µM), indicating that the C-23 configuration is associated with the cytotoxicity of these cycloartane derivatives. Compound 12 was revealed so as to partially induce apoptotic cell death in HL-60 cells, as was evident from morphology of HL-60 cells treated with 12.

Protective role of berberine and Coptischinensis extract on T2MD rats and associated islet Rin­5f cells.

The aim of the present study was to compare the different effects of berberine (Ber) and Coptischinensis extract (CCE) on a rat model of type 2 diabetes mellitus (T2DM), and the islet Rin­5f cell line was used to examine the differences between Ber and CCE and the underlying mechanisms. CCE was extracted and purified prior to analysis. Male Sprague­Dawley rats were provided with a high­fat diet to induce insulin resistance prior to injecting with streptozotocinto establish the T2DM model, the T2DM rats were treated with Ber and CCE, and blood samples and pancreatic tissues were obtained and compared to examine T2DM metabolic syndromes among the groups of rats, which included healthy rats, model rats, and model rats treated with Ber and CCE at different doses between 0 and 8 weeks. The protective effects of Ber and CCE on the Rin­5f islet cell line were also evaluated. The effects on Rin­5f cell proliferation and cell cycle, glucose­stimulated insulin release test (GSIS), the anti­apoptotic effects caused by fat induction, and protein expression levels of poly ADP­ribose polymerase (PARP­1) were evaluated. The results showed that the content of the prepared CCE was 96.07% for five alkaloids. When it was used for treatment of the T2DM rats, compared with Ber, metformin and rosiglitazone, the fasting blood glucose, glucosylated serum protein (GSP) and glucose infusion rate indicesin the fasting rats were ameliorated, compared with those in the T2MD rats, with no significant differences between treatment with Ber or CCE and metformin or rosiglitazone. The indices of mean optical density and fasting ß­cell function index (FBCI) were different following treatment with Ber and CCE, compared with those in the model rats, which may have stimulated the pancreatic secretion of insulin. When Ber and CCE were used to examine the protective effects on Rin­5F cells, it was found that the Rin­5f cell GSIS, cell cycle, lipotoxic islet cell proliferation and protein expression of PARP­1 were altered and improved, which may have protected pancreatic islet ß­cells by improving islet ß­cell proliferation and the protein expression of PARP­1. CCE and Ber exerted similar effects when used for the treatment of T2MD rats, and may have stimulated the pancreatic secretion of insulin through the protective effect on islet ß­cells via improving islet ß­cell proliferation and the protein expression of PARP­1.

Genetic structure of Hepatica nobilis var. japonica, focusing on within population flower color polymorphism.

How phenotypic or genetic diversity is maintained in a natural habitat is a fundamental question in evolutionary biology. Flower color polymorphism in plants is a common polymorphism. Hepatica nobilis var. japonica on the Sea of Japan (SJ) side of the Japanese mainland exhibits within population flower color polymorphism (e.g., white, pink, and purple), while only white flowers are observed on the Pacific Ocean (PO) side. To determine the relationships between flower color polymorphism, within and among populations, and the genetic structure of H. nobilis var. japonica, we estimated the genetic variation using simple sequence repeat (SSR) markers. First, we examined whether cryptic lineages corresponding to distinct flower colors contribute to the flower color polymorphisms in H. nobilis var. japonica. In our field observations, no bias in color frequency was observed among populations on Sado Island, a region with high variation in flower color. Simple sequence repeat (SSR) analyses revealed that 18% of the genetic variance was explained by differences among populations, whereas no genetic variation was explained by flower color hue or intensity (0% for both components). These results indicate that the flower color polymorphism is likely not explained by cryptic lineages that have different flower colors. In contrast, populations in the SJ and PO regions were genetically distinguishable. As with the other plant species in these regions, refugial isolation and subsequent migration history may have caused the genetic structure as well as the spatially heterogeneous patterns of flower color polymorphisms in H. nobilis var. japonica.

Salicylic Acid Treatment Increases the Levels of Triterpene Glycosides in Black Cohosh (Actaea Racemosa) Rhizomes.

Black cohosh (Actaea racemosa) serves as the host plant for the Appalachian azure butterfly, Celastrina neglectamajor. Overharvesting of Black cohosh for the dietary supplement industry may result in its extirpation, and may also cause the elimination of the dependent butterfly. One way to increase or maintain the number of host plants in forested environments would be to reduce the number harvested, for example by increasing the levels of the desired metabolites in Black cohosh rhizomes. The secondary metabolites actein and deoxyactein are triterpene glycosides and are among the compounds associated with the putative activity of Black cohosh extracts. Acetein and deoxyacetein are used to standardize Black cohosh supplements. To gain an understanding of mechanisms that may control actein and deoxyactein accumulation, Black cohosh rhizomes were treated with exogenous salicylic acid, jasmonic acid, or ethylene, or were mechanically wounded. Salicylic acid treatment significantly increased the levels of actein and deoxyactein in the rhizome of Black cohosh, suggesting that the synthesis of triterpene glycosides is controlled in part by salicylic acid. Using salicylic acid or related chemicals to increase the levels of actein and deoxyactein in rhizomes may help supply the supplement industry and, simultaneously, help conserve Black cohosh and species dependent upon it.

