| oxytetracycline inactivation by putative reactive oxygen species released to nutrient medium of helianthus annuus hairy root cultures. | when subjected to stress, plants produce reactive oxygen species (ros) as a part of the defense response. the oxidative response is also used to degrade organic pollutants. hairy roots of helianthus annuus (sunflower) are shown to oxidize oxytetracycline (otc) through the action of the ros released to the nutrient medium by the hairy root cultures. methyl jasmonate (meja) elicits ros formation in the hairy root cultures. the activities of the antioxidant enzymes, ascorbate peroxidase (apx), cata ... | 2005 | 16170825 |
| deciphering the 820 nm signal: redox state of donor side and quantum yield of photosystem i in leaves. | by recording leaf transmittance at 820 nm and quantifying the photon flux density of far red light (frl) absorbed by long-wavelength chlorophylls of photosystem i (ps i), the oxidation kinetics of electron carriers on the ps i donor side was mathematically analyzed in sunflower (helianthus annuus l.), tobacco (nicotiana tabacum l.) and birch (betula pendula roth.) leaves. ps i donor side carriers were first oxidized under frl, electrons were then allowed to accumulate on the ps i donor side duri ... | 2003 | 16245060 |
| [effects of alkali-stress on aneurolepidium chinense and helianthus annuus]. | employing monocotyledon aneurolepidium chinense and dicotyledon helianthus annuus, the two species with high alkali-saline resistance as test materials, and stressing them with neutral, alkalic, and mixed salts, this paper studied the characteristics of various stresses and their interrelations, with relative growth rate (rgr) as the main strain index. the results showed that under the same concentration, alkalic salt had a stronger effect than neutral salt, and the rgr of a. chinense and h. ann ... | 2005 | 16262066 |
| a possible role of sphingolipids in the aluminium resistance of yeast and maize. | the plasma membrane is most likely the major target for sensing of aluminium (al), leading to inhibition of plant root-growth. as a result of high external al, alterations in plasma membrane composition may be expected in order to maintain its properties. as sphingolipids are characteristic components of this membrane, their involvement in membrane adjustment to increased al concentrations was investigated. heterologous expression of a stereounselective long-chain base (lcb) (8e/z)-desaturase fr ... | 2006 | 16360801 |
| antisense expression of a nbs-lrr sequence in sunflower (helianthus annuus l.) and tobacco (nicotiana tabacum l.): evidence for a dual role in plant development and fungal resistance. | a partial sunflower cdna clone, plfor48, segregating with a resistance marker to plasmopara halstedii, the causal agent of downy mildew, has been cloned from the mildew resistant sunflower line, rha 266. plfor48 encodes a putative protein with a nucleotide-binding site and a leucine-rich repeat domain, showing significant homology with previously cloned resistance genes belonging to the tir-nbs-lrr family. southern blot analysis of non-transgenic sunflower suggests that plfor48 is part of a mult ... | 2006 | 16604458 |
| a cdna microarray approach to decipher sunflower (helianthus annuus) responses to the necrotrophic fungus phoma macdonaldii. | to identify the genes involved in the partial resistance of sunflower (helianthus annuus) to the necrotrophic fungus phoma macdonaldii, we developed a 1000-element cdna microarray containing carefully chosen genes putatively involved in primary metabolic pathways, signal transduction and biotic stress responses. a two-pass general linear model was used to normalize the data and then to detect differentially expressed genes. this method allowed us to identify 38 genes differentially expressed amo ... | 2006 | 16626474 |
| auxin transport: a new synthetic inhibitor. | the new synthetic plant growth regulator dpx1840 (3,3a-dihydro-2-(p-methoxyphenyl)-8h-pyrazolo [5,1-a] isoindol-8-one) was examined for its effects on auxin transport. at a concentration of 0.5 mm in the receiver agar cylinders dpx1840 significantly inhibited the basipetal transport of naphthaleneacetic acid-1-(14)c in stem sections of vigna sinensis endl., pisum sativum l., phaseolus vulgaris l., glycine max l., helianthus annuus l., gossypium hirsutum l., and zea mays l. without significantly ... | 1972 | 16658167 |
| evidence for two photoreactions and possible involvement of phytochrome in light-dependent stomatal opening. | leaves of the xantha mutant of helianthus annuus have a higher rate of transpiration and a lower diffusive resistance in the light than in the dark. stomates of this nonphotosynthetic mutant open in the light and close in the dark.comparative studies of tobacco, xantha mutant, and wild-type sunflower stomatal opening over a range of light intensities in isolated portions of the spectrum reveal two patterns of response: (a) a low intensity opening in the green and far red characterized by partial ... | 1973 | 16658366 |
| attempts to detect agrobacterium tumefaciens dna in crown-gall tumor tissue. | primary and secondary crown gall tissue cultures were established from sunflower plants (helianthus annuus, variety mammoth russian) wound-inoculated with agrobacterium tumefaciens (smith and townsend) conn strain b(6). growth rates of tumor tissues and habituated healthy sunflower stem section tissues on basal medium lacking auxin and cytokinin were compared to those of healthy sunflower stem section tissue grown on the same medium with added phytohormones. no difference was detected in the the ... | 1976 | 16659607 |
| in vivo synthesis of crown gall-specific agrobacterium tumefaciens-directed derivatives of basic amino acids. | several kinds of primary sunflower (helianthus annuus) crown gall tissues were established in tissue culture and then labeled in vivo with either [(14)c]arginine, [(14)c]histidine, [(3)h]lysine, or [(3)h]ornithine. crown gall tissues incited by agrobacterium tumefaciens strains that utilize octopine as a sole source of carbon or nitrogen for growth synthesized the four members of the n(2)-(1-carboxyethyl)-amino acid family: octopine, histopine, lysopine, and octopinic acid. those tissues incited ... | 1978 | 16660462 |
| characterization of the enzyme responsible for nopaline and ornaline synthesis in sunflower crown gall tissues. | extracts prepared from sunflower (helianthus annuus l.) crown gall tissues induced by agrobacterium tumefaciens strains c58 and t37 (nopaline utilizers) catalyze the synthesis of nopaline and ornaline. these compounds are not synthesized in extracts of crown gall tissues induced by strains b6, 15955 (octopine utilizers), and at1 (utilizes neither octopine nor nopaline) or in extracts of habituated sunflower callus. both synthetic activities require nadph, alpha-ketoglutarate, and either arginine ... | 1978 | 16660518 |
| purification and characterization of the crown gall-specific enzyme, octopine synthase. | a single enzyme catalyzes the synthesis of all four n(2)-(1-carboxyethyl)-amino acid derivatives found in a crown gall tumor tissue induced by agrobacterium tumefaciens (e. f. sm. and town.) conn strain b6 on sunflower (helianthus annuus l.). this enzyme, octopine synthase, has been purified by ammonium sulfate fractionation and chromatography on diethylaminoethylcellulose, blue agarose, and hydroxylapatite. the purified enzyme has all the n(2)-(1-carboxyethyl)-amino acid synthesizing activities ... | 1980 | 16661312 |
