Structure and function of shisham forests in central Himalaya, India: nutrient dynamics

The structure and function of Shisham (Dalbergia sissoo Roxb.) forests were investigated in relation to nutrient dynamics in 5- to 15-year-old stands growing in central Himalaya. Nutrient concentrations and storage in different layers of vegetation were in the order: tree > shrub > herb. Forest soil, litter and vegetation accounted for 80.1-91.9, 1.0-1.5 and 7.0-18.4%, respectively, of the total nutrients in the system. There were considerable reductions (trees 32.8-43.1; shrubs 26.2-32.4; and herbs 18-8-22-2%) in nutrient concentrations of leaves during senescence. Nutrient uptake by the vegetation as a whole and also by the different components, with and without adjustment for internal recycling, was investigated. Annual transfer of litter nutrients to the soil from vegetation was 74.8-108.4 kg ha(-1) year(-1) N, 56.8-4 kg ha(-1) year(-1) P and 38.7-46.9 kg ha(-1) year(-1) K. Turnover rate and time for different nutrients ranged between 56 and 66 % year(-1) and 1.5 and 1.8 years, respectively. The turnover rate of litter indicates that over 50% of nutrients in litter on the forest floor are released, which ultimately enhances the productivity of the forest stand. The nutrient use efficiency in Shisham forests ranged from 136 to 143 kg ha(-1) year(-1) for N, 1,441 to 1,570 kg ha(-1) year(-1) for P and 305 to 311 kg ha(-1) year(-1) for K. Compared with natural oak forest (265 kg ha(-1) year(-1) and an exotic eucalypt plantation (18 kg ha(-1) year(-1), a higher proportion of nutrients was retranslocated in Shisham forests, largely because of higher leaf tissue nutrient concentrations. This indicates a lower nutrient use efficiency of Shisham compared with eucalypt and oak. Compartment models for nutrient dynamics have been developed to represent the distribution of nutrients pools and net annual fluxes within the system.

Flavonoid compounds from Pyrus communis L. flowers

Five flavonoid glycosides: kaempferol 3-O-beta-D-glucopyranoside (IV), isorhamnetin 3-O-beta-D-glucopyranoside (V), isorhamnetin 3-O-beta-D-(6''-O-alpha-L-rhamnopyranosyl)-glucopyranoside (VIII), 8-methoxykaempferol 3-O-beta-D-(2''-O-alpha-D-glucopyranosyl)-glucopyranoside (VI), 8-methoxykaempferol 3-O-beta-D-(2''-O-alpha-L-rhamnopyranosyl)-glucopyranoside (VII) and chlorogenic acid (IX) were isolated from the flowers naturally growing Pyrus communis L. They were identified by chemical and spectroscopic methods.

Barbeyol: a new phenolic indane type component from Barbeya oleoides

The aerial parts of Barbeya oleoides Schweinf (Family: Barbeyaceae) has afforded a new phenolic indane type component, which has been characterized as (6R, 4aR, 5aR)-5, 4a, 5a-trihydroindeno- (1, 2-a) indane-2, 4, 9-triol-6-O-beta-acetate (1) on the basis of spectral analysis and has been designated as barbeyol.

Oxypropylation of cork and the use of the ensuing polyols in polyurethane formulations

Cork particles, recovered as byproducts of the processing of this natural material, were oxypropylated under pressure and relatively high temperature in the presence of KOH as catalyst. Various parameters were explored in order to assess the most suitable conditions, which led to the almost complete conversion of the solid cork into a viscous polyol. This product was a mixture of oxypropylated cork macromolecules and propylene oxide oligomers, which were thoroughly characterized. The use of these polyols as macromonomers in the synthesis of polyurethane foams gave promising results, thus showing that it should be possible to exploit the residues of this important renewable resource to manufacture original materials.

