| evaluating the contribution of soil properties to modifying lead phytoavailability and phytotoxicity. | soil properties affect pb bioavailability to human and ecological receptors and should be considered during ecological risk assessment of contaminated soil. we used path analysis (pa) to determine the relative contribution of soil properties (ph, organic c [oc], amorphous fe and al oxides [feal], and cation-exchange capacity [cec]) in modifying pb bioavailability. the response of biological endpoints (bioaccumulation and dry matter growth [dmg]) of lettuce (lactuca sativa) grown on 21 pb-spiked ... | 2006 | 16566156 |
| effect of scale of cd heterogeneity and timing of exposure on the cd uptake and shoot biomass, of plants with a contrasting root morphology. | a pot experiment was conducted to investigate the influence of spatial heterogeneity of cd distribution in soil on shoot biomass, shoot metal concentration and total shoot cd uptake by lettuce (lactuca sativa, variety tom thumb) and indian mustard (brassica juncea). five different soil treatments had similar overall concentration of cd per pot, but different scales of heterogeneity and also timing of plant exposure during the growth cycle. the presence and scale of heterogeneity and timing of ex ... | 2006 | 16600333 |
| pseudomonads associated with midrib rot and soft rot of butterhead lettuce and endive. | during the past ten years, bacterial soft rot and midrib rot of glasshouse-grown butterhead lettuce (lactuca sativa l. var. capitata) and field-grown endive (cichorium endivia l.) has become increasingly common in the region of flanders, belgium. severe losses and reduced market quality caused by bacterial rot represent an important economical threat for the production sector. symptoms of midrib rot are a brownish rot along the midrib of one or more inner leaves, often accompanied by soft rot of ... | 2005 | 16637164 |
| biological control of botrytis gray mould and sclerotinia drop in lettuce. | research was carried out to evaluate the effectiveness of the biological control of two most important fungal diseases of lettuce (lactuca sativa l.): 1) botrytis gray mould caused by botrytis cinerea pers. ex fr.; 2) sclerotinia drop caused by two pathogenic fungi, sclerotinia sclerotiorum (lib.) de bary and/or sclerotinia minorjagger. biological control in lettuce was carried out: 1) using coniothyrium minitans campbell, an antagonist fungus that attacks and destroys sclerotia within the soil; ... | 2005 | 16637171 |
| attempts to detect cyclic adenosine 3':5'-monophosphate in higher plants by three assay methods. | endogenous levels of cyclic adenosine-3':5'-monophosphate in coleoptile first leaf segments of oat (avena sativa l.), potato (solanum tuberosum l.) tubers, tobacco (nicotiana tabacum l.) callus, and germinating seeds of lettuce (lactuca sativa l.) were measured with a modified gilman binding assay and a protein kinase activation assay. the incorporation of adenosine-8-(14)c into compounds with properties similar to those of cyclic amp was also measured in studies with germinating lettuce seeds. ... | 1976 | 16659419 |
| growth and gibberellin a(1) metabolism in excised lettuce hypocotyls. | excised lettuce (lactuca sativa l. cv. arctic) hypocotyls retain the ability to elongate in response to exogenously supplied gibberellic acid and gibberellin a(1) (ga(1)). we have studied the relationship between metabolism of ga(1) and elongation in this tissue. in 24 hours at 28 c, hypocotyls treated with 3 mum ga(1) double in length while controls elongate less than 45%. after an exogenous hormone supply is removed, hypocotyls continue to grow faster than untreated controls, although as the h ... | 1977 | 16659819 |
| immunopurification and initial characterization of dicotyledonous phytochrome. | antiserum was prepared against proteolytically undegraded phytochrome obtained from etiolated zucchini squash (cucurbita pepo l., cv. black beauty). the antiserum was prepared by injecting into a rabbit immunoprecipitates between zucchini phytochrome and specific antiserum against undegraded oat (avena sativa l., cv. garry) phytochrome. specific antiphytochrome immunoglobulins were purified from this crude serum by an affinity column consisting of conventionally purified undegraded pea phytochro ... | 1982 | 16662209 |
| immobilized thylakoids in a cross-linked albumin matrix: effects of cations studied by electron microscopy, fluorescence emission, photoacoustic spectroscopy, and kinetic measurements. | immobilization of lettuce (lactuca sativa) thylakoids has been performed by using glutaraldehyde and bovine serum albumin. confirming previous reports, a stabilization of the o(2) evolution activity of the photosystem ii (psii) under storage and functional conditions has been observed. the present work is devoted to the role played by mono-and divalent cations, during the immobilization process itself, on the o(2) production. four types of measurements have been employed: kinetic measurements, l ... | 1982 | 16662563 |
| gibberellin-mediated synergism of xylogenesis in lettuce pith cultures. | major gibberellins (gas) in lettuce (lactuca sativa l. cv romaine) pith explants have been identified by gas chromatography-mass spectrometry (gc-ms) or gc-selected ion monitoring (gc-sim) as ga(1), 3-epi-ga(1), ga(8), ga(19), and ga(20). treatment of pith explants with indole-3-acetic acid (iaa) (57 micromolar) plus kinetic (0.5 micromolar) induced xylogenesis. in this xylogenic treatment, the concentration of a biologically active, polar ga-like substance(s) increased during the first 2 days o ... | 1987 | 16665571 |
| artefactual origins of cyclic amp in higher plant tissues. | a highly sensitive radioimmunoassay has been used to determine the levels of adenosine 3',5'-cyclic monophosphate (camp) in five higher plants (lactuca sativa, helianthus annuus, oryza sativa, pinus pinaster, nicotiana tabacum). particular attention was paid to the three main sources of errors in the characterization of camp in plants: presence of interfering substances in plant tissues; possible artefactual formation of camp from endogenous atp during extraction, purification, and assay; and mi ... | 1989 | 16667078 |
| phenotypic characterization of lettuce dwarf mutants and their response to applied gibberellins. | four monogenic, recessive dwarf mutants of lettuce (lactuca sativa l.), previously isolated from a population induced by ethyl methanesulfonate, were compared with the normal genotype (e-1) for plant height, weight, leaf area, as well as hypocotyl length and root length. these nonallelic dwarfs (dwf1, dwf2, and dwf3) exhibited reduced hypocotyl length, smaller, dark green leaves, and reduced stem length. another mutant, dwf2, allelic with dwf2, exhibited an intermediate phenotype. epidermal cell ... | 1991 | 16668106 |
| the endogenous gibberellins of dwarf mutants of lettuce. | the gibberellin (ga) content of e-1, a tall genotype of early flowering lettuce (lactuca sativa l.), and of three selected ga-responsive dwarfs, dwf1, dwf2, and dwf2(1), has been determined using (13)c-labeled internal standards and gas chromatographymass spectrometry (gc-ms). in the shoots of the e-1 parent, ga(1), 3-epi-ga(1), ga(3), ga(5), ga(8), ga(19), ga(20), ga(29), and ga(53) were identified by full scan gc-ms and kovats retention indices. purification by immunoaffinity chromatography se ... | 1991 | 16668107 |
| chryseobacterium wanjuense sp. nov., isolated from greenhouse soil in korea. | a taxonomic study was performed on strain r2a10-2(t), isolated from greenhouse soil cultivated with lettuce (lactuca sativa l.), collected in wanju province, korea. the bacterial cells were gram-negative, aerobic, short rods. the growth temperature and ph were 5-35 degrees c and 5.0-9.0, respectively. phylogenetic analysis based on 16s rrna gene sequences revealed that this isolate had 93.3-97.7 % similarity to chryseobacterium species: the highest sequence similarities were to the type strains ... | 2006 | 16825619 |
