| bridging physiological and evolutionary time-scales in a gene regulatory network. | gene regulatory networks (grns) govern phenotypic adaptations and reflect the trade-offs between physiological responses and evolutionary adaptation that act at different time-scales. to identify patterns of molecular function and genetic diversity in grns, we studied the drought response of the common sunflower, helianthus annuus, and how the underlying grn is related to its evolution. we examined the responses of 32,423 expressed sequences to drought and to abscisic acid (aba) and selected 145 ... | 2014 | 24786523 |
| [analysis of mineral elements of sunflower (helianthus annuus l.) grown on saline land in hetao irrigation district by icp-aes]. | the absorption and accumulation of ten mineral elements in four kinds of organs (root, steam, leaf and flower disc) in helianthus annuus l. plants cultured in hetao irrigation district under different level of salinity stress were determined by icp-aes with wet digestion (hno3 + hclo4). the results showed that: (1) the contents of fe, mn, zn, ca, and na were highest in roots, so was k in stems, b and mg in leaves and p in flower discs, while no significant difference was detected in the content ... | 2014 | 24783567 |
| light intensity alters the extent of arsenic toxicity in helianthus annuus l. seedlings. | the present study is aimed at assessing the extent of arsenic (as) toxicity under three different light intensities-optimum (400 μmole photon m(-2) s(-1)), sub-optimum (225 μmole photon m(-2) s(-1)), and low (75 μmole photon m(-2) s(-1))-exposed to helianthus annuus l. var. drsf-113 seedlings by examining various physiological and biochemical parameters. irrespective of the light intensities under which h. annuus l. seedlings were grown, there was an as dose (low, i.e., 6 mg kg(-1) soil, as1; an ... | 2014 | 24699829 |
| nongenotoxic effects and a reduction of the dxr-induced genotoxic effects of helianthus annuus linné (sunflower) seeds revealed by micronucleus assays in mouse bone marrow. | this research evaluated the genotoxicity of oil and tincture of h. annuus l. seeds using the micronucleus assay in bone marrow of mice. the interaction between these preparations and the genotoxic effects of doxorubicin (dxr) was also analysed (antigenotoxicity test). | 2014 | 24694203 |
| co-overexpression of two heat shock factors results in enhanced seed longevity and in synergistic effects on seedling tolerance to severe dehydration and oxidative stress. | we have previously reported that the seed-specific overexpression of sunflower (helianthus annuus l.) heat shock factor a9 (hahsfa9) enhanced seed longevity in transgenic tobacco (nicotiana tabacum l.). in addition, the overexpression of hahsfa9 in vegetative organs conferred tolerance to drastic levels of dehydration and oxidative stress. | 2014 | 24593798 |
| oospores of pustula helianthicola in sunflower seeds and their role in the epidemiology of white blister rust. | white blister rust (wbr) of sunflower caused by pustula helianthicola is an important and often underestimated disease in many countries of the world. the epidemiology of the pathogen is not yet fully understood; particularly the role of oospores in primary infection and long distance dispersal. we analysed wbr severity in sunflower under natural conditions and found disease incidence of 97-99 % in fields where infected sunflower had first been observed ca. 8 yr ago. besides the typical blisters ... | 2013 | 24563837 |
| selenium alleviates cadmium toxicity by preventing oxidative stress in sunflower (helianthus annuus) seedlings. | the present study investigated the possible mediatory role of selenium (se) in protecting plants from cadmium (cd) toxicity. the exposure of sunflower seedlings to 20μm cd inhibited biomass production, decreased chlorophyll and carotenoid concentrations and strongly increased accumulation of cd in both roots and shoots. similarly, cd enhanced hydrogen peroxides content and lipid peroxidation as indicated by malondialdehyde accumulation. pre-soaking seeds with se (5, 10 and 20μm) alleviated the n ... | 2014 | 24484961 |
| induction of a photomixotrophic plant cell culture of helianthus annuus and optimization of culture conditions for improved α-tocopherol production. | tocopherols, collectively known as vitamin e, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. the most biologically active form of vitamin e is α-tocopherol. most tocopherols are currently produced via chemical synthesis. nevertheless, this always results in a racemic mixture of different and less effective st ... | 2014 | 24318010 |
| biological activities and some physicochemical properties of sunflower honeys collected from the thrace region of turkey. | honey is a sweet food made by bees using nectar from flowers. its quality depends on a number of factors, such as floral type, ph, moisture, free acidity, diastase activity, invert sugar and sucrose. the aim of the study is to examine the qualities of 50 sunflower honey (helianthus annuus l.) collected from the thrace region of turkey, in terms of melissopalynological analysis, important chemical parameters and antioxidant activities . the total phenolic content of the honey samples was determin ... | 2012 | 24261112 |
| entrapment of a volatile lipophilic aroma compound (d-limonene) in spray dried water-washed oil bodies naturally derived from sunflower seeds (helianthus annus). | oil bodies are natural emulsions that can be extracted from oil seeds and have previously been shown to be stable after spray drying. the aim of the study was to evaluate for the first time if spray dried water-washed oil bodies are an effective carrier for volatile lipophilic actives (the flavour compound d-limonene was used as an example aroma compound). water-washed oil bodies were blended with maltodextrin and d-limonene and spray dried using a buchi b-191 laboratory spray dryer. lipid and d ... | 2013 | 24235784 |
| increased bioavailability of metals in two contrasting agricultural soils treated with waste wood-derived biochar and ash. | recycled waste wood is being increasingly used for energy production; however, organic and metal contaminants in by-products produced from the combustion/pyrolysis residue may pose a significant environmental risk if they are disposed of to land. here we conducted a study to evaluate if highly polluted biochar (from pyrolysis) and ash (from incineration) derived from cu-based preservative-treated wood led to different metal (e.g., cu, as, ni, cd, pb, and zn) bioavailability and accumulation in s ... | 2014 | 24217969 |
| influence of thiourea application on some physiological and molecular criteria of sunflower (helianthus annuus l.) plants under conditions of heat stress. | high temperature is a major factor limiting the growth of plant species during summer. understanding the mechanisms of plant tolerance to high temperature would help in developing effective management practices and heat-tolerant cultivars through breeding or biotechnology. the present investigation was carried out to study the role of thiourea in enhancing the tolerance of sunflower plants to heat stress. sunflower plants were subjected to temperature stress by exposing plants to 35 or 45 °c for ... | 2014 | 24178367 |
| influence of substituting dietary soybean for air-classified sunflower (helianthus annuus l.) meal on egg production and steroid hormones in early-phase laying hens. | soybean meal (sbm) is the most widely and expensive protein source used in the formulation of poultry diets; however, when the price of sbm increases, poultry nutritionists seek alternative sources that are more economical in formulating least-cost rations. this research aimed to evaluate the effects of dietary air-classified sunflower meal (sfm) on some productive parameters and plasma steroid hormones in laying hens. in this trial, 20-week-old laying hens (isa brown strain) in the early phase ... | 2014 | 24134610 |
