| hahb10, a sunflower hd-zip ii transcription factor, participates in the induction of flowering and in the control of phytohormone-mediated responses to biotic stress. | the transcription factor hahb10 belongs to the sunflower (helianthus annuus) hd-zip ii subfamily and it has been previously associated with the induction of flowering. in this study it is shown that hahb10 is expressed in sunflower leaves throughout the vegetative stage and in stamens during the reproductive stage. in short-day inductive conditions the expression of this gene is induced in shoot apexes together with the expression of the flowering genes haft and haap1. transgenic arabidopsis pla ... | 2010 | 21030388 |
| phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (helianthus annuus l.) achenes. | the phytotoxic effects of varying levels of nickel (0, 10, 20, 30, and 40 mg l(-1)) on growth, yield and accumulation of macro- and micro-nutrients in leaves and achenes of sunflower (helianthus annuus l.) were appraised in this study. a marked reduction in root and shoot fresh biomass was recorded at higher ni levels. nickel stress also caused a substantial decrease in all macro- and micro-nutrients in leaves and achenes. the lower level of ni (10 mg l(-1)) had a non-significant effect on vario ... | 2010 | 21074317 |
| perilla frutescens seed agar, a new medium for identification of the cryptococcus species complex: evaluation for all major molecular types. | here we present a new and simple medium made by perilla frutescens seed as a tool for identification of the cryptococcus species complex, namely cryptococcus neoformans and cryptococcus gattii. its usefulness was evaluated for all major molecular types within the cryptococcus species complex. as a result, this medium is better for identification of the species complex compared with guizotia abyssinica or helianthus annuus seed medium. | 2010 | 21182875 |
| the 20s proteasome α5 subunit of arabidopsis thaliana carries an rnase activity and interacts in planta with the lettuce mosaic potyvirus hcpro protein. | in plants, the ubiquitin/26s proteasome system (ups) plays a central role in protein degradation and is involved in many steps of defence mechanisms, regardless of the types of pathogen targeted. in addition to its proteolytic activities, the ups ribonuclease (rnase) activity, previously detected in 20s proteasome preparations from cauliflower and sunflower (helianthus annuus), has been shown to specifically target plant viral rnas in vitro. in this study, we show that recombinant arabidopsis th ... | 2010 | 21199564 |
| toxic effect of nickel (ni) on growth and metabolism in germinating seeds of sunflower (helianthus annuus l.). | to assess the toxic effect of nickel (ni) on the growth and some key metabolic processes in sunflower, varying levels of ni as ni(no(3))(2) up to 60 mg l(-1) were applied once to sunflower cultivars sf-187 and hysun-33 at sowing time in sand culture. an increase in ni in the growth medium adversely affected growth parameters, sugar concentration (both reducing and non-reducing), as well as the activities of α-amylase and protease. it also slowed down mobilization of stored proteins and amino aci ... | 2011 | 21240566 |
| sphingolipid base modifying enzymes in sunflower (helianthus annuus): cloning and characterization of a c4-hydroxylase gene and a new paralogous ?8-desaturase gene. | sphingolipids are components of plant cell membranes that participate in the regulation of important physiological processes. unlike their animal counterparts, plant sphingolipids are characterized by high levels of base c4-hydroxylation. moreover, desaturation at the ?8 position predominates over the ?4 desaturation typically found in animal sphingolipids. these modifications are due to the action of c4-hydroxylases and ?8-long chain base desaturases, and they are important for complex sphingol ... | 2011 | 21256623 |
| the extreme dwarf phenotype of the ga-sensitive mutant of sunflower, dwarf2, is generated by a deletion in the ent-kaurenoic acid oxidase1 (hakao1) gene sequence. | a dwarf mutant, dw arf 2 (dw2), was isolated from sunflower (helianthus annuus). the most obvious alterations of dw2 plants were the lack of stem growth, reduced size of leaves, petioles and flower organs, retarded flower development. pollen and ovules were produced but the filaments failed to extrude the anthers from the corolla. the dw2 phenotype was mainly because of reduced cell size. in dw2 leaves, the dark-green color was not so much due to higher pigment content, but was correlated with a ... | 2011 | 21279813 |
| downy mildew (pl ( 8 ) and pl ( 14 )) and rust (r ( adv )) resistance genes reside in close proximity to tandemly duplicated clusters of non-tir-like nbs-lrr-encoding genes on sunflower chromosomes 1 and 13. | nucleotide binding site-leucine rich repeat (nbs-lrr) proteins are encoded by a ubiquitous gene family in sunflower and frequently harbor disease resistance genes. we investigated nbs-lrr-encoding resistance gene candidates (rgcs) flanking the downy mildew resistance genes pl ( 8 ) and pl ( 14 ) and the rust resistance gene r ( adv ), which map on the nbs-lrr clusters of linkage groups 1 and 13 in sunflower genome. we shotgun sequenced bacterial artificial chromosome (bac) clones proximal to pl ... | 2011 | 21293840 |
| effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth. | naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. this study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant pseudomonas strains previously isolated from torch lake sediment. these strains showed variable susceptibility to different antibiotics. furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. b ... | 2011 | 21420236 |
| cloning and characterization of a cdna encoding type 1 diacylglycerol acyltransferase from sunflower (helianthus annuus l.). | a full-length cdna encoding a putative diacylglycerol acyltransferase (dgat; ec 2.3.1.20) was obtained from sunflower (helianthus annuus l.) seeds. the 1524-bp open reading frame of this cdna, designated as hadgat1, encodes a protein of 507 amino acids with a molecular mass of 58.5 kda showing high homology to dgat1 enzymes of other plants. the protein characters, such as a predicted structure with a long n-terminal hydrophilic domain followed by 9 transmembrane domains, acyl-coa-binding signatu ... | 2011 | 21476438 |
| inoculation of ni-resistant plant growth promoting bacterium psychrobacter sp. strain srs8 for the improvement of nickel phytoextraction by energy crops. | this study was conducted to elucidate effects of inoculating plant growth-promoting bacterium psychrobacter sp. srs8 on the growth and phytoextraction potential of energy crops ricinus communis and helianthus annuus in artificially ni contaminated soils. the toxicity symptom in plants under ni stress expressed as chlorophyll, protein content, growth inhibition, and fe, p concentrations were studied, and the possible relationship among them were also discussed. the pgpb srs8 was found capable of ... | 2011 | 21598781 |
| a comparative analysis of the lactuca and helianthus (asteraceae) plastid genomes: identification of divergent regions and categorization of shared repeats. | we have sequenced two complete chloroplast genomes in the asteraceae, helianthus annuus (sunflower), and lactuca sativa (lettuce), which belong to the distantly related subfamilies, asteroideae and cichorioideae, respectively. the helianthus chloroplast genome is 151 104 bp and the lactuca genome is 152 772 bp long, which is within the usual size range for chloroplast genomes in flowering plants. when compared to tobacco, both genomes have two inversions: a large 22.8-kb inversion and a smaller ... | 2007 | 21636403 |
