| apparent destruction and reutilization of heterologous dna applied to seeds of lactuca sativa [proceedings]. | | 1977 | 79399 |
| [presence of intestinal parasites in vegetables sold in the metropolitan region of são paulo, sp, brazil. i--search of helminths]. | vegetables in natura, commercially traded in the metropolitan area of s. paulo, were analysed by the appropriate methodology with a view to discovering an identifying the paths of transmission of enteroparasites of medical interest. the vegetables under study consisted of 50 samples of each variety listed below: lettuce (lactuca sativa)-oily leaves and crisphead varieties, endive (chicorium sp) and water-cress (nasturtium officinale). results showed high rates of contamination in all the vegetab ... | 1992 | 1342513 |
| [presence of intestinal parasites in vegetables sold in the metropolitan area of são paulo-sp, brazil. ii--research on intestinal protozoans]. | vegetables in nature, commercially traded in the metropolitan area of s. paulo, brazil, were analyzed by means of the appropriate methodology with a view to discovering and identifying protozoan cysts of medical interest. the vegetables under study consisted of 50 samples of each of the varieties listed below: lettuce (lactuca sativa)-oily leaves and crisp-head varieties, endive (chicorium sp) and watercress (nasturtium officinale). results showed high rates of contamination in all the varieties ... | 1992 | 1342522 |
| recent amplification of triose phosphate isomerase related sequences in lettuce. | a random cdna clone was identified as distinguishing near-isogenic lines for downy mildew resistance in lettuce. the clone detected multiple restriction fragments in genomic southern blots of lettuce. restriction fragment length polymorphisms (rflps) detected by this clone mapped to separate clusters of resistance genes; therefore, these sequences were studied in a greater detail. sequence analysis indicated that the cdna encoded the glycolytic enzyme triose phosphate isomerase (tpi). the lettuc ... | 1992 | 1356093 |
| glycosidic activities of candida albicans after action of vegetable latex saps (natural antifungals) and isoconazole (synthetic antifungal). | glycosidic activities have been examined in candida albicans grown on medium culture containing latex sap (natural antifungal) or isoconazole (synthetic antifungal). the different types of utilized latex sap were those of lactuca sativa (latex exuded from articulated laticifers) and asclepias curassavica (latex flowing from non-articulated laticifers). the same enzyme assays were performed on c. albicans grown without antifungal compounds. except for alpha-arabinosidase, all glycosidase activiti ... | 1991 | 1922192 |
| antifungal action of latex saps from lactuca sativa l. and asclepias curassavica l. | asclepias curassavica and lactuca sativa latex saps inhibit the growth of candida albicans because they degrade a great number of yeasts. this was confirmed by scanning and transmission electron microscopy observations. after a contact of 4 h and 6 h yeasts are deformed and emptied of their cytoplasmic content. moreover, it appears that these saps, particularly asclepias, also act on the cell wall: the substances presumed to be responsible for these effects were probably terpens and cardenolids ... | 1990 | 2090937 |
| mycoplasma lactucae sp. nov., a sterol-requiring mollicute from a plant surface. | strain 831-c4t (t = type strain), isolated from the surface of lettuce plants (lactuca sativa) obtained from a retail food market, was shown to be a sterol-requiring mollicute. morphological examination of this organism by electron and dark-field microscopic techniques showed that it consists of small, nonhelical, nonmotile, pleomorphic coccoid cells, with individual cells surrounded by a single cytoplasmic membrane. no evidence of a cell wall was observed. the organism grew rapidly in all conve ... | 1990 | 2223606 |
| phytochrome and temperature relations in lactuca sativa l. grand rapids seed germination after thermo-dormancy. | | 1972 | 4621828 |
| [morphological variability of myeoplasma-like bodies in the phloem of lactuca sativa l]. | | 1972 | 4679140 |
| biosynthesis of phytoquinones. homogentisic acid: a precursor of plastoquinones, tocopherols and alpha-tocopherolquinone in higher plants, green algae and blue-green algae. | 1. by means of (14)c tracer experiments and isotope competition experiments the roles of d-tyrosine, p-hydroxyphenylpyruvic acid, p-hydroxyphenylacetic acid, phenylacetic acid, homogentisic acid and homoarbutin (2-methylquinol 4-beta-d-glucoside) in the biosynthesis of plastoquinones, tocopherols and alpha-tocopherolquinone by maize shoots was investigated. it was established that d-tyrosine, p-hydroxyphenylpyruvic acid and homogentisic acid can all be utilized for this purpose, whereas p-hydrox ... | 1970 | 4986835 |
| chemical form and physiological availability of iodine in lettuce (lactuca sativa). | | 1967 | 6030612 |
| the aster yellows controversy: current status. | evidence for and against the spiroplasmal etiology of aster yellows (ay) disease is examined. a spiroplasma, serologically identical to spiroplasma citri, was cultivated by some workers from lettuce (lactuca sativa l.) plants claimed to be naturally infected with ay. the isolated spiroplasma was shown to be infectious by injecting macrosteles fascifrons with the cultured organisms and then confining the injected leafhoppers on healthy plants. the reports claiming that a spiroplasma is the etiolo ... | 1983 | 6382826 |
| an evaluation of acetone extracts from six plants in the ames mutagenicity test. | acetone extracts from six plants were evaluated for mutagenic activity with the salmonella/mammalian-microsome mutagenicity test (ames) utilizing tester strains ta98 and ta100 and in the presence and absence of induced rat liver microsomes. extracts from alfalfa (medicago sativa), lettuce (lactuca sativa) and thread-leaf groundsel (senecio longilobus) produced only negative responses. comfrey (symphytum officinale) and tansy ragwort (senecio jacobaea) extracts produced toxic responses that were ... | 1983 | 6836587 |
| the effect of phytohormones produced by arthrobacter sp. on the phosphatase activity in plant roots. | phytohormonal activity (auxins, gibberellins, cytokinins) was tested in the supernatant of a culture of arthrobacter sp. crude extract of the phytohormonal fraction was used as substrate for the growth of lactuca sativa seedlings. treating with bacterial hormones resulted in an increased plant develop- ment. furthermore, a sharp increase of the acid phosphatase activity was observed in the roots. | 1981 | 7262713 |
| a lactuca universal hybridizer, and its use in creation of fertile interspecific somatic hybrids. | a lactuca sativa cv. ardente line heterozygous for a gene encoding resistance to kanamycin, a positive and dominant trait, was crossed with cv. girelle, which is heterozygous for a recessive albinism marker. the resulting seeds yielded 25% albino seedlings, of which 50% were also resistant to kanamycin. such plantlets (kr, a) grown in vitro were used for preparation of universal hybridizer protoplasts, since green buds that can develop on kanamycin containing-medium should result from fusion wit ... | 1994 | 7816020 |
