| enzymic capacities for chlorophyll biosynthesis. activation and de novo synthesis of enzymes. | a previously published working model for the regulation of chlorophyll formation has been tested studying early steps of chlorophyll and porphyrin biosynthesis in developing cotyledons of helianthus annuus. the activities of delta-aminolevulinate synthetase (alas), delta-aminolevulinate dehydratase (alad), and the porphobilinogenase complex (pbgase) at any given time have been found to be strongly associated with endogenous developmental processes. highest activities in darkness have been observ ... | 1976 | 132041 |
| purification and characterization of the crown gall specific enzyme nopaline synthase. | nopaline synthase of sunflower (helianthus annuus l.) crown gall tissue induced by agrobacterium tumefaciens strain c58 or t37 (nopaline utilizers) was purified to homogeneity as judged by analytical disc gel electrophoresis. the native enzyme elutes from a column of ultrogen aca 34 as a single peak with an estimated molecular weight of 158,000. the dissociated enzyme migrates on nadodso4-polyacrylamide gels as a single band with a molecular weight of 40,000. thus, the native enzyme appears to b ... | 1979 | 476084 |
| [nutritive value of sunflower seeds (helianthus annus) (author's transl)]. | the nutritive value of sunflower seeds (helianthus annus) was studied and compared to that of casein. thirty-six male rats, wistar strain, aged 23 days, were divided into two groups and fed (a) a sunflower cake meal diet, and (b) a casein diet. the results indicate that due to its high protein level (52.06%) and coefficient of digestibility (95 cd) sunflower can be used as a feeding formula although its per does not recommend its use as a milk substitute. | 1977 | 905604 |
| assay of nitrogenase activity in intact plant systems. | nitrogenase activity was assayed in intact system of cichorium intybus, a non-leguminous commercially cultivated crop, dahlia pinnata and helianthus annus, and taraxacum officinale, a common weed plant. the assay was made in fabricated cylinders which could accomodate pot with plants. in such kind of assay along with rhizosphere microflora, the nitrogen fixed by phyllosphere nitrogen fixing microflora could also be accounted, which otherwise was difficult to be accounted for. | 1975 | 1211718 |
| cdna sequence of a sunflower oleosin and transcript tissue specificity. | oleosins (oil body membrane proteins) of 20.5 and 18 kda have been purified from sunflower (helianthus annuus) seeds and polyclonal antibodies raised against them. the precipitated rabbit immunoglobulin fraction was purified by affinity chromatography on cyanogen bromide-activated sepharose and specifically recognised polypeptides of 18 and 20.5 kda in sunflower homogenate and oil body fractions assayed by western blotting. a near-full-length cdna clone was isolated for the 20.5 kda oleosin. the ... | 1992 | 1643288 |
| feline meningitis due to cryptococcus neoformans var. neoformans and review of feline cryptococcosis. | cryptococcus neoformans var. neoformans was ascertained as the prime cause of fatal meningitis in a young-adult female domestic cat who was suspected of rabies. the pathogen was isolated in heavy growth from the infected brain specimen on simplified sunflower seed (helianthus annuus) medium at 30 degrees c. periodic acid-schiff stained impression smear revealed numerous cryptococcal cells. histologically, pia-arachnoid showed thickening along with many circular yeast cells with and without buddi ... | 1991 | 1803233 |
| isolation of cryptococcus neoformans var. neoformans from canine otitis. | cryptococcus neoformans was demonstrated in the clinical material of a 15-year-old male dog with a history of chronic otitis externa by employing helianthus annuus seed agar as a selective medium. the examination of the isolate for sexual compatibility on modified helianthus annuus seed medium revealed that it belonged to filobasidiella neoformans var. neoformans 'alpha' mating type. in the authors' view, this appears to be the first report of isolation of cr. neoformans var. neoformans from dis ... | 1990 | 2093842 |
| sunflower allergy. on the constituents of the trichomes of helianthus annuus l. (compositae). | sesquiterpene lactones (stl) of the sunflower, occurring in fragile multicellular capitate glandular hairs, have been shown to display a remarkable sensitizing capacity when investigated by experimental sensitization in guinea pigs. the strongest response was induced by the hemiketal form of 1-o-methyl-4,5-dihydroniveusin a. the stl content of 50 capitate glands was sufficient to elicit a remarkable response in the guinea pigs. thus, touching a sunflower plant (with up to 1000 capitate glands pe ... | 1989 | 2766700 |
| [use of sunflower (helianthus annus, l.) in human foods. i. preparation of sunflower flour, protein concentrate and supplementation of this flour with the amino acids lysine and methionine]. | in view of the importance that cultivation of sunflower (helianthus annus, l.) has from both the industrial and scientific points of view, to promote its wide utilization in human foods, this study was undertaken for the following purposes. to obtain an edible sunflower seed meal, as well as well to determine the effect thermic treatment exerted on its nutritional qualities. to evaluate through chemical and biological analyses, the nutritional quality of the flour and of its thermic treatment, a ... | 1988 | 3155292 |
| monitoring the fate of dietary proteins in rumen fluid using gel electrophoresis. | 1. when fractionated by sodium dodecylsulphate-polyacrylamide gel electrophoresis (sds-page), strained rumen fluid from sheep fed on pelleted lucerne (medicago sativa) hay showed no major protein components that stain with coomassie blue. this feature made it possible to monitor the fate of individual polypeptides within a protein mixture incubated in rumen fluid in vitro. 2. extracts from a number of seed meals (sunflower (helianthus annuus), lupin (lupinus angustifolius), rape (brassica napus) ... | 1988 | 3196671 |
| trypsin inhibitor content in some varieties of soya bean (glycine max l.) and sunflower seeds (helianthus annuus l.). | | 1974 | 4859576 |
| [tumorigenic action of nucleic acid of a bacteriophage present in tumoral tissue cultures of sunflower (helianthus annus)]. | | 1970 | 4987583 |
| the amino acid sequence of helianthus annuus l. (sunflower) cyrochrome c deduced from chymotryptic peptides. | peptides derived from digestion of 1 mumol of sunflower cytochrome c with chymotrypsin were separated by paper electrophoresis. the sequences of these peptides were determined by using the dansyl-edman method (gray & hartley, 1963) and confirmed by analysis of their amino acid composition. comparison of the set of peptides with the chymotryptic peptides of mung-bean (thompson, laycock, ramshaw & boulter, 1970) and wheat germ (stevens, glazer & smith, 1967) cytochrome c shows a clear homology. th ... | 1970 | 5500313 |
| factors affecting the development of the perithecial stage of powdery mildew of helianthus annuus l. in india. | | 1965 | 5876680 |
| isolation and identification of trachyloban-19-oic and (-)-kaur-16-en-19-oic acids as antimicrobial agents from the prairie sunflower, helianthus annuus. | | 1983 | 6361218 |