| he-ne laser-induced improvement in biochemical, physiological, growth and yield characteristics in sunflower (helianthus annuus l.). | the water-soaked seeds of sunflower were exposed to low power continuous wave he-ne laser irradiation of energies 0, 100, 300 and 500 mj to evaluate the effect on various biochemical, physiological, growth and yield parameters of sunflower. the experiments which consisted of four replicates arranged in a completely randomized design (crd) were carried out under the greenhouse conditions. the physiological attributes like, photosynthetic rate (a), transpiration rate (e), intrinsic co(2) concentra ... | 2011 | 21790619 |
| suntill: a tilling resource for gene function analysis in sunflower. | abstract: | 2011 | 21718494 |
| dermocosmetics for dry skin: a new role for botanical extracts. | dry skin is associated with a disturbed skin barrier and reduced formation of epidermal proteins and lipids. during recent years, skin-barrier-reinforcing properties of some botanical compounds have been described. searching the pubmed database revealed 9 botanical extracts that specifically improve skin barrier and/or promote keratinocyte differentiation in vivo after topical application. the topical application of aloe vera (leaf gel), betula alba (birch bark extract), helianthus annuus (sunfl ... | 2011 | 21709432 |
| estimation of mating system parameters in an evolving gynodioecous population of cultivated sunflower (helianthus annuus l.). | cultivated plants have been molded by human-induced selection, including manipulations of the mating system in the twentieth century. how these manipulations have affected realized parameters of the mating system in freely evolving cultivated populations is of interest for optimizing the management of breeding populations, predicting the fate of escaped populations and providing material for experimental evolution studies. to produce modern varieties of sunflower (helianthus annuus l.), self-inc ... | 2011 | 21915147 |
| naturally occurring phytotoxins in allelopathic plants help reduce herbicide dose in wheat. | field studies were carried out to evaluate the influence of allelopathic plant water extracts applied alone or tank-mixed with a reduced herbicide dose on the weeds of wheat. water extracts of sorghum (sorghum bicolor (l.) moench.) + sunflower (helianthus annuus l.) + mulberry (morus alba l.) were used alone (each at 20 l ha(-1)) or combined with iodo + mesosulfuron (3.6 and 7.2 g active ingredient (a.i.) ha(-1); 25 and 50% of the recommended dose, respectively). the recommended dose of herbicid ... | 2011 | 21854181 |
| Organ-specific rates of cellular respiration in developing sunflower seedlings and their bearing on metabolic scaling theory. | Fifty years ago Max Kleiber described what has become known as the "mouse-to-elephant" curve, i.e., a log-log plot of basal metabolic rate versus body mass. From these data, "Kleiber's 3/4 law" was deduced, which states that metabolic activity scales as the three fourths-power of body mass. However, for reasons unknown so far, no such "universal scaling law" has been discovered for land plants (embryophytes). Here, we report that the metabolic rates of four different organs (cotyledons, cotyledo ... | 2011 | 22016107 |
| cycloquest: identification of cyclopeptides via database search of their mass spectra against genome databases. | hundreds of ribosomally synthesized cyclopeptides have been isolated from all domains of life, the vast majority having been reported in the last 15 years. studies of cyclic peptides have highlighted their exceptional potential both as stable drug scaffolds and as biomedicines in their own right. despite this, computational techniques for cyclopeptide identification are still in their infancy, with many such peptides remaining uncharacterized. tandem mass spectrometry has occupied a niche role i ... | 2011 | 21851130 |
| evolution and diversification of the cyc/tb1 gene family in asteraceae - a comparative study in gerbera (mutisieae) and sunflower (heliantheae). | plant-specific tcp domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the asteraceae inflorescence that involves different types of flowers. we conducted comparative analysis of the cycloidea/teosinte branched1 (cyc/tb1) gene family in gerbera hybrida (gerbera) and helianthus annuus (sunflower), two species that represent distant tribes within asteraceae. our data confirms that the cyc/tb1 gene family has ... | 2011 | 22101417 |
| Identification and validation of Asteraceae miRNAs by the expressed sequence tag analysis. | MicroRNAs (miRNAs) are small non-coding RNA molecules that play a vital role in the regulation of gene expression. Despite their identification in hundreds of plant species, few miRNAs have been identified in the Asteraceae, a large family that comprises approximately one tenth of all flowering plants. In this study, we used the expressed sequence tag (EST) analysis to identify potential conserved miRNAs and their putative target genes in the Asteraceae. We applied quantitative Real-Time PCR (qR ... | 2011 | 22146318 |
| Transcriptomic analysis of the interaction between Helianthus annuus and its obligate parasite Plasmopara halstedii shows single nucleotide polymorphisms in CRN sequences. | Downy mildew in sunflowers (Helianthus annuus L.) is caused by the oomycete Plasmopara halstedii (Farl.) Berlese et de Toni. Despite efforts by the international community to breed mildew-resistant varieties, downy mildew remains a major threat to the sunflower crop. Very few genomic, genetic and molecular resources are currently available to study this pathogen. Using a 454 sequencing method, expressed sequence tags (EST) during the interaction between H. annuus and P. halstedii have been gener ... | 2011 | 21988821 |
| rapid light-induced changes in phosphoinositide kinases and h(+)-atpase in plasma membrane of sunflower hypocotyls. | irradiation of sunflower (helianthus annuus l. cv. russian mammoth) hypocotyls with white light resulted in a 51% decrease in plasma membrane phosphatidylinositol monophosphate (pip) kinase activity. as little as 10 s of white light irradiation was sufficient to lower the phosphatidylinositol bisphosphate (pip2) produced in the in vitro phosphorylation assay. this decrease was not caused by an increase in phospholipase c activity since analysis of the water-soluble products indicated no increase ... | 2007 | 2168392 |
| targeted mrna oxidation regulates sunflower seed dormancy alleviation during dry after-ripening. | after-ripening is the mechanism by which dormant seeds become nondormant during their dry storage after harvest. the absence of free water in mature seeds does not allow detectable metabolism; thus, the processes associated with dormancy release under these conditions are largely unknown. we show here that sunflower (helianthus annuus) seed alleviation of dormancy during after-ripening is associated with mrna oxidation and that this oxidation is prevented when seeds are maintained dormant. in vi ... | 2011 | 21642546 |
| low agrobacterium tumefaciens inoculum levels and a long co-culture period lead to reduced plant defense responses and increase transgenic shoot production of sunflower (helianthus annuus l.). | agrobacterium-mediated plant transformation is typically conducted by inoculating plant tissues with an agrobacterium suspension containing approximately 10(8)-10(9) bacteria ml(-1), followed by a 2-3-d co-culture period. use of longer co-culture periods could potentially increase transformation efficiencies by allowing more time for agrobacterium to interact with plant cells, but bacterial overgrowth is likely to occur, leading to severe tissue browning and reduced transformation and regenerati ... | 2016 | 27746666 |
