Publications

plant hormone interaction and phenolic metabolism in the regulation of russet spotting in iceberg lettuce.	russet spotting (rs) is a physiological disorder induced in iceberg lettuce (lactuca sativa l.) by exposure to parts per million levels of ethylene at 5 +/- 2 degrees c. ethylene induced phenylalanine ammonia-lyase and ionically bound peroxidase activities that correlated with development of rs symptoms. the ethylene-treated tissue had significantly higher lignin content than air control tissue with lignification localized in walls of rs-affected cells. ethylene also caused the accumulation of t ...	1988	16666434
sodium and potassium compartmentation and transport in the roots of intact lettuce plants.	in this report, we consider the accumulation in roots, and transport to the shoot, of na(+) and k(+) in intact lettuce plants (lactuca sativa cv black-seeded simpson). plants were grown in modified hoagland medium supplemented with 10 moles nacl per cubic meter. at this salinity, significant levels of na(+) were accumulated in roots and shoots, but there was no reduction in plant growth. transport characteristics for both na(+) and k(+) were qualitatively similar to those previously reported, fo ...	1988	16666455
a role for ethylene in the metabolism of cyanide by higher plants.	the action of ethylene on the capacity of plant tissues to metabolize cyanide to beta-cyanoalanine was examined. beta-cyanoalanine synthase (ec 4.4.1.9) catalyzes the reaction between cyanide and cysteine to form beta-cyanoalanine and hydrogen sulfide. levels of beta-cyanoalanine synthase activity in tissues of 6 day old etiolated pea (pisum sativum) seedlings were enhanced severalfold by 1 microliter per liter ethylene. the promotive effect of ethylene increased with increasing ethylene concent ...	1989	16666701
control processes in the induction and relief of thermoinhibition of lettuce seed germination : actions of phytochrome and endogenous ethylene.	germination of lettuce seeds (lactuca sativa l. cv grand rapids) in the dark was nearly 100% at 20 degrees c but was inhibited at 27 degrees c and higher temperatures (thermoinhibition). a single 5-minute exposure to red light completely overcame the inhibition at temperatures up to 28 degrees c, above which the effectiveness of single light exposures gradually declined to reach a negligible level at 32 degrees c. however, the promotive effect of light could be extended to 34 degrees c by repeat ...	1989	16666755
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
kinetin enhanced 1-aminocyclopropane-1-carboxylic acid utilization during alleviation of high temperatures stress in lettuce seeds.	the thermoinhibition at 35 and 32 degrees c of pregermination ethylene production and germination in lettuce (lactuca sativa l. cv mesa 659) seeds was synergistically or additively alleviated by 0.05 millimolar kinetin (kin) and 10 millimolar 1-aminocyclopropane-1-carboxylic acid (acc). the synergistic effect of kin + acc on ethylene production and germination at 35 degrees c was inhibited by co(2+) (44-46%) but not by aminoethoxyvinyl glycine (avg). the uptake of acc by the seed was not influen ...	1989	16667094
a water relations analysis of seed germination rates.	seed germination culminates in the initiation of embryo growth and the resumption of water uptake after imbibition. previous applications of cell growth models to describe seed germination have focused on the inhibition of radicle growth rates at reduced water potential (psi). an alternative approach is presented, based upon the timing of radicle emergence, to characterize the relationship of seed germination rates to psi. using only three parameters, a ;hydrotime constant' and the mean and stan ...	1990	16667786
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
separation of light-induced [c]ent-kaurene metabolism and light-induced germination in grand rapids lettuce seeds.	the effect of light on the metabolism of [(14)c]kaurene in light-requiring lettuce seeds (lactuca sativa l. cv grand rapids) was investigated. seeds were soaked in a solution of [(14)c]ent-kaurene in methylene chloride with 0.01% tween-20, dried, and incubated in 20% polyethylene glycol (peg) to prevent seedling development. labeled metabolites were extracted and analyzed by high performance liquid chromatography and gas chromatography-radio counting. [(14)c]ent-kaurenol and [(14)c]ent-kaurenal ...	1991	16668262
inhibition of lettuce seed germination by cycloheximide and chloramphenicol is alleviated by kinetin and oxygen.	kinetin alleviates cycloheximide inhibition and oxygen alleviates chloramphenicol inibition of germination of lettuce seeds (lactuca sativa l. cv grand rapids). the effect is not due to increased but rather a substitution for protein synthesis. a cytokinin and energy supply appear prime requirements for germination.	1991	16668478