| simultaneous measurements of steady state chlorophyll a fluorescence and co(2) assimilation in leaves: the relationship between fluorescence and photosynthesis in c(3) and c(4) plants. | rates of co(2) assimilation and steady state chlorophyll a fluorescence were measured simultaneously at different intercellular partial pressures of co(2) in attached cotton (gossypium hirsutum l. cv deltapine 16) leaves at 25 degrees c. electron transport activity for co(2) assimilation plus photorespiration was calculated for these experiments. under light saturating (1750 microeinsteins per square meter per second) and light limiting (700 microeinsteins per square meter per second) conditions ... | 1986 | 16664735 |
| continuous monitoring of plant water potential. | plant water potential was monitored continuously with a wescor hr-33t dewpoint hygrometer in conjunction with a l51 chamber. this commercial instrument was modified by replacing the ac-dc mains power converter with one stabilized by zener diode controlled transistors. the thermocouple sensor and electrical lead needed to be thermally insulated to prevent spurious signals. for rapid response and faithful tracking a low resistance for water vapor movement between leaf and sensor had to be provided ... | 1986 | 16664805 |
| the metabolism of sunflower phytoalexins ayapin and scopoletin: plant-fungus interactions. | the coumarin phytoalexins ayapin and scopoletin accumulate in longitudinal stem sections of sunflower (helianthus annuus l., compositae) following inoculation with fungi both pathogenic (alternaria helianthi) and nonpathogenic (helminthosporium carbonum) to this plant. both compounds were induced more rapidly, and they attained higher levels in tissue inoculated with the heterologous pathogen h. carbonum as compared with the sunflower pathogen a. helianthi. similarly, scopoletin and ayapin accum ... | 1986 | 16664986 |
| presence and identification of polyamines in xylem and phloem exudates of plants. | polyamines were identified by high performance liquid chromatography (benzoylation) and by thin layer chromatography (dansylation) in xylem exudates from stems of sunflowers (helianthus annuus [l.]), mung bean (vigna radiata [l.] wilczek), grapevine (vitis vinifera [l.] cv grenache), and orange (citrus sinensis [l.] osbeck, cv valencia), as well as in phloem sap (using elution into edta) of sunflower and mung bean plants. putrescine was the major polyamine detected, ranging in concentrations of ... | 1986 | 16665153 |
| cytokinin antagonist activity of substituted phenethylamines in plant cell culture. | a series of structurally related substituted phenethylamines shows extreme toxicity toward wild-type callus tissue cultures of tobacco (nicotiana tabacum), soybean (glycine max), corn (zea mays), and sunflower (helianthus annuus l.), but tobacco crown gall cultures are resistant to the compounds. the essential components that result in toxicity of the phenethylamines include one aromatic hydroxyl and one primary aliphatic amino group. a series of attenuated crown gall cultures, generated by tran ... | 1989 | 16666583 |
| artefactual origins of cyclic amp in higher plant tissues. | a highly sensitive radioimmunoassay has been used to determine the levels of adenosine 3',5'-cyclic monophosphate (camp) in five higher plants (lactuca sativa, helianthus annuus, oryza sativa, pinus pinaster, nicotiana tabacum). particular attention was paid to the three main sources of errors in the characterization of camp in plants: presence of interfering substances in plant tissues; possible artefactual formation of camp from endogenous atp during extraction, purification, and assay; and mi ... | 1989 | 16667078 |
| ethylene-mediated regulation of gibberellin content and growth in helianthus annuus l. | elongation of hypocotyls of sunflower can be promoted by gibberellins (gas) and inhibited by ethylene. the role of these hormones in regulating elongation was investigated by measuring changes in both endogenous gas and in the metabolism of exogenous [(3)h]- and [(2)h(2)]ga(20) in the hypocotyis of sunflower (helianthus annuus l. cv delgren 131) seedlings exposed to ethylene. the major biologically active gas identified by gas chromatography-mass spectrometry were ga(1), ga(19), ga(20), and ga(4 ... | 1991 | 16668111 |
| regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose, and hexose sugars. | in the present study, leaves of different plant species were girdled by the hot wax collar method to prevent export of assimilates. photosynthetic activity of girdled and control leaves was evaluated 3 to 7 days later by two methods: (a) carbon exchange rate (cer) of attached leaves was determined under ambient co(2) concentrations using a closed gas system, and (b) maximum photosynthetic capacity (a(max)) was determined under 3% co(2) with a leaf disc o(2) electrode. starch, hexoses, and sucros ... | 1992 | 16669056 |
| photosynthetic acclimation to elevated co2 in relation to rubisco gene expression in three c3 species. | wheat (triticum aestivum l. var. dl 1266-5), sunflower (helianthus annuus l. var. msfh 17) and mungbean [vigna radiata (l.) wilczek var. p 9072] were grown in field under atmospheric (360 +/- 10 cm3 m(-3), ac) and elevated (650 +/- 50 cm3 m(-3), ec) co2 concentrations in open top chambers for entire period of growth and development. photosynthetic acclimation to elevated co2 was examined by comparing photosynthesis rate (pn), pn/ci curves, leaf contents of rubp carboxylase/oxygenase (rubisco), c ... | 2006 | 16708896 |
| sesquiterpene lactones as allelochemicals. | six new sesquiterpene lactones, annuolide h (3), helivypolides f, h-j (4, 11-13), and helieudesmanolide a (6), together with known compounds, were isolated from polar bioactive fractions of helianthus annuus cv. sh-222 and stella fresh leaf water extracts. spectroscopic analysis of the new data for 1,2-anhydroniveusin a and 1-methoxy-4,5-dihydroniveusin a corrects some previous assignments. the compounds were tested using the etiolated wheat coleoptile bioassay, and the most active compounds wer ... | 2006 | 16724843 |
| chloroplast dna variation confirms a single origin of domesticated sunflower (helianthus annuus l.). | although sunflower was long thought to be the product of a single domestication in what is now the east-central united states, recent archaeological and genetic evidence have suggested the possibility of an independent origin of domestication, perhaps in mexico. we therefore used hypervariable chloroplast simple-sequence repeat markers to search for evidence of a possible mexican origin of domestication. this work resulted in the identification of 45 chloroplast haplotypes from 26 populations ac ... | 2006 | 16740625 |
| photosystem ii cycle and alternative electron flow in leaves. | sunflower (helianthus annuus l.) and tobacco (nicotiana tabacum l.) were grown in the laboratory and leaves were taken from field-grown birch trees (betula pendula roth). chlorophyll fluorescence, co2 uptake and o2 evolution were measured and electron transport rates were calculated, j(c) from the co2 uptake rate considering ribulose-1,5-bisphosphate (rubp) carboxylation and oxygenation, j(o) from the o2 evolution rate, and j(f) from chl fluorescence parameters. mesophyll diffusion resistance, r ... | 2006 | 16774929 |
| comparative effect of al, se, and mo toxicity on no3(-) assimilation in sunflower (helianthus annuus l.) plants. | here, we study the effect caused by three trace elements--al, se, and mo--applied at the same concentration (100 microm) and in their oxyanionic forms--naal(oh)(4), na(2)seo(4), and na(2)moo(4)--on no(3)(-) assimilation (no(3)(-), nitrate reductase (nr), nitrite reductase (nir), glutamine synthetase (gs), and glutamate synthase (gogat) activities, and concentrations of amino acids and proteins) in sunflower (helianthus annuus l. var. kasol) plants. the most harmful element for sunflower plants p ... | 2007 | 16806659 |