Malonyl-CoA:anthocyanin 5-O-glucoside-6"'-O-malonyltransferase from scarlet sage (Salvia splendens) flowers. Enzyme purification, gene cloning, expression, and characterization

The orange to blue coloration of flowers in nature is, in most cases, provided by anthocyanins, a class of plant flavonoids, many of which are modified by malonyl group(s). However, the identity of the enzyme catalyzing the malonylation reaction remains to be established. Here, we describe for the first time the purification, characterization, and cDNA cloning of an anthocyanin malonyltransferase from scarlet sage (Salvia splendens) flowers. The purified enzyme (termed Ss5MaT1) was a monomeric 50-kDa protein catalyzing the regiospecific transfer of the malonyl group from malonyl-CoA to the 6"'-hydroxyl group of the 5-glucosyl moiety of anthocyanins. Ss5MaT1 showed a k(cat) value of 7.8 s(-1) at 30 degrees C and pH 7.0 for the malonylation of bisdemalonylsalvianin (pelargonidin 3-(6"-O-caffeyl-beta-glucopyranoside)-5-beta-glucopyranoside) and K(m) values of 101 microm and 57 microm for bisdemalonylsalvianin and malonyl-CoA, respectively. p-Coumaric acid, which mimics an aromatic acyl group linked to the 3-glucosidic moiety of an anthocyanin substrate, was a competitive inhibitor with respect to the substrate. This strongly suggests that the presence of an aromatic acyl group at the 3-glucosidic moiety of anthocyanin is important for substrate recognition by the enzyme. On the basis of the partial amino acid sequences of the purified enzyme, we isolated a cDNA encoding Ss5MaT1. Ss5MaT1 consisted of 462 amino acids and shared motifs that are commonly found among members of a versatile plant acyltransferase family, which was recently shown to include numerous homologs of unknown biochemical functions. Northern blot analysis revealed that the transcripts of Ss5MaT1 were detected in petals, sepals, bracts, and red stems, in accordance with the pigment accumulation patterns. Phylogenetic analysis suggests that the aliphatic and aromatic acylations of anthocyanins are generally catalyzed by subfamily members of the plant acyltransferase family.

Alternate nitrogen amendments for organic fertilizers

The use of compost or manure in agriculture as an organic source of nutrients is common in many tropical, developing countries like Nigeria. One of the drawbacks of such materials is their low nitrogen (N) content (=1% N). Farmers commonly use chemical N fertilizers such as urea, calcium ammonium nitrate (CAN), and NPK formulations to obtain better crop growth and yield. These chemical supplements may have a negative impact on the environment through nitrate leaching into water, leading to eutrophication of surface waters that can affect public health. Gliricidia sepium, a fast-growing, tropical, perennial hedge plant was tested as a source of N in organo-mineral fertilizer formulations. Average nutrient content of Gliricidia is 3.8% N, 0.32% P, 1.8% K, 0.8% Ca, and 0.2% Mg. Using a sand culture and Amaranthus caudatus as a test crop, it was shown that amending commercial composts with 30% Gliricidia prunings would benefit many small-scale farmers and control environmental pollution.

Molecular analysis of medicinally-used Chinese and Japanese Curcuma based on 18S rRNA gene and trnK gene sequences

Curcuma drugs have been used discriminatingly for invigorating blood circulation, promoting digestion, and as a cholagogic in China. However, there is confusion about the drug's botanical origins and clinical uses because of morphological similarity of Curcuma plants and drugs. In order to develop an ultimate identification, molecular analysis based on 18S rRNA gene and trnK gene sequences were performed on 6 Curcuma species used medicinally in China and Japan. The 18S rRNA gene sequences were found to be of 1810 bps in length. In comparison with the common sequence of C. longa, C. phaeocaulis, C. wenyujin and C. aromatica, that of C. kwangsiensis had one base substitution, and the same base difference was observed between the Chinese and the Japanese populations of C. zedoaria. The trnK gene sequences were found to span 2698-2705 bps. There were base substitutions, small deletions or insertions at some sites between the trnK coding region and matK region among each species. Based on the base substitutions, C. zedoaria and C. kwangsiensis specimens were divided into two groups, respectively. An identical sequence was detected in C. phaeocaulis and in the Chinese population of C. zedoaria, as well as in the Japanese population of C. zedoaria and in one group of C. kwangsiensis with a purple-colored band in leaves. New taxonomic information to be used for authenticating Curcuma drugs was obtained.