Transcriptome analysis of 20 taxonomically related benzylisoquinoline alkaloid-producing plants.

BACKGROUND: Benzylisoquinoline alkaloids (BIAs) represent a diverse class of plant specialized metabolites sharing a common biosynthetic origin beginning with tyrosine. Many BIAs have potent pharmacological activities, and plants accumulating them boast long histories of use in traditional medicine and cultural practices. The decades-long focus on a select number of plant species as model systems has allowed near or full elucidation of major BIA pathways, including those of morphine, sanguinarine and berberine. However, this focus has created a dearth of knowledge surrounding non-model species, which also are known to accumulate a wide-range of BIAs but whose biosynthesis is thus far entirely unexplored. Further, these non-model species represent a rich source of catalyst diversity valuable to plant biochemists and emerging synthetic biology efforts. RESULTS: In order to access the genetic diversity of non-model plants accumulating BIAs, we selected 20 species representing 4 families within the Ranunculales. RNA extracted from each species was processed for analysis by both 1) Roche GS-FLX Titanium and 2) Illumina GA/HiSeq platforms, generating a total of 40 deep-sequencing transcriptome libraries. De novo assembly, annotation and subsequent full-length coding sequence (CDS) predictions indicated greater success for most species using the Illumina-based platform. Assembled data for each transcriptome were deposited into an established web-based BLAST portal ( www.phytometasyn.ca) to allow public access. Homology-based mining of libraries using BIA-biosynthetic enzymes as queries yielded ~850 gene candidates potentially involved in alkaloid biosynthesis. Expression analysis of these candidates was performed using inter-library FPKM normalization methods. These expression data provide a basis for the rational selection of gene candidates, and suggest possible metabolic bottlenecks within BIA metabolism. Phylogenetic analysis was performed for each of 15 different enzyme/protein groupings, highlighting many novel genes with potential involvement in the formation of one or more alkaloid types, including morphinan, aporphine, and phthalideisoquinoline alkaloids. Transcriptome resources were used to design and execute a case study of candidate N-methyltransferases (NMTs) from Glaucium flavum, which revealed predicted and novel enzyme activities. CONCLUSIONS: This study establishes an essential resource for the isolation and discovery of 1) functional homologues and 2) entirely novel catalysts within BIA metabolism. Functional analysis of G. flavum NMTs demonstrated the utility of this resource and underscored the importance of empirical determination of proposed enzymatic function. Publically accessible, fully annotated, BLAST-accessible transcriptomes were not previously available for most species included in this report, despite the rich repertoire of bioactive alkaloids found in these plants and their importance to traditional medicine. The results presented herein provide essential sequence information and inform experimental design for the continued elucidation of BIA metabolism.

Metabolome analysis of 20 taxonomically related benzylisoquinoline alkaloid-producing plants.

BACKGROUND: Recent progress toward the elucidation of benzylisoquinoline alkaloid (BIA) metabolism has focused on a small number of model plant species. Current understanding of BIA metabolism in plants such as opium poppy, which accumulates important pharmacological agents such as codeine and morphine, has relied on a combination of genomics and metabolomics to facilitate gene discovery. Metabolomics studies provide important insight into the primary biochemical networks underpinning specialized metabolism, and serve as a key resource for metabolic engineering, gene discovery, and elucidation of governing regulatory mechanisms. Beyond model plants, few broad-scope metabolomics reports are available for the vast number of plant species known to produce an estimated 2500 structurally diverse BIAs, many of which exhibit promising medicinal properties. RESULTS: We applied a multi-platform approach incorporating four different analytical methods to examine 20 non-model, BIA-accumulating plant species. Plants representing four families in the Ranunculales were chosen based on reported BIA content, taxonomic distribution and importance in modern/traditional medicine. One-dimensional (1)H NMR-based profiling quantified 91 metabolites and revealed significant species- and tissue-specific variation in sugar, amino acid and organic acid content. Mono- and disaccharide sugars were generally lower in roots and rhizomes compared with stems, and a variety of metabolites distinguished callus tissue from intact plant organs. Direct flow infusion tandem mass spectrometry provided a broad survey of 110 lipid derivatives including phosphatidylcholines and acylcarnitines, and high-performance liquid chromatography coupled with UV detection quantified 15 phenolic compounds including flavonoids, benzoic acid derivatives and hydroxycinnamic acids. Ultra-performance liquid chromatography coupled with high-resolution Fourier transform mass spectrometry generated extensive mass lists for all species, which were mined for metabolites putatively corresponding to BIAs. Different alkaloids profiles, including both ubiquitous and potentially rare compounds, were observed. CONCLUSIONS: Extensive metabolite profiling combining multiple analytical platforms enabled a more complete picture of overall metabolism occurring in selected plant species. This study represents the first time a metabolomics approach has been applied to most of these species, despite their importance in modern and traditional medicine. Coupled with genomics data, these metabolomics resources serve as a key resource for the investigation of BIA biosynthesis in non-model plant species.