induction of somatic embryogenesis using side chain and ring modified forms of phenoxy acid growth regulators.	the induction of somatic embryo development in cell cultures of alfalfa (medicago sativa), celery (apium graveolens), and lettuce (lactuca sativa) was compared for 2,4-dichlorophenoxy-acetic acid (2,4-d) and various phenoxy acid growth regulators. tests using a series of straight chain extensions to the phenoxy acid side chain indicate that phenoxybutanoic acid is active, whereas the phenoxypropanoic and phenoxypentanoic analogs are inactive for the induction of alfalfa embryogenesis. side branc ...	1992	16668836
mehler-peroxidase reaction mediates zeaxanthin formation and zeaxanthin-related fluorescence quenching in intact chloroplasts.	induction of zeaxanthin formation and the associated nonphotochemical quenching in iodoacetamide-treated, non-co(2)-fixing intact chloroplasts of lactuca sativa l. cv romaine is reported. the electron transport needed to generate the required deltaph for zeaxanthin formation and nonphotochemical quenching are ascribed to the mehler-ascorbate peroxidase reaction. kcn, an inhibitor of ascorbate peroxidase, significantly affected these activities without affecting linear electron transport to methy ...	1992	16669044
photosynthetic parameters as indicators of trinitrotoluene (tnt) inhibitory effect: change in chlorophyll a fluorescence induction upon exposure of lactuca sativa to tnt.	trinitrotoluene, as a compound of conventional explosive, may cause inhibitory effect on terrestrial plants. when lactuca sativa was exposed to different concentrations of trinitrotoluene (32-1000 mg/kg), photosynthetic process was investigated by using rapid chlorophyll fluorescence kinetic and pulse modulated fluorometry. the decrease of chlorophyll a variable fluorescence was seen to be caused by the deactivation of photosystem ii reaction centers. we found for rapid variable fluorescence to ...	2006	16721675
structures of bioactive carexanes from the roots of carex distachya desf.	four metabolites, named carexanes i-l, have been isolated from the roots of carex distachya desf, an herbaceous plant living in the mediterranean maquis, together with three known compounds, already isolated from the aerial part of the plant. all the compounds have been characterized on the basis of their spectroscopic properties. carexane i derived from the lose of a proton from the c-18 carbon of an intermediate isopropyl cation. its stereostructure has been elucidated by mosher's method, noes ...	2006	16730033
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
temporal and positional relationships between mn uptake and low-ph-induced root hair formation in lactuca sativa cv. grand rapids seedlings.	we investigated whether low-ph-induced manganese (mn) deficiency causes low-ph-induced root hair formation in lettuce seedlings. both the number and length of root hairs increased in 0 microm mn (mn-free) at ph 6 and decreased in 3 mm mn (excess mn) at ph 4 compared with the values in 10 microm mn (normal mn). these results indicate an inhibitory effect of mn on both root hair initiation and elongation. the time dependency of root hair induction caused by mn deficiency corresponded to that cause ...	2006	16850119
short-term bioassay responses to sludge products and leachate.	recycling of sewage sludge is needed in a sustainable society. quality aspects of sludge include hygiene (pathogens), nutrients (n and p), and toxicants (metals and organics). metals are of particular concern because they are not degradable, but their hazards are related to their bioavailability and chemical speciation. in this article, the effect on sludge quality of two treatment methods, incineration and pelletization, has been determined for digested sludge from two treatment plants. the com ...	2006	16865600
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
[calcium distribution in the egg cell, zygote and proembryo of lettuce (lactuca sativa l.)].	potassium antimonite precipitation was used to located calcium in the egg cells (before and after anthesis), zygotes and proembryos of lettuce (lactuca sativa l.). a few calcium precipitates (ppts) were located in the small vacuoles of cytoplasm of egg cell at 3 d before anthesis, when egg cells just formed. then the small vacuoles fused to form some bigger vacuoles in egg cell at 2d before anthesis. calcium ppts increased evidently in the cytoplasm and nucleus of egg cells at this time. at 1d b ...	2006	16944569
velvetbean (mucuna pruriens) extracts: impact on meloidogyne incognita survival and on lycopersicon esculentum and lactuca sativa germination and growth.	velvetbean (mucuna spp.) is a summer annual that has been used as a cover crop to reduce erosion, fix nitrogen and suppress weeds and plant-parasitic nematodes. crude aqueous extracts (1:15 dry weight plant/volume water) were made from velvetbean plant parts, and various concentrations of the extracts were evaluated in vitro for toxicities to different stages of meloidogyne incognita (kofoid and white) chitwood and for suppression of hypocotyl and root growth and inhibition of germination of tom ...	2006	16953489
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