| synthesis and assembly of escherichia coli heat-labile enterotoxin b subunit in transgenic lettuce (lactuca sativa). | escherichia coli heat-labile enterotoxin b subunit (ltb) strongly induces immune responses and can be used as an adjuvant for co-administered antigens. synthetic ltb (sltb) based on optimal codon usage by plants was introduced into lettuce cells (lactuca sativa) by agrobacterium tumefaciens-mediated transformation methods. the sltb gene was detected in the genomic dna of transgenic lettuce leaf cells by pcr dna amplification. synthesis and assembly of the sltb protein into oligomeric structures ... | 2007 | 16919472 |
| effectiveness of two-sided uv-c treatments in inhibiting natural microflora and extending the shelf-life of minimally processed 'red oak leaf' lettuce. | the use of uv-c radiation treatments to inhibit the microbial growth and extend the shelf-life of minimally processed 'red oak leaf' lettuce was investigated. initially, uv-c resistance of 20 bacterial strains from different genera often associated with fresh produce (enterobacter, erwinia, escherichia, leuconostoc, pantoea, pseudomonas, rahnela, salmonella, serratia and yersinia) were tested in vitro. most of the bacterial strains were inhibited with the minimum dose (30 j m(-2)). erwinia carot ... | 2006 | 16943010 |
| quantification of contamination of lettuce by gfp-expressing escherichia coli o157:h7 and salmonella enterica serovar typhimurium. | the primary objective of this study was to determine the possibility of internalization of gfp-expressing escherichia coli o157:h7 and salmonella enterica serovar typhimurium (s. typhimurium) strains mae 110 (multi-cellular morphology) and 119 (wild type morphology) into lettuce seedlings (lactuca sativa cv. tamburo) grown in an inoculated hydroponic and soil system. the second aim was to quantify the level of contamination with the use of a proper surface sterilization method. silver nitrate wa ... | 2007 | 16943102 |
| lettuce (lactuca sativa l.). | lettuce is a globally important leafy vegetable with the united states being the largest world producers. the crop is susceptible to a number of viruses that are aphid transmitted and also highly vulnerable to post harvest diseases. although wild species of lettuce are an important source of disease resistance genes, their introgression into commercial lettuce has been limited owing to sexual incompatibilities. hence, the development of a gene transfer system for lettuce would be extremely valua ... | 2006 | 16988367 |
| microbiological determinations of some vegetables from the xochimilco zone in mexico city, mexico. | vegetables intake is widely recommended because of its high content of vitamins, minerals and fiber. however, the irrigation of these vegetables, using wastewaters that have received inadequate treatment often carries unseen microbial pollution that becomes a high risk potential for humans. in the present research, two of the most consumed fresh vegetables cultivated in mexico city were analyzed, lettuce (lactuca sativa) and mexican coriander (eryngium foetidum). these vegetables are commonly co ... | 2002 | 17061512 |
| effect of methyl tert-butyl ether in standard tests for mutagenicity and environmental toxicity. | methyl tert-butyl ether (mtbe) is a synthetic compound that is used as a technological solution to problems created by air pollution from vehicle emissions. an important source of mtbe in the environment is leakage from underground storage tanks at gasoline stations or accidents during gasoline transport. the aim of this study was to evaluate the risk of mtbe leakage for the environment using the microtox (vibrio fischeri) toxicity test, lactuca sativa seed germination test, and ames bacterial m ... | 2006 | 17091504 |
| ecotoxicity monitoring of hydrocarbon-contaminated soil during bioremediation: a case study. | the ecotoxicity of hydrocarbon-contaminated soil originating from a brownfield site was evaluated during a 17-month biodegradation pilot test. the initial concentration of total petroleum hydrocarbons (tphs) in the soil was 6380 microg/g dry weight. an amount of 200 kg soil was inoculated with 1.5 l of the bacterial preparation gem-100 containing pseudomonas sp. and acinetobacter sp. strains (5.3 x 10(10) cfu.ml(-1)) adapted to diesel fuel. the concentration of tphs in the soil decreased by 65.5 ... | 2007 | 17106791 |
| heterologous expression of the mutated melon ethylene receptor gene cm-ers1/h70a produces stable sterility in transgenic lettuce (lactuca sativa). | the mutated melon ethylene receptor gene cm-ers1/h70a was introduced into tobacco and induced stable sterility in transgenic lines. this gene contains a missense mutation that converts the his(70) residue to ala in the melon ethylene receptor gene cm-ers1. to test the applicability of this inducible sterility system to other plants, lettuce (lactuca sativa) was transformed with the gene using agrobacterium, and putative transformants containing cm-ers1/h70a were obtained. thirteen randomly selec ... | 2007 | 17207555 |
| solid-state cultures of fusarium oxysporum transform aromatic components of olive-mill dry residue and reduce its phytotoxicity. | the present study mainly investigated the ability of solid-state cultures of the non-pathogenic fusarium oxysporum strain bafc 738 to transform aromatic components to reduce the phytotoxicity in olive-mill dry residue (dor), the waste from the two-phase manufacturing process. lignin, hemicellulose, fats and water-soluble extractives contents of dor colonized by the fungus for 20 weeks were reduced by 16%, 25%, 71% and 13%, respectively, while the cellulose content increased by 25%. in addition, ... | 2007 | 17207620 |
| comparison of virulence between clinical and environmental pseudomonas aeruginosa isolates. | new strains of pseudomonas aeruginosa were isolated from clinical and environmental settings in order to characterize the virulence properties of this opportunistic pathogen. p. aeruginosa was frequently recovered from oil-contaminated samples but not from non-oil-contaminated soils. the virulence of five environmental and five clinical strains of p. aeruginosa was tested using two different models, drosophila melanogaster and lactuca sativa var. capitata l. there was no difference in the virule ... | 2006 | 17236157 |
| a genetic map of lettuce (lactuca sativa l.) with restriction fragment length polymorphism, isozyme, disease resistance and morphological markers. | a detailed linkage map of lettuce was constructed using 53 genetic markers including 41 restriction fragment length polymorphism (rflp) loci, five downy mildew resistance genes, four isozyme loci and three morphological markers. the genetic markers were distributed into nine linkage groups and cover 404 cm which may be 25-30% of the lettuce genome. the majority (31 of 34) of the rflp probes detected single segregating loci, although seven of these may have been homologous to further monomorphic ... | 1987 | 17246387 |
| extreme size and sequence variation in the its rdna of bremia lactucae. | bremia lactucae regel (chromista, peronosporaceae) is an economically destructive pathogen, which causes downy mildew disease on lettuce (lactuca sativa l.) worldwide. the ribosomal internal transcribed spacer (its) of bremia lactucae isolates was analyzed for the first time. the its region of lettuce downy mildew was observed to have a size of 2458 bp; thereby, having one of the longest its sizes recorded to date. the majority of the extremely large sized its2 length of 2086 was attributed to t ... | 2007 | 17286165 |