| structure and synthesis of histopine, a histidine derivative produced by crown gall tumors. | histopine, an unusual amino acid derivative of histidine isolated from crown gall tumors of sunflowers (helianthus annus) inoculated with agrobacterium tumefaciens strain b6, was previously assigned the gross structure n-(1-carboxyethyl) histidine (2). a diastereomeric mixture containing histopine (2a and 2b) was readily prepared by reductive alkylation of (s)-histidine (1) with pyruvic acid and sodium cyanoborohydride. the individual diastereomers were prepared by reaction of (s)-histidine with ... | 1984 | 6466642 |
| the biosynthesis of triacylglycerols in microsomal preparations of developing cotyledons of sunflower (helianthus annuus l.). | the synthesis of triacylglycerols was investigated in microsomes (microsomal fractions) prepared from the developing cotyledons of sunflower (helianthus annuus). particular emphasis was placed on the mechanisms involved in controlling the c18- unsaturated-fatty-acid content of the oils. we have demonstrated that the microsomes were capable of: the transfer of oleate from acyl-coa to position 2 of sn-phosphatidylcholine for its subsequent desaturation and the return of the polyunsaturated product ... | 1984 | 6743281 |
| the synthesis of acetylcholine by plants. | choline acetyltransferase was demonstrated in nettles (urtica dioica), peas (pisum sativum), spinach (spinacia oleracea), sunflower (helianthus annuus) and blue--green algae by using a sepharose--coash affinity column. the column effected a 1500-fold purification of the enzyme from nettle homogenates and was required for demonstrating activity in the other higher plants. demonstration of the enzyme in blue-green algae suggests that acetylcholine was a biochemical necessity in the earliest photos ... | 1981 | 6796060 |
| significance of plant metabolism in the mutagenicity and toxicity of pesticides. | in an attempt to gain an overall estimate for the influence of plant metabolism on environmental mutagenesis, the mutagenicity of an assortment of agricultural pesticide preparations in the salmonella bio-assay was evaluated using both rat liver s9 and plant enzyme homogenates as activating systems. the study indicates that plant metabolism can alter the results of this short-term mutagenicity test: some compounds which are non mutagenic in the salmonella bio-assay (e.g. diquat) give positive re ... | 1982 | 7172099 |
| biological activities of sesquiterpene lactones from helianthus annuus: antimicrobial and cytotoxic properties; influence on dna, rna, and protein synthesis. | sesquiterpene lactones, produced in light and capable of inhibiting auxin-induced elongation growth of coleoptile and hypocotyl segments, were isolated from young leaves of helianthus annuus (spring and hager, planta in press, 1982). these compounds have an antibiotic effect on gram-negative and gram-positive bacteria as well as on some fungi. the minimal inhibiting concentration (mic) of compound ii (15-hydroxy-3-dehydrodesoxyfruticin, fig. 1), for example, is 15 micrograms/ml for bacillus brev ... | 1982 | 7183030 |
| [obtaining flour and a protein concentrate from seeds of the helianthus annuus (sunflower) and its addition in cookies]. | the objectives of the studies described herein were: 1) to obtain a sunflower flour and protein concentrate for human consumption, and 2) to explore possible ways for their utilization. the peredovik variety was selected, since it is most abundant in mexico. the procedure usually followed for the obtention of flours for animal feeds was used with some modifications. the hull was mechanically eliminated with a yield of 51%, with a satisfactory appearance of the almond. in order to facilitate the ... | 1980 | 7283630 |
| rhizosphere fungi of five plants in egypt. | 75 species which belong to 25 genera were collected during this investigation. all of these fungi were previously isolated from egyptian soils and other sources. the total count and the number of genera and species in the rhizosphere soil of the 5 plants were regularly higher than in non-rhizosphere soil. the composition of the rhizosphere fungus flora was considerably influenced by the type and the age of the plant. the most prevalent fungi in the rhizosphere of the test plants after 45, 90, an ... | 1980 | 7424047 |
| pollen allergen homologues in barley and other crop species. | pollen from 10 agricultural plant species was surveyed for the presence of proteins crossreactive with group i, group iv and group ix allergens. barley (hordeum vulgare), maize (zea mays), rye (secale cerale), triticale (xtriticosecale cereale), oats (avena sativa), canola (brassica napus) and sunflower (helianthus annus) pollens contained numerous allergen cognate proteins. northern blot analysis of barley pollen rna revealed the presence of group i and group ix allergen transcripts. the barley ... | 1995 | 7537171 |
| expression and in vitro targeting of a sunflower oleosin. | two distinct cdnas encoding oleosins (oil body proteins) have been identified by degenerate pcr as transcripts present in the developing seeds of sunflower (helianthus annuus l. cv. dwarf sunbred). one (psom) of these is closely related to a reported sunflower oleosin, whilst the other (pso5) has not been previously described. different expression patterns were observed for the two cdnas, pso5 being expressed earlier than psom in seed maturation and oil deposition. the results support the conten ... | 1995 | 7579191 |
| sensitization to sunflower pollen: only an occupational allergy? | sunflower (helianthus annuus) pollen sensitization has been reported as an occupational allergy. in this report, the sensitization of the general population living in sunflower-growing areas to helianthus pollen was studied. both rast results in 32 adults with summer symptoms previously diagnosed as allergic to artemisia pollen, and cross-reactivity studies between h. annuus and other compositae suggested that h. annuus pollen was the main allergen involved in the hypersensitivity reaction of th ... | 1994 | 7920032 |
| pattern of cross-sensitivity between 4 compositae plants, parthenium hysterophorus, xanthium strumarium, helianthus annuus and chrysanthemum coronarium, in indian patients. | to assess the pattern of cross-sensitivity between 4 members of the compositae family, namely parthenium hysterophorus l., xanthium strumarium l., helanthus annuus l. and chrysanthemum coronarium l., 63 patients clinically diagnosed to have airborne contact dermatitis, and 51 controls having well-defined patterns of contact dermatitis caused by agents other than plants, were patch tested with measured amounts of standardized aqueous extracts of these plants. positive reactions were obtained in 6 ... | 1994 | 8187516 |
| growth of corn (zea mays) and sunflower (helianthus annuus) plants is affected by water and sludge from a sewage treatment plant. | | 1996 | 8661913 |