cadmium assimilation in the terrestrial isopod, porcellio dilatatus--is trophic transfer important?	terrestrial isopods have become important tools for the ecotoxicological assessment of metal-contaminated soils. their value as an invertebrate model is partly because of their extraordinary capacity to bioaccumulate toxic metals from the environment. replication of this accumulation process in the laboratory has in the past relied on the amendment of organic food substrates through the addition of inorganic metal salts. however, the bioavailability of the metals when presented through doping re ...	2006	17055036
identification and comparison of natural rubber from two lactuca species.	renewed interest in the identification of alternative sources of natural rubber to hevea brasiliensis has focused on the compositae family. in our search for compositae models for rubber synthesis, we extracted latex from stems of two lettuce species: lactuca serriola, prickly lettuce, and lactuca sativa cv. salinas, crisphead lettuce. both species contained cis-1,4-polyisoprene rubber in the dichloromethane-soluble portions of their latex, and sesquiterpene lactones in their acetone-soluble por ...	2006	17055543
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
absorption of selenium by lactuca sativa as affected by carboxymethylcellulose.	several organic compounds of high molecular weight present in soil interact with selenium and may act as active binding agents affecting its availability in soil, and, consequently, selenium uptake by plants. this study is aimed at investigating the effects of polysaccharides on selenium speciation in soil and on selenium absorption by lactuca sativa l. plants. three-week-old seedlings were transplanted into pots filled with soil, and sodium selenite at rates of 1.5 and 5mgsekg(-1) of soil, or s ...	2007	17107704
hydroxamic acids in secale cereale l. and the relationship with their antifeedant and allelopathic properties.	contents of the hydroxamic acids 2,4-dihydroxy-1,4-benzoxazin-3-one (diboa), and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (dimboa) in leaves and roots of 14 cultivars of rye, secale cereale l., were determined. dynamics of accumulation in three cultivars were evaluated. diboa was the main cyclic hydroxamic acid in leaves but the contents differed significantly between the cultivars. both diboa and dimboa were present in the roots. maximum concentration of diboa in leaves and dimboa in roots ...	2015	17137112
[lettuce, lactuca sp., as a medicinal plant in polish publications of the 19th century].	mentions of lettuce lactuca sp. that have appeared since antiquity contained similar information on its curative properties, but such properties were ascribed to different species or varieties. apart from the wild and poisonous lettuce, also garden or common lettuce were identified as having curative action, and some publications lacked information enabling the precise identification of the lettuce in question. in the 19th century, attempts were made to put some order into the knowledge of lettu ...	2005	17153150
metabolite fingerprinting in transgenic lettuce.	metabolite fingerprinting has been achieved using direct atmospheric pressure chemical ionization-mass spectrometry (apci-ms) and linked gas chromatography (gc-apci/ei-ms) for transgenic lettuce (lactuca sativa l. cv. evola) plants expressing an ipt gene under the control of the senescence-specific sag12 promoter from arabidopsis thaliana (p(sag12)-ipt). mature heads of transgenic lettuce and their azygous controls were maintained under defined conditions to assess their shelf life. transgenic l ...	2005	17173617
genetic distance sampling: a novel sampling method for obtaining core collections using genetic distances with an application to cultivated lettuce.	this paper introduces a novel sampling method for obtaining core collections, entitled genetic distance sampling. the method incorporates information about distances between individual accessions into a random sampling procedure. a basic feature of the method is that automatically larger samples are obtained if accessions are further apart and smaller samples if accessions are closer together. genetic distance sampling can be used in conjunction with predefined stratifications of the accessions. ...	2007	17180377
chenoalbicin, a novel cinnamic acid amide alkaloid from chenopodium album.	the roots of chenopodium album were infused in meoh, and the extract was partitioned between acoet and h2o. acoet-soluble material was subjected to different silica-gel column chromatographies and then purified by reverse-phase hplc to afford a new cinnamic acid amide alkaloid as a racemic mixture. the new compound, named chenoalbicin (1), was characterized by extensive spectroscopic investigation, especially 1d and 2d nmr spectroscopy. its effects on the germination and growth of lactuca sativa ...	2004	17191801
structure elucidation and phytotoxicity of ecdysteroids from chenopodium album.	the leaves of chenopodium album were infused in h2o/meoh. the extract treated with cold acetone gave heavy precipitation, which was removed by centrifugation. solid material was fractionated into acidic and neutral fractions. the acidic material was subjected to different silica-gel column chromatographies, and then it was purified by reversed-phase hplc to afford four known ecdysteroids and the new 3beta,14alpha-dihydroxy-5beta-pregn-7-ene-2,6,20-trione that were characterized by extensive spec ...	2005	17191993