Non-destructive NIR-FT-Raman analyses in practice. Part I. Analyses of plants and historic textiles

Non-destructive analysis of natural substances in plants as well as of old dyed textiles by Raman spectroscopy has not been possible using conventional techniques. Exciting lines from the visible part of the spectrum produced photochemical and thermal decomposition of the objects as well as strong fluorescence. Using Nd:YAG laser excitation at 1,064 nm together with a special sample arrangement and interferometric recording, various polyacetylenes in Aethusa cynapium and in chamomile (Chamomilla recutita) and the main valuable substances in gentian species (Gentiana lutea and G. punctata), curcuma roots (Curcuma longa), cinnamon (Cinnamomum zeylanicum), fennel (Foeniculum vulgare), clove (Caryophyllus aromaticus), and ginger (Zingiber officinale) were analyzed non-destructively and discussed in comparison with the corresponding pure standard compounds. We further analyzed non-destructively the FT Raman spectra of collections of historical textiles and lakes used for dyeing. It is possible to distinguish the main dye component non-destructively by using Raman bands.

Composition of the essential oil of two Nepeta species and in vitro evaluation of their activity against Helicobacter pylori

The chemical composition of the essential oils obtained from the aerial parts of Nepeta camphorata and Nepeta argolica ssp. dirphya were analysed by GC-MS. A total of 52 components were identified and significant differences (qualitative and quantitative) were observed between the two samples. 1,8-Cineol and two nepetalactones were found to be the major components of the oil of N. camphorata and N. argolica ssp. dirphya respectively. The in vitro activity, of the two oils and the three above mentioned isolated compounds, against 25 clinically isolated and commercial strains of Helicobacter pylori was investigated and some activity was found.

Differential expression of two cytochrome P450s involved in the biosynthesis of flavones and anthocyanins in chemo-varietal forms of Perilla frutescens

In Perilla frutescens, there are two varietal forms of anthocyanin accumulation, i.e. red and green forms. The cDNA clones encoding flavone synthase II (FSII) and flavonoid 3'-hydroxylase (F3'H), two cytochrome P450s that are involved in the biosynthesis of flavones and anthocyanins, were isolated from P. frutescens. The FSII cDNA encoded a 57.1 kDa protein designated as CYP93B6, and the F3'H cDNA encoded 57.5 kDa protein designated as CYP75B4. Recombinant CYP93B6 expressed in yeast converted flavanones to flavones with K(m) values of 8.8-11.9 microM. Recombinant CYP75B4 catalyzed 3'-hydroxylation of flavanones to the corresponding compounds with K(m) values of 18-20 microM. The CYP93B6 transcript accumulated to an equal level in leaves of both red and green forms of P. frutescens, in agreement with the accumulation pattern of flavones in the leaves. However, the CYP75B4 transcript was predominantly expressed in the red form of P. frutescens, and its expression was induced by light in conjunction with other transcripts of biosynthetic enzymes of anthocyanin. These results indicate that gene expression of a set of anthocyanin biosynthetic enzymes including F3'H is regulated coordinately only in the red form of P. frutescens but not in the green form, whilst FSII gene expression is controlled in a similar manner in red and green forms of P. frutescens.

Analysis and evolution of two functional Y-linked loci in a plant sex chromosome system

White campion (Silene latifolia) is one of the few examples of plants with separate sexes and with X and Y sex chromosomes. The presence or absence of the Y chromosome determines which type of reproductive organs--male or female--will develop. Recently, we characterized the first active gene located on a plant Y chromosome, SlY1, and its X-linked homolog, SlX1. These genes encode WD-repeat proteins likely to be involved in cell proliferation. Here, we report the characterization of a novel Y-linked gene, SlY4, which also has a homolog on the X chromosome, SlX4. Both SlY4 and SlX4 potentially encode fructose-2,6-bisphosphatases. A comparative molecular analysis of the two sex-linked loci (SlY1/SlX1 and SlY4/SlX4) suggests selective constraint on both X- and Y-linked genes and thus that both X- and Y-linked copies are functional. Divergence between SlY4 and SlX4 is much greater than that between the SlY1 and SlX1 genes. These results suggest that, as for human XY-linked genes, the sex-linked plant loci ceased recombining at different times and reveal distinct events in the evolutionary history of the sex chromosomes.