| mutants of downy mildew resistance in lactuca sativa (lettuce). | as part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to bremia lactucae, the casual fungus of downy mildew. using a rapid and reliable screen, we identified 16 distinct mutants of latuca sativa that have lost activity of one of four different downy mildew resistance genes (dm). in all mutants, only a single dm specificity was affected. genetic analysis indicated that the lesions segregated as single, recessive mutations at the dm loci. dm3 ... | 1994 | 8088530 |
| phytogrowth-inhibitory activities of 2-thiophenecarboxylic acid and its related compounds. | 2-thiophenecarboxylic acid (i) exhibited growth-inhibitory activity in five kinds of plants. in particular, i strongly inhibited the growth of the roots of lactuca sativa l. var. longifolia lam and echinochloa utilis ohwi et yabuno, even at the low concentration of 5.0 x 10(-3) m. furthermore, all of the i-related compounds (ii-v and vii-x) except for vi, showed more or less obvious inhibitory activity on the seeds of sesamum indicum l. compounds vii-x, in which the carboxyl group of i was repla ... | 1994 | 8148810 |
| simple chromatographic systems permitting both dna purification and separation of 2'-deoxyribonucleoside 3'-monophosphates as substrates for 32p-postlabelling studies. | the 32p-postlabelling method has recently been applied to the measurement of oxidative dna damage. the assay requires the isolation of 2'-deoxyribonucleoside 3'-monophosphates subsequent to the extraction of dna followed by its enzymatic digestion. as an alternative to the use of toxic and oxidizing solvents such as phenol, a simple purification method is proposed, based mainly on size-exclusion chromatography carried out either with ready-made columns (nap-10, sec-2000) or, more conveniently, w ... | 1993 | 8491811 |
| anti-hyperglycemic effect of some edible plants. | the anti-hyperglycemic effect of 12 edible plants was studied on 27 healthy rabbits, submitted weekly to subcutaneous glucose tolerance tests after gastric administration of water, tolbutamide or a traditional preparation of the plant. tolbutamide, cucurbita ficifolia, phaseolus vulgaris, opuntia streptacantha, spinacea oleracea, cucumis sativus and cuminum cyminum decrease significantly the area under the glucose tolerance curve and the hyperglycemic peak. brassica oleracea var. botrytis, alliu ... | 1995 | 8569244 |
| molecular analysis of irradiation-induced and spontaneous deletion mutants at a disease resistance locus in lactuca sativa. | the major cluster of disease resistance genes in lettuce (lactuca sativa) contains at least nine downy mildew resistance genes (dm) spanning a genetic distance of 20cm and a physical distance of at least 6 mb. nine molecular markers that were genetically tightly linked to dm3 were used to analyze nine independent deletion mutants and construct a map of the region surrounding dm3. this analysis identified a linear order of deletion breakpoints and markers along the chromosome. there was no eviden ... | 1996 | 8676874 |
| rhizobium leguminosarum as a plant growth-promoting rhizobacterium: direct growth promotion of canola and lettuce. | early seedling root growth of the nonlegumes canola (brassica campestris cv. tobin, brassica napus cv. westar) and lettuce (lactuca sativa cv. grand rapids) was significantly promoted by inoculation of seeds with certain strains of rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. the growth-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. auxotrophic rhi ... | 1996 | 8868235 |
| inhalative occupational and ingestive immediate-type allergy caused by chicory (cichorium intybus). | we report a first case of occupational allergy to chicory (cichorium intybus) in a vegetable wholesaler. symptoms occurred after oral, cutaneous or inhalatory exposure. the patient also reported reactions after ingestion of botanically related endive (cichorium endivia) and lettuce (lactuca sativa). we identified the responsible allergen by sds-page and immunoblot to be a 48-kda protein, confined to the non-illuminated parts of the plants. no cross-reactivity was found with mugwort (artemisia vu ... | 1996 | 8877160 |
| molecular and functional characterization of slide, an ac-like autonomous transposable element from tobacco. | a new transposable element of tobacco, slide, was isolated from the tl mutant line, which shows somatic instability, after its transposition into a locus encoding nitrate reductase (nr). the slide-124 element is 3733 bp long and its coding sequences show similarities with conserved domains of the transposases of ac, tam3 and hobo. excision from the nr locus is detectable in somatic leaf tissues and slide mobility is triggered by in vitro tissue culture. slide excision events create footprints si ... | 1996 | 8879239 |
| a transgenic mutant of lactuca sativa (lettuce) with a t-dna tightly linked to loss of downy mildew resistance. | one hundred and ninety-two independent primary transformants of lettuce cv. diana were obtained by co-cultivation with agrobacterium tumefaciens carrying constructs containing maize ac transposase and ds. r2 families were screened for mutations at four genes (dm) for resistance to downy mildew. one family, designated dm3t524, had lost resistance to an isolate of bremia lactucae expressing the avirulence gene avr3. loss of resistance segregated as a single recessive allele of dm3. the mutation wa ... | 1997 | 9353944 |
| identification of a 37 kda plant protein that interacts with the turnip mosaic potyvirus capsid protein using anti-idiotypic-antibodies. | experimental data are provided for the presence of a plant protein that interacts with the capsid protein (cp) of turnip mosaic potyvirus (tumv). the receptor-like protein was identified by exploiting the molecular mimicry potential of anti-idiotypic antibodies. a single-chain fv molecule derived from the monoclonal antibody 7a (mab-7a), which recognizes the cp of tumv, was produced in escherichia coli and the recombinant protein was used to raise rabbit antibodies. the immune serum reacted with ... | 1998 | 9617793 |
| localized changes in peroxidase activity accompany hydrogen peroxide generation during the development of a nonhost hypersensitive reaction in lettuce | peroxidase activity was characterized in lettuce (lactuca sativa l.) leaf tissue. changes in the activity and distribution of the enzyme were examined during the development of a nonhost hypersensitive reaction (hr) induced by pseudomonas syringae (p. s.) pv phaseolicola and in response to an hrp mutant of the bacterium. assays of activity in tissue extracts revealed ph optima of 4.5, 6.0, 5.5 to 6.0, and 6.0 to 6.5 for the substrates tetramethylbenzidine, guaiacol, caffeic acid, and chlorogenic ... | 1998 | 9808752 |
| phytochrome regulates gibberellin biosynthesis during germination of photoblastic lettuce seeds. | germination of lettuce (lactuca sativa l.) seed is regulated by phytochrome. the requirement for red light is circumvented by the application of gibberellin (ga). we have previously shown that the endogenous content of ga1, the main bioactive ga in lettuce seeds, increases after red-light treatment. to clarify which step of ga1 synthesis is regulated by phytochrome, cdnas encoding ga 20-oxidases (ls20ox1 and ls20ox2, for l. sativa ga 20-oxidase) and 3beta-hydroxylases (ls3h1 and ls3h2 for l. sat ... | 1998 | 9847128 |
