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purification and properties of beta-mannanases i and ii from the germinated seeds of trifolium repens. mode of galactomannan degradation in vitro.two beta-mannanases (beta-mannosidases, ec 3.2.1.25) purified from the germinated seeds of trifolium repens by a procedure that included chromatography on hydroxyapatite, gel filtration on acrylamide/agarose (ultragel 5/4) and preparative polyacrylamide-gel-electrophoresis. the final purification step completely resolved two beta-mannanases with distinct specificities, which were termed beta-mannanase i and beta-mannanase ii. beta-mannanase i was purified 1400-fold and beta-mannanase ii 1000-fol ...199733664
nutritional improvement of food proteins by enzymatic modification, especially by plastein synthesis reaction.the present paper reviews our recents studies on the plastein reaction applied to improve nutritional quality of conventional and unconventional proteins, with special emphasis on the papaincatalyzed incorporation of essential amino acids (used in ethyl ester form) into the proteins : l-methionine into soybean protein, l-lysine into wheat gluten and l-tyrosine into fish protein (after removal of phenylalanine). the paper deals also with an attempt to improve proteins extracted from the photosynt ...1978360951
inhibitory effects of the herbicide trifluralin on the establishment of the clover root nodule symbiosis.trifluralin, a widely used herbicide (rahman, 1977), may act via interaction with plant microtubule protein (hess and bayer, 1974, 1977). in trifluralin treated seedlings of trifolium repens, root tips increased in diameter and decreased in length, cell elongation was decreased, cell wall deposition was abnormal, root hairs were deformed, and a marked reduction was seen in the number of infection threads induced by the bacterial symbionts. our observations support the hypothesis that trifluralin ...1978751777
isolation, sequencing and expression in e. coli of the urocanase gene from white clover (trifolium repens).the urocanase gene was detected in a clone obtained from a genomic library of white clover. the entire gene has been sequenced and expressed in the pt7-7/e. coli bl 21 (de 3) system. the deduced sequence of the plant urocanase is 72% homologous with that of the well-characterized urocanase from pseudomonas putida. the purification procedure, as well as kinetic and electrophoretic behaviour, of the new enzyme are described.19921356832
implant and copper oxide needles for steers grazing acremonium coenophialum-infected tall fescue pastures: effects on grazing and subsequent feedlot performance and serum constituents.two experiments were conducted to compare the effects of a progesterone-estradiol implant (pei) with no implant (ni) and 20 g of copper oxide needles (cuon) with no cuon on grazing, subsequent feedlot performance, and selected serum constituents of steers. in exp. 1, 114 limousin crossbred yearling steers (317 kg average initial bw) were stocked continuously on acremonium coenophialum-infected tall fescue (festuca arundinacea schreb.)-ladino clover (trifolium repens l.) pastures (c) or were rota ...19921429296
the intake, digestion and protein degradation of grazed herbage by early-weaned lambs.sixty-four intact lambs and twenty-four lambs fitted with a duodenal cannula were weaned at 6 weeks of age and grazed pure species swards of either lucerne (medicago sativa), white clover ((trifolium repens), ryegrass (lolium perenne) or prairie grass (bromus catharticus) for 6 weeks. intake and duodenal digesta flow were estimated when lambs were 8 and 12 weeks of age. lambs grazing the two legume species grew at a similar rate, as did lambs grazing the two grass species. legumes promoted a 38% ...19921445817
forage systems for beef production from conception to slaughter: i. cow-calf production.six year-round, all-forage, three-paddock systems for beef cow-calf production were used to produce five calf crops during a 6-yr period. forages grazed by cows during spring, summer, and early fall consisted of one paddock of 1) tall fescue (festuca arundinacea schreb.)-ladino clover (trifolium repens l.) or 2) kentucky blue-grass (poa pratensis l.)-white clover (trifolium repens l.). each of these forage mixtures was combined in a factorial arrangement with two paddocks of either 1) fescue-red ...19921548221
nitrogen transactions along the digestive tract of lambs concurrently infected with trichostrongylus colubriformis and ostertagia circumcincta.twelve lambs, paired on the basis of live weight, were cannulated in the abomasum, in the proximal jejunum approximately 4 m distal to the pylorus and in the terminal ileum. six were infected with 3000 trichostrongylus colubriformis and 3000 ostertagia circumcincta larvae each day for 18 weeks and the remainder were pair-fed to individual infected lambs. all animals were offered ryegrass (lolium perenne)-white clover (trifolium repens) pasture, cut daily. dry matter (dm) intake, live weight, fae ...19911760444