| successful gene tagging in lettuce using the tnt1 retrotransposon from tobacco. | the tobacco (nicotiana tabacum) element tnt1 is one of the few identified active retrotransposons in plants. these elements possess unique properties that make them ideal genetic tools for gene tagging. here, we demonstrate the feasibility of gene tagging using the retrotransposon tnt1 in lettuce (lactuca sativa), which is the largest genome tested for retrotransposon mutagenesis so far. of 10 different transgenic bushes carrying a complete tnt1 containing t-dna, eight contained multiple transpo ... | 2007 | 17351058 |
| ecotoxicity of a polycyclic aromatic hydrocarbon (pah)-contaminated soil. | soil samples from a former cokery site polluted with polycyclic aromatic hydrocarbons (pahs) were assessed for their toxicity to terrestrial and aquatic organisms and for their mutagenicity. the total concentration of the 16 pahs listed as priority pollutants by the us environmental protection agency (us-epa) was 2634+/-241 mg/kgdw in soil samples. the toxicity of water-extractable pollutants from the contaminated soil samples was evaluated using acute (vibrio fischeri; microtox test, daphnia ma ... | 2007 | 17382389 |
| the effects of cover crop on weed control in collard (brassica olerecea var acephala) and lettuce (lactuca sativa l.). | leafy vegetables are not very competitive and weed interference can cause considerable yield losses in collard (brassica olerecea var acephala) and lettuce (lactuca sativa l.). currently there are no pre or post emergence herbicides registered for weed control in these vegetables in turkey. for this reason, alternative weed control strategies need to be developed. cover crop residue could represent an alternative method of weed management in these crops. field studies were conducted in 2004 at t ... | 2006 | 17390812 |
| toxicity evaluation of the process effluent streams of a petrochemical industry. | the physico-chemical characteristics and the acute toxicity of several wastewater streams, generated in the industrial production of synthetic rubber, were determined. the acute toxicity was evaluated in bioassays using different organisms: danio rerio (fish), lactuca sativa (lettuce) and brachionus calyciflorus (rotifer). the removal of toxicity attained in the industrial wastewater treatment plant was also determined upstream and downstream of the activated sludge process. the results obtained ... | 2007 | 17396408 |
| physiological and molecular responses of lactuca sativa to colonization by salmonella enterica serovar dublin. | this paper describes the physiological and molecular interactions between the human-pathogenic organism salmonella enterica serovar dublin and the commercially available mini roman lettuce cv. tamburo. the association of s. enterica serovar dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. the latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and ... | 2007 | 17513585 |
| silencing of the major family of nbs-lrr-encoding genes in lettuce results in the loss of multiple resistance specificities. | the rgc2 gene cluster in lettuce (lactuca sativa) is one of the largest known families of genes encoding nucleotide binding site-leucine-rich repeat (nbs-lrr) proteins. one of its members, rgc2b, encodes dm3 which determines resistance to downy mildew caused by the oomycete bremia lactucae carrying the cognate avirulence gene, avr3. we developed an efficient strategy for analysis of this large family of low expressed genes using post-transcriptional gene silencing (ptgs). we transformed lettuce ... | 2007 | 17587302 |
| sulfamethazine uptake by plants from manure-amended soil. | animal manure is applied to agricultural land as a means to provide crop nutrients. however, animal manure often contains antibiotics as a result of extensive therapeutic and subtherapeutic use in livestock production. the objective of this study was to evaluate plant uptake of a sulfonamide-class antibiotic, sulfamethazine, in corn (zea mays l.), lettuce (lactuca sativa l.), and potato (solanum tuberosum l.) grown in a manure-amended soil. the treatments were 0, 50, and 100 microg sulfamethazin ... | 2007 | 17596632 |
| relay cropping cauliflower with lettuce as a means to manage first-generation cabbage maggot (diptera: anthomyiidae) and minimize cauliflower yield loss. | first-generation cabbage maggot, delia radicum (l.) (diptera: anthomyiidae), can cause extensive damage to newly transplanted brassica crops. this study investigated the use of relay cropping, a form of intercropping that involves overlapping two crops in the same field for a short period, as a means to 1) reduce first-generation d. radicum egg numbers by disrupting female host finding and 2) minimize yield loss by reducing the time that crops overlap. because of the high incidence of two other ... | 2007 | 17598546 |
| localisation and metabolism of reactive oxygen species during bremia lactucae pathogenesis in lactuca sativa and wild lactuca spp. | a plant's physiology is modified simultaneously with oomycete pathogen penetration, starting with release and accumulation of reactive oxygen species (ros). localisation of superoxide, hydrogen peroxide, peroxidase and variation in their activity, and the isoenzyme profile of antioxidant enzymes peroxidase (1.11.1.7), catalase (ec 1.11.1.6), superoxide dismutase (ec 1.15.1.1) were studied in six genotypes of four lactuca spp. (l. sativa, l. serriola, l. saligna and l. virosa) challenged with bre ... | 2007 | 17629488 |
| assessment of contamination potential of lettuce by salmonella enterica serovar newport added to the plant growing medium. | the capacity of salmonella enterica serovar newport to contaminate romaine lettuce (lactuca sativa l. cv. nogal) via the root system was evaluated in 17-, 20-, and 33-day-old plants. apparent internalization of salmonella via the root to the above-ground parts was identified in 33- but not 17- or 20-day-old plants and was stimulated by root decapitation. leaves of lettuce plants with intact and damaged roots harbored salmonella at 500 +/- 120 and 5,130 +/- 440 cfu/g of leaf, respectively, at 2 d ... | 2007 | 17685348 |
| overexpression of arabidopsis homogentisate phytyltransferase or tocopherol cyclase elevates vitamin e content by increasing gamma-tocopherol level in lettuce (lactuca sativa l.). | tocopherols, essential components of the human diet, are synthesized exclusively by photosynthetic organisms. to increase tocopherol content by increasing total flux to the tocopherol biosynthetic pathway, genes encoding arabidopsis homogentisate phytyltransferase (hpt/v-te2) and tocopherol cyclase (tc/vte1) were constitutively overexpressed in lettuce (lactuca sativa l.). total tocopherol content of the transgenic plants overexpressing either of the genes was increased by more than 2-fold mainl ... | 2007 | 17978586 |
| strong increase of foliar inulin occurs in transgenic lettuce plants (lactuca sativa l.) overexpressing the asparagine synthetase a gene from escherichia coli. | transgenic lettuce (lactuca sativa l. cv. 'cortina') lines expressing the asparagine synthetase a gene from escherichia coli were produced to alter the plant nitrogen status and eventually enhance growth. the relative molecular abundance of water-soluble metabolites was measured by 1h nmr in transgenic and conventional plants at early developmental stages and grown under the same conditions. nmr metabolic profiles assessed that a transgenic line and the wild-type counterpart shared the same comp ... | 2007 | 18044837 |
| shelf-life extension of fresh-cut iceberg lettuce (lactuca sativa l) by different antimicrobial films. | this study was conducted to investigate the antibacterial activity and shelf-life extension effect of iceberg lettuce packed in bn/pe film. the bn/pe film has a strong microbial suppression effect on pathogenic bacteria such as escherichia coli, salmonella enteritidis, and s. typhimurium. the number of psychrophiles and mesophiles during 5 days of cold storage of fresh-cut iceberg lettuce at 10 degrees c packaged in bn/pe film was strictly suppressed in comparison with other tested films (opp, p ... | 2007 | 18051596 |