| retention of microcystis aeruginosa and microcystin by salad lettuce (lactuca sativa) after spray irrigation with water containing cyanobacteria. | colonies and single cells of microcystis aeruginosa and the hepatotoxin microcystin were retained by salad lettuce after growth with spray irrigation water containing the microcystin-producing cyanobacteria. these findings are discussed in terms of crop spray irrigation with water containing cyanobacteria and potential human exposure to cyanobacterial toxins via plant foods grown in such circumstances. | 1999 | 10400301 |
| [the enteroparasitic contamination of commercial vegetables in the cities of niterói and rio de janeiro, brazil]. | the aim of this study was to evaluate the parasitological contamination of vegetables to be consumed raw and commercialized in niterói and rio de janeiro cities. we studied 128 samples of vegetables--lettuce (lactuca sativa) and watercress (nasturtium officinale)--from supermarkets, greengrocer shops and self-service restaurants. only 6.2% of the samples were positive for parasitic structures with morphological aspects similar to those of animal parasites. we detected acarids, acarid eggs, insec ... | 1999 | 10495664 |
| a plant-derived edible vaccine against hepatitis b virus. | the infectious hepatitis b virus represents 42 nm spherical double-shelled particles. however, analysis of blood from hepatitis b virus carriers revealed the presence of smaller 22 nm particles consisting of a viral envelope surface protein. these particles are highly immunogenic and have been used in the design of hepatitis b virus vaccine produced in yeast. upon expression in yeast, these proteins form virus-like particles that are used for parenteral immunization. therefore, the dna fragment ... | 1999 | 10506582 |
| identification of multi-gene families encoding isopentenyl diphosphate isomerase in plants by heterologous complementation in escherichia coli. | two cdnas encoding isopentenyl diphosphate isomerase (ipi) in adonis aestivalis, arabidopsis thaliana, and lactuca sativa, and single examples from oryza sativa and tagetes erecta were identified. an analysis of these and other ipi leads us to suggest a separate origin for green algal and plant genes and propose that a single gene encodes plastid and cytosolic ipi in plants. | 2000 | 10750717 |
| impact of insecticides and surfactant on lettuce physiology and yield. | insecticides are used extensively on lettuce, lactuca sativa l., grown in southwestern arizona because of heavy insect pressure that can potentially reduce lettuce productivity. multiple sprays are made per season to manage these insects in lettuce. one of the major concerns related to extensive insecticide applications in lettuce is the potential subtle impact of insecticides that may reduce lettuce photosynthesis and yield. we conducted field and greenhouse experiments to examine the impact of ... | 2000 | 10902331 |
| growth promoting effect of two sinorhizobium meliloti strains (a wild type and its genetically modified derivative) on a non-legume plant species in specific interaction with two arbuscular mycorrhizal fungi. | in the present study, we have investigated whether the ubiquitous rhizosphere soil organism sinorhizobium meliloti has a plant growth promoting (pgp) effect on non-leguminous plant species. such pgp activity was investigated for both a wild type strain and its genetically modified (gm) derivative, which had an enhanced biofertilizer capability. the pgp effect of these rhizobial strains was tested in interaction with two arbuscular-mycorrhizal (am) fungi: g. mosseae or g. intraradices on lettuce ... | 2000 | 11011093 |
| a comparison of peronospora parasitica (downy mildew) isolates from arabidopsis thaliana and brassica oleracea using amplified fragment length polymorphism and internal transcribed spacer 1 sequence analyses. | amplified fragment length polymorphism (aflp) fingerprints and internal transcribed spacer 1 (its1) sequences from 27 peronospora parasitica isolates (collected from arabidopsis thaliana or brassica oleracea), 5 albugo candida isolates (from the same hosts and from capsella bursa-pastoris), and 1 bremia lactucae isolate (from lactuca sativa) were compared. the aflp analysis divided the isolates into five groups that correlated with taxonomic species and, in most cases, with host origin. the only ... | 2000 | 11017765 |
| quantification of metal bioavailability for lettuce (lactuca sativa l.) in field soils. | understanding metal bioavailability of plants in soils requires, apart from physiological processes and symbiosis with arbuscular mycorrhizal fungi, the consideration of the chemical availability in the soil solution (the intensity of the toxic exposure) and the soil's capacity to supply the metal (capacity). in this contribution we report on the time-dependent accumulation of as, cd, cr, cu, ni, pb, and zn in lettuce (lactuca sativa l.). bioassays with 17 dutch field soils and two artificially ... | 2000 | 11031301 |
| recombination and spontaneous mutation at the major cluster of resistance genes in lettuce (lactuca sativa). | two sets of overlapping experiments were conducted to examine recombination and spontaneous mutation events within clusters of resistance genes in lettuce. multiple generations were screened for recombinants using pcr-based markers flanking dm3. the dm3 region is not highly recombinagenic, exhibiting a recombination frequency 18-fold lower than the genome average. recombinants were identified only rarely within the cluster of dm3 homologs and no crossovers within genes were detected. three popul ... | 2001 | 11157000 |
| one ring or two? determination of ring number in carotenoids by lycopene epsilon-cyclases. | carotenoids in the photosynthetic membranes of plants typically contain two beta-rings (e.g., beta-carotene and zeaxanthin) or one epsilon- and one beta-ring (e.g., lutein). carotenoids with two epsilon-rings are uncommon. we reported earlier that the arabidopsis thaliana lycopene epsilon-cyclase (lcye) adds one epsilon-ring to the symmetrical linear substrate lycopene, whereas the structurally related lycopene beta-cyclase (lcyb) adds two beta-rings. here we describe a cdna encoding lcye in rom ... | 2001 | 11226339 |
| assessment of toxicity reduction after metal removal in bioleached sewage sludge. | sewage sludge can be applied to land to supply and recycle organic matter and nutrients. trace elements in sludge, however, may accumulate in the soil with repeated sludge applications. reducing metal content may therefore reduce the adverse effects of sludge application. the objective of this study was to evaluate the efficiency of bioleaching technology in reducing metal content and toxicity as measured by a battery of terrestrial and liquid-phase bioassays. sludge-soil mixtures simulating the ... | 2001 | 11317888 |
| interlaboratory study for the validation of an ecotoxicological procedure to monitor the quality of septic sludge received at a wastewater treatment plant. | septic tank sludge is regularly hauled to the montreal urban community (muc) wastewater treatment plant. it is then discharged and mixed with the wastewater inflow before entering the primary chemical treatment process. an ecotoxicological procedure integrating chemical and toxicological analyses has been recently developed and applied to screen for the illicit discharge of toxic substances in septic sludge. the toxicity tests used were the microtox, the bacterial-respiration, and the lettuce (l ... | 2001 | 11339716 |