| peroxisomal plant 3-ketoacyl-coa thiolase structure and activity are regulated by a sensitive redox switch. | the breakdown of fatty acids, performed by the beta-oxidation cycle, is crucial for plant germination and sustainability. beta-oxidation involves four enzymatic reactions. the final step, in which a two-carbon unit is cleaved from the fatty acid, is performed by a 3-ketoacyl-coa thiolase (kat). the shortened fatty acid may then pass through the cycle again (until reaching acetoacetyl-coa) or be directed to a different cellular function. crystal structures of kat from arabidopsis thaliana and hel ... | 2010 | 20463027 |
| fluorescence imaging in the red and far-red region during growth of sunflower plantlets. diagnosis of the early infection by the parasite orobanche cumana. | broomrape, caused by the root holoparasite orobanche cumana, is the main biotic constraint to sunflower oil production worldwide. by the time broomrape emerges, most of the metabolic imbalance has been produced by o. cumana to sunflower plants. uv-induced multicolor fluorescence imaging (mcfi) provides information on the fluorescence emitted by chlorophyll (chl) a of plants in the spectral bands with peaks near 680 nm (red, f680) and 740 nm (far-red, f740). in this work mcfi was extensively appl ... | 2016 | 27446116 |
| effector polymorphisms of the sunflower downy mildew pathogen plasmopara halstedii and their use to identify pathotypes from field isolates. | the obligate biotroph oomycete plasmopara halstedii causes downy mildew on sunflower crop, helianthus annuus. the breakdown of several pl resistance genes used in sunflower hybrids over the last 25 years came along with the appearance of new pl. halstedii isolates showing modified virulence profiles. in oomycetes, two classes of effector proteins, key players of pathogen virulence, are translocated into the host: rxlr and crn effectors. we identified 54 putative crn or rxlr effector genes from t ... | 2016 | 26845339 |
| biological seed priming mitigates the effects of water stress in sunflower seedlings. | the sunflower (helianthus annuus l. cv. pac 36) seedlings were inoculated with plant growth promoting rhizobacteria (pgpr), viz. azotobacter chroococcum (a+), bacillus polymyxa (b+), separately and in combination of the two (ab+). relative water content and seedling growth were maximum in ab+ seedlings under control. water stress significantly decreased the rwc, growth and dry mass of non-inoculated seedlings. however, inoculated seedlings maintained higher growth even under water stress. pigmen ... | 2015 | 25964714 |
| overexpression of a gene encoding hydrogen peroxide-generating oxalate oxidase evokes defense responses in sunflower. | oxalate oxidase (oxo) converts oxalic acid (oa) and o(2) to co(2) and hydrogen peroxide (h(2)o(2)), and acts as a source of h(2)o(2) in certain plant-pathogen interactions. to determine if the h(2)o(2) produced by oxo can function as a messenger for activation of defense genes and if oxo can confer resistance against an oa-producing pathogen, we analyzed transgenic sunflower (helianthus annuus cv smf3) plants constitutively expressing a wheat (triticum aestivum) oxo gene. the transgenic leaf tis ... | 2003 | 12970484 |
| comparative genomic and population genetic analyses indicate highly porous genomes and high levels of gene flow between divergent helianthus species. | while speciation can be found in the presence of gene flow, it is not clear what impact this gene flow has on genome- and range-wide patterns of differentiation. here we examine gene flow across the entire range of the common sunflower, h. annuus, its historically allopatric sister species h. argophyllus and a more distantly related, sympatric relative h. petiolaris. analysis of genotypes at 26 microsatellite loci in 1015 individuals from across the range of the three species showed substantial ... | 2009 | 19473382 |
| molecular demographic history of the annual sunflowers helianthus annuus and h. petiolaris--large effective population sizes and rates of long-term gene flow. | hybridization between distinct species may lead to introgression of genes across species boundaries, and this pattern can potentially persist for extended periods as long as selection at some loci or genomic regions prevents thorough mixing of gene pools. however, very few reliable estimates of long-term levels of effective migration are available between hybridizing species throughout their history. accurate estimates of divergence dates and levels of gene flow require data from multiple unlink ... | 2008 | 18462213 |
| cloning and characterization of sidhn, a novel dehydrin gene from saussurea involucrata kar. et kir. that enhances cold and drought tolerance in tobacco. | saussurea involucrata kar. et kir. is a hardy, dicotyledonous plant featured by strong tolerance to severe stress conditions. in a previous study, we created a cdna library to characterize genetic factors associated with the cold acclimation response of s. involucrata. the full-length cdna of one dehydrin-like gene, sidhn, was obtained by rt-pcr and the sidhn gene was further characterized in this study. the full-length sidhn cdna consists of 703 base pairs (bp) with a 333bp open reading frame e ... | 2017 | 28167030 |
| sunflower (helianthus annuus l.). | sunflower (helianthus annuus l.) is still considered as a recalcitrant species to in vitro culture and transformation in spite of the publication of different protocols. here we describe a routine transformation system of this crop which requires mature ha89 genotype seeds and agrobacterium tumefaciens eha105 strain for gene delivery, being both easily available. selection of transformed shoots depends on root development in kanamycin-selective media, instead of shoot color, avoiding selection o ... | 2015 | 25416248 |
| agrobacterium tumefaciens mediated transient expression of plant cell wall-degrading enzymes in detached sunflower leaves. | for biofuel applications, synthetic endoglucanase e1 and xylanase (xyn10a) derived from acidothermus cellulolyticus were transiently expressed in detached whole sunflower (helianthus annuus l.) leaves using vacuum infiltration. three different expression systems were tested, including the constitutive camv 35s-driven, cmvar (cucumber mosaic virus advanced replicating), and trbo (tobacco mosaic virus rna-based overexpression vector) systems. for 6-day leaf incubations, codon-optimized e1 and xyla ... | 2014 | 25180328 |
| transformation of sunflower (helianthus annuus l.) following wounding with glass beads. | a procedure was developed for transformation of helianthus annuus (sunflower) using agrobacterium tumefaciens. cotyledons were removed from young seedlings, and the remaining tissue was uniformly wounded by shaking with glass beads. the wounded tissue was then co-cultivated with a hypervirulent strain of agrobacterium tumefaciens harboring the binary plasmid pcnl56. minimal use of defined medium was required, and no callus was observed. the polymerase chain reaction (pcr) followed by dna hybridi ... | 1995 | 24186761 |
| transformation of sunflower (helianthus annuus l.): a reliable protocol. | a reliable protocol for the transformation of cultivated sunflower (helianthus annuus l.) has been established, based on microprojectile bombardment of half shoot apices in combination with agrobacterium tumefaciens coculture. transgenic shoots have been obtained from 5 inbred lines, although transformation efficiencies varied with the genotype. plants expressing the transgenes could be recovered from up to 7% of the explants. a minority of plants was shown to be chimaeric for expression of ß-gl ... | 1994 | 24192870 |