| purification, characterization, and sequencing of two cysteine proteinase inhibitors, sca and scb, from sunflower (helianthus annuus) seeds. | two proteinaceous cysteine proteinase inhibitors (cystatins) referred to as sca and scb were purified to homogeneity from the seeds of sunflower (heliantas annuus) by gel filtration on sephadex g-75 followed by a series of ion-exchange column chromatographies and reverse-phase hplc (rp-hplc). the isoelectric points (pi) of sca and scb were estimated to be 5.6 and 9.6, respectively. the inhibitory potencies of these two cystatins were examined with cysteine proteinases from various sources, such ... | 1996 | 8827445 |
| triterpene alcohols from the flowers of compositae and their anti-inflammatory effects. | eleven tabular and nine ligulate flowers from 15 species of compositae plants were investigated for their triterpene alcohol constituents. this led to the isolation and identification of 11 triterpene alcohols as follows: heliaol, taraxasterol, psi-taraxasterol, alpha-amyrin, beta-amyrin, lupeol, taraxerol, cycloartenol, 24-methyl-enecycloartanol, tirucalla-7,24-dienol and dammaradienol. the tabular flowers of calendula officinalis, carthamus tinctorius, cosmos bipinnatus, chrysanthemum morifoli ... | 1996 | 8987908 |
| the predominant protein in peroxisomal cores of sunflower cotyledons is a catalase that differs in primary structure from the catalase in the peroxisomal matrix. | this paper describes a biochemical study on the protein composition of crystalline inclusions (cores) from plant peroxisomes. by sds/page and immunoblotting, a catalase of 59 kda was identified as the predominant protein component in purified cores from sunflower (helianthus annuus l.) cotyledons. a 55-kda catalase was the only additional peptide detected. in contrast to in cores, the 55-kda catalase was the major catalase protein in matrix fractions obtained from lysed peroxisomes. these findin ... | 1997 | 9151971 |
| recombinant dna technology in allergology: cloning and expression of plant profilins. | profilin, an ubiquitous protein involved in eukaryotic cytoskeleton regulation, has been previously described as allergen in grasses, weeds and trees and in many fruits and vegetables, and it is in part responsible for cross-reactivities pollen and food allergic patients. completed cdna clones coding for phleum pratense, olea europaea, cynodon dactylon, parietaria judaica and helianthus annuus pollen profilins were isolated and sequenced. the deduced amino acid sequences share high identity with ... | 1997 | 9208049 |
| production and characterization of profilin monoclonal antibodies. | profilins have been identified as a pan-allergen of different plant pollens and foods. in this paper, we describe the generation of monoclonal antibodies (mabs) by immunizing balb/c mice with helianthus annuus purified profilin in order to characterize this important and common allergen. a panel of forty mabs has been obtained, and twenty of them were used to map antigenic determinants in this molecule. at least two different antigenic determinants were recognized in h. annuus profilin by immuno ... | 1997 | 9208051 |
| in vitro photoinactivation of catalase isoforms from cotyledons of sunflower (helianthus annuus l.). | catalase (ec 1.11.1.6) isoforms cat 2 through cat 8 were purified from peroxisomes of sunflower (helianthus annuus l.) cotyledons and photoinactivated in vitro. action and absorbance spectra between 380 and 727 nm wavelength showed most prominent maxima at 405 nm suggesting an inactivation mediated by light absorption of heme groups. first order kinetics of inactivation were observed for cat 6 through cat 8 (isoform group b), which are composed of four 55-kda subunits. inactivation constants ki ... | 1997 | 9343368 |
| immunomodulatory and antitumoral effects of triterpenoid saponins. | genuine saponins of solidago virgaurea l., heteropappus altaicus (willd.) novopokr., heteropappus biennis (ldb.) tamamsch. and helianthus annuus l. (asteraceae) as well as related carbohydrate modified glycosides of polygalacic acid and echinocystic acid and some commercial available triterpenoid saponins were investigated in view of their immunomodulating and antitumoral effects. mitogeneic effects on murine spleen and thymus cells, as well on human mononuclear cells in vitro could be demonstra ... | 1997 | 9442560 |
| secondary structure of oleosins in oil bodies isolated from seeds of safflower (carthamus tinctorius l.) and sunflower (helianthus annuus l.). | oil bodies were isolated from mature seeds of sunflower (helianthus annuus l.) and safflower (carthamus tinctorius l.). oil body preparations containing only oleosin proteins could be obtained from safflower seeds by salt-washing followed by centrifugation on discontinuous sucrose density gradients. however, it was necessary to treat sunflower oil bodies with urea to obtain preparations of similar purity. incubation of the oil bodies with proteinases gave two fragments with molecular masses of 6 ... | 1998 | 9716507 |
| cloning and immunological characterization of the allergen hel a 2 (profilin) from sunflower pollen. | sunflower (helianthus annuus) sensitization is not always related with occupational allergy. we have isolated the allergen profilin (hel a 2) from this compositae plant, cloned and sequenced five cdnas encoding for full-length or partial hel a 2. natural sunflower profilin reacted with specific ige in the 121 sera tested, at a frequency of 30.5%. expression of the cdna encoding hel a 2 in escherichia coli and a simple purification procedure by poly-l-proline chromatography allowed immunological ... | 1998 | 9798651 |
| nutritional evaluation of zambia indigenous soy bean (glycine max) and sunflower (helianthus annus) as protein sources in poultry and pigs diets. | two trials were carried out to compare the nutritional values of two zambian indigenous plant protein sources--soy bean cake (sbc) and sunflower meal (sfm) in the diets of broilers and growing pigs. in trial 1, 120 one week old chickens (abbor acre strain) were used. there were no differences (p > 0.05) between chickens on sbc and sfm in voluntary feed intake. average daily gain of sbc chickens differed (p < 0.05) from those of sfm. the protein source had an effect (p < 0.05) on n retained [g/da ... | 1998 | 9829266 |
| plastome engineering of ribulose-1,5-bisphosphate carboxylase/oxygenase in tobacco to form a sunflower large subunit and tobacco small subunit hybrid. | targeted gene replacement in plastids was used to explore whether the rbcl gene that codes for the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase, the key enzyme of photosynthetic co2 fixation, might be replaced with altered forms of the gene. tobacco (nicotiana tabacum) plants were transformed with plastid dna that contained the rbcl gene from either sunflower (helianthus annuus) or the cyanobacterium synechococcus pcc6301, along with a selectable marker. three stable lines o ... | 1999 | 9880354 |
| characterization of closely related delta-tip genes encoding aquaporins which are differentially expressed in sunflower roots upon water deprivation through exposure to air. | we isolated five sunflower (helianthus annuus) cdnas belonging to the tip (tonoplast intrinsic protein) family. sunrb7 and sun gammatip (partial sequence) are homologous to tobacco tobrb7 and arabidopsis gamma-tip, respectively. suntip7, 18 and 20 (suntips) are closely related and homologous to arabidopsis delta-tip (suntip7 and 20 have already been presented in sarda et al., plant j. 12 (1997) 1103-1111). as was previously shown for suntip7 and 20, expression of suntip18 and sunrb7 in xenopus o ... | 1999 | 10394956 |