| the use of acute and chronic bioassays to determine the ecological risk and bioremediation efficiency of oil-polluted soils. | to compare the effectiveness of acute and chronic bioassays for the ecological risk assessment of polluted soils, soil samples from a site with an historical mineral oil contamination (< 50-3,300 mg oil/kg dry soil) at the petroleum harbour in amsterdam, the netherlands, were screened for ecological effects using acute and chronic bioassays. a two-step 0.001 m ca(no3)2 extraction at a final solution-to-soil ratio of 1:1 was used to prepare extracts for the acute bioassays. acute bioassays (< or ... | 2001 | 11434283 |
| production of dwarf lettuce by overexpressing a pumpkin gibberellin 20-oxidase gene. | we investigated the effect of overexpressing a pumpkin gibberellin (ga) 20-oxidase gene encoding an enzyme that forms predominantly biologically inactive products on ga biosynthesis and plant morphology in transgenic lettuce (lactuca sativa cv vanguard) plants. lettuce was transformed with the pumpkin ga 20-oxidase gene downstream of a strong constitutive promoter cassette (el2-35s-omega). the transgenic plants in which the pumpkin gene was detected by polymerase chain reaction were dwarfed in t ... | 2001 | 11457947 |
| chemical immobilization of lead, zinc, and cadmium in smelter-contaminated soils using biosolids and rock phosphate. | chemical immobilization, an in situ remediation method where inexpensive chemicals are used to reduce contaminant solubility in contaminated soil, has gained attention. we investigated the effectiveness of lime-stabilized biosolid (lsb), n-viro soil (nv), rock phosphate (rp), and anaerobic biosolid (ab) to reduce extractability and plant and gastrointestinal (gi) bioavailability in three cd-, pb-, and zn-contaminated soils from smelter sites. treated (100 g kg(-1) soil) and control soils were in ... | 2001 | 11476499 |
| reliability of trajectory identification for cosmic heavy ions and cytogenetic effects of their passage through plant seeds. | the potentially specific importance of the study of heavy ions from galactic cosmic rays for the understanding of radiation protection in manned spaceflight continues to stimulate spaceflight experiments in order to investigate the radiobiological properties of these ions. chromosome aberrations as an expression of a direct assault on the genome are of particular interest in view of carcinogenesis as the primary radiation risk for man in space. an essential technical ingredient of such spaceflig ... | 1990 | 11537512 |
| modification of yield and chlorophyll content in leaf lettuce by hps radiation and nitrogen treatments. | this study evaluated the potential of high photosynthetic photon flux (ppf) from high-pressure sodium (hps) lamps, alone or in combination with metal halide (mh) plus quartz iodide (qi) incandescent lamps, to support lettuce growth, with or without n supplementation. varying exposures to radiation from combined hps, mh, and qi lamps influenced dry weight gain and photosynthetic pigment content of hydroponically grown black-seeded simpson' lettuce (lactuca sativa l.) seedlings. cumulative leaf ... | 1991 | 11537726 |
| environmental modification of yield and nutrient composition of 'waldmann's green' leaf lettuce. | leaf number, dry weight, and nutrient composition of lactuca sativa l. cv. waldmann's green leaves were compared following 9 days of treatment in a controlled environment room under various combinations of photosynthetic photon flux (ppf:350 vs 800 micromoles m-2 s-1), atmospheric co2 level (ambient vs 1500 micromoles mol-1), and single-strength (1x:15 mm) vs double-strength (2x:30 mm) nitrogen (n) as no3- alone or as nh4(+) + no3- (1:5 molar ratio). co2 enrichment greatly enhanced leaf number u ... | 1997 | 11539875 |
| particle trajectories in seeds of lactuca sativa and chromosome aberrations after exposure to cosmic heavy ions on cosmos biosatellites 8 and 9. | the potentially specific importance of the heavy ions of the galactic cosmic radiation for radiation protection in manned spaceflight continues to stimulate in situ, i.e., spaceflight experiments to investigate their radiobiological properties. chromosome aberrations as an expression of a direct assault on the genome are of particular interest in view of cancerogenesis being the primary radiation risk for man in space. in such investigations the establishment of the geometrical correlation bet ... | 1994 | 11540038 |
| an ecotoxic risk assessment of residue materials produced by the plasma pyrolysis/vitrification (pp/v) process. | plasma is the fourth state of matter, following the three states of solid, liquid and gas. experience has amply demonstrated that solids exposed to the oxygen-deficient plasma flame are converted to liquid, and liquid exposed to the same flame is converted to gas. a low amount of vitrified solid residue material usually remains at the end of this process. plasma pyrolysis/vitrification (pp/v) has been demonstrated as a safe, efficient, cost-effective technology for the treatment of wastes, inclu ... | 2002 | 11952180 |
| cloning, expression, and biological activity of recombinant alpha-cinnamomin: toxicity to cranberry and other plant species. | elicitins produced by the pathogenic fungi phytophthora are known to exhibit the elicitin cinnamomin is of nonspecific toxicity to different solanaceous plant species. particular interest for its potential role in the hypersensitive-like cell death and in the biological response of cranberry plants to the fungal pathogen phytophthora cinnamomi. in order to understand the biochemical steps of the phytophthora root rot disease in cranberry, we investigated the alpha-cinnamomin-induced plant respon ... | 2002 | 12009117 |
| cloning and expression of sesquiterpene synthase genes from lettuce (lactuca sativa l.). | sesquiterpenoid lactones (sls) from lettuce (lactuca sativa l.) include constitutive components of latex such as lactucin and the induced phytoalexin, lettucenin a. a redundant primer strategy was used to recover two full length cdna clones (ltc1 and ltc2) encoding sesquiterpene synthases from a cdna library derived from seedlings with the red spot disorder, which accumulate phytoalexins. recombinant enzymes produced from ltc1 and ltc2 in escherichia coli catalysed the cyclisation of farnesyl di ... | 2002 | 12031443 |
| overview of results from the watertox intercalibration and environmental testing phase ii program: part 1, statistical analysis of blind sample testing. | there is an urgent need to evaluate the presence of toxicants in waters used for human consumption and to develop strategies to reduce and prevent their contamination. the international development research centre undertook an intercalibration project to develop and validate a battery of bioassays for toxicity testing of water samples. the project was carried out in two phases by research institutions from eight countries that formed the watertox network. results for the first phase were reporte ... | 2002 | 12112631 |
| ecotoxicological assessment of leachates from mswi bottom ashes. | in this paper, chemical and ecotoxicological data of leachates from bottom ashes collected in different municipal solid waste incinerators (mswi) are shown. the bottom ashes were collected in belgium (three incinerators--samples b1 to b3), france, germany, italy and united kingdom (one incinerator in each country--samples f1, d1, i1 and uk1, respectively). both chemical and ecotoxicological characterizations of leachates were done on the framework of the european directive 91/689/eec and the eur ... | 2002 | 12214969 |