| meristem transformation of sunflower via agrobacterium. | for transformation of sunflower (helianthus annuus l. cv. zebulon), shoot apical meristems were dissected from seeds and cocultivated with a disarmed agrobacterium tumefaciens strain harboring a binary vector carrying genes encoding gus- and nptii-activity. the influence of the media conditions, the time of cocultivation and the stage of the developing seed on shoot development and meristem transformation was analysed. transformants were selected by their ability to grow on kanamycin. transforma ... | 1990 | 24226429 |
| [submerse bacterial plant tumor on roots]. | spontaneous infections seem to indicate that not only the crown of herbeous plants is disposed to generate tumors. under substrate conditions such as those normally found at the crown, infections caused by agrobacterium tumefaciens will yield tumors in the entire area of the roots.roots of helianthus annuus and solanum lycopersicum grown in nutritive medium are disposed to tumor when given appropriate conditions of culture and inoculation. tissue culture, the most widely applied method for the a ... | 1968 | 24522818 |
| biologically active antimicrobial and antioxidant substances in the helianthus annuus l. bee pollen. | the objective of this study was to measure the content of flavonoids, polyphenols, and carotenoids in the helianthus annuus l. bee pollen. it was also to evaluate the ability of the dried, frozen, and freeze-dried extracts of sunflower (h. annuus) pollen, its scavenged free radicals and reducing action. another aim of this study was to investigate the antimicrobial in vitro action of the h. annuus pollen extracts against the gram-positive and gram-negative bacteria and fungi. all pollen extracts ... | 2016 | 26674447 |
| production of an endoinulinase from aspergillus niger aumc 9375, by solid state fermentation of agricultural wastes, with purification and characterization of the free and immobilized enzyme. | two different substrates, sunflower (helianthus annuus l.) tubers and lettuce (lactuca sativa) roots, were tested. using a mixture of both wastes resulted in higher production of endoinulinase than either waste alone. also, ten fungal species grown on these substrates as inexpensive, carbon sources were screened for the best production of endoinulinase activities. of these, aspergillus niger aumc 9375 was the most productive, when grown on the mixture using a 6:1 w/w ratio of sun flower: lettuce ... | 2014 | 24810318 |
| structure and absolute configuration of kongiidiazadione, a new phytotoxic 3-substituted-5-diazenylcyclopentendione produced by diaporthe kongii. | a new 3-substituted-5-diazenylcyclopentendione named kongiidiazadione was isolated from culture filtrates of diaporthe kongii, associated with stem cankers on sunflower in australia. kongiidiazadione was characterized by spectroscopic (essentially nuclear magnetic resonance [nmr] and high-resolution, electrospray ionization, mass spectrometry [hresims]) methods as (-)-5-diazenyl-3-hydroxymethyl-cyclopent-3-en-1,2-dione. the stereochemistry of the diazenyl group was determined by ir spectroscopy, ... | 2015 | 26011252 |
| heterologous expression of chloroplast-localized geranylgeranyl pyrophosphate synthase confers fast plant growth, early flowering and increased seed yield. | geranylgeranyl pyrophosphate synthase (ggps) is a key enzyme for a structurally diverse class of isoprenoid biosynthetic metabolites including gibberellins, carotenoids, chlorophylls and rubber. we expressed a chloroplast-targeted ggps isolated from sunflower (helianthus annuus) under control of the cauliflower mosaic virus 35s promoter in tobacco (nicotiana tabacum). the resulting transgenic tobacco plants expressing heterologous ggps showed remarkably enhanced growth (an increase in shoot and ... | 2016 | 25644367 |
| hahb-10, a sunflower homeobox-leucine zipper gene, is regulated by light quality and quantity, and promotes early flowering when expressed in arabidopsis. | homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. expression patterns of the sunflower homeobox-leucine zipper gene hahb-10 (helianthus annuus homeobox-10), that belongs to the hd-zip ii subfamily, were analysed. northern blots showed that hahb-10 is expressed primarily in mature leaves, although expression is clearly detectable in younger leaves and also in stems. considerably higher expression levels were detected in etiolated seedlings comp ... | 2005 | 16215272 |
| hahb-4, a sunflower homeobox-leucine zipper gene, is a developmental regulator and confers drought tolerance to arabidopsis thaliana plants. | homeodomain-leucine zipper proteins constitute a family of transcription factors found only in plants. hahb-4 is a member of helianthus annuus (sunflower) subfamily i. it is regulated at the transcriptional level by water availability and abscisic acid. in order to establish if this gene plays a functional role in drought responses, transgenic arabidopsis thaliana plants that overexpress hahb-4 under the control of the 35s cauliflower mosaic virus promoter were obtained. transformed plants show ... | 2005 | 16201409 |
| seed germination-influencing bioactive secondary metabolites secreted by the endophyte cladosporium cladosporioides lwl5. | the present study was aimed to isolate bioactive metabolites produced by a fungal endophyte from helianthus annuus, capsicum annuum, and cucumis sativus and to assess their role in seed germination. culture filtrate of the endophyte ha-3b from h. annuus was significantly inhibitory towards the germination and growth of lettuce seeds. ha-3b was identified as cladosporium cladosporioides lwl5 through molecular techniques. different concentrations (100, 500 and 1000 ppm) of the ethyl acetate extrac ... | 2013 | 24352011 |
| [evaluation of a new medium, eggplant (solanum melongena) agar as a screening medium for cryptococcus neoformans in environmental samples]. | cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. c.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. avian guano, decaying tree hollows and soil are the related known environmental niches. brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of c.neoformans. seeds of plants in ... | 2014 | 24819266 |
| isolation and characterization of a glyphosate-degrading rhizosphere strain, enterobacter cloacae k7. | plant-growth-promoting rhizobacteria exert beneficial effects on plants through their capacity for nitrogen fixation, phytohormone production, phosphate solubilization, and improvement of the water and mineral status of plants. we suggested that these bacteria may also have the potential to express degradative activity toward glyphosate, a commonly used organophosphorus herbicide. in this study, 10 strains resistant to a 10 mm concentration of glyphosate were isolated from the rhizoplane of vari ... | 2014 | 23545355 |
| anti-neuroblastoma properties of a recombinant sunflower lectin. | according to their sugar recognition specificity, plant lectins are proposed as bioactive proteins with potential in cancer treatment and diagnosis. helja is a mannose-specific jacalin-like lectin from sunflower which was shown to inhibit the growth of certain fungi. here, we report its recombinant expression in a prokaryotic system and its activity in neurobalstoma cells. helja coding sequence was fused to the pet-32 ek/lic, the enterokinase/ligation-independent cloning vector and a 35 kda prot ... | 2017 | 28075401 |