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
polyphenol content and antioxidative activity in some species of freshly consumed salads.	ten genotypes belonging to lactuca sativa, cicorium intybus, plantago coronopus, eruca sativa, and diplotaxis tenuifolia and used in fresh mixed salads were investigated for their polyphenol contents. flavonoids and hydroxycinnamic acids were characterized by high-performance liquid chromatography (hplc)/diode array detection/mass spectrometry. quercetin, kaempferol, luteolin, apigenin, and crysoeriol derivatives were identified; hydroxycinnamic acids were all caffeoyl derivatives. the total pol ...	2007	17279769
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
phytotoxicity of secondary metabolites from aptenia cordifolia.	from the fresh leaves or twigs of aptenia cordifolia, a total of 29 compounds were isolated, including the new tetranoroxyneolignan 18, the new dilignan 19, and the beta-ionone derivative 27, previously only known as a synthetic compound, together with 26 known compounds. the structures of the new products were determined by (1)h-, (13)c-, and 2d-nmr, as well as hr-ms analyses. the phytotoxic effects of the isolates on the germination and growth of the dicotyledon lactuca sativa l. (lettuce) wer ...	2007	17311224
preparation of 2h-furo[2,3-c]pyran-2-one derivatives and evaluation of their germination-promoting activity.	the butenolide, 3-methyl-2h-furo[2,3-c]pyran-2-one (1), has recently been identified as the germination stimulant present in smoke that promotes the germination of seeds from a wide range of plant species. in this paper, we describe the preparation of a number of analogues of 1 and compare their efficacy in promoting seed germination of three highly smoke-responsive plant species, lactuca sativa l. cv. grand rapids (asteraceae), emmenanthe penduliflora benth. (hydrophyllaceae), and solanum orbic ...	2007	17316021
determination of phytotoxicity of soluble elements in soils, based on a bioassay with lettuce (lactuca sativa l.).	in this work the different concentrations of soluble elements in soils from natural (peridotitic soils) and anthropogenic (soils affected by a pyrite-mine spill) origin, are used to determine the phytotoxicity in lettuce (lactuca sativa l.). the solutions are obtained from soil:water extracts (1:1), having neutral ph and high concentrations of as, pb, zn, mn, co and ni, with values exceeding the toxic level for soil solution [bohn hl, mcneal bl, o'connor ga. soil chemistry, wiley interscience. w ...	2007	17316769
qtls for shelf life in lettuce co-locate with those for leaf biophysical properties but not with those for leaf developmental traits.	developmental and biophysical leaf characteristics that influence post-harvest shelf life in lettuce, an important leafy crop, have been examined. the traits were studied using 60 informative f9 recombinant inbed lines (rils) derived from a cross between cultivated lettuce (lactuca sativa cv. salinas) and wild lettuce (l. serriola acc. uc96us23). quantitative trait loci (qtls) for shelf life co-located most closely with those for leaf biophysical properties such as plasticity, elasticity, and br ...	2007	17347132
molecular characterisation of lac s 1, the major allergen from lettuce (lactuca sativa).	ige sensitisation to non-specific lipid transfer proteins (nsltp), e.g., pru p 3 the major allergen from peach and most important allergenic ltp, is strongly associated with severe symptoms in food allergic patients. lac s 1, a member of the nsltp protein family, was recently identified as major allergen in lettuce (lactuca sativa), but has not yet been investigated on the molecular basis.	2007	17349693
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
a survey of syrphid predators of nasonovia ribisnigri in organic lettuce on the central coast of california.	organic lettuce, lactuca sativa l., producers on california's central coast rely on endemic syrphid flies (diptera: syrphidae) to suppress populations of nasonovia ribisnigri mosley (homoptera: aphididae) and other aphids affecting lettuce. growers are using various forms of habitat manipulation to enhance biological control. we surveyed syrphids collected from organic romaine in and around the salinas valley from march through september 2005 to gain a better understanding of the species respons ...	2007	17370807
behavioral responses of schistocerca americana (orthoptera: acrididae) to azadirex (neem)-treated host plants.	azadirex (azadirachtin and other biologically active extracts from neem trees) has been shown to have considerable potential to be used in integrated pest management systems based on its growth regulator/insecticide properties. less well known are the antifeedant properties. the feeding-deterrent properties of a commercial azadirex formulation (azatrol ec) were evaluated using both no-choice and choice tests, the american grasshopper, schistocerca americana (drury), and four host plants [savoy c ...	2007	17370818