| hrp mutant of pseudomonas syringae pv phaseolicola induces cell wall alterations but not membrane damage leading to the hypersensitive reaction in lettuce. | both wild-type (s21-wt) and hrpd- (s21-533) strains of pseudomonas syringae pv phaseolicola induced the formation of large paramural papillae in lettuce (lactuca sativa) mesophyll cells adjacent to bacterial colonies. localized alterations to the plant cell wall included deposition of hydroxyproline-rich glycoproteins, phe-nolics, and callose, and were associated with proliferation of the endoplasmic reticulum and multivesicular bodies. tissue collapse during the hypersensitive reaction caused b ... | 1995 | 12228488 |
| suspending lettuce type influences recoverability and radiation sensitivity of escherichia coli o157:h7. | an outbreak strain of escherichia coli o157:h7 was inoculated onto closely related but structurally distinct types of lettuce (lactuca sativa): boston (butterhead lettuce), iceberg (crisphead lettuce), and green leaf and red leaf (colored variants of looseleaf lettuce). the e. coli o157:h7 was inoculated either onto the surface of cut leaf pieces or into a homogenized leaf suspension. samples were gamma irradiated, and the radiation sensitivity of the inoculated bacteria was expressed as a d-val ... | 2002 | 12233847 |
| soil-to-root transfer and translocation of polycyclic aromatic hydrocarbons by vegetables grown on industrial contaminated soils. | polycyclic aromatic hydrocarbons (pahs) are possible contaminants in some former industrial sites, representing a potential risk to human health if these sites are converted to residential areas. this work was conducted to determine whether pahs present in contaminated soils are transferred to edible parts of selected vegetables. soils were sampled from a former gasworks and a private garden, exhibiting a range of pah concentrations (4 to 53 to 172 to 1263 and 2526 mg pahs kg-1 of dry soil), and ... | 2002 | 12371182 |
| [detection of enterococcus with high-level aminoglycoside and glycopeptide resistance in lactuca sativa (lettuce)]. | the aim of this study was to assess the presence of enterococci highly resistant to aminoglycosides and glycopeptides in foods eaten uncooked, in order to evaluate their role as reservoirs of antimicrobial resistance. | 2002 | 12372233 |
| phytol, ssadh inhibitory diterpenoid of lactuca sativa. | the succinic semialdehyde dehydrogenase (ssadh) inhibitory component was isolated from the etoac fraction of lactuca sativa through repeated column chromatography; then, it was identified as phytol, a diterpenoid, based on the interpretation of several spectral data. incubation of ssadh with the phytol results in a time-dependent loss of enzymatic activity, suggesting that enzyme modification is irreversible. the inactivation followed pseudo-first-order kinetics with the second-rate order consta ... | 2002 | 12433198 |
| effect of acute ingestion of fresh and stored lettuce (lactuca sativa) on plasma total antioxidant capacity and antioxidant levels in human subjects. | the present study investigated whether storage under modified-atmosphere packaging (map) affected the antioxidant properties of fresh lettuce (lactuca sativa). eleven healthy volunteers (six men, five women) consumed 250 g fresh lettuce, and blood was sampled before (0 h) and 2, 3 and 6 h after consumption. the protocol was repeated 3 d later with the same lettuce stored at 5 degrees c under map conditions (o2-n2 (5:95, v/v)). results showed that after ingestion of fresh lettuce, plasma total ra ... | 2002 | 12493083 |
| lactuca saligna, a non-host for lettuce downy mildew ( bremia lactucae), harbors a new race-specific dm gene and three qtls for resistance. | lactuca sativa (lettuce) is susceptible to bremia lactucae (downy mildew). in cultivated and wild lactuca species, dm genes have been identified that confer race-specific resistance. however, these genes were soon rendered ineffective by adaptation of the pathogen. lactuca saligna (wild lettuce) is resistant to all downy mildew races and can be considered as a non-host. therefore, l. saligna might be an alternative source for a more-durable resistance to downy mildew in lettuce. in order to anal ... | 2002 | 12582542 |
| identification of an emergent and atypical pseudomonas viridiflava lineage causing bacteriosis in plants of agronomic importance in a spanish region. | pseudomonas strains with an atypical lopat profile (where lopat is a series of determinative tests: l, levan production; o, oxidase production; p, pectinolitic activity; a, arginine dihydrolase production; and t, tobacco hypersensibility) can be regarded as emergent pathogens in the principality of asturias (spain), where they have been causing, since 1999, severe damage in at least three taxonomically unrelated orchard plants of agronomic importance: common bean (phaseolus vulgaris), kiwifruit ... | 2003 | 12732569 |
| reduction of arsenic uptake by lettuce with ferrous sulfate applied to contaminated soil. | soil contamination by arsenic (as) presents a hazard in many countries and there is a need for techniques to minimize as uptake by plants. a proposed in situ remediation method was tested by growing lettuce (lactuca sativa l. cv. kermit) in a greenhouse pot experiment on soil that contained 577 mg as kg(-1), taken from a former as smelter site. all combinations of iron (fe) oxides, at concentrations of 0.00, 0.22, 0.54, and 1.09% (w/w), and lime, at concentrations of 0.00, 0.27, 0.68, and 1.36% ... | 2003 | 12809277 |
| the eukaryotic translation initiation factor 4e controls lettuce susceptibility to the potyvirus lettuce mosaic virus. | the eif4e and eif(iso)4e cdnas from several genotypes of lettuce (lactuca sativa) that are susceptible, tolerant, or resistant to infection by lettuce mosaic virus (lmv; genus potyvirus) were cloned and sequenced. although ls-eif(iso)4e was monomorphic in sequence, three types of ls-eif4e differed by point sequence variations, and a short in-frame deletion in one of them. the amino acid variations specific to ls-eif4e(1) and ls-eif4e(2) were predicted to be located near the cap recognition pocke ... | 2003 | 12857809 |
| cross-contamination of lettuce (lactuca sativa l.) with escherichia coli o157:h7 via contaminated ground beef. | a lettuce outbreak strain of e. coli o157:h7 was used to quantitate the pathogen's survival in ground beef and its transfer to hands, cutting board surfaces, and lettuce. overnight storage of inoculated beef at 4 degrees c resulted in no pathogen growth, while room-temperature storage allowed multiplication. hamburger patty formation allowed the transfer of bacteria to hands. contaminated fingers subsequently transferred the pathogen to lettuce during handling. e. coli was transferred from hambu ... | 2003 | 12870750 |
| a method for profiling classes of plant hormones and their metabolites using liquid chromatography-electrospray ionization tandem mass spectrometry: an analysis of hormone regulation of thermodormancy of lettuce (lactuca sativa l.) seeds. | a highly selective and sensitive method for the simultaneous analysis of several plant hormones and their metabolites is described. the method combines high-performance liquid chromatography (hplc) with positive and negative electrospray ionization-tandem mass spectrometry (esi-ms/ms) to quantify a broad range of chemically and structurally diverse compounds. the addition of deuterium-labeled analogs for these compounds prior to sample extraction permits accurate quantification by multiple react ... | 2003 | 12887591 |