| sunflower (helianthus annuus) fatty acid synthase complex: β-hydroxyacyl-[acyl carrier protein] dehydratase genes. | two sunflower hydroxyacyl-[acyl carrier protein] dehydratases evolved into two different isoenzymes showing distinctive expression levels and kinetics' efficiencies. β-hydroxyacyl-[acyl carrier protein (acp)]-dehydratase (had) is a component of the type ii fatty acid synthase complex involved in 'de novo' fatty acid biosynthesis in plants. this complex, formed by four intraplastidial proteins, is responsible for the sequential condensation of two-carbon units, leading to 16- and 18-c acyl-acp. h ... | 2016 | 26433735 |
| peptide macrocyclization by a bifunctional endoprotease. | proteases usually cleave peptides, but under some conditions, they can ligate them. seeds of the common sunflower contain the 14-residue, backbone-macrocyclic peptide sunflower trypsin inhibitor 1 (sfti-1) whose maturation from its precursor has a genetic requirement for asparaginyl endopeptidase (aep). to provide more direct evidence, we developed an in situ assay and used (18)o-water to demonstrate that sfti-1 is excised and simultaneously macrocyclized from its linear precursor. the reaction ... | 2015 | 25960260 |
| cloning, heterologous expression and biochemical characterization of plastidial sn-glycerol-3-phosphate acyltransferase from helianthus annuus. | the acyl-[acyl carrier protein]:sn-1-glycerol-3-phosphate acyltransferase (gpat; e.c. 2.3.1.15) catalyzes the first step of glycerolipid assembly within the stroma of the chloroplast. in the present study, the sunflower (helianthus annuus, l.) stromal gpat was cloned, sequenced and characterized. we identified a single orf of 1344base pairs that encoded a gpat sharing strong sequence homology with the plastidial gpat from arabidopsis thaliana (ats1, at1g32200). gene expression studies showed tha ... | 2015 | 25618244 |
| sunflower (helianthus annuus) fatty acid synthase complex: enoyl-[acyl carrier protein]-reductase genes. | enoyl-[acyl carrier protein]-reductases from sunflower. a major factor contributing to the amount of fatty acids in plant oils are the first steps of their synthesis. the intraplastidic fatty acid biosynthetic pathway in plants is catalysed by type ii fatty acid synthase (fas). the last step in each elongation cycle is carried out by the enoyl-[acp]-reductase, which reduces the dehydrated product of β-hydroxyacyl-[acp] dehydrase using nadph or nadh. to determine the mechanisms involved in the bi ... | 2015 | 25204631 |
| molecular cloning and characterization of a heme oxygenase1 gene from sunflower and its expression profiles in salinity acclimation. | heme oxygenase1 (ho1) is involved in protecting plants from environmental stimuli. in this study, a sunflower (helianthus annuus l.) ho1 gene (haho1) was cloned and sequenced. it was confirmed that haho1 encodes a precursor protein of 32.93 kda with an n-terminal plastid transit peptide which was validated by subcellular localization. the amino acid sequence of haho1 shared high homology with other plant ho1s. the predicted three-dimensional structure showed a high degree of structural conservat ... | 2014 | 24562628 |
| sunflower (helianthus annuus) long-chain acyl-coenzyme a synthetases expressed at high levels in developing seeds. | long chain fatty acid synthetases (lacss) activate the fatty acid chains produced by plastidial de novo biosynthesis to generate acyl-coa derivatives, important intermediates in lipid metabolism. oilseeds, like sunflower, accumulate high levels of triacylglycerols (tags) in their seeds to nourish the embryo during germination. this requires that sunflower seed endosperm supports very active glycerolipid synthesis during development. sunflower seed plastids produce large amounts of fatty acids, w ... | 2014 | 24102504 |
| antioxidant and antimicrobial properties of monofloral bee pollen. | the main aim of this study was to determine antioxidant properties and antibacterial activity of monofloral bee pollen samples to pathogenic bacteria. these samples were collected in different localities in slovakia. the antioxidant properties of examined plant species were different and decreasing in the following order: brassica napus subsp. napus l > papaver somniferum l. > helianthus annuus l. the antimicrobial effect of the bee product samples were tested by using the agar well diffusion me ... | 2013 | 23305281 |
| molecular cloning and biochemical characterization of three phosphoglycerate kinase isoforms from developing sunflower (helianthus annuus l.) seeds. | three cdnas encoding different phosphoglycerate kinase (pgk, ec 2.7.2.3) isoforms, two cytosolic (hacpgk1 and hacpgk2) and one plastidic (happgk), were cloned and characterized from developing sunflower (helianthus annuus l.) seeds. the expression profiles of these genes showed differences in heterotrophic tissues, such as developing seeds and roots, where hacpgk1 was predominant, while happgk was highly expressed in photosynthetic tissues. the cdnas were expressed in escherichia coli, and the c ... | 2012 | 22552275 |
| evaluation of steam and soil solarization for meloidogyne arenaria control in florida floriculture crops. | steam and soil solarization were investigated for control of the root-knot nematode meloidogyne arenaria in 2 yr of field trials on a commercial flower farm in florida. the objective was to determine if preplant steam treatments in combination with solarization, or solarization alone effectively controlled nematodes compared to methyl bromide (mebr). trials were conducted in a field with naturally occurring populations of m. arenaria. treatments were solarization alone, steam treatment after sol ... | 2016 | 27765992 |
| evaluation of cover crops with potential for use in anaerobic soil disinfestation (asd) for susceptibility to three species of meloidogyne. | several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, meloidogyne arenaria, m. incognita, and m. javanica. crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (asd) applications. nematode juvenile (j2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (eruca sativa, cv. nemat), cowpea (vigna unguicula ... | 2013 | 24379486 |
| assembly and loss of the polar flagellum in plant-associated methylobacteria. | on the leaf surfaces of numerous plant species, inclusive of sunflower (helianthus annuus l.), pink-pigmented, methanol-consuming, phytohormone-secreting prokaryotes of the genus methylobacterium have been detected. however, neither the roles, nor the exact mode of colonization of these epiphytic microbes have been explored in detail. using germ-free sunflower seeds, we document that, during the first days of seedling development, methylobacteria exert no promotive effect on organ growth. since ... | 2014 | 24566997 |
| lipase-mediated conversion of vegetable oils into biodiesel using ethyl acetate as acyl acceptor. | ethyl acetate was explored as an acyl acceptor for immobilized lipase-catalyzed preparation of biodiesel from the crude oils of jatropha curcas (jatropha), pongamia pinnata (karanj) and helianthus annuus (sunflower). the optimum reaction conditions for interesterification of the oils with ethyl acetate were 10% of novozym-435 (immobilized candida antarctica lipase b) based on oil weight, ethyl acetate to oil molar ratio of 11:1 and the reaction period of 12h at 50 degrees c. the maximum yield of ... | 2007 | 16822671 |
| lipase-mediated transformation of vegetable oils into biodiesel using propan-2-ol as acyl acceptor. | propan-2-ol was used as an acyl acceptor for immobilized lipase-catalyzed preparation of biodiesel. the optimum conditions for transesterification of crude jatropha (jatropha curcas), karanj (pongamia pinnata) and sunflower (helianthus annuus) oils were 10% novozym-435 (immobilized candida antarctica lipase b) based on oil weight, alcohol to oil molar ratio of 4:1 at 50 degrees c for 8 h. the maximum conversions achieved using propan-2-ol were 92.8, 91.7 and 93.4% from crude jatropha, karanj and ... | 2006 | 16642301 |