ecotoxicological tests assessment of soils polluted by chromium (vi) or pentachlorophenol.	carbon mineralisation and plant germination and growth (lactuca sativa seeds) tests have been performed in two soils of different properties, experimentally spiked with pentachlorophenol (pcp) or cr (vi), in concentrations between 0.001 and 1000 mg kg(-1). the evaluation has been done considering the following parameters of carbon transformation test: soil cumulative basal respiration after 14 days incubation, substrate induced respiration after 12 h of glucose addition, and, in the plant germin ...	2007	17379274
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
allelopathy on bark of downed logs of chamaecyparis obtusa sieb. and zucc. var. formosana (hayata) rehder.	chamaecyparis obtusa sieb. and zucc. var. formosana (hayata) rehder is the dominant species in the temperate forest of yuanyang lake nature reserve (yyl), taiwan. although downed logs of c. obstusa var. formosana occupy only a small percentage of the forest floor area in yyl, they are important regeneration substrates. seedlings of this species often grow without competition on the new downed logs, and a few broadleaf trees grow with them. we hypothesized that the bark of the newly fallen logs p ...	2007	17476467
comparative cross-species alternative splicing in plants.	alternative splicing (as) can add significantly to genome complexity. plants are thought to exhibit less as than animals. an algorithm, based on expressed sequence tag (est) pairs gapped alignment, was developed that takes advantage of the relatively small intron and exon size in plants and directly compares pairs of ests to search for as. est pairs gapped alignment was first evaluated in arabidopsis (arabidopsis thaliana), rice (oryza sativa), and tomato (solanum lycopersicum) for which annotat ...	2007	17496110
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
effects of genotype and transpiration rate on the uptake and accumulation of perchlorate (clo4-) in lettuce.	although evidence of perchlorate accumulation in plants exists, there is a scarcity of information concerning the key factors and mechanisms involved. to ascertain whether genotypic variation in perchlorate accumulation occurs within lettuce, hydroponic plant uptake experiments were conducted with five types of lettuce (lactuca sativa l.), which were grown to market size atthree perchlorate (clo4-) concentrations (1, 5, or 10 microg/l). perchlorate accumulated in the leafy tissues to varying amo ...	2007	17539550
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
toxicity assessment of a complex industrial wastewater using aquatic and terrestrial bioassays daphnia pulex and lactuca sativa.	aquatic and terrestrial bioassays were used to assess toxicity at several stages in an industrial wastewater treatment plant that processes 400 l/s from a complex influent formed by wastewater from 135 industries. daphnia pulex and lactuca sativa were used to assess and compare toxicity between the influent wastewater and effluent wastewater from an activated sludge process, and compare their relationship with physicochemical parameters of biological oxygen demand (bod); chemical oxygen demand ( ...	2007	17680481
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
antifeedant and phytotoxic activity of cacalolides and eremophilanolides.	the antifeedant effect of six cacalolides and six eremophilanolides was tested against the herbivorous insects spodoptera littoralis, leptinotarsa decemlineata, and myzus persicae. the test compounds included several natural products isolated from senecio madagascariensis (14-isovaleryloxy-1,2-dehydrocacalol methyl ether, 4), s. barba-johannis (13-hydroxy-14-oxocacalohastine, 5; 13-acetyloxy-14-oxocacalohastine, 6) and s. toluccanus [6-hydroxyeuryopsin, 7; 1(10)-epoxy-6-hydroxyeuryopsin, 9; tolu ...	2017	17708441
withanolides from jaborosa kurtzii.	two new withanolides were isolated and characterized from the aerial parts of jaborosa kurtzii, namely, jaborosalactone 43 (1), with a spiranoid delta-lactone at c-22, and jaborosalactone 44 (2), a 12-oxowithanolide, which may function as a biosynthetic precursor to 1. these new compounds were fully characterized by a combination of spectroscopic methods. compound 1 showed selective phytotoxicity toward a dicotyledon species, lactuca sativa (lettuce).	2007	17711343
an assessment of the role of ethylene in mediating lettuce (lactuca sativa) root growth at high temperatures.	growth of temperate lettuce (lactuca sativa) plants aeroponically in tropical greenhouses under ambient root-zone temperatures (a-rzts) exposes roots to temperatures of up to 40 degrees c during the middle of the day, and severely limits root and shoot growth. the role of ethylene in inhibiting growth was investigated with just-germinated (24-h-old) seedlings in vitro, and 10-d-old plants grown aeroponically. compared with seedlings maintained at 20 degrees c, root elongation in vitro was inhibi ...	2007	17728295