| [change in incidence of parasite eggs and larvae from vegetable in the markets of taegu] | a survey on vegetables, which consisted of lettuce (lactuca sativa), young radish (raphanus sapivus), and chinese cabbage (brassica pekinensis) collected from 6 markets in the taegu city, was conducted for the discovery of helminth eggs and larvae, from july 1982 to june 1983. the results were compared with the data obtained from vegetables collected at the same markets by lee (1969) and choi and lee (1972). both sides of vegetable leaves were washed carefully with a hard brush, and the species ... | 1983 | 12902676 |
| incidence of parasites found on vegetables collected from markets and vegetable gardens in taegu area. | a parasitic survey on vegetables collected from markets and vegetable gardens in taegu area was conducted for the discovery of human parasitic eggs and larvae. three species of vegetable, lettuce (lactuca sativa), young radish(raphanus sapivus) and chinese cabbage (brassica pekinensis) were selected. all vegetable leaves were washed with a hard brush, and then species of parasites and the approximate mean number of parasitic eggs per 200 grams of vegetable leaves were investigated. when vegetabl ... | 1972 | 12913510 |
| [microbiological and parasitological contamination of lettuce (lactuca sativa) from self service restaurants of niterói city, rj]. | thirty samples of lettuces from self service restaurants of niterói were analyzed to detect bacteriological and parasitological contamination. sixteen samples presented fecal coliform, 16 mesophilic aerobic microorganisms greater than 10(7) ufc/g and 3 cysts of entamoeba coli. these data suggest the need of better orientation for food handlers regarding the hygiene of processed vegetables. | 2003 | 12937736 |
| essential oils from mediterranean lamiaceae as weed germination inhibitors. | the essential oils obtained from rosemary (rosmarinus officinalis l.), thyme (thymus vulgaris l.), and savory (satureja montana l.) and the four monoterpenes that are their major constituents have been analyzed by gc and gc-ms and tested for their allelopathic properties on the seeds of three different annual weeds (chenopodium album, portulaca oleracea, and echinochloa crus-galli) and three crops (raphanus sativus, capsicum annuum, and lactuca sativa), with the aim to evaluate in vitro their po ... | 2003 | 14518938 |
| inhibition of endogenous trypsin- and chymotrypsin-like activities in transgenic lettuce expressing heterogeneous proteinase inhibitor sapin2a. | sapin2a, a proteinase inhibitor ii from american black nightshade (solanum americanum mill.) is highly expressed in the phloem and could be involved in regulating proteolysis in the sieve elements. to further investigate the physiological role of sapin2a, we have produced transgenic lettuce (lactuca sativa l.) expressing sapin2a from the camv35s promoter by agrobacterium-mediated transformation. stable integration of the sapin2a cdna and its inheritance in transgenic lines were confirmed by sout ... | 2004 | 14574575 |
| [frequency of intestinal parasites in samples of lettuce (lactuca sativa) commercialized in lavras, minas gerais state]. | the aim of this study was to evaluate the parasitological contamination in samples of lettuce (lactuca sativa) commercialized in lavras city, minas gerais. the samples of lettuce showed low hygienic conditions, indicated by the presence of parasites of animal or human origin and high concentration of fecal coliforms. | 2003 | 14576879 |
| transfer of salmonella and campylobacter from stainless steel to romaine lettuce. | the degree of transfer of campylobacter jejuni and salmonella enterica serovar typhimurium was evaluated from a stainless steel contact surface to a ready-to-eat food (lettuce). stainless steel coupons (25 cm2) were inoculated with a 20-microl drop of either c. jejuni or salmonella typhimurium to provide an inoculum level of approximately 10(6) cfu/28 mm2. wet and dry lettuce (lactuca sativa var. longifolia) pieces (9 cm2) were placed onto the inoculated stainless steel surface for 10 s after th ... | 2003 | 14672218 |
| alkylperoxyl radical scavenging activity of red leaf lettuce (lactuca sativa l.) phenolics. | although lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, lettuce leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. after determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (orac) values, the phenolic compounds from red leaf lettuce were separated by reverse-phase high-performance liquid chromatography (h ... | 2003 | 14705882 |
| a simple and efficient method for testing lettuce mosaic virus resistance in in vitro cultivated lettuce. | the potential of a new in vitro inoculation and propagation method developed for lettuce mosaic virus (lmv) on lettuce (lactuca sativa l.) was evaluated by studying lmv infection on in vitro cultivated seedlings or on newly regenerated plantlets. lettuce cultivars differing by their lmv-resistance status were inoculated with various natural lmv isolates as well as with green fluorescent protein (gfp)-tagged recombinant virus isolates. a good correlation was observed between the known resistance ... | 2004 | 14738978 |
| joint effects of elevated levels of ultraviolet-b radiation, carbon dioxide and ozone on plants. | there is growing interest regarding the joint effects of elevated levels of surface ultraviolet b (uv-b) radiation, carbon dioxide (co2) and ozone (o3) on plants. our current knowledge of this subject is too limited to draw any specific conclusions, although one might state that such effects are likely to be highly species dependent and may be more than additive, additive or less than additive. there are a number of uncertainties associated with the experimental protocols used and the conclusion ... | 2003 | 14743861 |
| the effect of ph, time and dietary source of cadmium on the bioaccessibility and adsorption of cadmium to/from lettuce (lactuca sativa l. cv. ostinata). | this study evaluated the influence of three variables in the effectiveness of an in vitro digestion protocol used to determine bioaccessibility of cadmium from the diet. the percentage of solubilized metal was measured in relation to digestion time, ph of each digestion phase and the dietary source of the metal in the diet. because it would be convenient to add the metal to the diet before digestion instead of growing contaminated vegetables, the importance of metal incorporation in the plant in ... | 2004 | 15046830 |
| zapoteca formosa: sulfur chemistry and phytotoxicity. | chemical analysis of zapoteca formosa extracts show that a variety of volatile sulfur-containing components, including cyclic polysulfides, are responsible for the distinctive odor of its germinating seeds and young plants. the major sulfur-containing compounds include acetyl djenkolic acid, djenkolic acid, taurine, cystine, benzothiazole, dimethyl disulfide, 2,4-dithiapentane, 2-hydroxyethylmethylsulfide, trithiane, 1,2,4-trithiolane, and 1,2,4,6-tetrathiepane. decreased amounts of djenkolic ac ... | 2004 | 15112733 |