| antimycobacterial activity of medicinal plants used by the mayo people of sonora, mexico. | tuberculosis (tb) is an infectious disease mainly caused by mycobacterium tuberculosis (mtb), which generates 9 million new cases worldwide each year. the mayo ethnicity of southern sonora, mexico is more than 2000 years old, and the mayos possess extensive knowledge of traditional medicine. | 2016 | 27262564 |
| host suitability of commercial sunflower hybrids to pratylenchus zeae. | host suitability of commercial sunflower hybrids to pratylenchus zeae was studied in the field and greenhouse. for comparison, one maize and one grain sorghum inbred line, both susceptible to p. zeae, were included in the greenhouse experiments. pratylenchus zeae densities extracted from the roots of sunflower hybrids grown in naturally infested soil were low. in the first greenhouse experiment, p. zeae densities per 5 g roots and per root system were lower (p = 0.05) in four sunflower hybrids t ... | 1989 | 19287672 |
| integrated micro-biochemical approach for phytoremediation of cadmium and zinc contaminated soils. | the integrated potential of oilcake manure (om), elemental sulphur (s(0)), glomus fasciculatum and pseudomonas putida by growing helianthus annuus l for phytoremediation of cadmium and zinc contaminated soils was investigated under pot experiment. the integrated treatment (2.5 g kg(-1) om, 0.8 g kg(-1) s(0) and co-inoculation with g. fasciculatum and p. putida promoted the dry biomass of the plant. the treatment was feasible for enhanced cadmium accumulation up to 6.56 and 5.25 mg kg(-1) and zin ... | 2015 | 25450919 |
| sunflower hagpat9-1 is the predominant gpat during seed development. | in oil crops, triacylglycerol biosynthesis is an important metabolic pathway in which glycerol-3-phosphate acyltransferase (gpat) performs the first acylation step. mass spectrometry analysis of developing sunflower (helianthus annuus) seed membrane fractions identified an abundant gpat, hagpat9 isoform 1, with a n-terminal peptide that possessed two phosphorylated residues with possible regulatory function. hagpat9-1 belongs to a broad eukaryotic gpat family, similar to mammalian gpat3, and it ... | 2016 | 27717477 |
| identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (helianthus annuus l., asteraceae). | sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. a bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. based on sequence similarity with a known bisabolene synthases from arabidopsis thaliana attps12, candidate genes of helianthus were searched in est-database and used to ... | 2016 | 26880289 |
| sunflower metallothionein family characterisation. study of the zn(ii)- and cd(ii)-binding abilities of the hamt1 and hamt2 isoforms. | plant metallothioneins (mts) constitute a family of small cys-rich proteins capable of coordinating metal ions, significantly differing from microbial and animal mts. they are divided into four subfamilies depending on the cys pattern in their sequence. in this work, the mt system of the sunflower plant (helianthus annuus) has been defined, with ten genes coding for mts (hamt) belonging to the four plant mt subfamilies; three hamt1, four hamt2, one hamt3 and two hamt4 isoforms. the gene expressi ... | 2015 | 25770010 |
| genetic mapping, marker assisted selection and allelic relationships for the pu 6 gene conferring rust resistance in sunflower. | rust resistance in the sunflower line p386 is controlled by pu 6 , a gene which was reported to segregate independently from other rust resistant genes, such as r 4 . the objectives of this work were to map pu 6 , to provide and validate molecular tools for its identification, and to determine the linkage relationship of pu 6 and r 4 . genetic mapping of pu 6 with six markers covered 24.8 cm of genetic distance on the lower end of linkage group 13 of the sunflower consensus map. the marker most ... | 2014 | 25320555 |
| genetic mapping of rust resistance genes in confection sunflower line ha-r6 and oilseed line rha 397. | few widely effective resistance sources to sunflower rust, incited by puccinia helianthi schwein., have been identified in confection sunflower (helianthus annuus l.). the usda inbred line ha-r6 is one of the few confection sunflower lines resistant to rust. a previous allelism test indicated that rust resistance genes in ha-r6 and rha 397, an oilseed-type restorer line, are either allelic or closely linked; however, neither have been characterized nor molecularly mapped. the objectives of this ... | 2013 | 23719761 |
| molecular mapping of a sunflower rust resistance gene from har6. | sunflower rust, caused by puccinia helianthi schw., can result in significant yield losses in cultivated sunflower (helianthus annuus l. var. macrocarpus ckll.). har6 is a germplasm population resistant to most predominant rust races. the objectives of this study were to map the resistance factor present in har6 (r har6 ), and to provide and validate molecular tools for the identification of this gene for marker assisted selection purposes. virulence reaction of seedlings for the f2 population a ... | 2013 | 23641190 |
| molecular tagging of a novel rust resistance gene r(12) in sunflower (helianthus annuus l.). | sunflower production in north america has recently suffered economic losses in yield and seed quality from sunflower rust (puccinia helianthi schwein.) because of the increasing incidence and lack of resistance to new rust races. rha 464, a newly released sunflower male fertility restorer line, is resistant to both of the most predominant and most virulent rust races identified in the northern great plains of the usa. the gene conditioning rust resistance in rha 464 originated from wild helianth ... | 2013 | 22907633 |
| genetics and mapping of the r₁₁ gene conferring resistance to recently emerged rust races, tightly linked to male fertility restoration, in sunflower (helianthus annuus l.). | sunflower oil is one of the major sources of edible oil. as the second largest hybrid crop in the world, hybrid sunflowers are developed by using the pet1 cytoplasmic male sterility system that contributes to a 20 % yield advantage over the open-pollinated varieties. however, sunflower production in north america has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus puccinia helianthi schwein. rf ann-1742, an 'ha 89' backcross restorer li ... | 2012 | 22610307 |
| plant population heterogeneity and pathogen and herbivore levels: a field experiment. | the identity of neighbouring plants in a population is thought to affect the disease levels of an individual plant: disease levels are expected to be higher for susceptible plants surrounded by other susceptible plants as compared to susceptible plants that have resistant plants as neighbours. to explore this idea, plants in a natural population of the annual sunflower, helianthus annuus, were scored in 1988 for levels of the rust pathogen puccinia helianthi. progeny of plants with high rust lev ... | 1991 | 28313168 |
| agricultural reuse of reclaimed water and uptake of organic compounds: pilot study at mutah university wastewater treatment plant, jordan. | the residues of polynuclear aromatic hydrocarbons (pahs), polychlorinated biphenyls (pcbs), chlorinated benzenes (cbs) and phenols were investigated for soil, wastewater, groundwater and plants. the uptake concentration of these compounds was comparatively determined using various plant types: zea mays l., helianthus annus l., capsicum annum l., abelmoschus esculentus l., solanum melongena l. and lycopersicon esculentum l. which were grown in a pilot site established at mutah university wastewat ... | 2008 | 18471853 |