| eastern north america as an independent center of plant domestication. | the status of eastern north america as an independent center of plant domestication has recently been called into question by a number of genetic and archaeological studies, which suggest that the region may not have witnessed the independent domestication of local crop plants, but rather may have been on the receiving end of domesticated crop plants introduced from mexico. here, i provide a synthesis of the currently available archaeological and genetic evidence from both eastern north america ... | 2006 | 16894156 |
| sunflower (helianthus annuus l.). | sunflower (helianthus annuus l.) is considered one of the recalcitrant species in terms of transformation and regeneration. a routine transformation system of this crop requires competent cell cultures for efficient plant regeneration as well as an effective method for gene delivery. a transformation system was developed by an agrobacterium tumefaciens-mediated method using split mature embryonic axis explants from the ha89 genotype. mean transformation efficiency obtained (measured as pcr+ plan ... | 2006 | 16988353 |
| improved resistance to controlled deterioration in transgenic seeds. | we show that seed-specific overexpression of the sunflower (helianthus annuus) hahsfa9 heat stress transcription factor (hsf) in tobacco (nicotiana tabacum) enhances the accumulation of heat shock proteins (hsps). among these proteins were hsp101 and a subset of the small hsps, including proteins that accumulate only during embryogenesis in the absence of thermal stress. levels of late embryogenesis abundant proteins or seed oligosaccharides, however, were not affected. in the transgenic seeds, ... | 2006 | 16998084 |
| functional characterization of a plastidial omega-3 desaturase from sunflower (helianthus annuus) in cyanobacteria. | fatty acid desaturases (fad) play an important role in plant lipid metabolism and they can be found in several subcellular compartments such as the plastids and endoplasmic reticulum. lipids are critical components of the cell membrane and, as a consequence, they are fundamental for the proper growth and development of all living organisms. we have used sequences from the conserved regions of known omega-3-desaturases to design degenerated oligonucleotides and clone a cdna encoding a plastidial ... | 2006 | 17064923 |
| fluidization of membrane lipids enhances the tolerance of saccharomyces cerevisiae to freezing and salt stress. | unsaturated fatty acids play an essential role in the biophysical characteristics of cell membranes and determine the proper function of membrane-attached proteins. thus, the ability of cells to alter the degree of unsaturation in their membranes is an important factor in cellular acclimatization to environmental conditions. many eukaryotic organisms can synthesize dienoic fatty acids, but saccharomyces cerevisiae can introduce only a single double bond at the delta(9) position. we expressed two ... | 2007 | 17071783 |
| haplotyping and mapping a large cluster of downy mildew resistance gene candidates in sunflower using multilocus intron fragment length polymorphisms. | downy mildew (plasmopara halstedii (farl.) berlese et de toni) is a serious foliar pathogen of cultivated sunflower (helianthus annuus l.). genetic resistance is conditioned by several linked downy mildew resistance gene specificities in the hargc1 cluster of tir-nbs-lrr resistance gene candidates (rgcs) on linkage group 8. the complexity and diversity of the hargc1 cluster was assessed by multilocus intron fragment length polymorphism (iflp) genotyping using a single pair of primers flanking a ... | 2003 | 17156030 |
| the interaction of light quality and irradiance with gibberellins, cytokinins and auxin in regulating growth of helianthus annuus hypocotyls. | a reduced red to far-red (r/fr) light ratio and low photosynthetically active radiation (par) irradiance are both strong signals for inducing etiolation growth of plant stems. under natural field conditions, plants can be exposed to either a reduced r/fr ratio or lower par, or to a combination of both. we used helianthus annuus l., the sunflower, to study the effect of reduced r/fr ratio, low par or their combination on hypocotyl elongation. to accomplish this, we attempted to uncouple light qua ... | 2007 | 17238906 |
| rampant gene exchange across a strong reproductive barrier between the annual sunflowers, helianthus annuus and h. petiolaris. | plant species may remain morphologically distinct despite gene exchange with congeners, yet little is known about the genomewide pattern of introgression among species. here we analyze the effects of persistent gene flow on genomic differentiation between the sympatric sunflower species helianthus annuus and h. petiolaris. while the species are strongly isolated in testcrosses, genetic distances at 108 microsatellite loci and 14 sequenced genes are highly variable and much lower (on average) tha ... | 2007 | 17277373 |
| crop-weed competition between sunflower (helianthus annuus l.) and convolvulus arvensis l. in substitutive experiments. | the main characteristics of a substitutive experiment is that the proportions of two species in the mixtures are varied while the overall density of the two species is maintained constant - a replacement series. in our experiments early competition between sunflower and field bindweed (convolvulus arvensis) was studied in a replacement studies under glasshouse conditions. pot experiments were set up with the following treatments: 1, sunflower 100% (6 plants pot(-1)); 2, sunflower 66.6% (4 plants ... | 2006 | 17390820 |
| triterpene glycosides from the flower petals of sunflower (helianthus annuus) and their anti-inflammatory activity. | two new oleanane-type triterpene glycosides, named helianthosides 4 (4) and 5 (5), along with four known triterpene glycosides, helianthosides 1 (1), 2 (2), 3 (3), and b (6), were isolated from an n-butanol-soluble fraction of a methanol extract of sunflower (helianthus annuus) petals. the structures of the two new compounds were determined on the basis of spectroscopic and chemical methods. upon evaluation of compounds 1-6 for inhibitory activity against 12-o-tetradecanoylphorbol-13-acetate (tp ... | 2007 | 17480100 |
| uncoupling light quality from light irradiance effects in helianthus annuus shoots: putative roles for plant hormones in leaf and internode growth. | an attempt has been made to uncouple the effects of the two primary components of shade light, a reduced red to far-red (r/fr) ratio and low photosynthetically active radiation (par), on the elongation of the youngest internode of sunflower (helianthus annuus) seedlings. maximal internode growth (length and biomass) was induced by a shade light having a reduced r/fr ratio (0.85) under the low par of 157 micromol m(-2) s(-1). reducing the r/fr ratio under normal par (421 micromol m(-2) s(-1)) gav ... | 2007 | 17490995 |
| impacts of t-phylloplanin gene knockdown and of helianthus and datura phylloplanins on peronospora tabacina spore germination and disease potential. | t-phylloplanin proteins secreted to aerial surfaces of tobacco (nicotiana tabacum) by short procumbent trichomes inhibit spore germination and blue mold disease caused by the oomycete pathogen peronospora tabacina. many other plants were found to contain water-washed leaf surface proteins (phylloplanins), but the functions and properties of these are not known. here we extend earlier evidence for the antifungal activity of t-phylloplanins using a reverse genetics approach. rna interference of th ... | 2007 | 17573541 |
| mechanism of cata3 induction by cadmium in sunflower leaves. | one of the main antioxidant enzymes, catalase (cat, ec 1.11.1.6), is capable of catalyzing the dismutation of h(2)o(2). this enzyme is involved in signal transduction pathway in plants, controlling the cellular level of this reactive oxygen species. four different genes, cata1-cata4, were identified in helianthus annuus l. cotyledons. incubation of sunflower leaf discs with 300 and 500 microm cdcl(2) under light conditions increased cata3 transcript level. however, it was not induced by cd(2+) i ... | 2007 | 17583519 |