Floral transcription factor AGAMOUS interacts in vitro with a leucine-rich repeat and an acid phosphatase protein complex

We are interested in identifying potential protein interactors of MADS domain transcription factors during Arabidopsis thaliana flower development. We based our biochemical search on a conserved motif in the MADS domain that includes putative phosphatase and phosphorylation sites that may mediate protein interactions. An affinity column with this motif and a few surrounding hypervariable amino acids derived from the AGAMOUS sequence was prepared and used to isolate potential interactors from floral crude extracts. Only two proteins were specifically bound to the affinity column. The first corresponds to a carpel specific storage protein, VSP1, that presents acid phosphatase activity, and the second is a novel leucine-rich repeat protein that we have named FLOR1. Coimmunoprecipitation, two-hybrid yeast, and affinity column assays show that the FLOR1-VSP1 complex interacts with AGAMOUS and that this transcription factor directly interacts with FLOR1. This is the first assay to show an interaction between plant MADS domain factors and non-MADS proteins.

Cycloartane glycosides from Cimicifuga dahurica

A new cycloartane bisdesmoside and two new trinorcycloartane glycosides, along with four known cycloartane compounds, were isolated from the rhizomes of Cimicifuga dahurica (Ranunculaceae). The structures of the new compounds were elucidated as 3-O-alpha-L-arabinopyranosyl cimigenol 15-O-beta-D-glucopyranoside, 24-hydroxy-12beta-acetoxy-25,26,27-trinorcycloartan-16,23-dione 3beta-O-alpha-L-arabinopyranoside, and 16alpha,24alpha-dihydroxy-12beta acetoxy-25,26,27-trinor-16,24-cyclocycloartan-23-one 3beta-O-alpha-L-arabinopyranoside by extensive NMR methods, FAB-MS, and hydrolysis.

Total phenolics concentration and antioxidant potential of extracts of medicinal plants of Pakistan

Thirty-seven plant organs, traditionally used as drugs, collected in Pakistan, were extracted with 70% acetone and analyzed for their total phenolics concentration and antioxidant potential. Seven extracts showed more than 85% inhibition of lipid peroxidation in vitro as compared with blank. Butylated hydroxytoluene (BHT) (IC50 = 233.6 microg/l +/- 28.3) was the strongest antioxidant in our test system. The IC50 results indicate that the extracts of Nymphaea lotus L. flowers, Acacia nilotica (Linn.) Delile beans, Terminalia belerica Roxb. fruits, and Terminalia chebula Retz. (fruits, brown) were stronger antioxidants than alpha-tocopherol, while Terminalia chebula Retz. (fruit coat), Terminalia chebula Retz. (fruits, black) and Ricinus communis L. leaves were weaker antioxidant extracts than alpha-tocopherol and BHT. Total phenolics concentration, expressed as gallic acid equivalents, showed close correlation with the antioxidant activity. High performance liquid chromatographic analysis with diode array detection at 280 nm, of the seven extracts indicated the presence of hydroxybenzoic acid derivatives, hydroxycinnamic acid derivatives, flavonol aglycones and their glycosides as main phenolics compounds. This information, based on quick screening methods, enables us to proceed towards more detailed chemical and pharmacological understanding of these plant materials.

Comparative studies and quantitative determination of flavonoid compounds in the flowers of some species of the Aquilegia L. genus

The flowers of nine species of Aquilegia L. genus: A. hybrida Scott-Eliot, A. olympica Boiss., A. flabellata Sieb et Zucc., A. alpina L., A. atrata W.D.J. Koch, A. vitoleili L., A. caerulea James, A. canadensis L., A. pyrenaica D.C., were co-chromatographed with the flavonoids and the extract from A. vulgaris L. The content of flavonoids in these species were determined by the Christ-Müller method.