relationship between lead uptake by lettuce and water-soluble low-molecular-weight organic acids in rhizosphere as influenced by transpiration.	the relationship between pb uptake by leaf lettuce ( lactuca sativa l.) and water-soluble low-molecular-weight organic acids (lmwoas) in rhizosphere, as influenced by transpiration (high and low), has been studied. studies were carried out by culturing lettuce plants grown for 2 weeks in pots filled with quartz sand mixed with anion-exchange resin and then for 30 days in a greenhouse. the potted lettuce plants were subjected to stress by the addition of pb(no 3) 2 solutions (100, 200, and 300 mg ...	2007	17894455
mechanism of selective phytotoxicity of l-3,4-dihydroxyphenylalanine (l-dopa) in barnyardgrass and lettuce.	l-3,4-dihydroxyphenylalanine (l-dopa) is one of the few allelochemicals in which the phytotoxic action mechanism has been studied. excess exogenous l-dopa suppresses root elongation in some plant species, and the inhibitory action is species-selective. the main factor of phytotoxicity of l-dopa is considered to be oxidative damage by reactive oxygen species (ros) and/or free radical species (frs). this study was performed to elucidate the mechanism of species-selective phytotoxicity. the involve ...	2007	17899281
cinnamic ester derivatives from oxalis pes-caprae (bermuda buttercup).	seven new cinnamic ester derivatives ( 1- 7) were isolated from a methanol extract of the fresh leaves and twigs of oxalis pes-caprae (bermuda buttercup). the structures of these new compounds were determined by spectroscopic data interpretation. the effects of compounds 1- 7 on the germination and growth of lactuca sativa (lettuce) were studied.	2007	17922549
simultaneous modelling of the thermal degradation kinetics of pectin methylesterase in lettuce (lactuca sativa l.) and carrot (daucus carota l.) extracts: analysis of seasonal variation and tissue type.	the thermal degradation kinetics of pectin methylesterase (pme) from carrot and lettuce were studied. fresh extracts were exposed to temperatures from 55 to 70 degrees c until the enzyme was inactivated. a model based on the presence of two forms of the enzyme, one active and one non-active, is proposed. the natural variability of the pme activity was taken into the model in the form of normally distributed random effects. the common model parameters obtained (cleavage constant (0.0395+/-0.0062 ...	2007	17928712
[studies on the calcium distribution in developing synergids of lettuce (lactuca sativa l.)].	potassium antimonite was used to locate calcium in the synergids of lettuce (lactuca sativa l) during their development. the two synergids on 3d before anthesis formed evident polarity with most cytoplasm located in the micropylar end and nucleus in the middle and a big vacuole in the chalazal end. at this time, calcium precipitates were a few in both cells. calcium precipitates in the two synergids began to increase on 2d before anthesis. synergid wall in the micropylar end thickened on 1d befo ...	2007	17966463
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
effect of methyl jasmonate on phenolic compounds and carotenoids of romaine lettuce (lactuca sativa l.).	the effect of exogenous methyl jasmonate (meja) on antioxidative compounds of romaine lettuce ( lactuca sativa l.) was investigated. lettuces were treated with various meja solutions (0, 0.05, 0.1, 0.25, and 0.5 mm) before harvest. total phenolic compounds content and antioxidant capacity of romaine lettuce significantly increased after meja treatments (0.1, 0.25, and 0.5 mm). the total content of phenolic compounds of the romaine lettuce treated with 0.5 mm meja (31.6 microg of gallic acid equi ...	2007	17990849
effect of combined physico-chemical processes on the phytotoxicity of olive mill wastewaters.	a pool of laboratory experiments is planned with the aim of evaluating the possibility to reduce the phytotoxicity of olive mill wastewater (omw) with combined physico-chemical processes (centrifugation-ozonation, centrifugation-solar photolysis, centrifugation-solar modified photofenton, centrifugation-solar modified photofenton-ozonation). a moderate cod removal of an omw is reached by using ozonation or solar modified photofenton separately or solar modified photofenton/o(3) combined process ...	2008	18006039
phytotoxic eremophilanes from ligularia macrophylla.	systematic bioassay-guided fractionation of the methylene chloride extract of the roots from ligularia macrophylla was performed to identify both phytotoxic and antifungal compounds. four phytotoxic eremophilanes (furanoeremophilan-14beta,6alpha-olide, 6beta-angeloyloxy-10beta-hydroxyfuranoeremophilane, eremophil-7(11)-ene-12,8alpha;14beta,6alpha-diolide, and 3alpha-angeloyloxybakkenolide a) and two antifungal fatty acids (linoleic acid and alpha-linolenic acid) were isolated. the x-ray crystal ...	2007	18044832
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
phytotoxicity evaluation of five pharmaceutical pollutants detected in surface water on germination and growth of cultivated and spontaneous plants.	the phytotoxicity of 5 pharmaceuticals detected in italian rivers, atorvastatin (7-[2-(4-fluorophenyl)-3-phenyl-4-(phenylcarbamoyl)-5-propan-2-yl-pyrrol-1-yl]-3,5-dihydroxy-heptanoic acid), gemfibrozil (5-(2,5-dimethylphenoxy)-2,2-dimethyl-pentanoic acid), tamoxifene (2-[4-(1,2-diphenylbut-1-enyl)phenoxy]-n,n-dimethyl-ethanamine), ethinyl estradiol (17-ethynyl-13-methyl-7,8,9,11, 12,13,14,15,16,17-decahydro-6h-cyclopenta[a]phenanthrene-3,17-diol) and sildenafil (methyl-9-propyl-2,4,7,8-tetrazabi ...	2008	18205060