| preceding crop affects grain cadmium and zinc of wheat grown in saline soils of central iran. | enhanced cd concentrations in wheat (triticum aestivum l.) grain produced on saline soils of central iran have been recently reported. because wheat bread is a major dietary component for the iranian people, practical approaches to decrease cd concentration in wheat grain were investigated. this study investigated the influence of sunflower-wheat vs. cotton-wheat rotations on extractable cd and on cd uptake by wheat in these salt-affected soils. two fields with different levels of cd contaminati ... | 2007 | 17596621 |
| mating compatibility among helicoverpa armigera (lepidoptera: noctuidae) occurring on selected host plants and bt cotton survivors. | helicoverpa armigera (hiibner) (lepidoptera: noctuidae) is a well-known polyphagous insect pest. mating compatibility among the insects occurring on different host plants is essential for free gene flow among populations. we tested the extent of crossability and fecundity of the insects that survived on bacillus thuringiensis (bt) cotton with those occurring on pigeon pea, cajanus cajun (l.) millsp., non-bt cotton, gossypium hirsutum l.; sunflower, helianthus annuus; sorghum, sorghum bicolor l. ... | 2007 | 17598554 |
| endophytic bacteria in sunflower (helianthus annuus l.): isolation, characterization, and production of jasmonates and abscisic acid in culture medium. | this study was designed to isolate and characterize endophytic bacteria from sunflower (helianthus annuus) grown under irrigation and water stress (drought) conditions, to analyze growth of isolated bacteria under drought condition, and to evaluate the ability of bacteria isolated from plants cultivated under drought to produce jasmonates (jas) and abscisic acid (aba). bacteria were isolated from soil samples collected when sunflower plants were at the end of the vegetative stage. a total of 29 ... | 2007 | 17657487 |
| genetics and evolution of weedy helianthus annuus populations: adaptation of an agricultural weed. | agricultural weeds are a major cost to economies throughout the world, and have evolved from numerous plant species in many different plant families. despite their ubiquity, we do not yet know how easily or often weeds evolve from their wild ancestors or the kinds of genes underlying their evolution. here we report on the evolution of weedy populations of the common sunflower helianthus annuus. we analysed 106 microsatellites in 48 individuals from each of six wild and four weed populations of t ... | 2008 | 17725567 |
| oxygenated fatty acids of oil from sunflower seeds after prolonged storage. | chemical analysis of a number of sunflower (helianthus annuus) seed oil samples revealed a low and variable percentage of hydrogen bromide-reactive material. to characterize the compounds responsible for this reactivity, oil was extracted from selected introductions from uruguay, turkey, and yugoslavia that had been subjected to prolonged storage. two epoxy fatty acids and two conjugated dienolic acids were isolated from the methyl esters derived from these sunflower seed oils by using a combina ... | 1968 | 17805802 |
| impact of combining planting date and chemical control to reduce larval densities of stem-infesting pests of sunflower in the central plains. | the guild of stem-infesting insect pests of sunflower, helianthus annuus l., within the central plains is a concern to producers chiefly due to losses caused by plant lodging from the sunflower stem weevil, cylindrocopturus adspersus (leconte) (coleoptera: curculionidae), and dectes texanus texanus leconte (coleoptera: cerambycidae). the incidence of a root boring moth, pelochrista womonana (kearfott) (lepidoptera: tortricidae), also has increased. experiments were conducted in three locations i ... | 2007 | 17849877 |
| lateral co2 diffusion inside dicotyledonous leaves can be substantial: quantification in different light intensities. | substantial lateral co(2) diffusion rates into leaf areas where stomata were blocked by grease patches were quantified by gas exchange and chlorophyll a fluorescence imaging in different species across the full range of photosynthetic photon flux densities (ppfd). the lateral co(2) flux rate over short distances was substantial and very similar in five dicotyledonous species with different vascular anatomies (two species with bundle sheath extensions, sunflower [helianthus annuus] and dwarf bean ... | 2007 | 17905868 |
| impact of irrigation on larval density of stem-infesting pests of cultivated sunflower in kansas. | the guild of stem-infesting insect pests of cultivated sunflower, helianthus annuus l., within the central plains is a concern to producers, chiefly due to losses caused by plant lodging from the sunflower stem weevil, cylindrocopturus adspersus (leconte) (coleoptera: curculionidae), and dectes texanus texanus leconte (coleoptera: cerambycidae). the incidence of a root boring moth, pelochrista womonana (kearfott) (lepidoptera: tortricidae), also has increased. experiments were conducted in kansa ... | 2007 | 17972632 |
| expression of a lipid transfer protein in escherichia coli and its phosphorylation by a membrane-bound calcium-dependent protein kinase. | ha-ap10 is a basic antifungal peptide from sunflower seeds (helianthus annuus antifungal peptide of 10 kda) belonging to the family of plant lipid transfer proteins. we report here its expression in e. coli [glutathione s-transferase (gst) system] and its phosphorylation by endogenous membrane-bound calcium-dependent protein kinases. | 2007 | 17979821 |
| photorespiratory and respiratory decarboxylations in leaves of c3 plants under different co2 concentrations and irradiances. | we used an advanced radiogasometric method to study the effects of short-term changes in co2 concentration ([co2]) on the rates and substrates of photorespiratory and respiratory decarboxylations under steady-state photosynthesis and in the dark. experiments were carried out on plantago lanceolata, poa trivialis, secale cereale, triticum aestivum, helianthus annuus and arabidopsis thaliana plants. rates of photorespiration and respiration measured at a low [co2] (40 micromol mol(-1)) were equal ... | 2007 | 17986155 |
| the catalytic properties of hybrid rubisco comprising tobacco small and sunflower large subunits mirror the kinetically equivalent source rubiscos and can support tobacco growth. | plastomic replacement of the tobacco (nicotiana tabacum) rubisco large subunit gene (rbcl) with that from sunflower (helianthus annuus; rbcl(s)) produced tobacco(rst) transformants that produced a hybrid rubisco consisting of sunflower large and tobacco small subunits (l(s)s(t)). the tobacco(rst) plants required co(2) (0.5% v/v) supplementation to grow autotrophically from seed despite the substrate saturated carboxylation rate, k(m), for co(2) and co(2)/o(2) selectivity of the l(s)s(t) enzyme m ... | 2008 | 17993544 |
| mitochondrial nad2 gene is co-transcripted with cms-associated orfb gene in cytoplasmic male-sterile stem mustard (brassica juncea). | the transcriptional patterns of mitochondrial respiratory related genes were investigated in cytoplasmic male-sterile and fertile maintainer lines of stem mustard, brassica juncea. there were numerous differences in nad2 (subunit 2 of nadh dehydrogenase) between stem mustard cms and its maintainer line. one novel open reading frame, hereafter named orfb gene, was located at the downstream of mitochondrial nad2 gene in the cms. the novel orfb gene had high similarity with ymf19 family protein, or ... | 2009 | 18046626 |