[Monodesmosidic saponins in Cynara cardunculus L]

From an ethanolic extract of the flower buds of Cynara cardunculus L. (Asteraceae), two monodesmosidic saponins, cynarasaponin B and a new cynarasaponin K, were isolated. The isolated compounds were identified by spectroscopic means and by comparison with standards and the literature data.

[Comparison of the quality of Melissa officinalis L. cultivar Citra with Mellissas of European origin]

Within two vegetation periods, melissas from 17 European regions and the inland cultivar Citra were examined. Melissas differed in height, foliage, and essential oil content. In the cultivating conditions under study, two collections were possible in one year. In both experimental years at the stage just before blooming, or at the onset of blooming, plants 60-80 cm in height prevailed in the set. The share of leaves in the tops was 35-70%. In the second repeated harvest, plants with newly formed sprouts reached a height of 15-35 cm and had the best foliage (60-95%). The essential oil content in the leaves at the stage just prior to blooming, or at the onset of blooming, ranged from 0.06 to 0.16% (V/m), and the maximal essential oil content was in the plants from the second harvest (0.09-0.45%). The cultivar Citra was characterized by medium height (75-80 cm), stable values of foliage (1st harvest 55-60%, 2nd harvest 70-80%), and essential oil content (1st harvest 0.13%, 2nd harvest 0.23-0.27%).

[Qualitative characteristics of selected species of the genus Echinacea Moench]

The paper examined the effect of production-technological conditions in relation to the ontogenetic stage of plants in three different species of the genus Echinacea Moench., comparing the species Echinacea purpurea, Echinacea atrorubens, and Echinacea pallida. It also examined the differences in the content of essential oil in different plant organs and evaluated the representation of individual components in the essential oils of the species under study at the stage of the optimal maturity for collection.

The potato tuber transcriptome: analysis of 6077 expressed sequence tags

This is the first report of the biosynthetic potential of a tuber storage organ investigated by expressed sequence tag sequencing. A cDNA library was generated from the mature tuber of field grown potato (Solanum tuberosum var. Kuras). Partial sequences obtained from 6077 clones were assembled into 828 clusters and 1533 singletons. The average read length was 592 bp, and 2254 clones were full length. 5717 clones showed homology to genes from other organisms. Genes involved in protein synthesis, protein destination and cell defense predominated in tuber compared to stolon, shoot and leaf organs. 1063 clones were unique to tuber. Transcripts of starch metabolizing enzymes showed similar relative levels in tuber and stolon.

Identification of chemical components of corn kernel pericarp wax associated with resistance to Aspergillus flavus infection and aflatoxin production

Kernel pericarp wax of the corn breeding population GT-MAS:gk has been associated with resistance to Aspergillus flavus infection and aflatoxin production. GT-MAS:gk wax, previously compared to waxes of three susceptible genotypes, was presently compared to wax of a different, and more numerous, group of susceptible lines. Wax separation by TLC confirmed previous findings, demonstrating a unique GT-MAS:gk band and a unique "susceptible" band. Only GT-MAS:gk wax inhibited the growth of A. flavus; however, no association was established, as before, between kernel wax abundance and resistance. Gas chromatography-mass spectroscopy (GC-MS) analysis of kernel whole wax showed a higher percentage of phenol-like compounds in wax from GT-MAS:gk than in waxes from the susceptible lines. The GT-MAS:gk unique band contained phenol-like compounds and ethyl-hexadecanoate; butyl-hexadecanoate was preeminent in most of the "susceptible bands". Alkylresorcinol (phenolic compounds) content was dramatically higher in GT-MAS:gk wax than in the wax of susceptible lines. An alkylresorcinol, 5-methylresorcinol, also inhibited in vitro growth of A. flavus. These and other phenolic compounds may contribute to kernel wax inhibition of A. flavus infection/aflatoxin production. Further investigation is needed to confirm a role for them in GT-MAS:gk resistance.