postharvest changes in water status and chlorophyll content of lettuce (lactuca sativa l.) and their relationship with overall visual quality.	the purpose of this study was to evaluate water status, chlorophyll content (c), and overall visual quality (ovq) of fresh butter lettuce (lactuca sativa var. lores) as well as these indexes' evolution during storage and their relationships, if any. whole lettuce plants were stored at optimal postharvest conditions (0 to 2 degrees c and 97% to 99% relative humidity). measured parameters during each sampling day were relative water content (rwc), water content (wc), free water (fw), bound water ( ...	2008	18211369
chromosomal study of lettuce and its allied species (lactuca spp., asteraceae) by means of karyotype analysis and fluorescence in situ hybridization.	in this study, in addition to the karyotype analysis, the chromosomal distributions of 5 s and 18 s rdnas, and the arabidopsis-type (t3ag3) telomeric sequences were detected by means of fluorescence in situ hybridization (fish) to promote the information of chromosomal organization and evolution in the cultivated lettuce and its wild relatives, l. sativa, l. serriola, l. saligna and l. virosa. the karyotype analysis revealed the dissimilarity between l. virosa and the remaining species. in all f ...	2007	18215246
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
separating the effects of hypobaria and hypoxia on lettuce: growth and gas exchange.	the objectives of this research were to determine the influence of hypobaria (reduced atmospheric pressure) and reduced partial pressure of oxygen (po2) [hypoxia] on carbon dioxide (co2) assimilation (c(a)), dark-period respiration (dpr) and growth of lettuce (lactuca sativa l. cv. buttercrunch). lettuce plants were grown under variable total gas pressures [25 and 101 kpa (ambient)] at 6, 12 or 21 kpa po2)(approximately the partial pressure in air at normal pressure). growth of lettuce was compa ...	2007	18251894
biotic interactions modify the transfer of cesium-137 in a soil-earthworm-plant-snail food web.	the present study investigated the possible influence of the earthworm aporrectodea tuberculata on the transfer of cesium-137 ((137)cs) from a contaminated (130 bq/kg) deciduous forest soil to the lettuce lactuca sativa and to the snail cantareus aspersus (formerly helix aspersa) in two laboratory experiments. in the first experiment, the international organization for standardization 15952 test was used to expose snails for five weeks to contaminated soil with or without earthworms. in these co ...	2008	18266477
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
selecting single-copy nuclear genes for plant phylogenetics: a preliminary analysis for the senecioneae (asteraceae).	compared to organelle genomes, the nuclear genome comprises a vast reservoir of genes that potentially harbor phylogenetic signal. despite the valuable data that sequencing projects of model systems offer, relatively few single-copy nuclear genes are being used in systematics. in part this is due to the challenges inherent in generating orthologous sequences, a problem that is ameliorated when the gene family in question has been characterized in related organisms. here we illustrate the utility ...	2008	18305978
arabidopsis r2r3-myb transcription factor atmyb60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (lactuca sativa).	the myb transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. we evaluated the possible roles of the arabidopsis r2r3-myb transcription factors in flavonoid biosynthesis because they are induced by uv-b irradiation but their associated phenotypes are largely unexplored. we isolated their genes by race-pcr, and performed transgenic approach and metabolite analyses in lettuce (lactuca sativa). we found that one member of this prote ...	2008	18317777
preparation and phytotoxicity of novel kaurane diterpene amides with potential use as herbicides.	novel kaurane ditepene monoamides were synthesized in good yields directly from kaurenoic ( 1) and grandiflorenic ( 2) acids and unprotected symmetrical diamines, using a modified protocol for monoacylation. amides from 1 and 2 and monoamines were also obtained and tested against seed germination and growth of radicle and shoot of lactuca sativa (lettuce), at 10 (-3), 10 (-5), and 10 (-7) m. amides from symmetrical diamines showed significant inhibitory activity at higher concentrations.	2008	18393433
response of five lettuce cultivars to root-knot nematode, meloidogyne incognita.	the root-knot nematode, meloidogyne incognito (kofoid et white) chitwood is an important pathogen of vegetables. five commercial cultivars of lettuce (lactuca sativa l.) were evaluated under greenhouse conditions for resistance to meloidogyne incognita, benguet population. plants were inoculated with 1000 eggs collected from 'apollo' tomato (lycopersicon esculentum) roots. the degree of galling and number of egg masses were assessed 4 and 8 weeks after inoculation. host plant response was classi ...	2007	18399501