| phytoremediation of soil co-contaminated with heavy metals and tnt using four plant species. | we investigated the germination, growth rates and uptake of contaminants of four plant species, barnyard grass (echinochloa crusgalli), sunflower (helianthus annuus), indian mallow (abutilon avicennae) and indian jointvetch (aeschynomene indica), grown in soil contaminated with cadmium (cd), lead (pb) and 2,4,6-trinitrotoluene (tnt). these contaminants are typically found at shooting ranges. experiments were carried out over 180 days using both single plant cultures and cultures containing an eq ... | 2007 | 17990167 |
| weed control in sunflower (helianthus annuus l.) with post-emergent herbicides. | sunflower is the most important oil crop in hungary, is the base of the production of cooking oil and moreover takes an important part in production of margarine too. extracted sunflower groats as a secondary product origining from the mentioned procedure can be used in forage successfully. the amount of harvested sunflower reaches the 20-25% of the eu's yield. the sowing area approaches 500 thousand hectares. the essential condition of successful crop production is the perfect weed control. sow ... | 2005 | 16637218 |
| effect of drive row ground covers on hop (rosales: cannabaceae) yard arthropod pests in vermont, usa. | alternatives to pesticides are necessary for the management of hop (humulus lupulus l.) arthropod pests. the three major arthropod pests in northeastern us hop production include two-spotted spider mite, tetranychus urticae koch, hop aphid phorodon humuli (schrank), and potato leafhopper, empoasca fabae harris. this 3-yr study (2012-2014) in vermont investigated the effect of flowering ground covers on arthropod pest abundance. hop cultivars 'nugget' and 'cascade' were evaluated under a strip-sp ... | 2017 | 28334066 |
| suitability of different pollen as alternative food for the predatory mite amblyseius swirskii (acari, phytoseiidae). | the predacious mite amblyseius swirskii athias-henriot is used as a biological control agent against various pests in greenhouses. pollen offered as supplementary food is reported to improve their fast establishment and performance. however, the nutritional suitability of different pollens for a. swirskii is not sufficiently known yet. pollens of 21 plant species were offered to the mites as exclusive food during preimaginal development. preimaginal mortality and developmental time have been ass ... | 2013 | 23670826 |
| complete chloroplast genome sequences of mongolia medicine artemisia frigida and phylogenetic relationships with other plants. | artemisia frigida willd. is an important mongolian traditional medicinal plant with pharmacological functions of stanch and detumescence. however, there is little sequence and genomic information available for artemisia frigida, which makes phylogenetic identification, evolutionary studies, and genetic improvement of its value very difficult. we report the complete chloroplast genome sequence of artemisia frigida based on 454 pyrosequencing. | 2013 | 23460871 |
| microbially assisted phytoremediation approaches for two multi-element contaminated sites. | phytoremediation is an environmental friendly, cost-effective technology for a soft restoration of abandoned mine sites. the grasses agrostis capillaris, deschampsia flexuosa and festuca rubra, and the annual herb helianthus annuus were combined with microbial consortia in pot experiments on multi-metal polluted substrates collected at a former uranium mine near ronneburg, germany, and a historic copper mine in kopparberg, sweden, to test for phytoextraction versus phytostabilization abilities. ... | 2014 | 24081921 |
| plant growth promotion by inoculation with selected bacterial strains versus mineral soil supplements. | in the process of remediation of mine sites, the establishment of a vegetation cover is one of the most important tasks. this study tests two different approaches to manipulate soil properties in order to facilitate plant growth. mine waste from ingurtosu, sardinia, italy rich in silt, clay, and heavy metals like cd, cu, and zn was used in a series of greenhouse experiments. bacteria with putative beneficial properties for plant growth were isolated from this substrate, propagated and consortia ... | 2014 | 23990253 |
| the lack of correlation between the rate of rrna transport from nucleoli into cytoplasm and the duration of g1 and g2 phases in root meristem cells. | in root meristems of 3 species (secale cereale l., vicia faba l. subsp. minor, allium cepa l.) the durations of cell cycles and their phases were calculated using 3h-thymidine labelling. in the above species and in helianthus annuus l. (parameters of the cell cycle determined earlier) the g1 and g2 phase durations were different: g1 + 1/2 m from 3 h to 6.1 h, g2 + 1/2 m from 1.1. h to 8.3 h, depending on the species. the rate of rrna transport from nucleoli into cytoplasm during recovery after c ... | 1989 | 2767280 |
| temperature and the cell cycle. | during the period between successive divisions, a cell traverses three stages of interphase: g1 (pre-synthetic interphase), s-phase (dna synthetic interphase) and g2 (post-synthetic interphase). the time taken for all cells in a meristem to divide (the cell doubling time (cdt] decreases in response to an increase in temperature. for example, the cdt in root meristems of zea mays decreases 21-fold as the temperature is increased from 3 to 25 degrees c. whether all phases of the cell cycle alter p ... | 1988 | 3077857 |
| effects of day and night temperature and temperature variation on photosynthetic characteristics. | net photosynthetic rates and mesophyll conductances were measured under standardized conditions for leaves of two c3 and one c4 annual species grown at temperatures of 20 to 32°c. plants were grown with varying day and night temperatures, and also at constant temperatures equal to all the day and night temperatures used. plants were grown with 8, 12, and 16 hours of light per day. this design allowed determination of whether photosynthetic characteristics were best correlated with day, night, me ... | 1985 | 24442876 |
| plant uptake of depleted uranium from manure-amended and citrate treated soil. | six plant species were tested for their ability to accumulate depleted uranium in their above-ground biomass from deployed munitions contaminated soil in new mexico. in greenhouse experiments, kochia (kochia scoparia l. schrad.) and pigweed (amaranthus retroflexus l) were grown with steer manure added at rates of 22.4, 44.8, and 89.6 mg ha(-1). citric acid and glyphosate (n-(phosphonomethyl) glycine) applied at the end of the growing season increased du concentrations from 2.5 to 17 times. leaf ... | 2010 | 21166280 |
| stable oxygen and hydrogen isotope composition of leaf water in c3 and c4 plant species under field conditions. | in this paper we make comparisons between the observed oxygen and hydrogen stable isotope composition of leaf water and the predictions of the craig-gordon model of evaporative isotopic enrichment. comparisons were made among two c3 species (chenopodium album and helianthus annuus) and two c4 species (amaranthus retroflexus and kochia scoparia), when plants were exposed to natural environmental conditions in the field. there were significant differences among the species for the hydrogen and oxy ... | 1991 | 28313802 |