Biochemical analysis of elastic and rigid cuticles of Cirsium horridulum

The cuticle is a complex structure of soluble lipids, lipid polymers and polysaccharides. In addition to its functions to reduce water loss and provide a protective barrier, its mechanical properties may be significant to plant growth and development. We investigated the cuticle of Cirsium horridulum Michx. because of its involvement in the thigmonastic contraction of staminal filaments. The staminal filaments and portions of the style are surrounded by a highly elastic cuticle in contrast to the rigid cuticle of the corolla and leaves. Our aim was to determine if the biochemical composition affected the elasticity of the cuticle. We discovered that the ratio of carbohydrates to lipids is 1:7 in floral parts but 2:1 in leaf cuticle. Esterified cutin components represented about 80% of the cuticle and di-hydroxyhexadecanoic acids were the major monomers of cutin, regardless of origin. The cutin of elastic tissues is characterized by a higher content of tri-hydroxy monomers than the cutin of rigid tissues. The data suggest that hydroxyl groups enhance the hydrophilic character of the cuticle and contribute to cuticular elasticity.

Effects of water-soluble hemicellulose from soybean hull on serum antibody levels and activation of macrophages in rats

Effects of soybean hull water-soluble hemicellulose (WSHC) on serum immunoglobulin (Ig) concentration and production of NO and IL-1beta from peritoneal macrophages were examined and compared with those of Agaricus blazei in the rat system. WSHC consisted of arabinose, galactose, xylose, glucose, and rhamnose, and the molecular weight was approximately 500000. Rats were ip administrated each sample at a dose of 0.67, 13.4, or 26.9 mg/kg/day for 14 days. The administration of WSHC resulted in significantly higher productions of IgM (p < 0.01 on day 6, p < 0.05 on day 14) and IgG (p < 0.05 on day 6) than those in other groups. When peritoneal macrophages were stimulated with various concentrations of sample (0.67, 13.4, or 26.9 mg/mL), WSHC significantly increased both NO and IL-1beta productions only at the concentration of 13.4 (mg/mL) compared with those of a saline group. These findings demonstrate that WSHC enhances humoral immunity and activation of macrophages, thereby leading to the augmentation of immune responses in rats.

Enzymatic oxidative treatments of wheat bran layers: effects on ferulic acid composition and mechanical properties

Enzymatic treatments known to induce the gelation of feruloylated arabinoxylans solutions were applied to tissue strips isolated from peripheral layers of wheat grain to tentatively produce in situ arabinoxylan reticulation. The treatments by horseradish peroxidase (HRP) and manganese dependent peroxidase (MnP) induced a dimerization of ferulic acid (FA) in wheat bran with concomitant decrease of arabinoxylan solubility. Similar results were obtained, but to a lesser extent, by simple incubation of bran strips in water, suggesting the action of endogenous peroxidases. The fact that these treatments proved to be ineffective on the isolated aleurone layer and pericarp suggested that dimerization occurred mostly at the aleurone-pericarp interface. In addition, the MnP system generated a consumption of monomer and dimer of ferulic acid in the pericarp, perhaps due to their incorporation into lignin. Micro-mechanical tests using DMTA were performed on isolated tissue strips and showed that oxidation of wheat bran increased their mechanical strength (increase of stress and strain to rupture).

New flavanol derivatives from grape (Vitis vinifera) byproducts. Antioxidant aminoethylthio-flavan-3-ol conjugates from a polymeric waste fraction used as a source of flavanols

A new family of antioxidants has been obtained from a residual fraction of polymeric polyphenols of grape origin. The integral exploitation of resources is important in any sustainable production scheme. Many byproducts and residues generated by the agroindustries contain polyphenols with potential application as preventative agents against cancer and cardiovascular diseases. Among these polyphenols oligomeric proanthocyanidins are particularly significant. The polymeric forms, considered of less interest because of their astringent properties, constitute the largest portion of the biologically active plant proanthocyanidins. The new compounds described here result from the breakdown of polymeric flavanols in the presence of cysteamine and bear an amino function, which facilitates their isolation from complex mixtures by cation-exchange gels or resins. In this way, valuable antioxidant molecules can be efficiently obtained from otherwise wasted polymers. The new molecules appear to be as effective as their underivatized counterparts (flavan-3-ols) as antioxidants.