| modelled hydraulic redistribution by sunflower (helianthus annuus l.) matches observed data only after including night-time transpiration. | the movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (hr), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. the realized hydrologic, biogeochemical and ecological consequences of hr depend on the amount of redistributed water, whereas the ability to assess these impacts requires models that correctly capture hr magnitude and timing. using several soil types and tw ... | 2014 | 24118010 |
| ontogeny strongly and differentially alters leaf economic and other key traits in three diverse helianthus species. | the leaf economics spectrum (les) describes large cross-species variation in suites of leaf functional traits ranging from resource-acquisitive to resource-conservative strategies. such strategies have been integral in explaining plant adaptation to diverse environments, and have been linked to numerous ecosystem processes. the les has previously been found to be significantly modulated by climate, soil fertility, biogeography, growth form, and life history. one largely unexplored aspect of les ... | 2013 | 24078673 |
| spatio-temporal decoupling of stomatal and mesophyll conductance induced by vein cutting in leaves of helianthus annuus. | reduction of hydraulic conductance to the canopy has been shown to result in stomatal responses to limit transpiration. to test for similar responses to perturbations of the hydraulic network in leaves, we simultaneously measured leaf gas exchange with spatially explicit chlorophyll-a fluorescence and leaf temperature to examine the effects of cutting a primary leaf vein in helianthus annuus. we repeated the leaf treatment at each of three different vapor pressure deficits and monitored the shor ... | 2013 | 24065972 |
| the role of bacterial consortium and organic amendment in cu and fe isotope fractionation in plants on a polluted mine site. | copper and iron isotope fractionation by plant uptake and translocation is a matter of current research. as a way to apply the use of cu and fe stable isotopes in the phytoremediation of contaminated sites, the effects of organic amendment and microbial addition in a mine-spoiled soil seeded with helianthus annuus in pot experiments and field trials were studied. results show that the addition of a microbial consortium of ten bacterial strains has an influence on cu and fe isotope fractionation ... | 2014 | 24057964 |
| divergence is focused on few genomic regions early in speciation: incipient speciation of sunflower ecotypes. | early in speciation, as populations undergo the transition from local adaptation to incipient species, is when a number of transient, but potentially important, processes appear to be most easily detected. these include signatures of selective sweeps that can point to asymmetry in selection between habitats, divergence hitchhiking, and associations of adaptive genes with environments. in a genomic comparison of ecotypes of the prairie sunflower, helianthus petiolaris, occurring at great sand dun ... | 2013 | 24033161 |
| a novel fluorescence imaging approach to monitor salt stress-induced modulation of ouabain-sensitive atpase activity in sunflower seedling roots. | seedlings exposed to salt stress are expected to show modulation of intracellular accumulation of sodium ions through a variety of mechanisms. using a new methodology, this work demonstrates ouabain (ou)-sensitive atpase activity in the roots of sunflower seedlings subjected to salt stress (120 mm nacl). 9-anthroylouabain (a derivative of ouabain known to inhibit na(+), k(+) -atpase activity in animal systems, ec 3.6.3.9) has been used as a probe to analyze ou-sensitive atpase activity in sunflo ... | 2014 | 24032541 |
| capitate glandular trichomes of helianthus annuus (asteraceae): ultrastructure and cytological development. | previous studies have shown that capitate glandular trichomes (cgt) of the common sunflower, helianthus annuus, produce sesquiterpene lactones (stl) and flavonoids, which are sequestered and accumulated between the apical cuticle and the wall of the tip cells. to explore the cellular structures required and putatively involved in the stl biosynthesis and secretion, the present study was focused on the development of cgt and the comparison of the ultrastructure of its different cell types. gradua ... | 2014 | 23921677 |
| dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead. | sunflower (helianthus annuus l.) has been considered as a good candidate for bioaccumulation of heavy metals. in the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. biomass, cd and pb uptake, three organic acids and ph in cultures were investigated. results showed that the existence of cd and pb showed different interactions on the organic acids exudation. in single cd treatments, malic and acetic acids in cd10 showed an incremental tendency with ... | 2013 | 23819268 |
| the effect of subambient to elevated atmospheric co₂ concentration on vascular function in helianthus annuus: implications for plant response to climate change. | plant gas exchange is regulated by stomata, which coordinate leaf-level water loss with xylem transport. stomatal opening responds to internal concentrations of co₂ in the leaf, but changing co₂ can also lead to changes in stomatal density that influence transpiration. given that stomatal conductance increases under subambient concentrations of co₂ and, conversely, that plants lose less water at elevated concentrations, can downstream effects of atmospheric co₂ be observed in xylem tissue? we ap ... | 2013 | 23731256 |
| genome-scale transcriptional analyses of first-generation interspecific sunflower hybrids reveals broad regulatory compatibility. | interspecific hybridization creates individuals harboring diverged genomes. the interaction of these genomes can generate successful evolutionary novelty or disadvantageous genomic conflict. annual sunflowers helianthus annuus and h. petiolaris have a rich history of hybridization in natural populations. although first-generation hybrids generally have low fertility, hybrid swarms that include later generation and fully fertile backcross plants have been identified, as well as at least three ind ... | 2013 | 23701699 |
| a biomarker based on gene expression indicates plant water status in controlled and natural environments. | plant or soil water status is required in many scientific fields to understand plant responses to drought. because the transcriptomic response to abiotic conditions, such as water deficit, reflects plant water status, genomic tools could be used to develop a new type of molecular biomarker. using the sunflower (helianthus annuus l.) as a model species to study the transcriptomic response to water deficit both in greenhouse and field conditions, we specifically identified three genes that showed ... | 2013 | 23639099 |
| comparative study of sos2 and a novel pmp3-1 gene expression in two sunflower (helianthus annuus l.) lines differing in salt tolerance. | gene expression pattern of two important regulatory proteins, salt overly sensitive 2 (sos2) and plasma membrane protein 3-1 (pmp3-1), involved in ion homeostasis, was analyzed in two salinity-contrasting sunflower (helianthus annuus l.) lines, hysun-38 (salt tolerant) and s-278 (moderately salt tolerant). the pattern was studied at selected time intervals (24 h) under 150 mm nacl treatment. using reverse transcription pcr, sos2 gene fragment was obtained from young leaf and root tissues of oppo ... | 2013 | 23636650 |