| development of a polymerase chain reaction diagnostic test for the detection of the biotrophic pathogen plasmopara halstedii in sunflower. | the obligate parasitic fungus-like organism plasmopara halstedii (farl.) berl. et de toni, is the causal agent of downy mildew disease in sunflower (helianthus annuus). new races of this economically important parasite are regularly detected throughout the world. in addition, fungicide-resistant isolates have been reported in europe and north america. these observations of parasite evolution, as well as the risk of propagation of the disease by infected seeds, means that it is necessary to guara ... | 1999 | 10526404 |
| evidence for mutualism between a plant growing in a phosphate-limited desert environment and a mineral phosphate solubilizing (mps) rhizobacterium. | alkaline desert soils are high in insoluble calcium phosphates but deficient in soluble orthophosphate (pi) essential for plant growth. in this extreme environment, one adaptive strategy could involve specific associations between plant roots and mineral phosphate solubilizing (mps) bacteria. the most efficient mps phenotype in gram-negative bacteria results from extracellular oxidation of glucose to gluconic acid via the quinoprotein glucose dehydrogenase. a unique bacterial population isolated ... | 1999 | 10568838 |
| sunflower (helianthus annuus) variability in antioxidant enzyme defenses. | in order to investigate the existence of genetic variability in antioxidant enzyme defenses in sunflower, twelve inbred lines, six cytoplasmic male-sterile and six restorer lines, commonly used in breeding programs have been compared with respect to (a) their levels of constitutive superoxide dismutase (sod, ec 1.15.1.1), catalase (cat, ec 1.11.1.6), ascorbate peroxidase (apx, ec 1.11.1.11), glutathione reductase (gr, ec 1.6.4.2) and guaiacol-dependent peroxidase (gpx, ec 1.11.1.7), and (b) thei ... | 1999 | 10694064 |
| foraging resources of adult mexican corn rootworm (coleoptera: chrysomelidae) in bell county, texas. | pollen analyses were used to determine pollen foraging resources of adult mexican corn rootworms, diabrotica virgifera zeae krysan & smith, captured near temple, bell county, tx, in 1996 and 1997. in 1996, adult mexican corn rootworms were captured in a corn, zea mays l., field. in 1997, nine locations outside of cornfields were added. overall, 92% of the beetles (n = 1,323) contained pollen. more than 142,000 pollen grains were counted, representing 45 families, 63 genera, and 27 species. overa ... | 2000 | 10902309 |
| rhizosphere soil aggregation and plant growth promotion of sunflowers by an exopolysaccharide-producing rhizobium sp. strain isolated from sunflower roots. | root-adhering soil (ras) forms the immediate environment where plants take up water and nutrients for their growth. we report the effect of an exopolysaccharide (eps)-producing rhizobacterium (strain yas34) on the physical properties of sunflower (helianthus annuus l.) ras, associated with plant growth promotion, under both water stress and normal water supply conditions. strain yas34 was isolated as a major eps-producing bacterium from the rhizoplane of sunflowers grown in a french dystric camb ... | 2000 | 10919797 |
| expression of a biologically active plant cytochrome b5 in escherichia coli. | cytochrome b5 from tobacco (nicotiana tabacum) was expressed in escherichia coli using a t7 polymerase/promoter system as described by studier, rosenberg, dunn and dubendorff (1990) (methods enzymol. 185, 60-89). transformed cells were red in colour and accumulated cytochrome b5 to a level of around 30% of the total cell protein. the purified cytochrome had oxidized, reduced and low-temperature absorbance spectra characteristic of plant microsomal cytochrome b5, and exhibited a c.d. spectrum res ... | 1994 | 7945268 |
| biological quality of a lipoprotein concentrate from sunflower seed (helianthus annuus l.). | | 1971 | 5127161 |
| further characterization of delta(8)-sphingolipid desaturases from higher plants. | a previously cloned cdna from helianthus annuus codes for a fusion protein composed of an n-terminal cytochrome b(5) and a c-terminal desaturase domain. for a functional identification, this cdna was expressed in saccharomyces cerevisiae and the structures of sphingolipid long-chain bases were analysed. the expression of this sunflower enzyme resulted in the formation of new delta(8)-trans/cis-phytosphingenine from c(18)- and c(20)-phytosphinganine present in wild-type yeast cells. to elucidate ... | 2000 | 11171153 |
| developmentally regulated expression of a sunflower 11s seed protein gene in transgenic tobacco. | helianthinin is the major 11s seed storage protein of sunflower (helianthus annuus). like most seed proteins, helianthinin is encoded by a small gene family; two members of this gene family, hag3-a and hag3-d, have been isolated and characterized. tobacco was transformed with a 6 kb fragment of hag3-a containing the helianthinin coding region flanked by 3.8 kb upstream and 0.4 kb downstream sequence. expression of helianthinin was developmentally regulated in seeds of transgenic tobacco plants; ... | 1990 | 2233680 |
| electron transport through photosystem ii in leaves during light pulses: acceptor resistance increases with nonphotochemical excitation quenching. | light response curves of photosystem (ps) ii electron transport from oxygen evolving complex to plastoquinone (pq) were measured in sunflower (helianthus annuus l.), cotton (gossypium hirsutum l.) and tobacco (nicotiana tabacum l.) leaves by recording o(2) evolution and fluorescence in 5-200 ms light pulses of 500-13500 micromol absorbed quanta m(-2) s(-1). the leaves were pre-adapted at 60-2000 micromol quanta m(-2) s(-1) for 60 min to obtain different nonphotochemical excitation quenching, whi ... | 2000 | 11106767 |
| cavitation fatigue. embolism and refilling cycles can weaken the cavitation resistance of xylem. | although cavitation and refilling cycles could be common in plants, it is unknown whether these cycles weaken the cavitation resistance of xylem. stem or petiole segments were tested for cavitation resistance before and after a controlled cavitation-refilling cycle. cavitation was induced by centrifugation, air drying of shoots, or soil drought. except for droughted plants, material was not significantly water stressed prior to collection. cavitation resistance was determined from "vulnerability ... | 2001 | 11161035 |
| identification and characterisation of pex6 orthologues from plants. | the sunflower (helianthus annuus) orthologue of pex6, an aaa atpase essential for the biogenesis of peroxisomes in yeasts and mammals, was isolated. hapex6p is immunologically related to pichia pastoris pex6p. like other genes involved in peroxisome biogenesis and function hapex6 mrna and protein levels peak in early post-germinative growth and mrna levels also increase in senescent tissue. hapex6 identifies probable orthologues in arabidopsis and rice. | 2001 | 11389979 |