environmental fate and effects of nicotine released during cigarette production.	a variety of test methods were used to study the gradation, bioaccumulation, and toxicity of nicotine. studies included determination of the octanol-water partition coefficient, conversion to co2 in soil and activated sludge, and evaluation of the effects on microbiological and algal inhibition as well as plant germination and root elongation. the partitioning of nicotine between octanol and water indicated that nicotine will not bioaccumulate regardless of the ph of the medium. the aqueous and ...	2008	18399728
development of a biomarker for metal bioavailability: the lettuce fatty acid composition.	because lactuca sativa l. is a plant widely used in ecotoxicological analyses, a study was developed to determine whether the fatty acid composition of lettuce leaves could be used as an additional biomarker of soil contamination by metals such as pb, cu, zn, and cd. unlike seed germination or seedling growth, the fatty acid composition of lettuce leaves differed significantly between uncontaminated and field metal-contaminated soils. hence, this lipid biomarker might provide an early indication ...	2008	18419182
salt in irrigation water affects the nutritional and visual properties of romaine lettuce (lactuca sativa l.).	the influence of salinity stress on the growth, appearance, and nutritional compounds, especially phenolic compounds and carotenoids, of romaine lettuce (lactuca sativa l.), a low salt tolerant plant, was studied. the dry weight, height, and color of the lettuce plants were significantly changed by long-term irrigation (15 days) with higher nacl concentration (i.e., >100 mm). however, no significant differences were observed in the growth and appearance among the control, all short-term treatmen ...	2008	18439016
toxicity of perfluorooctane sulfonate and perfluorooctanoic acid to plants and aquatic invertebrates.	acute toxicities of perfluorooctane sulfonate (pfos) and perfluorooctanoic acid (pfoa) were tested on four freshwater species and three plant species. pfos was more toxic than pfoa for all species tested in this study. similar time-response patterns of pfos and pfoa toxicity were observed for each tested species. values of the 48-h lc(50) of pfos for all test species ranged from 27 to 233 mg/l and values of the 96-h lc(50) for three of the species ranged from 10 to 178 mg/l. values of the 48-h l ...	2009	18461560
[calcium distribution in the central cell of lettuce (lactuca sativa l.) before and after pollination].	potassium antimonite precipitation was used to locate calcium in the central cell of lettuce (lactuca sativa l.) before and after pollination. at 3d before anthesis, two polar nuclei of central cell separately located at two polarity of the cell, and few calcium precipitates (ppts) appeared in the polar nuclei and cytoplasm, but some ppts in its small vacuoles. at 2d before anthesis, two polar nuclei moved toward the middle of the cell and fused to form a secondary nucleus, and the ppts evidentl ...	2008	18464591
identification, genetic localization, and allelic diversity of selectively amplified microsatellite polymorphic loci in lettuce and wild relatives (lactuca spp.).	selectively amplified microsatellite polymorphic locus (sampl) analysis is a method of amplifying microsatellite loci using generic pcr primers. sampl analysis uses one aflp primer in combination with a primer complementary to microsatellite sequences. sampl primers based on compound microsatellite sequences provided the clearest amplification patterns. we explored the potential of sampl analysis in lettuce to detect pcr-based codominant microsatellite markers. fifty-eight sampls were identified ...	1997	18464878
mycorrhizal and non-mycorrhizal lactuca sativa plants exhibit contrasting responses to exogenous aba during drought stress and recovery.	the arbuscular mycorrhizal (am) symbiosis enhances plant tolerance to water deficit through the alteration of plant physiology and the expression of plant genes. these changes have been postulated to be caused (among others) by different contents of abscisic acid (aba) between am and non-am plants. however, there are no studies dealing with the effects of exogenous aba on the expression of stress-related genes and on the physiology of am plants. the aim of the present study was to evaluate the i ...	2008	18469324
differentiation of nearly identical germplasm accessions by a combination of molecular and morphologic analyses.	polymerase chain reaction (pcr) based random amplified polymorphic dna (rapd) markers were used to study the extent of redundancy (duplication of genetic materials) within a genetic resources collection. nine nearly phenotypically and identical accessions of butterhead lettuce (lactuca sativa l.) were assayed for their genetic identities. a nonuniform, heterogeneous butterhead line and a crisphead cultivar were added for population comparison. pcr amplification using 13 oligonucleotide primers g ...	1994	18470101
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