| using high resolution computed tomography to visualize the three dimensional structure and function of plant vasculature. | high resolution x-ray computed tomography (hrct) is a non-destructive diagnostic imaging technique with sub-micron resolution capability that is now being used to evaluate the structure and function of plant xylem network in three dimensions (3d) (e.g. brodersen et al. 2010; 2011; 2012a,b). hrct imaging is based on the same principles as medical ct systems, but a high intensity synchrotron x-ray source results in higher spatial resolution and decreased image acquisition time. here, we demonstrat ... | 2013 | 23609036 |
| cell division and turgor-driven stem elongation in juvenile plants: a synthesis. | the growth of hypocotyls and epicotyls has been attributed to the turgor-driven enlargement of cells, a process that is under the control of phytohormones such as auxin. however, the experiments presented here and elsewhere using developing sunflower (helianthus annuus l.) seedlings raised either in darkness (skotomorphogenesis) or in white light (wl) (photomorphogenesis) indicate that auxin-mediated segment elongation ceases after 1 day, whereas hypocotyl growth continues in the intact system. ... | 2013 | 23602098 |
| physiological and proteome study of sunflowers exposed to a polymetallic constraint. | the new energy requirements of the growing world population together with the actual ecological trend of phytoremediation have made challenging the cultivation of energetic crops on nonagricultural lands, such as those contaminated with trace elements. in this study, phenotypical characterization and biochemical analyses were combined to emphasize the global response of young sunflowers (helianthus annuus l.) grown in hydroponic media contaminated with different cd, ni, and zn concentrations. le ... | 2013 | 23595958 |
| inoculating helianthus annuus (sunflower) grown in zinc and cadmium contaminated soils with plant growth promoting bacteria--effects on phytoremediation strategies. | plant growth promoting bacteria (pgpr) may help reducing the toxicity of heavy metals to plants in polluted environments. in this work the effects of inoculating metal resistant and plant growth promoting bacterial strains on the growth of helianthus annuus grown in zn and cd spiked soils were assessed. the pgpr strains ralstonia eutropha (b1) and chrysiobacterium humi (b2) reduced losses of weight in metal exposed plants and induced changes in metal bioaccumulation and bioconcentration - with s ... | 2013 | 23582407 |
| association mapping and the genomic consequences of selection in sunflower. | the combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. here, we describe the detailed genotypic and phenotypic analysis of a sunflower (helianthus annuus l.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. we used these data to characterize overall pat ... | 2013 | 23555290 |
| the lipidome and proteome of oil bodies from helianthus annuus (common sunflower). | in this paper we report the molecular profiling, lipidome and proteome, of the plant organelle known as an oil body (ob). the ob is remarkable in that it is able to perform its biological role (storage of triglycerides) whilst resisting the physical stresses caused by changes during desiccation (dehydration) and germination (rehydration). the molecular profile that confers such extraordinary physical stability on obs was determined using a combination of (31)p/(1)h nuclear magnetic resonance (nm ... | 2013 | 23532185 |
| florets of sunflower (helianthus annuus l.): potential new sources of dietary fiber and phenolic acids. | ray florets (rf) and disc florets (df) are agricultural byproducts of sunflower seeds. their nutrition-related compounds were determined. the dietary fiber contents in rf and df were 42.90 mg/100 g and 58.97 mg/100 g. in both florets, palmitic, linoleic, and linolenic acids were identified as the three most abundant fatty acids, and the saturated ones constitute approximately two-thirds (w/w) of the total fatty acids. lysine was the limiting amino acid in both florets by world health organizatio ... | 2013 | 23510166 |
| smart--sunflower mutant population and reverse genetic tool for crop improvement. | sunflower (helianthus annuus l.) is an important oilseed crop grown widely in various areas of the world. classical genetic studies have been extensively undertaken for the improvement of this particular oilseed crop. pertaining to this endeavor, we developed a "chemically induced mutated genetic resource for detecting snp by tilling" in sunflower to create new traits. | 2013 | 23496999 |
| functional role of the mads-box transcriptional factor ham59 in the flower development in helianthus annuus l. | | 2013 | 23479015 |
| impact of wheat straw biochar addition to soil on the sorption, leaching, dissipation of the herbicide (4-chloro-2-methylphenoxy)acetic acid and the growth of sunflower (helianthus annuus l.). | biochar addition to agricultural soils might increase the sorption of herbicides, and therefore, affect other sorption-related processes such as leaching, dissipation and toxicity for plants. in this study, the impact of wheat straw biochar on the sorption, leaching and dissipation in a soil, and toxicity for sunflower of (4-chloro-2-methylphenoxy)acetic acid (mcpa), a commonly used ionizable herbicide, was investigated. the results showed that mcpa sorption by biochar and biochar-amended soil ( ... | 2013 | 23474069 |
| combined linkage and association mapping of flowering time in sunflower (helianthus annuus l.). | association mapping and linkage mapping were used to identify quantitative trait loci (qtl) and/or causative mutations involved in the control of flowering time in cultivated sunflower helianthus annuus. a panel of 384 inbred lines was phenotyped through testcrosses with two tester inbred lines across 15 location × year combinations. a recombinant inbred line (ril) population comprising 273 lines was phenotyped both per se and through testcrosses with one or two testers in 16 location × year com ... | 2013 | 23435733 |
| transcriptional dynamics of ltr retrotransposons in early generation and ancient sunflower hybrids. | hybridization and abiotic stress are natural agents hypothesized to influence activation and proliferation of transposable elements in wild populations. in this report, we examine the effects of these agents on expression dynamics of both quiescent and transcriptionally active sublineages of long terminal repeat (ltr) retrotransposons in wild sunflower species with a notable history of transposable element proliferation. for annual sunflower species helianthus annuus and h. petiolaris, neither e ... | 2013 | 23335122 |
| toward a molecular cytogenetic map for cultivated sunflower (helianthus annuus l.) by landed bac/bibac clones. | conventional karyotypes and various genetic linkage maps have been established in sunflower (helianthus annuus l., 2n = 34). however, the relationship between linkage groups and individual chromosomes of sunflower remains unknown and has considerable relevance for the sunflower research community. recently, a set of linkage group-specific bacterial /binary bacterial artificial chromosome (bac/bibac) clones was identified from two complementary bac and bibac libraries constructed for cultivated s ... | 2013 | 23316437 |