| air-borne contact dermatitis in varanasi. | forty-six patients suspected to have air borne contact dermatitis were tested with various plant antigens. thirteen patients turned out to be sensitive to one or more antigens. the plant antigens, used for testing, were parthenium hysterophorus, lantana camara, cynodon dactylon, bougainvaled spectabills, calotropis procera, argimone mexicana, acacia arabica, azadiracha indica, eucalyptus rostrata, saraka indica, triticum vulgare, triticum aestivum, dryopteris filix, nerium indicum, eclipta alba, ... | 2017 | 28150592 |
| an affinity-effect relationship for microbial communities in plant-soil feedback loops. | feedback loops involving soil microorganisms can regulate plant populations. here, we hypothesize that microorganisms are most likely to play a role in plant-soil feedback loops when they possess an affinity for a particular plant and the capacity to consistently affect the growth of that plant for good or ill. we characterized microbial communities using whole-community dna fingerprinting from multiple "home-and-away" experiments involving giant ragweed (ambrosia trifida l.) and common sunflowe ... | 2014 | 24402363 |
| diurnal variations in leaf fluorescence induction kinetics: variable fluorescence in crassulacean acid metabolism plants. | the variable fluorescence of leaves from kalanchoë daigremontiana and pineapple, ananas comosus, both cam plants, was found to change over a 24-hour cycle and to exhibit high temperature-dependent maxima during the night period. the time course of the induced fluorescence was correlated with malic acid accumulation but not with other aspects of cam such as with the nature of the decarboxylation pathway or with stomatal movements. the variable fluorescences of sunflower (helianthus annuus l.) and ... | 1983 | 16663024 |
| the use of stable carbon isotope analysis in rooting studies. | stable carbon isotope analysis was evaluated as a means of predicting the relative proportions of c3 and c4 root phytomass in species mixtures. the following mixtures of c3 and c4 species were used: 1) big bluestem (andropogon gerardii)/cheatgrass (bromus tectorum), 2) little bluestem (schizachyrium scoparium)/cheatgrass, and 3) sorghum (sorghum bicolor)/sunflower (helianthus annuus). there was a significant correlation (p<0.01) between % c4 phytomass and stable carbon isotope values for each of ... | 1985 | 28311309 |
| fatty acid and proximate composition of bee bread. | palynological spectrum, proximate and fatty acid (fa) composition of eight bee bread samples of different botanical origins were examined and significant variations were observed. the samples were all identified as monofloral, namely castanea sativa (94.4%), trifolium spp. (85.6%), gossypium hirsutum (66.2%), citrus spp. (61.4%) and helianthus annuus (45.4%). each had moisture content between 11.4 and 15.9%, ash between 1.9 and 2.54%, fat between 5.9 and 11.5%, and protein between 14.8 and 24.3% ... | 2016 | 28115909 |
| sunflower (helianthus annuus) pollination in california's central valley is limited by native bee nest site location. | the delivery of ecosystem services by mobile organisms depends on the distribution of those organisms, which is, in turn, affected by resources at local and landscape scales. pollinator-dependent crops rely on mobile animals like bees for crop production, and the spatial relationship between floral resources and nest location for these central-place foragers influences the delivery of pollination services. current models that map pollination coverage in agricultural regions utilize landscape-lev ... | 2016 | 27209786 |
| interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the argentine pampas. | pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. it is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. in the intensively managed argentine pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "si ... | 2012 | 22303477 |
| validation of a method using queenless bombus terrestris micro-colonies for testing the nutritive value of commercial pollen mixes by comparison with queenright colonies. | the nutritive value of pollen blends purchased by bumble bee producers from beekeepers is a key factor of successful mass rearing. we have already devised a method for quality ranking of pollen diets. it was a 1-mo bioassay using queenless micro-colonies of three callow workers (bombus terrestris l.; apidae: bombinae). in the current study, we tested three pollen diets through the micro-colony method and compared the results to the development of queenright colonies supplied with the same diets. ... | 2008 | 19133450 |
| selection and estimation of the heritability of sunflower (helianthus annuus) pollen collection behavior in apis mellifera colonies. | we selected honey bee colonies (apis mellifera l.) with a high tendency to collect sunflower pollen and estimated the heritability of this trait. the percentage of sunflower pollen collected by 74 colonies was evaluated. five colonies that collected the highest percentages of sunflower pollen were selected. nineteen colonies headed by daughters of these selected queens were evaluated for this characteristic in comparison with 20 control (unselected) colonies. the variation for the proportion of ... | 2007 | 17624860 |
| influence of pollen quality on ovarian development in honeybee workers (apis mellifera scutellata). | protein-rich diets are known to promote ovarian and egg development in workers of the honeybee, apis mellifera, even in the presence of a queen. since the main source of protein for honeybees is pollen, its quality and digestibility might be important dietary factors determining reproductive capacity. we have compared the effect of two types of pollen-sunflower, helianthus annuus, and aloe, aloe greatheadii var davyana-on ovarian development in a. mellifera scutellata workers. under queenright c ... | 2007 | 17543984 |
| distribution of [(14)c]imidacloprid in sunflowers (helianthus annuus l.) following seed treatment. | imidacloprid, a neonicotinic insecticide, has been used as a seed dressing (gaucho) to protect crops against soil and aerial insects. however, french beekeepers observed abnormal behavior of bees foraging on sunflowers and suspected a link between the imidacloprid seed treatment and the observed bee syndrome. this work studies the distribution of [(14)c-imidazolidin]imidacloprid (1 mg/seed) in three stages of gaucho-treated sunflowers grown in an outdoor lysimeter. plants absorbed <10% of [(14)c ... | 2003 | 14690387 |
| africanized honey bees (hymenoptera: apidae) have a greater fidelity to sunflowers than european bees. | a study of sunflower, helianthus annuus l., pollen collection by africanized and european honey bees, apis mellifera l., was conducted in a hybrid seed production field in argentina. africanized honey bees collected significantly larger proportions of sunflower pollen than did european honey bees. the result suggests that africanized bees would be more efficient for commercial sunflower seed production. | 2000 | 10826177 |
| characterization of a small acyl-coa-binding protein (acbp) from helianthus annuus l. and its binding affinities. | acyl-coa-binding proteins (acbps) bind to acyl-coa esters and promote their interaction with other proteins, lipids and cell structures. small class i acbps have been identified in different plants, such as arabidopsis thaliana (atacbp6), brassica napus (bnacbp) and oryza sativa (osacbp1, osacbp2, osacbp3), and they are capable of binding to different acyl-coa esters and phospholipids. here we characterize haacbp6, a class i acbp expressed in sunflower (helianthus annuus) tissues, studying the s ... | 2016 | 26938582 |