| phytochrome- and gibberellin-mediated regulation of abscisic acid metabolism during germination of photoblastic lettuce seeds. | germination of lettuce (lactuca sativa) 'grand rapids' seeds is regulated by phytochrome. the action of phytochrome includes alterations in the levels of gibberellin (ga) and abscisic acid (aba). to determine the molecular mechanism of phytochrome regulation of aba metabolism, we isolated four lettuce cdnas encoding 9-cis-epoxycarotenoid dioxygenase (biosynthesis; lsnced1-lsnced4) and four cdnas for aba 8'-hydroxylase (catabolism; lsaba8ox1-lsaba8ox4). measurements of aba and its catabolites sho ... | 2008 | 18184730 |
| efficient qtl detection for nonhost resistance in wild lettuce: backcross inbred lines versus f(2) population. | in plants, several population types [f(2), recombinant inbred lines, backcross inbred lines (bils), etc.] are used for quantitative trait locus (qtl) analyses. however, dissection of the trait of interest and subsequent confirmation by introgression of qtls for breeding purposes has not been as successful as that predicted from theoretical calculations. more practical knowledge of different qtl mapping approaches is needed. in this recent study, we describe the detection and mapping of quantitat ... | 2008 | 18251002 |
| biological and chemical evaluation of sewage water pollution in the rietvlei nature reserve wetland area, south africa. | macroinvertebrate communities in rietvlei nature reserve wetland area and their relationship with water quality were studied with the aim to evaluate their use as potential indicators of pollution. sampling locations were selected to include outlets from sewage effluent, agricultural and informal residential runoff. a large increase in nutrient concentrations was observed downstream from discharged treated sewage with an associated decrease in species richness. bioassays performed included: daph ... | 2008 | 18280017 |
| bioactive triterpene derivatives from latex of two euphorbia species. | we have investigated the antifeedant and toxic effects of 23 semisynthetic terpenoid derivatives obtained through chemical modifications of the major components of euphorbia resinifera (alpha-euphol and alpha-euphorbol) and e. officinarum (obtusifoliol and 31-norlanostenol) latex on several insect species (spodoptera littoralis, myzus persicae and rhopalosiphum padi), their selective cytotoxicity on insect sf9 and mammalian cho cells and their phytotoxic effects on lactuca sativa. the conversion ... | 2008 | 18304594 |
| novel mechanism of modulating natural antioxidants in functional foods: involvement of plant growth promoting rhizobacteria nrrl b-30488. | the significance of plant growth-promoting rhizobacteria (pgpr) mediated increase in antioxidant potential in vegetables is yet unknown. the plant growth-promoting bacterium bacillus lentimorbus nrrl b-30488 (b-30488) mediated induction of dietary antioxidant in vegetables ( trigonella foenum-graecum, lactuca sativa, spinacia oleracea, and daucus carota) and fruit ( citrus sinensis) after minimal processing (fresh, boiled, and frozen) was tested by estimating the total phenol content, level of a ... | 2008 | 18491912 |
| transient expression of chicken alpha interferon gene in lettuce. | we investigated the possibility of producing chicken alpha interferon (chifn-alpha) in transgenic plants. the cdna encoding chifn-alpha was introduced into lettuce (lactuca sativa l.) plants by using an agro-infiltration transient expression system. the chifn-alpha gene was correctly transcribed and translated in the lettuce plants according to rt-pcr and elisa assays. recombinant protein exhibited antiviral activity in vitro by inhibition of vesicular stomatitis virus (vsv) replication on chick ... | 2008 | 18500773 |
| plant response to heavy metal toxicity: comparative study between the hyperaccumulator thlaspi caerulescens (ecotype ganges) and nonaccumulator plants: lettuce, radish, and alfalfa. | thlaspi caerulescens (alpine pennycress) is one of the best-known heavy metal (hm) hyperaccumulating plant species. it exhibits the ability to extract and accumulate various hm at extremely high concentrations. in this hydroponic study, the performance of t. caerulescens (ecotype ganges) to accumulate cd, zn, and cu was compared with that of three nonaccumulator plants: alfalfa (medicago sativa), radish (raphanus sativus), and lettuce (lactuca sativa). plants were exposed to the separately disso ... | 2008 | 18528911 |
| uptake of sigmaddt, arsenic, cadmium, copper, and lead by lettuce and radish grown in contaminated horticultural soils. | horticultural soils can contain elevated concentrations of selected trace elements and organochlorine pesticides as a result of long-term use of agrichemicals and soil amendments. a glasshouse study was undertaken to assess the uptake of weathered sigmaddt {sum of the p, p'- and o, p-isomers of ddt [1,1,1-trichloro-2,2- bis( p-chlorophenyl)ethane], dde [1,1-dichloro-2,2- bis( p-chlorophenyl)ethylene] and ddd[1,1-dichloro-2,2- bis( p-chlorophenyl)ethane]}, arsenic (as), cadmium (cd), copper (cu), ... | 2008 | 18624413 |
| does subcellular distribution in plants dictate the trophic bioavailability of cadmium to porcellio dilatatus (crustacea, isopoda)? | the present study examined how subcellular partitioning of cd in plants with different strategies to store and detoxify cd may affect trophic transfer of cd to the isopod porcellio dilatatus. the plant species used were lactuca sativa, a horticultural metal accumulator species; thlaspi caerulescens, a herbaceous hyperaccumulator species; and the nonaccumulator, t. arvense. taking into account that differences in subcellular distribution of cd in plants might have an important role in the bioavai ... | 2008 | 18624580 |
| ssrs and indels mined from the sunflower est database: abundance, polymorphisms, and cross-taxa utility. | simple sequence repeats (ssrs) are abundant and frequently highly polymorphic in transcribed sequences and widely targeted for marker development in eukaryotes. sunflower (helianthus annuus) transcript assemblies were built and mined to identify ssrs and insertions-deletions (indels) for marker development, comparative mapping, and other genomics applications in sunflower. we describe the spectrum and frequency of ssrs identified in the sunflower est database, a catalog of 16,643 est-ssrs, a col ... | 2008 | 18633591 |
| germination of photoblastic lettuce seeds is regulated via the control of endogenous physiologically active gibberellin content, rather than of gibberellin responsiveness. | phytochrome regulates lettuce (lactuca sativa l. cv. grand rapids) seed germination via the control of the endogenous level of bioactive gibberellin (ga). in addition to the previously identified lsga20ox1, lsga20ox2, lsga3ox1, lsga3ox2, lsga2ox1, and lsga2ox2, five cdnas were isolated from lettuce seeds: lscps, lsks, lsko1, lsko2, and lskao. using an escherichia coli expression system and functional assays, it is shown that lscps and lsks encode ent-copalyl diphosphate synthase and ent-kaurene ... | 2008 | 18653696 |
| lettuce mosaic virus: from pathogen diversity to host interactors. | taxonomy: lettuce mosaic virus (lmv) belongs to the genus potyvirus (type species potato virus y) in the family potyviridae. physical properties: the virion is filamentous, flexuous with a length of 750 nm and a width of 15 nm. the particles are made of a genomic rna of 10 080 nucleotides, covalently linked to a viral-encoded protein (the vpg) at the 5' end and with a 3' poly a tail, and encapsidated in a single type of capsid protein. the molecular weight of the capsid protein subunit has been ... | 2008 | 18705846 |