| diversifying sunflower germplasm by integration and mapping of a novel male fertility restoration gene. | the combination of a single cytoplasmic male-sterile (cms) pet-1 and the corresponding fertility restoration (rf) gene rf1 is used for commercial hybrid sunflower (helianthus annuus l., 2n = 34) seed production worldwide. a new cms line 514a was recently developed with h. tuberosus cytoplasm. however, 33 maintainers and restorers for cms pet-1 and 20 additional tester lines failed to restore the fertility of cms 514a. here, we report the discovery, characterization, and molecular mapping of a no ... | 2013 | 23307903 |
| rapid auxin-induced nitric oxide accumulation and subsequent tyrosine nitration of proteins during adventitious root formation in sunflower hypocotyls. | using no specific probe (mnip-cu), rapid nitric oxide (no) accumulation as a response to auxin (iaa) treatment has been observed in the protoplasts from the hypocotyls of sunflower seedlings (helianthus annuus l.). incubation of protoplasts in presence of npa (auxin efflux blocker) and ptio (no scavenger) leads to significant reduction in no accumulation, indicating that no signals represent an early signaling event during auxin-induced response. a surge in no production has also been demonstrat ... | 2013 | 23299324 |
| development of an ultra-dense genetic map of the sunflower genome based on single-feature polymorphisms. | the development of ultra-dense genetic maps has the potential to facilitate detailed comparative genomic analyses and whole genome sequence assemblies. here we describe the use of a custom affymetrix genechip containing nearly 2.4 million features (25 bp sequences) targeting 86,023 unigenes from sunflower (helianthus annuus l.) and related species to test for single-feature polymorphisms (sfps) in a recombinant inbred line (ril) mapping population derived from a cross between confectionery and o ... | 2012 | 23284684 |
| efficacy of newly formulated ointment containing 20% active antimicrobial honey in treatment of burn wound infections. | honey has been familiar to possess antimicrobial potential to clear infection against burn wound infecting bacteria since ancient times. the objective of the study was to evaluate the efficacy of the newly formulated honey ointment during the treatment of burn wound infections. the experimental (non comparative) study was conducted at outpatient department of dermatology, fauji foundation hospital, rawalpindi from november 2009 to october 2010. | 2014 | 25098080 |
| interacting duplications, fluctuating selection, and convergence: the complex dynamics of flowering time evolution during sunflower domestication. | changes in flowering time and its regulation by environmental signals have played crucial roles in the evolutionary origin and spread of many cultivated plants. recent investigations into the genetics of flowering time evolution in the common sunflower, helianthus annuus, have provided insight into the historical and mechanistic dynamics of this process. genetic mapping studies have confirmed phenotypic observations that selection on flowering time fluctuated in direction over sunflower's multis ... | 2013 | 23267017 |
| tyrosine nitration provokes inhibition of sunflower carbonic anhydrase (β-ca) activity under high temperature stress. | protein tyrosine nitration is a post-translational modification (ptm) mediated by reactive nitrogen species (rns) and it is a new area of research in higher plants. previously, it was demonstrated that the exposition of sunflower (helianthus annuus l.) seedlings to high temperature (ht) caused both oxidative and nitrosative stress. the nitroproteome analysis under this stress condition showed the induction of 13 tyrosine-nitrated proteins being the carbonic anhydrase (ca) one of these proteins. ... | 2013 | 23266784 |
| root biomass response to foliar application of imazapyr for two imidazolinone tolerant alleles of sunflower (helianthus annuus l.). | imisun and clplus are two imidazolinone tolerance traits in sunflower (helianthus annuus l.) determined by the expression of two alleles at the locus ahasl1. both traits differed in their tolerance level to imazapyr -a type of imidazolinone herbicide- when aboveground biomass is considered, but the concomitant herbicide effect over the root system has not been reported. the objective of this work was to quantify the root biomass response to increased doses of imazapyr in susceptible (ahasl1/ahas ... | 2012 | 23226083 |
| reduced drought tolerance during domestication and the evolution of weediness results from tolerance-growth trade-offs. | the increased reproductive potential, size, shoot allocation, and growth rate of weedy plants may result from reduced resource allocation to other aspects of plant growth and defense. to investigate whether changes in resource allocation occurred during domestication or the evolution of weediness, we compared the mycorrhizal responsiveness, growth, and drought tolerance of nine native ruderal, nine agriculturally weedy (four u.s. weedy and five australian weedy), and 14 domesticated populations ... | 2012 | 23206138 |
| how to escape from crop-to-weed gene flow: phenological variation and isolation-by-time within weedy sunflower populations. | the evolution of crop-related weeds may be constrained by recurrent gene flow from the crop. however, flowering time variation within weedy populations may open the way for weed adaptation by allowing some weeds to escape from this constraint. we investigated this link between phenology, gene flow and adaptation in weedy sunflower populations that have recently emerged in europe from crop-wild hybridization. we studied jointly flowering phenology and genetic diversity for 15 microsatellite loci ... | 2013 | 23181709 |
| an extracellular lipid transfer protein is relocalized intracellularly during seed germination. | plant lipid transfer proteins (ltps) constitute a family of small proteins recognized as being extracellular. in agreement with this notion, several lines of evidence have shown the apoplastic localization of haap10, a ltp from helianthus annuus dry seeds. however, haap10 was recently detected intracellularly in imbibing seeds. to clarify its distribution, immunolocalization experiments were performed during the course of germination and confirmed its intracellular localization upon early seed i ... | 2012 | 23162115 |
| plant response to lead in the presence or absence edta in two sunflower genotypes (cultivated h. annuus cv. 1114 and interspecific line h. annuus × h. argophyllus). | the aim of the present work was to study the response of two sunflower genotypes (cultivated sunflower helianthus annuus cv. 1114 and newly developed genotype h. annuus × helianthus argophyllus) to pb medium-term stress and the role of exogenously applied edta in alleviating pb toxicity in hydroponics. plant growth, morpho-anatomical characteristics of the leaf tissues, electrolyte leakage, total antioxidant activity, free radical scavenging capacity, total flavonoid content, and superoxide dism ... | 2013 | 23135752 |
| acetohydroxyacid synthase (ahas) in vivo assay for screening imidazolinone-resistance in sunflower (helianthus annuus l.). | the objective of this work was to evaluate the in vivo acetohydroxyacid synthase (ahas) activity response to imidazolinones and its possible use as a selection method for evaluating ahas inhibitor resistance. in vivo ahas assay and the comparison of parameters from dose-response curves have been used as a valid tool for comparing sunflower lines and hybrids differing in imidazolinone resistance. the sunflower resistant genotypes evaluated here were 100-fold and 20-fold more resistant compared wi ... | 2012 | 23123550 |