| stable transformation of sunflower (helianthus annuus l.) using a non-meristematic regeneration protocol and green fluorescent protein as a vital marker. | stable transformation of sunflower was achieved using a non-meristematic hypocotyl explant regeneration protocol of public inbred ha300b. uniformly transformed shoots were obtained after co-cultivation with agrobacterium tumefaciens carrying a gfp (green fluorescent protein) gene containing an intron that blocks expression of gfp in agrobacterium. easily detectable, bright green fluorescence of transformed tissues was used to establish an optimal regeneration and transformation procedure. by sou ... | 2001 | 11708653 |
| mineral status of female rats affects the absorption and organ distribution of dietary cadmium derived from edible sunflower kernels (helianthus annuus l.). | the intake of food cadmium (cd) in microg/day over time can increase the body burden of this element. some human populations that consume subsistence rice-based diets low in calcium (ca), iron (fe), and zinc (zn) are more susceptible to cd poisoning than populations that consume more nutritious diets. this study determined the effects of marginal deficiencies of these essential elements on the absorption and organ retention of cd from a natural food that contains cd, edible sunflower kernels (he ... | 2001 | 11237510 |
| chemistry and biology of phototropism-regulating substances in higher plants. | most people are familiar with the sight of a young seedling bending towards a window or the brightest source of light to which it is exposed. this directional growth response is known as phototropism, which is caused by a lateral growth-promoting auxin in the bending organ (cholodny-went theory, cited in high school textbook). recently, however, bruinsma et al., weiler et al., and hasegawa et al. independently found that the shaded half did not contain more auxin than the illuminated one. instea ... | 2001 | 11933243 |
| two gpx-like proteins from lycopersicon esculentum and helianthus annuus are antioxidant enzymes with phospholipid hydroperoxide glutathione peroxidase and thioredoxin peroxidase activities. | this study investigated the enzymatic function of two putative plant gpxs, gpxle1 from lycopersicon esculentum and gpxha2 from helianthus annuus, which show sequence identities with the mammalian phospholipid hydroperoxide glutathione peroxidase (phgpx). both purified recombinant proteins expressed in escherichia coli show phgpx activity by reducing alkyl, fatty acid and phospholipid hydroperoxides but not hydrogen peroxide in the presence of glutathione. interestingly, both recombinant gpxle1 a ... | 2002 | 11985625 |
| sensitization to sunflower pollen and lung functions in sunflower processing workers. | this study aimed to investigate whether exposure to sunflower pollen (helianthus annuus) increases both sensitization and respiratory symptoms, and whether or not it affects lung functions in sunflower processing workers. | 2002 | 11991286 |
| reversible heat-induced inactivation of chimeric beta-glucuronidase in transgenic plants. | we compared the expression patterns in transgenic tobacco (nicotiana tabacum) of two chimeric genes: a translational fusion to beta-glucuronidase (gus) and a transcriptional fusion, both with the same promoter and 5'-flanking sequences of ha hsp17.7 g4, a small heat shock protein (shsp) gene from sunflower (helianthus annuus). we found that immediately after heat shock, the induced expression from the two fusions in seedlings was similar, considering chimeric mrna or gus protein accumulation. su ... | 2002 | 12011363 |
| targeting and membrane-insertion of a sunflower oleosin in vitro and in saccharomyces cerevisiae: the central hydrophobic domain contains more than one signal sequence, and directs oleosin insertion into the endoplasmic reticulum membrane using a signal anchor sequence mechanism. | a range of n- and c-terminal deletions of an oleosin from helianthus annuus l. were used to study the endoplasmic reticulum (er) targeting and membrane insertion of this protein both in vitro and in vivo in yeast ( saccharomyces cerevisiae). neither the n- nor the c-terminal hydrophilic domains are important for targeting and/or membrane insertion, with all the information required for these processes located within the central hydrophobic region of the protein. however, in vitro membrane-insert ... | 2002 | 12029479 |
| selective activation of the developmentally regulated ha hsp17.6 g1 promoter by heat stress transcription factors. | using two well-characterized heat stress transcription factors (hsfs) from tomato (lycopersicon peruvianum; lphsfa1 and lphsfa2), we analyzed the transcriptional activation of the ha hsp17.6 g1 promoter in sunflower (helianthus annuus) embryos. in this system, we observed transient promoter activation only with lphsfa2. in contrast, both factors were able to activate mutant versions of the promoter with improved consensus hsf-binding sites. exclusive activation by lphsfa2 was also observed in ye ... | 2002 | 12114574 |
| candidate disease resistance genes in sunflower cloned using conserved nucleotide-binding site motifs: genetic mapping and linkage to the downy mildew resistance gene pl1. | disease resistance gene candidates (rgcs) belonging to the nucleotide-binding site (nbs) superfamily have been cloned from numerous crop plants using highly conserved dna sequence motifs. the aims of this research were to (i) isolate genomic dna clones for rgcs in cultivated sunflower (helianthus annuus l.) and (ii) map rgc markers and pl1, a gene for resistance to downy mildew (plasmopara halstedii (farl.) berl. & de toni) race 1. degenerate oligonucleotide primers targeted to conserved nbs dna ... | 2001 | 11341730 |
| influence of analogue-resistant mutants of azotobacter chroococcum solubilizing phosphate on yield and quality of sunflower (helianthus annuus). | two phosphate-solubilizing analogue-resistant mutants of azotobacter chroococcum showed a positive interactive effect on sunflower (helianthus annuus). plant height, leaf area, seed mass, seed yield, protein and oil content increased significantly by inoculation with a. chroococcum mutants. both levels of fertilizers applied (80n + 30p2o5 and 80n + 60p2o5 kg/hm2 showed increased seed yield. likewise, inoculation resulted in a significantly higher yield. application of p-solubilizing a. chroococc ... | 2000 | 11347259 |
| sunflower (helianthus annuus l.) pathogenesis-related proteins (induction by aspirin (acetylsalicylic acid) and characterization). | sunflower leaf discs floated on a solution containing aspirin (acetylsalicylic acid) produced a set of new proteins extractable at ph 5.2 and excreted into the intercellular space. more than 80% of the proteins found in the intercellular fluids of induced leaf discs have been identified as pathogenesis-related (pr) proteins by their immunological relationship with tobacco pr proteins. members of the four major classes of pr proteins have been characterized. sunflower pr proteins of type 1 (pr1) ... | 1993 | 12231738 |