| an allelopathic substance in red pine needles (pinus densiflora). | aqueous methanol extracts of red pine (pinus densiflora) needles inhibited the growth of roots and shoots of cress (lepidium sativum), lettuce (lactuca sativa), alfalfa (medicago sativa), ryegrass (lolium multiflorum), timothy (pheleum pratense), digitaria sanguinalis and echinochloa crus-galli. increasing the extract concentration increased inhibition, suggesting that the pine needles may have growth inhibitory substances and possess allelopathic potential. the aqueous methanol extract of the p ... | 2009 | 18755523 |
| cerebroside elicitor confers resistance to fusarium disease in various plant species. | abstract in the rice blast fungus pathosystem, cerebroside, a compound categorized as a sphingolipid, was found in our previous study to be a non-racespecific elicitor, which elicits defense responses in rice. here we describe that cerebroside c is produced in diverse strains of fusarium oxysporum, a common soilborne agent of wilt disease affecting a wide range of plant species. in addition, some type of cerebroside elicitor involving cerebroside a, b, or c was detected in other soilborne phytop ... | 2004 | 18943100 |
| nonhost versus host resistance to the grapevine downy mildew, plasmopara viticola, studied at the tissue level. | following inoculation of host and nonhost plants with plasmopara viticola, the grapevine downy mildew, a histological survey was undertaken to identify the stage where its development is contained in nonhosts and in resistant host plants. three herbaceous nonhost species, beta vulgaris, lactuca sativa, and capsicum annuum, and three grapevine species displaying different level of resistance (vitis vinifera [susceptible], vitis riparia [partially resistant] and muscadinia rotundifolia [totally re ... | 2008 | 18943253 |
| identification of race 1 of fusarium oxysporum f. sp. lactucae on lettuce by inter-retrotransposon sequence-characterized amplified region technique. | abstract fusarium wilt of lettuce, caused worldwide by fusarium oxysporum f. sp. lactucae, is an emerging seed-transmitted disease on lactuca sativa. in order to develop a molecular diagnostic tool for identifying race 1 (vcg0300) of the pathogen on vegetable samples, an effective technique is presented. inter-retrotransposon amplified polymorphism polymerase chain reaction (pcr), a technique based on the amplification of genomic regions between long terminal repeats, was applied. it was shown t ... | 2007 | 18943639 |
| characterization of race-specific interactions among isolates of verticillium dahliae pathogenic on lettuce. | abstract verticillium wilt, caused by verticillium dahliae, poses a major threat to lettuce (lactuca sativa) production in california. incorporation of resistance into commercial lettuce cultivars offers the least expensive technique of sustaining production in infested areas. to test the breadth of the resistance identified in field experiments, a pair of susceptible ('salinas' and 'sniper') and resistant ('la brillante' and 'little gem') lettuce cultivars were used as differentials and individ ... | 2006 | 18943671 |
| comparison of lettuce diseases and yield under subsurface drip and furrow irrigation. | abstract subsurface drip and furrow irrigation were compared on lettuce (lactuca sativa) cvs. salinas and misty day for yield and incidence and severity of three important diseases of lettuce in the salinas valley, ca. experiments were conducted between 1993 and 1995 during the spring and fall seasons. the diseases examined included lettuce drop (sclerotinia minor), downy mildew (bremia lactucae), and corky root (rhizomonas suberifaciens). replicated plots of subsurface drip and furrow irrigatio ... | 1997 | 18945057 |
| biological and molecular variability of lettuce mosaic virus isolates. | abstract lettuce mosaic potyvirus (lmv) causes severe disease of commercial lettuce crops. lmv isolates show wide biological variability, particularly in their ability to overcome the resistance genes described in lactuca sativa. for a better understanding of the molecular interaction between lettuce and lmv, biological and molecular characterization of a collection of 10 lmv isolates known to differ in virulence or aggressiveness was performed. the ability of these isolates to overcome the resi ... | 1997 | 18945118 |
| the genomic architecture of disease resistance in lettuce. | genbank and the compositae genome project database, containing over 42,000 lettuce unigenes from lactuca sativa cv. salinas and l. serriola accession uc96us23 were mined to identify 702 candidate genes involved in pathogen recognition (rgcs), resistance signal transduction, defense responses, and disease susceptibility. in addition, to identify sequences representing additional sub-families of nucleotide binding site (nbs)-leucine-rich repeat encoding genes; the major classes of resistance genes ... | 2009 | 19005638 |
| use of polishing pond effluents to cultivate lettuce (lactuca sativa) in a hydroponic system. | the sanitary quality and productivity of hydroponic lettuce (lactuca sativa l.) plants cultivated under greenhouse conditions and treated with effluent from anaerobic reactor + polishing pond followed by physical-chemical treatment was evaluated. two hydroponic cultivations were performed at summer and winter time at vitoria-es, brazil. the treatments for both cultivations were: t1) conventional nutrient solution, t2) effluent from physical-chemical treatment, t3) effluent from polishing pond, a ... | 2008 | 19039187 |
| effects of dietary supplementation with red-pigmented leafy lettuce (lactuca sativa) on lipid profiles and antioxidant status in c57bl/6j mice fed a high-fat high-cholesterol diet. | the present study was undertaken to assess the beneficial effects of a daily consumption of 8 % freeze-dried red-pigmented leafy lettuce (lactuca sativa) on cvd. c57bl/6j mice were fed a high-fat high-cholesterol diet supplemented with or without red-pigmented leafy lettuce for 4 weeks. the present results showed that the red-pigmented leafy lettuce-supplemented diet significantly decreased the level of total and ldl-cholesterol and tag in the plasma of the mice. the atherosclerotic index was ca ... | 2009 | 19243638 |
| hypochlorite treatments are not a significant source of perchlorate exposure in lettuce. | leafy vegetables, such as lettuce ( lactuca sativa l), have been identified as a potential source of perchlorate exposure to humans. perchlorate is of concern because excessive amounts may impair thyroid function by inhibiting iodide uptake by the sodium iodide symporter. perchlorate has been identified as an oxidation product in sodium hypochlorite. dilute hypochlorite solutions are widely used on lettuce as a preservative and as a treatment to reduce microbial food risks. however, the potentia ... | 2009 | 19245207 |
| pseudomonas cichorii as the causal agent of midrib rot, an emerging disease of greenhouse-grown butterhead lettuce in flanders. | bacterial midrib rot of greenhouse-grown butterhead lettuce (lactuca sativa l. var. capitata) is an emerging disease in flanders (belgium) and fluorescent pseudomonads are suspected to play an important role in the disease. isolations from infected lettuces, collected from 14 commercial greenhouses in flanders, yielded 149 isolates that were characterized polyphasically, which included morphological characteristics, pigmentation, pathogenicity tests by both injection and spraying of lettuce, lop ... | 2009 | 19157742 |
| efficacy of bacillus thuringiensis, paecilomyces marquandii,and streptomyces costaricanus with and without organic amendments against meloidogyne hapla infecting lettuce. | chitin, wheat mash, or brewery compost were incorporated into unfumigated and methyl bromide-fumigated organic soils placed in microplots formed from cylindrical drainage tiles (0.25 m-diam. clay tile). after 3 weeks, meloidogyne hapla and cell or spore suspensions of bacillus thuringiensis, paecilomyces marquandii, and streptomyces costaricanus were individually added to the soils of designated microplots. a b. thuringiensis + s. costaricanus combination was also tested. lettuce seedlings, cv. ... | 2000 | 19270951 |