| development, characterization and experimental validation of a cultivated sunflower (helianthus annuus l.) gene expression oligonucleotide microarray. | oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, h. annuus l., which lacks full genome sequences. the goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. a large scale est (>130,000 ests) curation, assembly and sequence annotation was performed using ... | 2012 | 23110046 |
| morphological variation of mutant sunflowers (helianthus annuus) induced by space flight and their genetic background detection by ssr primers. | after sunflower seeds were exposed to space conditions, various mutant plants were screened from the descendent plants. the morphological characters of plants changed in flower color from golden to yellow, light yellow, or even to yellowish green. the ligulate petals of the unisexual floret broadened, or became thin, while the short tubular petals of bisexual floret elongated to some extent, or even turned into semi-ligulate petals or ligulate petals, making the phenotype of the whole infloresce ... | 2012 | 23079831 |
| a gene-phenotype network based on genetic variability for drought responses reveals key physiological processes in controlled and natural environments. | identifying the connections between molecular and physiological processes underlying the diversity of drought stress responses in plants is key for basic and applied science. drought stress response involves a large number of molecular pathways and subsequent physiological processes. therefore, it constitutes an archetypical systems biology model. we first inferred a gene-phenotype network exploiting differences in drought responses of eight sunflower (helianthus annuus) genotypes to two drought ... | 2012 | 23056196 |
| endogenous ascorbate restrains apoplastic peroxidase activity during sunflower leaf development. | several apoplastic enzymes have been implicated in the control of elongation growth of plant cells. among them, peroxidases contribute to both loosening and stiffening of the cell wall. they appear to be regulated by various mechanisms, including the action of extracellular inhibitors. to obtain evidence of the role of the enzyme-inhibitor interaction during leaf development, the intercellular washing fluids from helianthus annuus leaves of different ages were isolated using standard methods of ... | 2013 | 23043732 |
| malic acid or orthophosphoric acid-heat treatments for protecting sunflower (helianthus annuus) meal proteins against ruminal degradation and increasing intestinal amino acid supply. | the protection of sunflower meal (sfm) proteins by treatments with solutions of malic acid (1 m) or orthophosphoric acid (0.67 m) and heat was studied in a 3 × 3 latin-square design using three diets and three rumen and duodenum cannulated wethers. acid solutions were applied to sfm at a rate of 400 ml/kg under continuous mixing. subsequently, treated meals were dried in an oven at 150°c for 6 h. diets (ingested at 75 g/kg bw0.75) were isoproteic and included 40% italian ryegrass hay and 60% con ... | 2013 | 23032153 |
| phenotypic characterization, genetic mapping and candidate gene analysis of a source conferring reduced plant height in sunflower. | reduced height germplasm has the potential to increase stem strength, standability, and also yields potential of the sunflower crop (helianthus annuus l. var. macrocarpus ckll.). in this study, we report on the inheritance, mapping, phenotypic and molecular characterization of a reduced plant height trait in inbred lines derived from the source ddr. this trait is controlled by a semidominant allele, rht1, which maps on linkage group 12 of the sunflower public consensus map. phenotypic effects of ... | 2013 | 22972203 |
| gene expression assays for actin, ubiquitin, and three microsatellite-encoding genes in helianthus annuus (asteraceae). | the "tuning knob" model of king et al. (endeavor 21: 36-40, 1997) postulates that microsatellite mutations can alter phenotypes in a stepwise fashion. some proposed mechanisms involve regulation of gene expression. to study the effect of microsatellites harbored in untranslated regions on gene expression in helianthus annuus, we have developed taqman assays for three microsatellite-encoding genes, and two constitutively expressed genes, actin and ubiquitin, to serve as standards. | 2012 | 22935362 |
| total synthesis of natural enantiomers of heliespirones a and c via the diastereoselective intramolecular hosomi-sakurai reaction. | a full account of the development of a novel type of the intramolecular hosomi-sakurai reactions of the substrates with a p-benzoquinone and an allylsilane moieties connected by an ether linkage is described. this transformation proceeds via an addition-elimination sequence and provides the products with two stereogenic centers through a 1,3(or 1,4)-asymmetric induction in good to excellent diastereoselectivities. a reasonable mechanistic possibility for the reaction, determination of the stereo ... | 2012 | 22924604 |
| development of a 10,000 locus genetic map of the sunflower genome based on multiple crosses. | genetic linkage maps have the potential to facilitate the genetic dissection of complex traits and comparative analyses of genome structure, as well as molecular breeding efforts in species of agronomic importance. until recently, the majority of such maps was based on relatively low-throughput marker technologies, which limited marker density across the genome. the availability of high-throughput genotyping technologies has, however, made possible the efficient development of high-density genet ... | 2012 | 22870395 |
| role of recently evolved mirna regulation of sunflower hawrky6 in response to temperature damage. | micrornas (mirnas) are small 21-nucleotide rnas that post-transcriptionally regulate gene expression. mir396 controls leaf development by targeting grf and bhlh transcription factors in arabidopsis. wrky transcription factors, unique to plants, have been identified as mediating varied stress responses. the sunflower (helianthus annuus) hawrky6 is a particularly divergent wrky gene exhibiting a putative target site for the mir396. a possible post-transcriptional regulation of hawrky6 by mir396 wa ... | 2012 | 22846054 |
| growth under elevated atmospheric co(2) concentration accelerates leaf senescence in sunflower (helianthus annuus l.) plants. | some morphogenetic and metabolic processes were sensitive to a high atmospheric co(2) concentration during sunflower primary leaf ontogeny. young leaves of sunflower plants growing under elevated co(2) concentration exhibited increased growth, as reflected by the high specific leaf mass referred to as dry weight in young leaves (16 days). the content of photosynthetic pigments decreased with leaf development, especially in plants grown under elevated co(2) concentrations, suggesting that high co ... | 2012 | 22818664 |
| the tolerance efficiency of panicum maximum and helianthus annuus in tnt-contaminated soil and nzvi-contaminated soil. | this study was designed to compare the initial method for phytoremediation involving germination and transplantation. the study was also to determine the tolerance efficiency of panicum maximum (purple guinea grass) and helianthus annuus (sunflower) in tnt-contaminated soil and nzvi-contaminated soil. it was found that the transplantation of panicum maximum and helianthus annuus was more suitable than germination as the initiate method of nano-phytoremediation potting test. the study also showed ... | 2012 | 22702809 |
| the sunflower (helianthus annuus l.) genome reflects a recent history of biased accumulation of transposable elements. | aside from polyploidy, transposable elements are the major drivers of genome size increases in plants. thus, understanding the diversity and evolutionary dynamics of transposable elements in sunflower (helianthus annuus l.), especially given its large genome size (∼3.5 gb) and the well-documented cases of amplification of certain transposons within the genus, is of considerable importance for understanding the evolutionary history of this emerging model species. by analyzing approximately 25% of ... | 2012 | 22691070 |