| evaluation of vegetal extracts as biological herbi- and pesticides for their use in cuban agriculture. | the idea of an interuniversity project between the universidad central de las villas, cuba and the university of ghent, belgium was conceived in order to improve the quality of the cuban agriculture and to stimulate its independence from foreign chemical farm inputs, starting with an applied ethnobotanical investigation as basis for the development of sustainable agricultural practices. the project consists of three parts. the first, ethnobotanical part, subtends the two subsequent stages, i.e. ... | 2001 | 12425066 |
| molecular diversity of male sterility inducing and male-fertile cytoplasms in the genus helianthus. | the organisation of mtdna was investigated for 28 sources of cytoplasmic male sterility (cms) and a fertile line (normal cytoplasm) of helianthus annuus by southern hybridisation. in addition to nine known mitochondrial genes ( atp6, atp9, cob, coxi, coxii, coxiii, 18s, 5s and nd5) three probes for the open reading frames in the rearranged area of pet1, orfh522, orfh708 and orfh873, were used. genetic similarities of the investigat-ed cytoplasms varied between 0.3 and 1. cluster analyses using t ... | 2002 | 12582659 |
| cloning and expression of fatty acids biosynthesis key enzymes from sunflower (helianthus annuus l.) in escherichia coli. | to further characterize the stearoyl-acyl carrier protein (acp) desaturase (ec 1.14.99.6) and the acyl-acp thioesterase fatb (ec 3.1.2.14) activities from sunflower seeds, we cloned, sequenced and expressed the recombinant genes in escherichia coli. we obtained two partially purified proteins, his-sad and his-fatb, each of about 45000 da. the expression of either proteins produced changes in the e. coli fatty acid profile indicating the functionality of the recombinant proteins. while the expres ... | 2003 | 12651018 |
| characterization and modelling of the hydrophobic domain of a sunflower oleosin. | the oleosins are a group of hydrophobic proteins present on the surface of oil bodies in seeds, where they are thought to prevent coalescence. they contain a central hydrophobic domain of 68-74 residues that is thought to form a loop into the triacylglycerol matrix of the oil body, but the conformation adopted by this sequence is uncertain. we have therefore expressed an oleosin cdna from sunflower (helianthus annuus l.) in escherichia coli as a fusion with maltose-binding protein (mbp) and isol ... | 2002 | 11925038 |
| initial crop growth in soil collected from a closed animal waste lagoon. | in the 21st century, remediation of the soil beneath animal waste lagoons will become an important issue, as they are closed due to environmental regulations or to abandonment. the possibility of growing crops in the soil, which has high concentrations of ammonium-n, has not been studied. the objective of this experiment was to determine if crop species would germinate and grow in lagoon soil. soil was gathered from a lagoon that had received wastes from swine (sus scrofa) and beef (bos taurus) ... | 2003 | 12733569 |
| importance of the chiral centers of jasmonic acid in the responses of plants (activities and antagonism between natural and synthetic analogs). | the importance of the two chiral centers at c-3 and c-7 in the molecular structure of jasmonic acid in plant responses was investigated. we separated methyl jasmonate (meja) into (3r)- and (3s)-isomers with a fixed stereochemistry at c-3, but epimerization at c-7 is possible. the four isomers of the nonepimerizable analog 7-methyl meja were synthesized. these six esters and their corresponding acids were tested in three bioassays: (a) senescence in sunflower (helianthus annuus) cotyledons; (b) p ... | 1997 | 12223716 |
| [cloning and expression analysis of a lim-domain protein gene from cotton (gossypium hirsuturm l.)]. | lim-domain protein plays an important role in various cellular processes, including construction of cytoskeleton, transcription control and signal transduction. based on cotton fiber est database and contig analysis, the coding region of a cotton lim-domain protein gene (ghlim1) was obtained by rt-pcr from 4dpa (day post anthesis) ovule with fiber. the cloned fragment of 848 bp contains an open reading frame of 570 bp, coding for a polypeptide of 189 amino acids. it was demonstrated that the ded ... | 2003 | 12776607 |
| quantum yields and rate constants of photochemical and nonphotochemical excitation quenching (experiment and model). | sunflower (helianthus annuus l.), cotton (gossypium hirsutum l.), tobacco (nicotiana tabacum l.), sorghum (sorghum bicolor moench.), amaranth (amaranthus cruentus l.), and cytochrome b6f complex-deficient transgenic tobacco leaves were used to test the response of plants exposed to differnt light intensities and co2 concentrations before and after photoinhibition at 4000 [mu]mol photons m-2 s-1 and to thermoinhibition up to 45[deg]c. quantum yields of photochemical and nonphotochemical excitatio ... | 1997 | 12223845 |
| systemic acquired resistance in sunflower (helianthus annuus l.). | systemic acquired resistance (sar) to infection by botrytis cinerea in the leaves of sunflower (helianthus annuus l.) plants was induced following cotyledon inoculation with b. cinerea or treatment with abiotic inducers. salicylic acid (sa), benzo-(1,2,3)-thiadiazole-7-carbothioic s-methyl ester (bth), 2,6-dichloroisonicotinic acid (ina) or edta protected sunflower plants against botrytis infection, that was revealed by a reduction in the number and area of the necrotic lesions in upper leaves a ... | 2003 | 12945177 |
| healing of experimental wounds with helianthus annus. | | 1965 | 14344963 |
| changes in antioxidant and lignifying enzyme activities in sunflower roots (helianthus annuus l.) stressed with copper excess. | treatment with 50 microm cuso4 for five days caused significant decrease in dry-matter production and protein level of ten-day-old sunflower seedling roots. an increase of lipoperoxidation product rate was also observed. the involvement of some enzyme activities in the sunflower root defence against cu-induced oxidative stress was studied. copper treatment induced several changes in antioxidant enzymes. sod (superoxide dismutase, ec 1.15.1.1) activity was reduced but cat (catalase, ec 1.11.1.6) ... | 2003 | 14556383 |
| the origin of ecological divergence in helianthus paradoxus (asteraceae): selection on transgressive characters in a novel hybrid habitat. | diploid hybrid speciation in plants is often accompanied by rapid ecological divergence between incipient neospecies and their parental taxa. one plausible means by which novel adaptation in hybrid lineages may arise is transgressive segregation, that is, the generation of extreme phenotypes that exceed those of the parental lines. early generation (bc2) hybrids between two wild, annual sunflowers, helianthus annuus and helianthus petiolaris, were used to study directional selection on transgres ... | 2003 | 14575321 |
| molecular variability of sunflower downy mildew, plasmopara halstedii, from different continents. | downy mildew of sunflower (helianthus annuus l.), caused by the pathogen plasmopara halstedii, is a potentially devastating disease. seventy-seven isolates of p. halstedii collected in twelve countries from four continents were investigated for rapd polymorphism with 21 primers. the study led to a binary matrix, which was subjected to various complementary analyses. this is the first report on the international genetic diversity of the pathogen. similarity indices ranged from 89% to 100%. neithe ... | 2003 | 14608384 |