| suppression of meloidogyne hapla and its damage to lettuce grown in a mineral soil amended with chitin and biocontrol organisms. | chitin was used as soil amendment in fiberglass field microplots, alone or with one or a combination of two to three species of hirsutella rhossiliensis, paecilomyces marquandii, verticillium chlamydosporium, bacillus thuringiensis, and streptomyces costaricanus. sudangrass and rapeseed were planted as cover crops and incorporated into soil as green manure amendments. chitin amendment alone increased the marketable yield of lettuce in 1995 and reduced root-galling ratings and the reproduction of ... | 1999 | 19270942 |
| survey of crop losses in response to phytoparasitic nematodes in the united states for 1994. | previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the university of georgia, the beltwide cotton conference, and selected groups concerned with soybean. the society of nematologists extension committee contacted extensio ... | 1999 | 19270925 |
| hirsutella rhossiliensisand verticillium chlamydosporium as biocontrol agents of the root-knot nematode meloidogyne hapla on lettuce. | hirsutella rhossiliensis and verticillium chlamydosporium infected second-stage juveniles (j2) and eggs of meloidogyne hapla, respectively, in petri dishes and in organic soil in pots planted to lettuce in the greenhouse. in vitro, h. rhossiliensis produced 78 to 124 spores/infected j2 of m. hapla. the number of j2 in roots of lettuce seedlings decreased exponentially with increasing numbers of vegetative colonies of h. rhossiliensis in the soil. at an infestation of 8 m. hapla eggs/cm(3) soil, ... | 2000 | 19270953 |
| evaluation of treatments for elimination of foodborne pathogens on the surface of leaves and roots of lettuce (lactuca sativa l.). | several outbreaks of salmonella and escherichia coli o157:h7 infections have been associated with consumption of leafy greens. questions remain concerning the ability of these pathogens to become internalized within lettuce and spinach tissues. an effective validated surface disinfection method for lettuce is needed before factors affecting internalization of pathogens can be studied. the objective of this study was to develop a surface disinfection method for lettuce leaves and roots. iceberg l ... | 2009 | 19350966 |
| impact of light variation on development of photoprotection, antioxidants, and nutritional value in lactuca sativa l. | lettuce plants were grown at low (ll), middle (ml), and high light (hl) conditions to examine the relationship between photoacclimatory plasticity, light energy utilization, and antioxidant capacity. with the increase in light intensity from ll to ml, the energy flux via deltaph- and xanthophylls-regulated thermal dissipation, fluorescence and constitutive thermal dissipation, and electron transport for photorespiratory carbon oxidation all increased significantly. however, plants at hl exhibite ... | 2009 | 19435354 |
| comparison of sensitivity of grasses (lolium perenne l. and festuca rubra l.) and lettuce (lactuca sativa l.) exposed to water contaminated with microcystins. | the effects of aqueous extracts from microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: festuca rubra l., lolium perenne l., and lactuca sativa l. there was a clear inhibition of root growth for l. sativa exposed to strains containing microcystins (5.9-56.4 microg l(-1)). the strain that produced the most pronounced effects contained the lowest concentration of m ... | 2009 | 19436926 |
| microbial enumeration of different functional groups and bacterial behavior in acid basic conditions of a biotoxic landfill leachate of bahía blanca, argentina. | leachate is liquid waste from refuse biological decomposition or rainwater percolation in a landfill. this research focused on leachate produced by a landfill in bahia blanca, buenos aires, argentina. the research studied the main microbial populations involved in wastewater treatment, analyzed the behavior of bacteria isolated from leachate at different ph values, and appraised leachate biotoxicity. the number of bacteria varied by type, ranging from 1 x 10(4) to 1 x 10(5) cuf/ml aerobic hetero ... | 2009 | 19472947 |
| differential effects of pseudomonas mendocina and glomus intraradices on lettuce plants physiological response and aquaporin pip2 gene expression under elevated atmospheric co2 and drought. | arbuscular mycorrhizal (am) symbiosis and plant-growth-promoting rhizobacterium (pgpr) can alleviate the effects of water stress in plants, but it is unknown whether these benefits can be maintained at elevated co2. therefore, we carried out a study where seedlings of lactuca sativa were inoculated with the am fungus (amf) glomus intraradices n.c. schenk & g.s. sm. or the pgpr pseudomonas mendocina palleroni and subjected to two levels of watering and two levels of atmospheric co2 to ascertain t ... | 2009 | 19495853 |
| comparative large-scale analysis of interactions between several crop species and the effector repertoires from multiple pathovars of pseudomonas and ralstonia. | bacterial plant pathogens manipulate their hosts by injection of numerous effector proteins into host cells via type iii secretion systems. recognition of these effectors by the host plant leads to the induction of a defense reaction that often culminates in a hypersensitive response manifested as cell death. genes encoding effector proteins can be exchanged between different strains of bacteria via horizontal transfer, and often individual strains are capable of infecting multiple hosts. host p ... | 2009 | 19571308 |
| transgenic lettuce producing a candidate protein for vaccine against edema disease. | pig edema disease is a bacterial disease caused by shiga toxin 2e-producing escherichia coli belonging mainly to serotypes o138, o139, and o141. the b subunit of shiga toxin 2e (stx2eb) is a candidate protein for use in a vaccine against edema disease. we produced this protein in transgenic lettuce (lactuca sativa), an edible plant that can be cultivated in a factory setting. in a transient expression system, we found that ntadh 5'-untranslated region (5'-utr) functions as a translational enhanc ... | 2009 | 19584542 |
| transgenic lettuce seedlings carrying hepatitis b virus antigen hbsag. | the obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. here we report a strategy for genetic transformation of lettuce plants (lactuca sativa l.) using the surface antigen hbsag of hepatitis b virus. transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. genetic transformation process was acquired by cocultivation of cotyledons with a ... | 2008 | 19287831 |
| effect of temperature on infection and survival of rotylenchulus reniformis. | from infestation of lettuce with preinfective females to egg deposition, populations of rotylenchulus reniformis from baton rouge, louisiana; lubbock and weslaco, texas; and mayaguez, puerto rico, required 41, 13, 7, and 7 days at 15, 20, 25, and 34 c, respectively. no nematode infection occurred at 10 c with any r. reniformis population, and the population from puerto rico did not reproduce at 15 c. nematode survival was not influenced by temperature, since populations from texas and louisiana ... | 1988 | 19290223 |