| response of sunflower (helianthus annuus l.) leaf surface defenses to exogenous methyl jasmonate. | helianthus annuus, the common sunflower, produces a complex array of secondary compounds that are secreted into glandular trichomes, specialized structures found on leaf surfaces and anther appendages of flowers. the primary components of these trichome secretions are sesquiterpene lactones (stl), a diverse class of compounds produced abundantly by the plant family compositae and believed to contribute to plant defense against herbivory. we treated wild and cultivated h. annuus accessions with e ... | 2012 | 22623991 |
| evidence of selection on fatty acid biosynthetic genes during the evolution of cultivated sunflower. | the identification of genes underlying the phenotypic transitions that took place during crop evolution, as well as the genomic extent of resultant selective sweeps, is of great interest to both evolutionary biologists and applied plant scientists. in this study, we report the results of a molecular evolutionary analysis of 11 genes that underlie fatty acid biosynthesis and metabolism in wild and cultivated sunflower (helianthus annuus). seven of these 11 genes showed evidence of selection at th ... | 2012 | 22580969 |
| accumulation of cadmium, zinc, and copper by helianthus annuus l.: impact on plant growth and uptake of nutritional elements. | we investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of cd; 5 and 300 mg kg(-1) of cd and zn, respectively; 5, 300, and 400 mg kg(-1) of cd, zn, and cu, respectively. contaminants applied did not produce large effects on growth, except in cd-zn-cu treatment in which leaf area and total dry matter were reduced, by 15%. the contamination with cd alone did not affect neither growth nor physi ... | 2012 | 22567714 |
| phytoremediation potential of helianthus annuus l in sewage-irrigated indo-gangetic alluvial soils. | the study of phytoremediation potential of helianthus annuus l was conducted in the sewage-irrigated indo-gangetic alluvial soils, india. calcium @ 1.0% and zn @ 40 ppm enhanced the yield of h. annuus l and minimized the toxicity of cr in the investigated soils. the study indicated that h. annuus l is highly sensitive to cr and zn in terms of metallic pollution; and may be used as indicator plant. for cr-phytoremediation, humic acid treatment @ 500 ml/acre induced the cr-accumulation in roots (p ... | 2012 | 22567708 |
| a transposon-mediate inactivation of a cycloidea-like gene originates polysymmetric and androgynous ray flowers in helianthus annuus. | in several eudicots, including members of the asteraceae family, the cycloidea (cyc) genes, which belong to the tcp class of transcription factors, are key players for floral symmetry. the sunflower inflorescence is heterogamous (radiate capitulum) with sterile monosymmetric ray flowers located in the outermost whorl of the inflorescence and hermaphrodite polysymmetric disk flowers. in inflorescence of heliantheae tribe, flower primordia development initiates from the marginal ray flowers while ... | 2011 | 22552535 |
| reconciling extremely strong barriers with high levels of gene exchange in annual sunflowers. | in several cases, estimates of gene flow between species appear to be higher than we might predict given the strength of interspecific barriers separating these species pairs. however, as far as we are aware, detailed measurements of reproductive isolation have not previously been compared with a coalescent-based assessment of gene flow. here, we contrast these two measures in two species of sunflower, helianthus annuus and h. petiolaris. we quantified the total reproductive barrier strength bet ... | 2012 | 22519784 |
| cynarin-rich sunflower (helianthus annuus) sprouts possess both antiglycative and antioxidant activities. | the present study examined the antiglycative and antioxidant properties of four edible sprouts popular in chinese markets. in a protein-reducing sugar model, the sunflower sprout helianthus annuus exhibited the strongest inhibitory effects against the formation of advanced glycation end products (ages). at a concentration of 1.0 mg/ml, its inhibitory rate achieved 83.29%, which is stronger than that of aminoguanidine (1 mm), a well-known synthetic antiglycative agent (with an inhibitory rate of ... | 2012 | 22394088 |
| capture of sunflower seedlings lipase using polyclonal antibodies. | true lipolytic activity is observed in different subcellular fractions of germinating sunflower seedlings (helianthus annuus l.) in delipidated oleosomes and microsomes. triacylglycerol lipase (ec. 3.1.1.3) catalyses the first catabolic step of lipolysis. to our knowledge, this plant lipase has not yet been identified. our aim was to develop a method to collect the lipase for further studies. an immunological method was used to capture sunflower seedling lipase from oleosomes and microsomes. thi ... | 2012 | 22309314 |
| snp discovery and development of a high-density genotyping array for sunflower. | recent advances in next-generation dna sequencing technologies have made possible the development of high-throughput snp genotyping platforms that allow for the simultaneous interrogation of thousands of single-nucleotide polymorphisms (snps). such resources have the potential to facilitate the rapid development of high-density genetic maps, and to enable genome-wide association studies as well as molecular breeding approaches in a variety of taxa. herein, we describe the development of a snp ge ... | 2012 | 22238659 |
| the population genomics of sunflowers and genomic determinants of protein evolution revealed by rnaseq. | few studies have investigated the causes of evolutionary rate variation among plant nuclear genes, especially in recently diverged species still capable of hybridizing in the wild. the recent advent of next generation sequencing (ngs) permits investigation of genome wide rates of protein evolution and the role of selection in generating and maintaining divergence. here, we use individual whole-transcriptome sequencing (rnaseq) to refine our understanding of the population genomics of wild specie ... | 2012 | 24832509 |
| molecular cloning and characterization of gene coding for γ-tocopherol methyltransferase from lettuce (lactuca sativa). | γ-tocopherol methyltransferase is an important rate-limiting enzyme involved in tocopherol biosynthesis. the full-length cdna encoding γ-tocopherol methyltransferase (designated as lstmt) was cloned from lactuca sativa for the first time by rapid amplification of cdna ends and characterized by means of quantitative rt-pcr. the full-length cdna of lstmt was 1131 bp, with an open reading frame of 897 bp encoding a γ-tocopherol methyltransferase protein of 298 amino acids, with a calculated molecul ... | 2011 | 22194177 |
| sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the u.s. southwest? | classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. here, we use this approach to search for biological control agents of the sunflower stem weevil (cylindrocopturus adspersus leconte), an economically important pest of commercial sunflower. we conducted surveys of weevil natural enemy diversity and abundance across a transect running from the northern great plains to the southwestern u.s. (the presumed area of endemi ... | 2011 | 22182606 |