| expressed sequence tags from the oomycete plasmopara halstedii, an obligate parasite of the sunflower. | sunflower downy mildew is a major disease caused by the obligatory biotrophic oomycete plasmopara halstedii. little is known about the molecular mechanisms underlying its pathogenicity. in this study we used a genomics approach to gain a first insight into the transcriptome of p. halstedii. | 2007 | 18062809 |
| aqueous extract of the helianthus annuus seed alleviates asthmatic symptoms in vivo. | molecular inflammation is a pivotal process in various degenerative immune diseases, including asthma and atopic dermatitis. in this study, we examined the effects of helianthus annuus seed (has) aqueous extract on an in vivo anti-asthmatic model. ovalbumin-induced mice were orally administered the aqueous extract of helianthus annuus seeds, and their lungs were assessed by hematoxylin and eosin staining. moreover, the expression levels of il-4/il-13 cytokines and ige were determined. has extrac ... | 2008 | 18097616 |
| methylotrophic bacteria on the surfaces of field-grown sunflower plants: a biogeographic perspective. | plant-associated methylobacteria of the genus methylobacterium colonize the foliage and roots of embryophytes, living on the volatile compound methanol emitted from the cells of their host organism. in this study we analyzed these surface-dwelling pink-pigmented epiphytes in three contrasting habitats of field-grown sunflower plants (helianthus annuus). using the methanol-ammonium salts agar surface impression method and a polymerase chain reaction (pcr)-based assay, we document the occurrence a ... | 2008 | 18193314 |
| modulation of inflammatory responses by diterpene acids from helianthus annuus l. | fractionation of a petroleum ether extract of helianthus annuus l. led to the isolation of three diterpene acids: grandiflorolic, kaurenoic and trachylobanoic acids. these compounds were studied for potential anti-inflammatory activity on the generation of inflammatory mediators in lipopolysaccharide (lps)-activated raw 264.7 macrophages. at non-toxic concentrations, these compounds reduced, in a concentration-dependent manner nitric oxide (no), prostaglandin e(2) (pge(2)) and tumor necrosis fac ... | 2008 | 18313400 |
| biological performance of quercetin on the cotton leaf-worm larvae, spodoptera littoralis boisd. (lep., noctuidae) and prevailing natural enemies in the egyptian cotton fields. | the egyptian cotton (gossypium barbadense l.) accounts for 65 % of the world production of long stable cultivars. taking into consideration the competition of other cotton producing countries, it should be of great importance to control pests, which attack the cotton plants to improve the yield and its quality. the main objective of this study is to develop new approaches for the management of the cotton leafworm spodoptera littoralis boisd. within an ipm program, that include synthetic insectic ... | 2007 | 18399494 |
| sunflower (helianthus annuus l.) as a pre-columbian domesticate in mexico. | mexico has long been recognized as one of the world's cradles of domestication with evidence for squash (cucurbita pepo) cultivation appearing as early as 8,000 cal b.c. followed by many other plants, such as maize (zea mays), peppers (capsicum annuum), common beans (phaseolus vulgaris), and cotton (gossypium hirsutum). we present archaeological, linguistic, ethnographic, and ethnohistoric data demonstrating that sunflower (helianthus annuus) had entered the repertoire of mexican domesticates by ... | 2008 | 18443289 |
| single nucleotide polymorphisms reveal multiple introductions into france of plasmopara halstedii, the plant pathogen causing sunflower downy mildew. | plasmopara halstedii, the causal agent of sunflower downy mildew, displays a gene-for-gene interaction with its host plant, helianthus annuus and other species of the genus. monitoring of the evolution of virulent races in france over a 19-year period led to the identification of 14 different races (or pathotypes). twelve expressed sequence tag (est)-derived markers displaying snps and insertion-deletion variations have recently been identified in p. halstedii. we used these markers to study the ... | 2008 | 18450523 |
| quantification of seed oil from species with varying oil content using supercritical fluid extraction. | the quantity and composition of seed oil affects seed viability and storability and hence the value of a species as a resource for nutrition and plant conservation. supercritical fluid extraction with carbon dioxide (sfe-co2) offers a rapid, environmentally friendly alternative to traditional solvent extraction. | 2008 | 18473329 |
| osmoregulation and antioxidant metabolism in drought-stressed helianthus annuus under triadimefon drenching. | a pot-culture experiment was conducted to estimate the ameliorating effect of triadimefon (tdm) on drought stress in sunflower (helianthus annuus l.) plants. the plants were subjected to 3-, 6-, and 9-day-interval drought (did) stress and drought stress with tdm @ 15 mg l(-1) and 15 mg l(-1) tdm alone from the 30th day after sowing (das). one-day-interval irrigation was kept as control. the plant samples were collected on and separated into root, stem and leaf for estimating the amino acid (aa), ... | 2008 | 18510994 |
| genetic diversity and genomic distribution of homologs encoding nbs-lrr disease resistance proteins in sunflower. | three-fourths of the recognition-dependent disease resistance genes (r-genes) identified in plants encode nucleotide binding site (nbs) leucine-rich repeat (lrr) proteins. nbs-lrr homologs have only been isolated on a limited scale from sunflower (helianthus annuus l.), and most of the previously identified homologs are members of two large nbs-lrr clusters harboring downy mildew r-genes. we mined the sunflower est database and used comparative genomics approaches to develop a deeper understandi ... | 2008 | 18553106 |
| ssrs and indels mined from the sunflower est database: abundance, polymorphisms, and cross-taxa utility. | simple sequence repeats (ssrs) are abundant and frequently highly polymorphic in transcribed sequences and widely targeted for marker development in eukaryotes. sunflower (helianthus annuus) transcript assemblies were built and mined to identify ssrs and insertions-deletions (indels) for marker development, comparative mapping, and other genomics applications in sunflower. we describe the spectrum and frequency of ssrs identified in the sunflower est database, a catalog of 16,643 est-ssrs, a col ... | 2008 | 18633591 |
| hahb4, a sunflower hd-zip protein, integrates signals from the jasmonic acid and ethylene pathways during wounding and biotic stress responses. | the helianthus annuus (sunflower) hahb4 transcription factor belongs to the hd-zip family and its transcript levels are strongly induced when sunflower plants are attacked by herbivores, mechanically damaged or treated with methyl-jasmonic acid (meja) or ethylene (et). promoter fusion analysis, in arabidopsis and in sunflower, demonstrated that induction of hahb4 expression by these treatments is regulated at the transcriptional level. in transiently transformed sunflower plants hahb4 expression ... | 2008 | 18643970 |
| immunomodulatory activity of plant residues on ovine neutrophils. | neutrophils play an essential role in host defense and inflammation. plants have long been used to improve the immune function, but for most of them specific investigations on animal health are lacking. in the present study, water and hydroethanolic extracts from 11 plant wastes have been screened on immune responses of ovine neutrophils. eight sheep clinically healthy, not lactating, non-pregnant were selected and used for the experiment. freshly isolated neutrophils were incubated with the ext ... | 2008 | 18667240 |