| analgesic and anti-inflammatory activity of lactuca sativa seed extract in rats. | lactuca sativa (lettuce) is a member of compositae family. in folk medicine of iran, the seeds of this plant were used for relieving of inflammation and osteodynia. in this study, anti-nociceptive and anti-inflammatory activities of a crude methanol/petroleum ether (70/30, v/v) extract of the seeds have been evaluated. the extract exhibited a time- and dose-dependent analgesic effect in formalin test and also a dose-dependent anti-inflammatory activity in a carrageenan model of inflammation. the ... | 2004 | 15138019 |
| toxicity assessment of contaminated soils from an antitank firing range. | explosives are released into the environment at production and processing facilities, as well as through field use. these compounds may be toxic at relatively low concentrations to a number of ecological receptors. a toxicity assessment was carried out on soils from an explosive-contaminated site at a canadian forces area training center. toxicity studies on soil organisms using endpoints such as microbial processes (potential nitrification activity, dehydrogenase activity, substrate-induced res ... | 2004 | 15223256 |
| assessment of the use of industrial by-products to remediate a copper- and arsenic-contaminated soil. | two water treatment sludges (wts-a, wts-b), two red muds (rm), and red gypsum (rg), all rich in iron oxy-hydroxides, were added to a soil highly polluted with as and cu at 2% (w/w) to reduce metal bioavailability. because the amendments increased soil ph to approximately 6, a lime treatment to the same ph and an unamended treatment were included for comparison. all the amendments had significant positive effects on the soil microbial biomass and growth of ryegrass (lolium multiflorum lam. cv. av ... | 2004 | 15224926 |
| isolation and characterisation of a class of carbohydrate oxidases from higher plants, with a role in active defence. | in a search for novel plant-derived antimicrobial proteins, we screened extracts from salicylic acid (sa)-treated lettuce and sunflower leaves. these extracts displayed very potent antimicrobial activity against a set of phytopathogens. characterisation of these extracts revealed that in both extracts, proteins of approximately 60 kda were responsible for the antimicrobial activity. further characterisation of these proteins and cloning of the respective cdnas revealed close homology to a range ... | 2004 | 15225281 |
| chryseobacterium formosense sp. nov., isolated from the rhizosphere of lactuca sativa l. (garden lettuce). | a yellow-pigmented bacterial strain (cc-h3-2t), isolated from the rhizosphere of lactuca sativa l. (garden lettuce) in taiwan, was investigated using a polyphasic taxonomic approach. the cells were gram-negative, rod-shaped and non-spore-forming. phylogenetic analyses using the 16s rrna gene sequence of the isolate indicated that the organism belongs to the genus chryseobacterium, with the highest sequence similarity to the type strains of chryseobacterium indoltheticum (97.7 %), chryseobacteriu ... | 2005 | 15653912 |
| effects of several applications of digested sewage sludge on soil and plants. | sewage sludge production has significantly increased during the last years in european union (eu) countries, being primarily used for agricultural purposes. in this study, digested sewage sludge was applied to greenhouse soil over a three-year period (2001--2003), with three sludge treatments in the first two years (2, 4, and 6 kg m(-2)) and three more applications using a greater quantity in the last year (6, 8, and 10 kg m(-2)). the effects of sewage sludge application on soil and on a leafy c ... | 2005 | 15717786 |
| the lettuce infectious yellows virus (liyv)-encoded p26 is associated with plasmalemma deposits within liyv-infected cells. | cytological, immunological, and mutagenesis approaches were used to identify the viral factors associated with the formation of plasmalemma deposits (plds) in whole plants and protoplasts infected by lettuce infectious yellows virus (liyv). transmission electron microscopy and immunogold labeling using polyclonal antibodies to four of the five liyv rna 2-encoded large proteins, capsid protein (cp), minor capsid protein (cpm), hsp70 homolog (hsp70h), and p59, showed specific labeling of liyv viri ... | 2005 | 15721368 |
| the application of bioassays as indicators of petroleum-contaminated soil remediation. | bioremediation has proven successful in numerous applications to petroleum contaminated soils. however, questions remain as to the efficiency of bioremediation in lowering long-term soil toxicity. in the present study, the bioassays spirotox, microtox, ostracodtoxkit f, umu-test with s-9 activation, and plant assays were applied, and compared to evaluate bioremediation processes in heavily petroleum contaminated soils. six higher plant species (secale cereale l., lactuca sativa l., zea mays l., ... | 2005 | 15722101 |
| biological and molecular characterization of lettuce mosaic virus from tehran province in iran. | in this study, lettuce samples having lmv infection symptoms were collected from tehran fields during 2003. samples tested for lmv infection by immuno printing. three positive samples in immuno printing collected and their characteristics were determined. in mechanical inoculation, these isolates produced symptoms on chenopodium quinoa, c. amaranticolor, gomphrena globosa, nicotiana benthamiana, lactuca sativa cv. mantilia and cv. terocadero (which contains the mol1 resistance gene and susceptib ... | 2004 | 15756833 |
| host-associated populations in the lettuce root aphid, pemphigus bursarius (l.). | pemphigus bursarius is a host-alternating aphid in which annual rounds of sexual reproduction on its primary host, populus nigra, are interspersed with parthenogenesis on a range of secondary hosts. evidence was sought for the existence of genetically distinct populations, associated with different secondary hosts, in p. bursarius. microsatellite markers revealed that genetically distinct populations were present on three different secondary host species. microsatellites were also used, in conju ... | 2005 | 15785781 |
| plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid. | spiraea thunbergii sieb. contains 1-o-cis-cinnamoyl-beta-d-glucopyranose (cg) and 6-o-(4'-hydroxy-2'-methylene-butyroyl)-1-o-cis-cinnamoyl-beta-d-glucopyranose (bcg) as major plant growth inhibiting constituents. in the present study, we determined the inhibitory activity of cg and bcg on root elongation of germinated seedlings of lettuce (lactuca sativa), pigweed (amaranthus retroflexus), red clover (trifolium pratense), timothy (phleum pratense), and bok choy (brassica rapa var chinensis) in c ... | 2005 | 15898503 |
| evaluation of the role of genes encoding for dehydrin proteins (lea d-11) during drought stress in arbuscular mycorrhizal glycine max and lactuca sativa plants. | in this study, it has been determined whether the arbuscular mycorrhizal (am) symbiosis is able to alter the pattern of dehydrin (lea d-11 group) transcript accumulation under drought stress, and whether such a possible alteration functions in the protection of the host plants against drought. two dehydrin-encoding genes have been cloned from glycine max (gmlea 8 and gmlea 10) and one from lactuca sativa (lslea 1) and they have been analysed for their contribution to the response against drought ... | 2005 | 15911559 |