| characterization of long transcribed microsatellites in helianthus annuus (asteraceae). | research on the evolutionary role of exonic microsatellites currently lacks an understanding of the evolutionary pressures that promote or limit their expansion. contrasting levels of variability and genetic structures at anonymous and transcribed microsatellite loci of varying lengths are likely to provide useful insights regarding the relative strength of selection acting on different classes of microsatellites. we have developed primers for long transcribed microsatellites in helianthus annuu ... | 2011 | 22130271 |
| copper phytoextraction in tandem with oilseed production using commercial cultivars and mutant lines of sunflower. | use of sunflower (helianthus annuus l.) for cu phytoextraction and oilseed production on cu-contaminated topsoils was investigated in afield trial at a former wood preservation site. six commercial cultivars and two mutant lines were cultivated in plots with and without the addition of compost (5% w/w) and dolomitic limestone (0.2% w/w). total soil cu ranged from 163 to 1170 mg kg(-1). in soil solutions, cu concentration varied between 0.16-0.93 mg l(-1). the amendment increased soil ph, reduced ... | 2011 | 22046751 |
| greenhouse gas emissions and plant characteristics from soil cultivated with sunflower (helianthus annuus l.) and amended with organic or inorganic fertilizers. | agricultural application of wastewater sludge has become the most widespread method of disposal, but the environmental effects on soil, air, and crops must be considered. the effect of wastewater sludge or urea on sunflower's (helianthus annuus l.) growth and yield, the soil properties, and the resulting co(2) and n(2)o emissions are still unknown. the objectives of this study were to investigate: i) the effect on soil properties of organic or inorganic fertilizer added to agricultural soil cult ... | 2011 | 22033361 |
| increased growth in sunflower correlates with reduced defences and altered gene expression in response to biotic and abiotic stress. | cultivated plants have been selected by humans for increased yield in a relatively benign environment, where nutrient and water resources are often supplemented, and biotic enemy loads are kept artificially low. agricultural weeds have adapted to this same benign environment as crops and often have high growth and reproductive rates, even though they have not been specifically selected for yield. considering the competing demands for resources in any plant, a key question is whether adaptation t ... | 2011 | 21988641 |
| response to imazapyr and dominance relationships of two imidazolinone-tolerant alleles at the ahasl1 locus of sunflower. | imisun and clplus are two imidazolinone (imi) tolerance traits in sunflower (helianthus annuus l.) determined by the expression of different alleles at the same locus, ahasl1-1 and ahasl1-3, respectively. this paper reports the level of tolerance expressed by plants containing both alleles in a homozygous, heterozygous and in a heterozygous stacked state to increasing doses of imi at the enzyme and whole plant levels. six genotypes of the ahasl1 gene were compared with each other in three differ ... | 2012 | 21964993 |
| a study on the waste metal remediation using floriculture at east calcutta wetlands, a ramsar site in india. | use of specific plant species in remediation of heavy metal-contaminated soil and water was a promising eco-friendly technology. the present study indicated the possibilities of phytoremediation of metal-contaminated (namely ca, cr, mn, fe, cu, zn, and pb) soil by using plant species important for floriculture of east calcutta wetlands, a ramsar site at the eastern fringe of calcutta city. plant species like sunflower (helianthus annuus), marigold (tagetes patula), and cock's comb (celocia crist ... | 2012 | 21960361 |
| influence of copper on root exudate patterns in some metallophytes and agricultural plants. | a hydroponic experiment was carried out to determine the root exudation patterns in two cu-metallophytes (oenothera picensis and imperata condensata) and two agricultural plants (lupinus albus and helianthus annuus). plants were grown in nutrient solution at increasing cu doses (0, 0.125, 0.25, 0.5, 1 and 2mgcul(-1)), and plant growth, root elongation, cu accumulation and root exudates were measured. all plants showed a decrease of over 60% in root elongation at the highest cu supply level, bein ... | 2012 | 21937112 |
| pollen aroma fingerprint of two sunflower (helianthus annuus l.) genotypes characterized by different pollen colors. | samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (helianthus annuus l.) and characterized by a different color, i.e., white-cream (wc) and orange (o), were analyzed by the hs-spme (headspacesolid phase microextraction)/gc/ms technique. this study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. in the gc/ms fingerprints of the wc and o g ... | 2011 | 21922665 |
| shedding light on the evolution of plasticity in natural populations. | plasticity allows for changes in phenotype in response to environmental cues, often facilitating local adaptation to seasonal environments. phenotypic plasticity alone, however, may not always be sufficient to ensure adaptation to new localities. in particular, changing cues associated with shifting seasonal regimes may no longer induce appropriate phenotypic responses in new environments (nicotra et al. 2010). plastic responses must thus evolve to avoid being maladaptive. to date, the extent to ... | 2011 | 21884290 |
| impact of planting dates on a seed maggot, neotephritis finalis (diptera: tephritidae), and sunflower bud moth (lepidoptera: tortricidae) damage in cultivated sunflower. | neotephritisfinalis (loew) (diptera: tephritidae), and sunflower bud moth, suleima helianthana (riley) (lepidoptera: tortricidae) are major head-infesting insect pests of cultivated sunflower (helianthus annuus l.). planting date was evaluated as a cultural pest management strategy for control of n. finalis and s. helianthana in several production regions of north dakota during 2009 and 2010. results of the nine site-year study revealed that late planting date (early to mid-june) reduced damage ... | 2011 | 21882688 |
| dna alteration and programmed cell death during ageing of sunflower seed. | sunflower (helianthus annuus l.) seed viability is affected by moisture content (mc) during ageing and is related to accumulation of hydrogen peroxide and changes in energy metabolism. the aim of the present work was to investigate the effect of ageing on dna alteration events by rapd (random amplification of polymorphic dna) analysis and to determine whether loss of seed viability might correspond to a controlled programmed cell death (pcd). ageing of sunflower seeds was carried out at 35 °c fo ... | 2011 | 21765164 |
| catalase is a key enzyme in seed recovery from ageing during priming. | ageing induces seed deterioration expressed as the loss of seed vigour and/or viability. priming treatment, which consists in soaking of seeds in a solution of low water potential, has been shown to reinvigorate aged seeds. we investigate the importance of catalase in oxidation protection during accelerated ageing and repair during subsequent priming treatment of sunflower (helianthus annuus l.) seeds. seeds equilibrated to 0.29g h2og(-1) dry matter (dm) were aged at 35°c for different durations ... | 2011 | 21763542 |
| connecting the sun to flowering in sunflower adaptation. | species living in seasonal environments often adaptively time their reproduction in response to photoperiod cues. we characterized the expression of genes in the flowering-time regulatory network across wild populations of the common sunflower, helianthus annuus, that we found to be adaptively differentiated for photoperiod response. the observed clinal variation was associated with changes at multiple hierarchical levels in multiple pathways. paralogue-specific changes in ft homologue expressio ... | 2011 | 21676045 |