| characterization of metal-resistant plant-growth promoting bacillus weihenstephanensis isolated from serpentine soil in portugal. | a metal-resistant bacterial strain sm3 isolated from a serpentine soil in the north-east of portugal was characterized as bacillus weihenstephanensis based on the morphological and biochemical characteristics and on the comparative analysis of the partial 16s ribosomal dna sequence. bacillus weihenstephanensis sm3 showed a high degree of resistance to nickel (1500 mg l(-1)), copper (500 mg l(-1)) and zinc (700 mg l(-1)) and also to antibiotics (ampicillin, penicillin, kanamycin and streptomycin) ... | 2008 | 18785659 |
| residual effects of applied chemical fertilisers on growth and seed yields of sunflower (helianthus annuus cv. high sun 33) after the harvests of initial main crops of maize (zea mays l.), soybean (glycine max l.) and sunflower (helianthus annuus). | the experiments consisted of two locations, i.e., the first one was carried out on a growers's upland area at saraburi province, central plane region of thailand with the use of chatturat soil series (typic haplustalfs, fine, mixed) and the second experiment was carried out at suranaree technology university experimental farm, suranaree technology university northeast thailand with the use of korat soil series (oxic paleustults). the experiments aimed to investigate the effect of residual effect ... | 2007 | 19069898 |
| effects of crop residues of sunflower (helianthus annuus), maize (zea mays l.) and soybean (glycine max) on growth and seed yields of sunflower. | this pot experiment was carried out at suranaree technology university experimental farm, northeast thailand to investigate effects of crop residues of sunflower, maize and soybean on total dry weight, top dry weight, plant height, root dry weight and seed yield of sunflower plants with the use of korat soil series (oxic paleustults) during the rainy season (july-october) of the 2001. the experiment was laid in a split plot arranged in a completely randomized design (crd) with four replications ... | 2007 | 19069929 |
| comparative study of the major iranian cereal cultivars and some selected spices in relation to support aspergillus parasiticus growth and aflatoxin production. | aflatoxins are toxic fungal metabolites enable to contaminate a wide range of natural substrates. this contamination can be host-specific for different plant species. in this study, the ability of a toxigenic aspergillus parasiticus to produce various aflatoxins on major iranian cereals was evaluated with special focus on plant susceptibility to toxin production at cultivar level. | 2008 | 19079537 |
| strategies to use phytoextraction in very acidic soil contaminated by heavy metals. | in microcosm experiments, the use of inorganic and organic amendments has been studied as potential agents to reduce heavy metal bioavailability in an acidic soil highly contaminated by cu, zn and ni, that has to be remediated by phytoremediation. the concentrations of heavy metals in the original soil (o-soil) produced phytotoxic effects with a strong reduction in biomass yield that hinder the utilization of this technology. to overcome phytotoxicity the use of three immobilizing agents was eva ... | 2009 | 19217142 |
| isolation and characterization of bioactive and antibacterial compound from helianthus annuus linn. | a bioactive compound with antibacterial activity was isolated and purified from the extract of leaves of sunflower, helianthus annuus. the bioactive compound was characterized using 1h and 13c nmr. the compound induced auxin, gibberellins and cytokinin in oryza sativa and phaseolus mungo. it also showed activity against xanthomonas oryzae pv. oryzae. | 2008 | 19245180 |
| full-length sequence analysis of a distinct isolate of bidens mottle virus infecting sunflower in taiwan. | the full-length genome of a potyvirus, previously known as sunflower chlorotic spot virus isolate sf-1 (scsv-sf-1) which causes novel symptoms on sunflowers (helianthus annuus), was sequenced and analyzed. the genome of scsv-sf-1 is 9,741 nucleotides long, encoding a polyprotein of 3,071 amino acids containing the consensus motifs of potyviruses. sequence comparison revealed that the 3'-terminus of scsv-sf-1 shared over 96% similarities with isolates of bidens mottle virus (bimov). however, scsv ... | 2009 | 19308314 |
| effect of the ferredoxin electron donor on sunflower (helianthus annuus) desaturases. | ferredoxins are proteins that participate in photosynthesis and in other processes that require reducing equivalents, such as the reduction of nitrogen or fatty acid desaturation. two classes of ferredoxins have been described in plants: light-regulated photosynthetic ferredoxins and heterotrophic ferredoxins whose activity is not influenced by light. genes encoding the two forms of ferredoxin have been cloned and characterized in developing sunflower cotyledons. here, these genes were overexpre ... | 2009 | 19342250 |
| role of the polypeptide backbone and post-translational modifications in cross-reactivity of art v 1, the major mugwort pollen allergen. | artemisia vulgaris (mugwort) is one of the main causes of late summer pollinosis in europe, with >95% of patients sensitized to the glycoallergen art v 1. despite the importance of this allergen, little is known about its cross-reactive behavior. here we investigated the occurrence of conserved art v 1 antigenic determinants in sources known to display clinically relevant cross-reactivity with mugwort pollen. for this purpose, monoclonal antibodies specific for a cysteine-stabilized epitope of t ... | 2009 | 19361284 |
| siderophores mediate reduced and increased uptake of cadmium by streptomyces tendae f4 and sunflower (helianthus annuus), respectively. | as a toxic metal, cadmium (cd) affects microbial and plant metabolic processes, thereby potentially reducing the efficiency of microbe or plant-mediated remediation of cd-polluted soil. the role of siderophores produced by streptomyces tendae f4 in the uptake of cd by bacteria and plant was investigated to gain insight into the influence of siderophores on cd availability to micro-organisms and plants. | 2009 | 19457036 |
| in vitro assessment of the bioaccessibility of tocopherol and fatty acids from sunflower seed oil bodies. | the in vitro digestibility (proteolytic and lipolytic) and bioaccessibility of nutritionally important compounds (alpha-tocopherol and fatty acids) have been studied for natural sunflower ( helianthus annuus ) oil body suspensions in comparison to artificial emulsions emulsified with polyoxyethylene-20-sorbitan-monolaurate (tween 20) or whey protein isolate. proteolytic digestion of emulsions with pepsin (ph 2) promoted significant increases in mean particle size of the whey protein isolate stab ... | 2009 | 19492840 |
| effect of microbial inoculation and edta on the uptake and translocation of heavy metal by corn and sunflower. | a greenhouse experiment was carried out to study the effect of microbial inoculation and edta as synthetic chelator on heavy metals (zn, cu, pb and cd) uptake into and translocation within corn (zea mays) and sunflower (helianthus annuus) grown on contaminated soil. four treatments were included: the control, edta as synthetic chelator, inoculation with arbuscular mycorrhizal fungi (amf), and the inoculation with yeast. microbial inoculation increased biomass of both species of agricultural crop ... | 2009 | 19524998 |
| the hadreb2 transcription factor enhances basal thermotolerance and longevity of seeds through functional interaction with hahsfa9. | transcription factor hadreb2 was identified in sunflower (helianthus annuus l.) as a drought-responsive element-binding factor 2 (dreb2) with unique properties. hadreb2 and the sunflower heat shock factor a9 (hahsfa9) co-activated the hahsp17.6g1 promoter in sunflower embryos. both factors could be involved in transcriptional co-activation of additional small heat stress protein (shsp) promoters, and thus contribute to the hahsfa9-mediated enhancement of longevity and basal thermotolerance of se ... | 2009 | 19545370 |