| sunpollenol and five other rearranged 3,4-seco-tirucallane-type triterpenoids from sunflower pollen and their inhibitory effects on epstein-barr virus activation. | six new rearranged 3,4-seco-tirucallane-type triterpenoids (1-6) have been isolated from the diethyl ether extract of the pollen grains of sunflower (helianthus annuus). these compounds were evaluated with respect to their inhibitory effects on the induction of epstein-barr virus early antigen (ebv-ea) induced by the tumor promoter 12-o-tetradecanoylphorbol 13-acetate (tpa) in raji cells. all of the compounds tested showed potent inhibitory effects on ebv-ea activation (97-100% inhibition at 1 x ... | 2003 | 14640522 |
| isolation, structural elucidation, and inhibitory effects of terpenoid and lipid constituents from sunflower pollen on epstein-barr virus early antigen induced by tumor promoter, tpa. | eight fatty acid esters of triterpene alcohols (1-8), four free triterpene alcohols (9, 12, 17, and 18), four diterpene acids (19-22), two tocopherol-related compounds (23 and 24), four estolides (25-28), three syn-alkane-4,6-diols (29-31), one 1,3-dioxoalkanoic acid (32), and one aliphatic ketone (33), along with the mixture of free fatty acids, were isolated from the diethyl ether extract of the pollen grains of sunflower (helianthus annuus). among these compounds, 14 (2-8, 12, 23, 25-28, and ... | 2003 | 12720376 |
| catalase activity and expression in developing sunflower seeds as related to drying. | changes in catalase (cat) activity and in cat isoform pattern and expression were investigated in developing sunflower (helianthus annuus l.) seeds during desiccation on the mother plant and after artificial drying on the flowerheads. seeds regularly desiccated during their development on the mother plant and reached mass maturity at c. 42 d after flowering (daf). freshly harvested seeds did not germinate at any stage of development because they were dormant, but their dormancy was broken after ... | 2004 | 14739269 |
| scanning electron microscopic studies and growth response of the plants of helianthus annuus l. grown on tannery sludge amended soil. | the plants of helianthus annuus l. var. modern were grown in the soil amended with different amounts of tannery sludge (10%, 25%, 35%, 50%, 75% and 100%), collected from wastewater treatment plant jajmau, kanpur (uttar pradesh, india) under field conditions. the effect of tannery sludge amendments was studied on the growth performance of the plant, i.e. root length, shoot length, leaf area and number of leaves after 30, 60 and 90 days of exposures. the root length of the plant increased up to 35 ... | 2004 | 14987871 |
| development of pcr markers for the pl5/pl8 locus for resistance to plasmopara halstedii in sunflower, helianthus annuus l. from complete cc-nbs-lrr sequences. | sunflower downy mildew, caused by plasmopara halstedii, is one of the major diseases of this crop. development of elite sunflower lines resistant to different races of this oomycete seems to be the most efficient method to limit downy mildew damage. at least two different gene clusters conferring resistance to different races of p. halstedii have been described. in this work we report the cloning and mapping of two full-length resistance gene analogs (rga) belonging to the cc-nbc-lrr class of pl ... | 2004 | 15007505 |
| comparative genetic analysis of quantitative traits in sunflower (helianthus annuus l.) 3. characterisation of qtl involved in resistance to sclerotinia sclerotiorum and phoma macdonaldi. | one hundred and fifty f(2)-f(3) families from a cross between two inbred sunflower lines fu and paz2 were used to map quantitative trait loci (qtl) for resistance to white rot (sclerotinia sclerotiorum) attacks of terminal buds and capitula, and black stem ( phoma macdonaldii). a genetic linkage map of 18 linkage groups with 216 molecular markers spanning 1,937 cm was constructed. disease resistances were measured in field experiments for s. sclerotiorum and under controlled conditions for p. ma ... | 2004 | 15141292 |
| simplified sunflower (helianthus annuus) seed agar for differentiation of candida dubliniensis from candida albicans. | this study evaluated sunflower (helianthus annuus) seed agar (ssa) for differentiation of candida dubliniensis from candida albicans on the basis of colony characteristics and chlamydospore production. simplified ssa without creatinine and kh(2)po(4) was also used. on both media, c. dubliniensis isolates (n = 25) developed rough colonies and formed abundant chlamydospores after incubation for 24-48 h at 28 degrees c, while c. albicans isolates (n = 53) showed smooth colonies with no evidence of ... | 2004 | 15191394 |
| identification of non-tir-nbs-lrr markers linked to the pl5/ pl8 locus for resistance to downy mildew in sunflower. | the resistance of sunflower, helianthus annuus l., to downy mildew, caused by plasmopara halstedii, is conferred by major genes denoted by pl. using degenerate and specific primers, 16 different resistance gene analogs (rgas) have been cloned and sequenced. sequence comparison and southern-blot analysis distinguished six classes of rga. two of these classes correspond to tir-nbs-lrr sequences while the remaining four classes correspond to the non-tir-nbs-lrr type of resistance genes. the genetic ... | 2003 | 12750787 |
| isolation and characterisation of a class of carbohydrate oxidases from higher plants, with a role in active defence. | in a search for novel plant-derived antimicrobial proteins, we screened extracts from salicylic acid (sa)-treated lettuce and sunflower leaves. these extracts displayed very potent antimicrobial activity against a set of phytopathogens. characterisation of these extracts revealed that in both extracts, proteins of approximately 60 kda were responsible for the antimicrobial activity. further characterisation of these proteins and cloning of the respective cdnas revealed close homology to a range ... | 2004 | 15225281 |
| improved agrobacterium-mediated transformation of sunflower (helianthus annuus l.): assessment of macerating enzymes and sonication. | agrobacterium -mediated transformation of shoot apices of sunflower (helianthus annuus l.) was evaluated following wounding by cell-wall-digesting enzymes and sonication. the frequency of explants with regenerated shoots expressing gus (beta-glucuronidase) or gfp (green fluorescent protein) increased following treatment with the macerating enzymes cellulase onozuka r-10 and pectinase boerozym m5, whereas treatment with macerozyme r-10 had a negative effect. when a combination of cellulase (0.1%) ... | 2003 | 12789451 |
| bioactive apocarotenoids annuionones f and g: structural revision of annuionones a, b and e. | the polar bioactive fractions of helianthus annuus cv. stella and sh-222 have yielded eight apocarotenoids, two of them isolated for the first time as natural products (annuionones f and g). the isolation of higher amounts of annuionones a and e allowed us to realize a more comprehensive spectroscopical study. we propose a revised structure for annuionone a, b and e based on careful re-analyses of new spectroscopical data. | 2004 | 15504441 |