| analysis of bacteria, parasites, and heavy metals in lettuce (lactuca sativa) and rocket salad (eruca sativa l.) irrigated with treated effluent from a biological wastewater treatment plant. | this study aimed to evaluate the viability of using treated residuary water from the biological wastewater treatment plant of ribeirão preto to grow vegetables, through the characterization and quantification of parasites, coliforms, and heavy metals. three equal cultivation areas were prepared. the first was irrigated with treated/chlorinated (0.2 mg l(-1)) wastewater, the second one with treated wastewater without chlorination, and the third site with potable water, which was the control group ... | 2010 | 19639268 |
| three combined quantitative trait loci from nonhost lactuca saligna are sufficient to provide complete resistance of lettuce against bremia lactucae. | the nonhost resistance of wild lettuce (lactuca saligna) to downy mildew (bremia lactucae) is based on at least 15 quantitative trait loci (qtl), each effective at one or more plant developmental stages. we used qtl pyramiding (stacking) to determine how many of these qtl from l. saligna are sufficient to impart complete resistance towards b. lactucae to cultivated lettuce, l. sativa. the alleles of four of the most promising qtl, rbq4, rbq5, rbq6+11, and rbq7 are effective at both the young and ... | 2009 | 19656050 |
| impact of preinoculation culture conditions on the behavior of escherichia coli o157:h7 inoculated onto romaine lettuce (lactuca sativa) plants and cut leaf surfaces. | inoculum preparation methods can impact growth or survival of organisms inoculated into foods, thus complicating direct comparison of results among studies. the objective of this study was to evaluate preinoculation culture preparation for impact on escherichia coli o157:h7 inoculated onto leaves of romaine lettuce plants and cut leaf surfaces. e. coli o157:h7 was grown quiescently or shaken at 15, 25, or 37 degrees c to different growth phases in tryptic soy or m9 minimal salts broth or agar. c ... | 2009 | 19681285 |
| environmental stresses induce health-promoting phytochemicals in lettuce. | plants typically respond to environmental stresses by inducing antioxidants as a defense mechanism. as a number of these are also phytochemicals with health-promoting qualities in the human diet, we have used mild environmental stresses to enhance the phytochemical content of lettuce, a common leafy vegetable. five-week-old lettuce (lactuca sativa l.) plants grown in growth chambers were exposed to mild stresses such as heat shock (40 degrees c for 10 min), chilling (4 degrees c for 1d) or high ... | 2009 | 19297184 |
| tobacco streak virus isolated from lettuce. | tobacco streak virus (tsv) is an ilarvirus with a worldwide distribution. this virus infects many plants and causes significant yield losses. in this study, 300 samples of lettuce were collected from lettuce fields in tehran province. infected plants show symptoms such as: mosaic, vein clearing, vein necrosis, yellowing and leaf distortion. das-elisa (double antibody sandwich-elisa) was used with a polyclonal antiserum against tsv. five isolates (t1, t2, t3, t4 and t5), which are collected, resp ... | 2009 | 19634475 |
| are uranium-contaminated soil and irrigation water a risk for human vegetables consumers? a study case with solanum tuberosum l., phaseolus vulgaris l. and lactuca sativa l. | the knowledge of uranium concentration, in the products entering the human diet is of extreme importance because of their chemical hazard to health. controlled field experiments with potatoes, beans and lettuce (solanum tuberosum l., phaseolus vulgaris l. and lactuca sativa l.) were carried out in a contaminated soil used by local farmers located near a closed portuguese uranium mine (cunha baixa, mangualde). the soil with high average uranium levels (64-252 mg/kg) was divided in two plots, and ... | 2009 | 19590953 |
| lack of internalization of escherichia coli o157:h7 in lettuce (lactuca sativa l.) after leaf surface and soil inoculation. | survival and internalization characteristics of escherichia coli o157:h7 in iceberg, romaine, and leaf lettuce after inoculation of leaf surfaces and soil were determined. a five-strain mixture of e. coli o157:h7 in water and cow manure extract was used as an inoculum for abaxial and adaxial sides of leaves at populations of 6 to 7 log and 4 log cfu per plant. the five strains were individually inoculated into soil at populations of 3 and 6 log cfu/g. soil, leaves, and roots were analyzed for th ... | 2009 | 19833024 |
| potential internalisation of caliciviruses in lettuce. | fresh produce such as lettuce (lactuca sativa) has often been linked to epidemic viral gastroenteritis. in these cases, it is unknown whether the viral contamination has occurred during the growing or the processing of the implicated product. in this study lettuce was grown in the presence of enteric viruses, and the uptake of viruses via the roots into the edible parts (leaves and stem) of the lettuce plants was investigated, for plants with both intact and damaged roots. the roots of lettuce, ... | 2009 | 19720414 |
| in situ stabilization of cadmium-, lead-, and zinc-contaminated soil using various amendments. | chemical stabilization is an in situ remediation method that uses inexpensive amendments to reduce contaminant availability in polluted soil. we tested the effects of several amendments (limestone, red-mud, and furnace slag) on the extractability of heavy metals, microbial activities, phytoavailability of soil metals (assessed using lettuce, lactuca sativa l.), and availability of heavy metals in ingested soil to the human gastrointestinal system (assessed using the physiologically based extract ... | 2009 | 19786291 |
| heat and drought stress during growth of lettuce (lactuca sativa l.) does not promote internalization of escherichia coli o157:h7. | studies were done to determine the effect of heat stress on internalization of escherichia coli o157:h7 in lettuce subjected to different watering practices during growth. iceberg and romaine lettuce were grown in sandy soil in an environmental chamber at 23 degrees c during the day and 7 degrees c at night, with a 12-h photoperiod. thirty days after transplanting seedlings, potting soil was inoculated with a five-strain mixture of green fluorescent protein-labeled e. coli o157:h7 at populations ... | 2009 | 20003727 |
| characterization of acc deaminase gene in pseudomonas entomophila strain ps-pjh isolated from the rhizosphere soil. | the enzyme 1-aminocyclopropane-1-carboxylate (acc) deaminase cleaves the ethylene precursor acc into alpha-ketobutyrate and ammonia. the decreased level of ethylene allows the plant to be more resistant to a wide environmental stress including plant pathogens. in the present study, we characterized the acc deaminase activity of a pseudomonas entomophila strain ps-pjh isolated from the red pepper rhizosphere region of red pepper grown at jinan, korea. the isolate produced 23.8 +/- 0.4 micromol of ... | 2010 | 20082369 |
| variations in bioactive substance contents and crop yields of lettuce (lactuca sativa l.) cultivated in soils with different fertilization treatments. | changes in crop yields and bioactive substance contents were studied in lettuce crop concerning the influence of soil nutritional status as a result of compost and vermicompost additions obtained from different organic substrates. plant productions and main pigment contents in lettuce were higher in all the fertilized soils than in the untreated soil, with the exception of the one treated with urban solid waste compost. these positive effects correlate with nitrogen level increase in soil. howev ... | 2009 | 19821565 |
| [bio-objects and biological methods of space radiation effects evaluation]. | the unique conditions of space experiments place austere requirements to bio-objects and biological methods of radiation effects evaluation. the paper discusses suitability of a number of bio-objects varying in stage of evolution and metabolism for space researches aimed to state common patterns of the radiation damage caused by heavy ions (hi), and character of hi-cell interaction. physical detectors in space experiments of the bioblock series make it possible to identify bio-objects hit by spa ... | 2009 | 20120909 |