| inheritance and molecular mapping of a downy mildew resistance gene, pl (13) in cultivated sunflower (helianthus annuus l.). | the inheritance of resistance to sunflower downy mildew (sdm) derived from ha-r5 conferring resistance to nine races of the pathogen has been determined and the new source has been designated as pl ( 13 ) . the f(2) individuals and f(3) families of the cross ha-r5 (resistant) x ha 821 (susceptible) were screened against the four predominant sdm races 300, 700, 730, and 770 in separate tests which indicated dominant control by a single locus or a cluster of tightly linked genes. bulked segregant ... | 2009 | 19557383 |
| identification, functional characterization and developmental regulation of sesquiterpene synthases from sunflower capitate glandular trichomes. | sesquiterpene lactones are characteristic metabolites of asteraceae (or compositae) which often display potent bioactivities and are sequestered in specialized organs such as laticifers, resin ducts, and trichomes. for characterization of sunflower sesquiterpene synthases we employed a simple method to isolate pure trichomes from anther appendages which facilitated the identification of these genes and investigation of their enzymatic functions and expression patterns during trichome development ... | 2009 | 19580670 |
| resistance among cultivated sunflower germplasm to stem-infesting pests in the central great plains. | a 7-yr field study evaluated 61 oilseed sunflower, helianthus annuus l., accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, cylindrocopturus adspersus (leconte) (coleoptera: curculionidae); a longhorned beetle, dectes texanus leconte (coleoptera: cerambycidae); and a root boring moth, pelochrista womonana (kearfott) (lepidoptera: tortricidae), at two locations in the central great plains. g ... | 2009 | 19610449 |
| characterization of a plasmopara species on ambrosia artemisiifolia, and notes on p. halstedii, based on morphology and multiple gene phylogenies. | common ragweed (ambrosia artemisiifolia) is an invasive and highly allergenic plant species, on which two species, plasmopara halstedii and plasmopara angustiterminalis, have been recognized to cause downy mildew disease. in this study, morphological and molecular patterns of seven plasmopara specimens collected from a. artemisiifolia in canada, hungary, and usa were compared with those of p. halstedii and p. angustiterminalis from helianthus and xanthium, respectively. analyses of partial seque ... | 2009 | 19619650 |
| rubisco in planta kcat is regulated in balance with photosynthetic electron transport. | site turnover rate (k(cat)) of rubisco was measured in intact leaves of different plants. potato (solanum tuberosum l.) and birch (betula pendula roth.) leaves were taken from field-growing plants. sunflower (helianthus annuus l.), wild type (wt), rubisco-deficient (-rbc), fnr-deficient (-fnr), and cyt b(6)f deficient (-cbf) transgenic tobacco (nicotiana tabacum l.) were grown in a growth chamber. rubisco protein was measured with quantitative sds-page and fnr protein content with quantitative i ... | 2009 | 19661266 |
| selenium concentrations of common weeds and agricultural crops grown in the seleniferous soils of northwestern india. | the plants grown in seleniferous soils constitute a major source of toxic selenium levels in the food chain of animals and human beings. greenhouse and field experiments were conducted to study selenium concentrations of weeds, forages and cereals grown on seleniferous soils located between 31.0417 degrees to 31.2175 degrees n and 76.1363 degrees to 76.4147 degrees e in northwestern india. eleven winter season (november-april) weed plants were grown in the greenhouse in a soil treated with diffe ... | 2009 | 19800657 |
| phytoremediation of metal-contaminated soil in temperate humid regions of british columbia, canada. | the suitability of five plant species was studied for phytoextraction and phytostabilisation in a region with temperate maritime climate of coastal british columbia, canada. pot experiments were conducted using lolium perenne l (perennial rye grass), festuca rubra l (creeping red fescue), helianthus annuus l (sunflower), poa pratensis l (kentucky bluegrass) and brassica napus l (rape) in soils treated with three different metal (cu, pb, mn, and zn) concentrations. the bio-metric characters of pl ... | 2009 | 19810356 |
| novel neofusapyrones isolated from verticillium dahliae as potent antifungal substances. | novel fusapyrone analogs, deoxyneofusapyrone and 7-desmethyldeoxyneofusapyrone were isolated from a pathogenic fungus, verticillium dahliae, which causes verticillium wilt disease in helianthus annuus. spectral analyses revealed that these are 2-pyrone type analogs of deoxyfusapyrone and its 7-desmethyl derivative, respectively. biological assay disclosed that 10microg of deoxyneofusapyrone inhibited the growth of mrsa clinical isolate 87-7927. | 2010 | 19962895 |
| application of small-spot energy dispersive x-ray fluorescence instrumentation in phytoremediation activities around metal mines. | in view of the considerable number of analyses necessary in phytoremediation and plant biology studies, it is important that the analytical procedures used for elemental determination in plant tissues should be fast and cheap, with simple sample preparation, and of adequate accuracy and precision. the aim of the present work was focused on the possibilities and drawbacks of a low-cost benchtop energy dispersive x-ray fluorescence (edxrf) instrument to be used as an analytical technique for study ... | 2009 | 20030986 |
| phospholipase dalpha from sunflower (helianthus annuus): cloning and functional characterization. | d type phospholipases (pld) are enzymes that hydrolyze the head group of phospholipids to produce phosphatidic acid. this activity is ubiquitous in plant tissues, and has been isolated and characterized from different species and organs. several families of these proteins have been described in plants on the basis of their gene sequences (pld alpha, beta, gamma, delta, zeta and epsilon). they have been shown to be involved in many metabolic events, such as response to abiotic stress, signal tran ... | 2010 | 20116883 |
| self-reported use of traditional, complementary and over-the-counter medicines by hiv-infected patients on antiretroviral therapy in pretoria, south africa. | current management of hiv involves the use of conventional prescription medicines, called 'antiretroviral drugs' (arv), over-the-counter (otc), complementary and alternative medicines (cam), as well as african traditional medicine (atm). the aim of this study was to determine the prevalence of use of traditional, complementary and over-the-counter medicines. a cross-sectional survey of hiv-infected patients who started art between july 2004 and august 2005 at dr george mukhari hospital (pretoria ... | 2007 | 20161889 |
| xanthium italicum, xanthium strumarium and arctium lappa as new hosts for diaporthe helianthi. | sunflower (helianthus annuus) stem canker caused by diaporthe helianthi is one of the most important sunflower diseases in croatia. until recently, sunflower was the only known host for d. helianthi. in our research carried out in the area of eastern croatia, isolates of diaporthe/phomospis were collected from xanthium italicum, x. strumarium and arctium lappa. using morphological, cultural and molecular its rdna data, isolates from these weeds were identified as d. helianthi. the following isol ... | 2010 | 20182800 |