Distribution of Two bioactive compounds in flowers of Trollius chinensis.

A comprehensive procedure was established, which combined a high-performance liquid chromatography (HPLC) assay for the simultaneous quantification of 2″-O-ß-L-galactopyranosylorientin (OGA) and veratric acid and a gravimetric analysis for the determination of the mass fraction of the floral parts (calyx, corolla, stalk, stamens and pistils and ovary) of Trollius chinensis, to investigate the distribution and identify the enriched floral part(s) of these two compounds in the flowers. The calculated mean distributions of OGA in calyx, corolla, stamens and pistils, stalk and ovary were 83.62, 7.76, 4.35, 2.92 and 1.35%, respectively, whereas those of veratric acid in the corresponding floral parts were 46.41, 9.01, 18.41, 4.11 and 22.06%, respectively, indicating the uneven and noncorresponding distribution of these two compounds. This study extends the application of the HPLC assay and favors the production of OGA and veratric acid from the flowers of T. chinensis in addition to the benefits of breeding, cultivation and utilization of these flowers.

Disruption of the petal identity gene APETALA3-3 is highly correlated with loss of petals within the buttercup family (Ranunculaceae).

Absence of petals, or being apetalous, is usually one of the most important features that characterizes a group of flowering plants at high taxonomic ranks (i.e., family and above). The apetalous condition, however, appears to be the result of parallel or convergent evolution with unknown genetic causes. Here we show that within the buttercup family (Ranunculaceae), apetalous genera in at least seven different lineages were all derived from petalous ancestors, indicative of parallel petal losses. We also show that independent petal losses within this family were strongly associated with decreased or eliminated expression of a single floral organ identity gene, APETALA3-3 (AP3-3), apparently owing to species-specific molecular lesions. In an apetalous mutant of Nigella, insertion of a transposable element into the second intron has led to silencing of the gene and transformation of petals into sepals. In several naturally occurring apetalous genera, such as Thalictrum, Beesia, and Enemion, the gene has either been lost altogether or disrupted by deletions in coding or regulatory regions. In Clematis, a large genus in which petalous species evolved secondarily from apetalous ones, the gene exhibits hallmarks of a pseudogene. These results suggest that, as a petal identity gene, AP3-3 has been silenced or down-regulated by different mechanisms in different evolutionary lineages. This also suggests that petal identity did not evolve many times independently across the Ranunculaceae but was lost in numerous instances. The genetic mechanisms underlying the independent petal losses, however, may be complex, with disruption of AP3-3 being either cause or effect.

Change in protein content during seed germination of a high altitude plant Podophyllum hexandrum Royle.

Podophyllum hexandrum Royle (=Sinopodophyllum hexandrum) is a high-altitude medicinal plant exploited for its etoposides which are potential anticancer compounds. An effective, conventional propagation method is by seed. However, seed germination is erratic, and seedling survival is low. A marginal increase in Podophyllum seed germination was attained with organic solvents. In the present study an attempt was made to decipher the physiological and biochemical barriers in terms of change in proteins during seed germination of Podophyllum. Comparative 2-DE analysis between un-germinated (dormant) and germinating seeds revealed nearly 113 differentially expressed proteins, whereas Peptide Mass Fingerprint (PMF) analysis of 97 protein spots revealed appearance of 27 proteins, up-accumulation of 11 proteins, down-accumulation of 19 proteins and disappearance of 40 proteins with germination. Identified 59 proteins in the homology search were involved in metabolism (carbohydrate and amino acid metabolism; 20 proteins), ABA/GA signaling (17 proteins) and stress (15 proteins) related proteins. Seven proteins were with unknown function. Two-DE, and MS/MS analysis in conjunction with semi-quantitative RT-PCR data of cell wall hydrolyzing genes, revealed that in Podophyllum the radicle protrusion occurs might be because of the up-accumulation of cell wall hydrolases i.e. ß-1, 3-glucanase and XET which weakens the thick walled micropylar endosperm.