| response of antioxidants in sunflower (helianthus annuus l.) grown on different amendments of tannery sludge: its metal accumulation potential. | the interaction of metals present in tannery waste and their tolerance in the plants of sunflower (helianthus annuus l.) was studied in the present paper under field conditions. effects of 100% tannery sludge and various amendments of tannery sludge (10%, 25%, 35%, 50%, 75%) along with one set of control were studied on the physiological and biochemical parameters of the plant along with their metal accumulation potential after 30, 60 and 90d after sowing. the plants of h. annuus were found effe ... | 2004 | 15519412 |
| phytoaccumulation of lead by sunflower (helianthus annuus), tobacco (nicotiana tabacum), and vetiver (vetiveria zizanioides). | the ability of three plant species: helianthus annuus, nicotiana tabacum, and vetiveria zizanioides for phytoaccumulation of pb was studied. plants were grown in hydroponic solution containing pb(no3)2 at concentration of 0.25 and 2.5 mm pb in the presence or absence of chelating agents (edta or dtpa). lead (pb) transport and localization within the tissues of the plant species was determined using scanning electron microscope equipped with energy dispersive x-ray spectrometers (sem-eds). the ad ... | 2005 | 15663304 |
| liquid growth conditions for abundant chlamydospore formation in candida dubliniensis. | staib liquid medium (syn. guizotia abyssinica creatinine medium) was evaluated for the induction of chlamydospores in the yeast species candida dubliniensis. during growth in this liquid medium c. dubliniensis produced abundant chlamydospores at the tips of pseudohyphal elements, whereas c. albicans produced only round to oval blastospores. chlamydospore formation could be induced with the same efficiency by use of a liquid growth medium in which helianthus annuus (sunflower) seeds, another plan ... | 2005 | 15679667 |
| cloning, characterization and structural model of a fata-type thioesterase from sunflower seeds (helianthus annuus l.). | the substrate specificity of acyl-acyl carrier protein (acp) thioesterases (ec 3.1.2.14) determines the fatty acids available for the biosynthesis of storage and membrane lipids in seeds. in order to determine the mechanisms involved in the biosynthesis of fatty acids in sunflower seeds (helianthus annuus l.), we isolated, cloned and sequenced a cdna clone of acyl-acp thioesterase from developing sunflower seeds, hafata1. through the heterologous expression of hafata1 in escherichia coli we have ... | 2005 | 15841386 |
| hairy roots of helianthus annuus: a model system to study phytoremediation of tetracycline and oxytetracycline. | the release of antibiotics to the environment has to be controlled because of serious threats to human health. hairy root cultures of helianthus annuus (sunflower), along with their inherent rhizospheric activity, provide a fast growing, microbe-free environment for understanding plant-pollutant interactions. the root system catalyzes rapid disappearance of tetracycline (tc) and oxytetracycline (otc) from aqueous media, which suggests roots have potential for phytoremediation of the two antibiot ... | 2005 | 15932255 |
| control of cytochrome b6f at low and high light intensity and cyclic electron transport in leaves. | the light-dependent control of photosynthetic electron transport from plastoquinol (pqh(2)) through the cytochrome b(6)f complex (cyt b(6)f) to plastocyanin (pc) and p700 (the donor pigment of photosystem i, psi) was investigated in laboratory-grown helianthus annuus l., nicotiana tabaccum l., and naturally-grown solidago virgaurea l., betula pendula roth, and tilia cordata p. mill. leaves. steady-state illumination was interrupted (light-dark transient) or a high-intensity 10 ms light pulse was ... | 2005 | 15949986 |
| growth in liverworts of the marchantiales is promoted by epiphytic methylobacteria. | liverworts, the most basal lineage of extant land plants, have been used as model systems in the reconstruction of adaptations to life on land. in this study, we used gemmae (specialized propagules) that were isolated from mature gemma cups of two distantly related species of liverworts, marchantia polymorpha l. and lunularia cruciata l. (order marchantiales). we show that methylobacteria (genus methylobacterium), microbes that inhabit the surfaces of land plants where they secrete phytohormones ... | 2005 | 15965759 |
| plarg from helianthus argophyllus is unlinked to other known downy mildew resistance genes in sunflower. | the plarg locus in the sunflower (helianthus annuus l.) inbred line arg1575-2 conferring resistance to at least four tested races (300, 700, 730, 770) of downy mildew (plasmopara halstedii) was localized by the use of simple sequence repeat (ssr) markers. bulked segregant analysis (bsa) was conducted on 126 individuals of an f2 progeny from a cross between a downy mildew susceptible line, cmsha342, and arg1575-2. twelve ssr markers linked to the plarg locus were identified. all markers were loca ... | 2004 | 15221147 |
| bacterial cr(vi) reduction concurrently improves sunflower (helianthus annuus l.) growth. | four cr(vi)-reducing bacterial strains (ochrobactrum intermedium, crt-2, crt-3 and crt-4) previously isolated from chromium-contaminated sites were inoculated on to seeds of sunflower (helianthus annuus var sf-187), which were germinated and grown along with non-inoculated controls with chromate salts (300 microg crcl3 or k2cro4 ml(-1)). severe reduction (20%) in seed germination was observed in cr(vi) stress. plant height decreased (36%) with cr(vi) when compared with chromium-free control, whi ... | 2005 | 16091890 |
| origin of extant domesticated sunflowers in eastern north america. | eastern north america is one of at least six regions of the world where agriculture is thought to have arisen wholly independently. the primary evidence for this hypothesis derives from morphological changes in the archaeobotanical record of three important crops--squash, goosefoot and sunflower--as well as an extinct minor cultigen, sumpweed. however, the geographical origins of two of the three primary domesticates--squash and goosefoot--are now debated, and until recently sunflower (helianthu ... | 2004 | 15241413 |
| in vitro investigation of the toxic effects of extracts of allium sativum bulbs on adults of hyalomma marginatum rufipes and rhipicephalus pulchellus. | the toxic effects of the extracts of allium sativum (garlic) were evaluated against adults of hyalomma marginatum rufipes and rhipicephalus pulchellus using three types (types a, b and c) of contact toxicity bioassays. a. sativum bulbs were extracted with acetone, ethanol and dichloromethane (dcm) solvents. among these three solvents, it is the dcm extract of a. sativum that appears to have anti-tick activity. in the type a contact toxicity bioassay, dcm extracts of a. sativum demonstrated a hig ... | 2005 | 16108529 |
| 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 |