| the role of beta-ketoacyl-acyl carrier protein synthase iii in the condensation steps of fatty acid biosynthesis in sunflower. | the beta-ketoacyl-acyl carrier protein synthase iii (kas iii; ec 2.3.1.180) is a condensing enzyme catalyzing the initial step of fatty acid biosynthesis using acetyl-coa as primer. to determine the mechanisms involved in the biosynthesis of fatty acids in sunflower (helianthus annuus l.) developing seeds, a cdna coding for hakas iii (ef514400) was isolated, cloned and sequenced. its protein sequence is as much as 72% identical to other kas iii-like ones such as those from perilla frutescens, ja ... | 2010 | 20221630 |
| dyella thiooxydans sp. nov., a facultatively chemolithotrophic, thiosulfate-oxidizing bacterium isolated from rhizosphere soil of sunflower (helianthus annuus l.). | a gram-negative, aerobic, motile, rod-shaped, thiosulfate-oxidizing bacterium, designated atsb10(t), was isolated from rhizosphere soil of sunflower (helianthus annuus l.). phylogenetic analysis based on 16s rrna gene sequences revealed that strain atsb10(t) was closely related to members of the genera dyella (96.4-98.1 % 16s rrna gene sequence similarity) and luteibacter (96.4-97.0 %) and fulvimonas soli lmg 19981(t) (96.7 %) and frateuria aurantia ifo 3245(t) (97.8 %). the predominant fatty ac ... | 2011 | 20305058 |
| impact of the stem borer, dectes texanus, on yield of the cultivated sunflower, helianthus annuus. | foliar and soil-drench insecticide treatments were used in attempts to manipulate infestation of cultivated sunflower plants, helianthus annuus leconte (asterales: asteraceae) by dectes texanus leconte, (coleoptera: cerambycidae) a serious pest of sunflowers in the high plains of the usa. seed yields were assessed on a per-plant basis for both oilseed and confection type sunflower hybrids in two years. both insecticide treatments (foliar ë-cyhalothrin and soil-drench carbofuran) improved yield o ... | 2007 | 20307233 |
| adaptive introgression of abiotic tolerance traits in the sunflower helianthus annuus. | *adaptive trait introgression is increasingly recognized as common. however, it is unclear whether adaptive genetic exchanges typically affect only a single trait, or instead affect multiple aspects of the phenotype. here, we examine introgression of abiotic tolerance traits between two hybridizing north american sunflower species, helianthus annuus and helianthus debilis. *in two common gardens in the hybrid range, we measured 10 ecophysiological, phenological, and architectural traits for pare ... | 2010 | 20345635 |
| the sunflower plastidial omega3-fatty acid desaturase (hafad7) contains the signalling determinants required for targeting to, and retention in, the endoplasmic reticulum membrane in yeast but requires co-expressed ferredoxin for activity. | although plant plastidial omega3-desaturases are closely related to microsomal desaturases, heterologous expression in yeast of the helianthus annuus fad7 omega3-desaturase showed low activity in contrast to similar expression of microsomal fad3 omega3-desaturases. however, the removal of the plastidial transit peptide and the incorporation of a kknl motif to the c-terminus of hafad7 increased the activity by 10-fold compared to the native protein. n-terminal fusion of transmembrane-domains from ... | 2010 | 20472257 |
| identification and functional characterization of a new sunflower germacrene a synthase (hagas3). | sesquiterpenes and sesquiterpene lactones are major natural compounds found in linear and capitate glandular trichomes of sunflower, helianthus annuus l. in addition to two recently identified germacrene a synthases hagas1 and hagas2, found in capitate trichome gland cells, reverse transcription-pcr experiments have now allowed identification of a third enzyme of this type, hagas3. its cdna sequence was established and its functional characterization as a germacrene a synthase was achieved throu ... | 2010 | 20521533 |
| conformational studies on the delta8(e,z)-sphingolipid desaturase from helianthus annuus with chiral fluoropalmitic acids as mechanistic probes. | the delta(8)-sphingolipid desaturase from sunflower (helianthus annuus) converts phytosphinganine into a mixture of delta(8)-(e)- and -(z)-phytosphingenines by removal of two syn-hydrogen atoms from anti-, and gauche-conformations of the substrate. with chiral (r)-6-, (s)-6-, (r)-7-, and (s)-7-fluoropalmitic acids the importance of conformations for the formation of (e)- and (z)-isomers was investigated by using growing yeast cells expressing the desaturase from h. annuus. the fluoropalmitic aci ... | 2010 | 20575587 |
| differential expression of proteins induced by lead in the dwarf sunflower helianthus annuus. | the dwarf sunflower (helianthus annuus) is a hyperaccumulator of toxic metals including cadmium (cd), mercury (hg), nickel (ni), and lead (pb). in order to identify stress response to pb, plants were exposed to a mixture of 30 mg/l of three ions, cd, cr, and ni, with and without pb. soluble proteins were resolved by two-dimensional gel electrophoresis. four proteins were differentially expressed and very abundant in the leaf samples after plants were exposed to all these four metals. the first p ... | 2010 | 20599235 |
| cloning, biochemical characterisation, tissue localisation and possible post-translational regulatory mechanism of the cytosolic phosphoglucose isomerase from developing sunflower seeds. | lipid biosynthesis in developing sunflower (helianthus annuus l.) seeds requires reducing power. one of the main sources of cellular nadph is the oxidative pentose phosphate pathway (oppp), generated from the oxidation of glucose-6-phosphate. this glycolytic intermediate, which can be imported to the plastid and enter in the oppp, is the substrate and product of cytosolic phosphoglucose isomerase (cpgi, ec 5.3.1.9). in this report, we describe the cloning of a full-length cdna encoding cpgi from ... | 2010 | 20628759 |
| fine mapping of the sunflower resistance locus pl(arg) introduced from the wild species helianthus argophyllus. | downy mildew, caused by plasmopara halstedii, is one of the most destructive diseases in cultivated sunflower (helianthus annuus l.). the dominant resistance locus pl(arg) originates from silverleaf sunflower (h. argophyllus torrey and gray) and confers resistance to all known races of p. halstedii. we mapped pl(arg) on linkage group (lg) 1 of (cms)ha342 × arg1575-2, a population consisting of 2,145 f(2) individuals. further, we identified resistance gene candidates (rgcs) that cosegregated with ... | 2010 | 20700574 |
| modulation of salt (nacl)-induced effects on oil composition and fatty acid profile of sunflower (helianthus annuus l.) by exogenous application of salicylic acid. | salicylic acid (sa) is a potential endogenous plant hormone that plays an important role in plant growth and development. since sunflower yield and its seed oil yield are adversely affected by salinity, in this study the role of sa in modulating salt (nacl)-induced effects on various yield and oil characteristics of sunflower was investigated. for this purpose a greenhouse experiment comprising two sunflower hybrid lines (hysun-33 and sf-187), two nacl levels (0 and 120 mmol l(-1)) and four sa l ... | 2010 | 20718031 |
| cloning, biochemical characterization and expression of a sunflower (helianthus annuus l.) hexokinase associated with seed storage compounds accumulation. | a full-length hexokinase cdna, hahxk1, was cloned and characterized from helianthus annuus l. developing seeds. based on its sequence and phylogenetic relationships, hahxk1 is a membrane-associated (type-b) hexokinase. the predicted structural model resembles known hexokinase structures, folding into two domains of unequal size: a large and a small one separated by a deep cleft containing the residues involved in the enzyme active site. a truncated version, without the 24 n-terminal residues, wa ... | 2011 | 20889232 |