| [pesticide detection in costarican vegetables based on the inhibition of serum and erythrocytic human cholinesterases]. | a simple and low cost method able to detect the presence of pesticides, organophosphates and carbamates based on the inhibition of serum and erythrocytic cholinesterases, was used in lettuce (lactuca sativa), cilantro (coriandum santivum) and celery (apium graveolens) obtained from the ferias del agricultor from valle central of costa rica. the percentage inhibition of cholinesterases is related to the presence of plaguicide in the vegetable. thirteen percent of the analyzed samples were positiv ... | 2004 | 15969271 |
| accumulation and perchlorate exposure potential of lettuce produced in the lower colorado river region. | the colorado river is contaminated with perchlorate concentrations of 1.5-8 microg/l, an anion linked to thyroid dysfunction. over 90% of the lettuce (lactuca sativa l.) consumed during the winter months in the united states is produced in the lower colorado river region. studies were conducted in this region to survey the potential for lettuce perchlorate accumulation and estimate potential human exposure to perchlorate from lettuce. total uptake of perchlorate in the above-ground plant of iceb ... | 2005 | 15969537 |
| systematic silencing of a tobacco nitrate reductase transgene in lettuce (lactuca sativa l.). | a population of 50 independent transgenic lettuces transformed with a nitrate reductase coding sequence under the control of the 35s promoter was studied. none of them showed significantly lower nitrate levels when compared with the untransformed plants, despite the presence of nitrate reductase (nr) activity that derives from the transgene in at least four of the transformants. no repercussion on total nr activity (endogenous+transgenic) was detected in these plants. nevertheless, 28% of the tr ... | 2005 | 16014365 |
| uptake and transport of radioactive nickel and cadmium into three vegetables after wet aerial contamination. | knowledge of radionuclide or trace element retention and translocation to plants following an aerial contamination event, for example, sprinkling with contaminated water, is necessary for the evaluation of human exposure through consumption of contaminated vegetables. the fate of 63ni and 109cd in all plant parts of three different vegetables after wet deposition on leaves or on fruits was studied. lettuce (lactuca sativa l.), radish (raphanus sativus l.), and bean (phaseolus vulgaris l.) grown ... | 2005 | 16091602 |
| ecotoxicity of sodium fluoroacetate (compound 1080) to soil organisms. | sodium fluoroacetate (compound 1080) is applied as a vertebrate pesticide in new zealand for control of introduced mammalian pests. despite its widespread use, little is known about the soil ecotoxicity of 1080. therefore, the hazard of 1080 to soil invertebrates, plants, and soil microorganisms was evaluated in a series of controlled laboratory tests. no earthworm (eisenia fetida) mortality was reported with 1080 exposures up to 865 mg/kg soil. the lowest-observable-effect concentration and the ... | 2005 | 16111002 |
| bioactive metabolites from the fungus nectria galligena, the main apple canker agent in chile. | the phytopathogenic fungus nectria galligena bres. is the most common canker disease agent of hardwood trees. the terpenoids colletochlorin b, colletorin b, ilicicolin c, e, and f, as well as the phytotoxin alpha,beta-dehydrocurvularin have been isolated from liquid cultures of n. galligena obtained from the xylem of infected apple trees in central chile. ilicicolin c and f and alpha,beta-dehydrocurvularin were active against pseudomonas syringae with ic50 values of 28.5, 28.5, and 14.2 microg/m ... | 2005 | 16190620 |
| stable plastid transformation in lettuce (lactuca sativa l.). | although plastid transformation in higher plants was first demonstrated in the early 1990s it is only recently that the technology is being extended to a broader range of species. to date, the production of fertile transplastomic plants has been reported for tobacco, tomato, petunia, soybean, cotton and lesquerella fendleri (brassicaceae). in this study we demonstrate a polyethylene glycol-mediated plastid transformation system for lettuce that generates fertile, homoplasmic, plastid-transformed ... | 2005 | 16240172 |
| a detailed linkage map of lettuce based on ssap, aflp and nbs markers. | molecular markers based upon a novel lettuce ltr retrotransposon and the nucleotide binding site-leucine-rich repeat (nbs-lrr) family of disease resistance-associated genes have been combined with aflp markers to generate a 458 locus genetic linkage map for lettuce. a total of 187 retrotransposon-specific ssap markers, 29 nbs-lrr markers and 242 aflp markers were mapped in an f(2) population, derived from an interspecific cross between a lactuca sativa cultivar commonly used in europe and a wild ... | 2006 | 16341837 |
| phytotoxicity and accumulation of anthracene applied to the foliage and sandy substrate in lettuce and radish plants. | the effects of anthracene (ant) on the growth of two species of vegetable plants (lactuca sativa l. and raphanus sativus l.), which play an important role in the human diet, were studied. ant was applied to the leaves of these plants by foliar deposition, in aerosol form, and to the sandy substrate in which the plants were grown in a greenhouse. it was found that ant affected plant biomass, especially root biomass, in the case of both foliar and soil application. under conditions of induced chem ... | 2007 | 16368141 |
| perchlorate and nitrate in leafy vegetables of north america. | in previous studies trace levels of perchlorate were found in lettuce (lactuca sativa l.) irrigated with colorado river water, which is contaminated with low levels of perchlorate from aerospace and defense related industries. in this paper, we report the results of a survey conducted across north america to evaluate the occurrence of perchlorate in leafy vegetables produced outside the lower colorado river region, and evaluate the relative iodide uptake inhibition potential to perchlorate and n ... | 2005 | 16475313 |
| evidence of an antilisterial factor induced by wounding of iceberg lettuce tissues. | to examine the influence of wound-associated reactions in cut iceberg lettuce (lactuca sativa l.) tissues on the fate of listeria monocytogenes. | 2006 | 16478519 |
| effects of arbuscular-mycorrhizal glomus species on drought tolerance: physiological and nutritional plant responses. | the tolerance of lettuce plants (lactuca sativa l. cv. romana) to drought stress differed with the arbuscular-mycorrhizal fungal isolate with which the plants were associated. seven fungal species belonging to the genus glomus were studied for their ability to enhance the drought tolerance of lettuce plants. these fungi had different traits that affected the drought resistance of host plants. the ranking of arbuscular-mycorrhizal fungal effects on drought tolerance, based on the relative decreas ... | 1995 | 16534929 |
| selecting a battery of bioassays for ecotoxicological characterization of wastes. | this study was conducted in france within the context of waste classification (hazardous waste council directive 91/689/eec), and focused on "ecotoxic" property (h14). in 1998, an experimental test strategy was developed to assess ecotoxicological properties of wastes using a battery of six standardized bioassays. this combined direct and indirect approaches integrating two solid-phase tests: emergence and growth inhibition of lactuca sativa (14 days), mortality of eisenia fetida (14 days) and f ... | 2006 | 16545863 |