Palatability of selected alpine plant litters for the decomposer Lumbricus rubellus (Lumbricidae).

On alpine pastureland the decline in large-bodied earthworm numbers and biomass after abandonment of management might be the result of a shift from highly palatable grass litter to poorly digestible leaf litter of dwarf shrubs. To test this hypothesis, we analysed nitrogen, phosphorous and total phenolic contents of fresh and aged litter of eight commonly occuring alpine plant species and compared consumption rates of these food sources in a controlled feeding experiment with Lumbricus rubellus (Lumbricidae). Furthermore, we analysed the microbial community structure of aged litter materials to check for a relationship between the microbial characteristics of the different plant litter types and the food choice of earthworms. Plant litters differed significantly in their chemical composition, earthworms, however, showed no preference for any litter species, but generally rejected fresh litter material. Microbial community structures of the litter types were significantly different, but we could find no evidence for selective feeding of L. rubellus. We conclude that L. rubellus is a widespread, adaptable ubiquist, which is able to feed on a variety of food sources differing in quality and palatability, as long as they have been exposed to wheathering.

Transport of sucrose, not hexose, in the phloem.

Several lines of evidence indicate that glucose and fructose are essentially absent in mobile phloem sap. However, this paradigm has been called into question, especially but not entirely, with respect to species in the Ranunculaceae and Papaveraceae. In the experiments in question, phloem sap was obtained by detaching leaves and placing the cut ends of the petioles in an EDTA solution. More hexose than sucrose was detected. In the present study, these results were confirmed for four species. However, almost identical results were obtained when the leaf blades were removed and only petiole stubs were immersed. This suggests that the sugars in the EDTA solution represent compounds extracted from the petioles, rather than sugars in transit in the phloem. In further experiments, the leaf blades were exposed to (14)CO(2) and, following a chase period, radiolabelled sugars in the petioles and EDTA exudate were identified. Almost all the radiolabel was in the form of [(14)C]sucrose, with little radiolabelled hexose. The data support the long-held contention that sucrose is a ubiquitous transport sugar, but hexoses are essentially absent in the phloem stream.

Transcript and metabolite profiling in cell cultures of 18 plant species that produce benzylisoquinoline alkaloids.

Benzylisoquinoline alkaloids (BIAs) are a large and diverse group of ~2500 specialized metabolites found predominantly in plants of the order Ranunculales. Research focused on BIA metabolism in a restricted number of plant species has identified many enzymes and cognate genes involved in the biosynthesis of compounds such as morphine, sanguinarine and berberine. However, the formation of most BIAs remains uncharacterized at the molecular biochemical level. Herein a compendium of sequence- and metabolite-profiling resources from 18 species of BIA-accumulating cell cultures was established, representing four related plant families. Our integrated approach consisted of the construction of EST libraries each containing approximately 3500 unigenes per species for a total of 58,787 unigenes. The EST libraries were manually triaged using known BIA-biosynthetic genes as queries to identify putative homologs with similar or potentially different functions. Sequence resources were analyzed in the context of the targeted metabolite profiles obtained for each cell culture using electrospray-ionization and collision-induced dissociation mass spectrometry. Fragmentation analysis was used for the identification or structural characterization coupled with the relative quantification of 72 BIAs, which establishes a key resource for future work on alkaloid biosynthesis. The metabolite profile obtained for each species provides a rational basis for the prediction of enzyme function in BIA metabolism. The metabolic frameworks assembled through the integration of transcript and metabolite profiles allow a comparison of BIA metabolism across several plant species and families. Taken together, these data represent an important tool for the discovery of BIA biosynthetic genes.

Discrimination of Radix Pseudostellariae according to geographical origins using NIR spectroscopy and support vector data description.

Near infrared (NIR) spectroscopy combined with support vector data description (SVDD) was attempted to identify geographical origins of Radix Pseudostellariae. Original spectra of eggs in wavelength range of 10000-4000 cm(-1) were acquired. SVDD was performed to calibrate discrimination model, and some parameters of SVDD model were optimized. Meanwhile, conversional two-class classification method-support vector machine (SVM) was used comparatively for classification. Compared with SVM classification, SVDD model showed its superior ability in dealing with imbalance training samples. When the proportion of the number of Radix Pseudostellariae from Anhui province (the area where genuine crude Radix Pseudostellariae was cultivated) and other provinces was one to sixteen, the identification rate of SVDD model was 92.5% in prediction set. This work indicates that NIR spectroscopy combined with SVDD is an excellent choice in building one-class calibration model for discrimination of genuine crude Radix Pseudostellariae.