| the role of heterologous chloroplast sequence elements in transgene integration and expression. | heterologous regulatory elements and flanking sequences have been used in chloroplast transformation of several crop species, but their roles and mechanisms have not yet been investigated. nucleotide sequence identity in the photosystem ii protein d1 (psba) upstream region is 59% across all taxa; similar variation was consistent across all genes and taxa examined. secondary structure and predicted gibbs free energy values of the psba 5' untranslated region (utr) among different families reflecte ... | 2010 | 20130101 |
| anti-leukaemic effects of two extract types of lactuca sativa correlate with the activation of chk2, induction of p21, downregulation of cyclin d1 and acetylation of alpha-tubulin. | the water extract of the lettuce lactuca sativa, but not the ethyl acetate extract, inhibited the growth of hl-60 leukaemia cells and mcf-7 breast cancer cells. this correlated with the activation of checkpoint kinase 2 (chk2), the induction of the tumour suppressor p21, and the severe downregulation of the proto-oncogene cyclin d1. the ethyl acetate extract, but not the water extract, induced hl-60 cell death, which correlated with the acetylation of alpha-tubulin. the acetylation of alpha-tubu ... | 2010 | 20204303 |
| hydrolysis of benzonitrile herbicides by soil actinobacteria and metabolite toxicity. | the soil actinobacteria rhodococcus rhodochrous pa-34, rhodococcus sp. ndb 1165 and nocardia globerula nhb-2 grown in the presence of isobutyronitrile exhibited nitrilase activities towards benzonitrile (approx. 1.1-1.9 u mg(-1) dry cell weight). the resting cell suspensions eliminated benzonitrile and the benzonitrile analogues chloroxynil (3,5-dichloro-4-hydroxybenzonitrile), bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) and ioxynil (3,5-diiodo-4-hydroxybenzonitrile) (0.5 mm each) from reacti ... | 2010 | 20204468 |
| relative tolerance of a range of australian native plant species and lettuce to copper, zinc, cadmium, and lead. | the tolerance of wild flora to heavy-metal exposure has received very little research. in this study, the tolerance of four native tree species, four native grass species, and lettuce to copper (cu), zinc (zn), cadmium (cd), and lead (pb) was investigated in a root-elongation study using petri dishes. the results of these studies show a diverse range of responses to cu, zn, cd, and pb amongst the tested plant species. toxicity among metals decreased in the following order: cd ~ cu > pb > zn. met ... | 2010 | 20213195 |
| phosphomannose isomerase gene for selection in lettuce (lactuca sativa l.) transformation. | a positive selection system using phosphomannose isomerase was employed for agrobacterium tumefaciens mediated transformation of lettuce (lactuca sativa l. var. 'achát'). it was shown that the mannose-based selection system works very well with the lettuce genotype used, reaching up to 25% transformation efficiency on the medium with 20 g/l mannose and 20 g/l sucrose. the best transformation efficacy with the commonly-used kanamycin at 100 mg/l as a selection agent was 21%. southern blot analyse ... | 2010 | 20234883 |
| [agrobacterium-mediated transformation of lettuce (lactuca sativa l.) with vectors bearing genes of bacterial antigenes from mycobacterium tuberculosis]. | transgenic plants of lettuce lactuca sativa l. cv. eralash, sniezinka, rubinovoje kruzevo with genes coding synthesis of tuberculosis antigenes have been obtained by agrobacterium-mediated transformation. cotyledons of in vitro seedlings were used as the initial material for transformation with plasmids pcb063 (genes esat6, nptii) and pcb064 (genes esat6:ag85b(-tmd), nptii). pcr-analysis has shown the presence both selective and target genes in all plants analyzed. at the same time, the rt-pcr h ... | 2009 | 19938623 |
| host range and complete genome sequence of cucurbit chlorotic yellows virus, a new member of the genus crinivirus. | cucurbit chlorotic yellows virus (ccyv) causes chlorotic yellows on cucumber (cucumis sativus) and melon (cucumis melo) and is transmitted by bemisia tabaci biotype b and q whiteflies. to characterize the host range of ccyv, 21 cucurbitaceous and 12 other plant species were inoculated using whitefly vectors. all tested cucumis spp. except cucumis anguria and cucumis zeyheri were systemically infected with ccyv, although infection rates varied among species. citrullus lanatus, cucurbita pepo, and ... | 2010 | 20465411 |
| photosynthetic responses of lettuce to downy mildew infection and cytokinin treatment. | changes in primary metabolism of lettuce, lactuca sativa l. (cv. cobham green), induced by compatible interaction with the biotrophic oomycete pathogen bremia lactucae regel (race bl 16), under two intensities of illumination in the presence and absence of exogenous cytokinins were studied by chlorophyll fluorescence imaging. thirteen days post-inoculation leaf discs infected by b. lactucae exhibited impairments of photosynthesis associated with biotrophic infections, including: reductions in ph ... | 2010 | 20471849 |
| influence of soil fumigation by methyl bromide and methyl iodide on rhizosphere and phyllosphere microbial community structure. | rhizosphere and phyllosphere microbial communities were evaluated on roots and leaves of growth chamber-grown lettuce (lactuca sativa (l.) cv. green forest) plants by culture-dependent and -independent methods after soil fumigation. denaturing gradient gel electrophoresis (dgge) with 16s rrna primers followed by cloning and sequencing was used to identify major rrna bands from the rhizosphere and phyllosphere. three weeks after fumigation, there were no differences (p = 0.16) in rhizosphere micr ... | 2010 | 20512733 |
| hydroxylation at carbon-2 of ent-16-oxo-17-norkauran-19-oic acid by fusarium proliferatum. | a new product of biotransformation of ent-16-oxo-17-norkauran-19-oic acid (1) by fusarium proliferatum was isolated and identified as a 2beta-hydroxy derivative (2). the structure of 2 was elucidated on the basis of spectroscopic data interpretation and single-crystal x-ray diffraction analysis. the allelopathic activity of compound 2 was evaluated on the growth of radicals and shoots of lactuca sativa (lettuce). this is the first time that fungal hydroxylation at position c-2 has been reported ... | 2010 | 20617817 |
| rin4 causes hybrid necrosis and race-specific resistance in an interspecific lettuce hybrid. | some inter- and intraspecific crosses may result in reduced viability or sterility in the offspring, often due to genetic incompatibilities resulting from interactions between two or more loci. hybrid necrosis is a postzygotic genetic incompatibility that is phenotypically manifested as necrotic lesions on the plant. we observed hybrid necrosis in interspecific lettuce (lactuca sativa and lactuca saligna) hybrids that correlated with resistance to downy mildew. segregation analysis revealed a sp ... | 2009 | 19855048 |
| flow cytometric assessment of cd genotoxicity in three plants with different metal accumulation and detoxification capacities. | cadmium (cd) is a widespread environmental contaminant, strongly mutagenic and known to cause dna damage in plants. in this work, flow cytometry (fcm) was applied to determine if in vivo exposure to cd would induce genotoxic effects at the genome level. the hyper-accumulator thlaspi caerulescens (j. & c. presl), the related non-accumulator thlaspi arvense l. and the accumulator crop species lactuca sativa l. were germinated in distilled water and grown in modified hoagland's medium with increasi ... | 2010 | 20663557 |