| high temperature triggers the metabolism of s-nitrosothiols in sunflower mediating a process of nitrosative stress which provokes the inhibition of ferredoxin-nadp reductase by tyrosine nitration. | high temperature (ht) is considered a major abiotic stress that negatively affects both vegetative and reproductive growth. whereas the metabolism of reactive oxygen species (ros) is well established under ht, less is known about the metabolism of reactive nitrogen species (rns). in sunflower (helianthus annuus l.) seedlings exposed to ht, no content as well as s-nitrosoglutathione reductase (gsnor) activity and expression were down-regulated with the simultaneous accumulation of total s-nitroso ... | 2011 | 21676000 |
| physiology and proteomics of drought stress acclimation in sunflower (helianthus annuus l.). | an easy and manageable in vitro screening system for drought tolerance of sunflower seedlings based on ms media supplemented with polyethylene glycol 6000 was evaluated. morphological and physiological parameters were compared between control (-0.05 mpa) and drought-stressed (-0.6 mpa) seedlings of helianthus annuus l. cv. peredovick. there was a significant growth deficit in drought-stressed plants compared to control plants in terms of hypocotyl length, and shoot and root fresh mass. shoot gro ... | 2011 | 21668604 |
| detection of single copy sequences using bac-fish and c-prins techniques in sunflower chromosomes. | bacterial artificial chromosome-fluorescence in situ hybridization (bac-fish) and cycling-primed in situ labeling (c-prins) techniques were evaluated for integration of physical and genetic maps of sunflower (helianthus annuus l.). single-site ssr markers were selected from three linkage groups of a high-density sunflower genetic map. this selection was based on previously identified qtl associated to s. sclerotiorum. these markers were used to select bacs contaning single copy sequences for bac ... | 2011 | 21667668 |
| selection on seedling emergence timing and size in an annual plant, helianthus annuus (common sunflower, asteraceae). | variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. to explore the adaptive significance of seedling emergence timing, it should be studied under realistic conditions and in the context of other traits that influence fitness. | 2011 | 21653510 |
| genetic diversity and population structure in cultivated sunflower and a comparison to its wild progenitor, helianthus annuus l. | crop germplasm collections are valuable resources for ongoing plant breeding efforts. to fully utilize such collections, however, researchers need detailed information about the amount and distribution of genetic diversity present within collections. here, we report the results of a population genetic analysis of the primary gene pool of sunflower (helianthus annuus l.) based on a broad sampling of 433 cultivated accessions from north america and europe, as well as a range-wide collection of 24 ... | 2011 | 21638000 |
| the origin and evolution of a recent agricultural weed: population genetic diversity of weedy populations of sunflower (helianthus annuus l.) in spain and france. | the recurrent evolution of crop-related weeds during agricultural history raises serious economic problems and challenging scientific questions. weedy forms of sunflower, a species native from america, have been reported in european sunflower fields for a few decades. in order to understand their origin, we analysed the genetic diversity of a sample of weedy populations from france and spain, and of conventional and ornamental varieties. a crop-specific maternally inherited marker was present in ... | 2011 | 25567998 |
| molecular cloning and characterization of a tocopherol cyclase gene from lactuca sativa (asteraceae). | tocopherol cyclase is a rate-limiting enzyme involved in tocopherol biosynthesis. the full-length cdna encoding tocopherol cyclase (designated as lstc) was cloned from lettuce (lactuca sativa) for the first time by rapid amplification of cdna ends (race) and characterized by means of quantitative rt-pcr. the full-length cdna of lstc was 1675 bp, with an open reading frame of 1521 bp, encoding a tocopherol cyclase protein of 506 amino acids, with a calculated molecular mass of 56.76 kd and an iso ... | 2011 | 21523658 |
| suppression subtractive hybridization reveals differential gene expression in sunflower grown in high p. | sunflower (helianthus annuus l.) is a commercially important oilseed crop. previous studies proved that this crop is a promising plant species for phytoextraction of excess soil phosphorus (p) because of its superior p accumulating characteristics. suppression subtractive hybridization (ssh) strategy was employed to isolate and characterize genes that are induced in response to high p in this crop. ssh library was prepared using cdna generated from plants treated with high p as the 'tester'. bas ... | 2011 | 21463950 |
| structure of the stigma and style in sunflower (helianthus annuus l.). | this is the first report of the ultrastructure of the stigma and style during and after anthesis in helianthus annuus l. using light and transmission electron microscopy. the stigma is bifid with unicellular papillae. there is no secretion of lipids, carbohydrates or proteins at anthesis. the style is semisolid in the upper portion, closer to the stigma, and becomes solid below. ultrastructural changes on cells of the stigma and the style are described. the transmitting tissue of the ovule is fi ... | 2010 | 21443143 |
| an optimized preparation method to obtain high-quality rna from dry sunflower seeds. | in an attempt to isolate high-quality, intact total rna from sunflower (helianthus annuus) seeds for investigation of the molecular mechanisms of mutations, we tested various procedures, using kits, including rnaiso plus, rnaiso plus+rnaiso-mate for plant tissue, trizol, and the qi method, but no high-quality total rna of high integrity was obtained with any of these methods, probably due to the high content of polyphenols, polysaccharides, and secondary metabolites in mature sunflower seeds. mo ... | 2011 | 21308657 |
| ontogenetic changes in the scaling of cellular respiration with respect to size among sunflower seedlings. | the respiration rates r (oxygen uptake per min) and body mass m (mg per individual) of sunflower (helianthus annuus l.) seedlings were measured for populations raised in the dark (scotomorphogenesis) and for plants subsequently grown in white light (photomorphogenesis) to determine the allometric (scaling) relationship for r vs. m. based on ordinary least squares and reduced major axis regression protocols, cellular respiration rates were found to increase non-linearly as a 'broken-stick' curve ... | 2011 | 21301213 |
| transposable element proliferation and genome expansion are rare in contemporary sunflower hybrid populations despite widespread transcriptional activity of ltr retrotransposons. | hybridization is a natural phenomenon that has been linked in several organismal groups to transposable element derepression and copy number amplification. a noteworthy example involves three diploid annual sunflower species from north america that have arisen via ancient hybridization between the same two parental taxa, helianthus annuus and h. petiolaris. the genomes of the hybrid species have undergone large-scale increases in genome size attributable to long terminal repeat (ltr) retrotransp ... | 2011 | 21282712 |