nucleotide and derived amino acid sequence of the cyanogenic beta-glucosidase (linamarase) from white clover (trifolium repens l.).the nucleotide sequence and derived amino acid sequence of two different beta-glucosidase cdna clones were determined. one clone (tre104) was identified as the cyanogenic beta-glucosidase by homology with the n-terminal and internal peptide amino acid sequence of the purified enzyme. the biological function of the other beta-glycosidase (tre361) is not known. co-segregation of genomic restriction fragments uniquely identified by each cdna clone shows that these two genes are linked in the white ...19911907511
technical note: sampling technique and drying method effects on chemical composition of tall fescue or fescue-ladino clover pasture samples.although esophageal extrusa is the most readily accepted representation of forage consumed by grazing ruminants, esophageal sampling is demanding from the standpoint of animal care and maintenance and extrusa processing. this experiment was conducted with a split-plot design to evaluate the effects of pasture type, pasture sampling technique and drying method on estimation of grazed forage composition. ten esophageally fistulated steers grazed pastures of either tall fescue (festuca arundinacea ...19912005036
theoretical considerations in the estimation of rumen fractional outflow rate from various sampling sites in the digestive tract.the digesta markers 103ruthenium phenanthroline (ru-p) and 51cr-edta were continuously infused into the rumen of young lambs offered clover hay ad lib. indoors or grazing pure species swards of either lucerne (medicago sativa), white clover (trifolium repens), ryegrass (lolium perenne) or prairie grass (bromus catharticus). following the cessation of infusion the fractional outflow rate (for) of markers from the rumen was estimated from the rate of decline of marker concentration in rumen and ab ...19892789986
interference between rhizobium meliloti and rhizobium trifolii nodulation genes: genetic basis of r. meliloti dominance.transfer of an incp plasmid carrying the rhizobium meliloti nodfe, nodg, and nodh genes to rhizobium trifolii enabled r. trifolii to nodulate alfalfa (medicago sativa), the normal host of r. meliloti. using transposon tn5-linked mutations and in vitro-constructed deletions of the r. meliloti nodfe, nodg, and nodh genes, we showed that r. meliloti nodh was required for r. trifolii to elicit both root hair curling and nodule initiation on alfalfa and that nodh, nodfe, and nodg were required for r. ...19882848012
kinetic aspects of calcium metabolism in lactating sheep offered herbages with different ca concentrations and the effect of protein supplementation.1. two experiments are described in which kinetic aspects of calcium metabolism were studied in housed lactating sheep consuming different fresh herbage species. the importance of protein supply was also investigated. 2. in expt. 1, two groups (n 4) were offered, ad lib., a freshly cut ryegrass (lolium perenne l.)-white clover (trifolium repens l.) pasture containing 5.48 g ca/kg dry matter (dm). one group was supplemented daily with 100 g protected casein. a third group (n 4) was offered, ad li ...19892923856
faecal endogenous loss of calcium in young sheep.1. two groups of eight 6-7-month-old wether lambs were offered either a frozen ryegrass (lolium perenne l.)-white clover (trifolium repens l.) pasture or a ryegrass-white clover hay, containing 12.1 and 6.4 g calcium/kg dry matter (dm) respectively. within groups the amounts offered to individual sheep ranged from 0.5 to 2.0 times the estimated maintenance energy requirements. 2. a single intravenous injection of 150 microci 45ca as cacl2.2h2o, and stable balances were used to determine absorpti ...19892923857
the molecular biology of cyanogenesis.the cyanogenic polymorphism in trifolium repens l. (white clover) has been used as the basis of a study of the genetic control of cyanogenesis. the ac locus controls the presence of two cyanoglucosides in white clover. biochemical characterization of cyanoglucoside biosynthesis in plants containing different ac alleles has shown that this is a complex locus which affects more than one step in the pathway. a study of the in vivo synthesis and processing of the cyanogenic beta-glucosidase (linamar ...20113149931
importance of body tissues as sources of nutrients for milk synthesis in the cow, using 13c as a marker.1. the proportions of carbon in individual milk constituents derived from feed and body tissues in dairy cows, were estimated by taking advantage of the natural variations which occur in the ratio, 13c:12c present in c3- and c4-plant species. 2. four cows, which had previously grazed c3 plants (ryegrass (lolium spp.) and white clover (trifolium repens)), were accustomed to indoor feeding on a ration of c3-plant material (cut pastures and barley meal). the ration was then changed abruptly to one ...19883219327
root nodule specific gene regulation: analysis of the soybean nodulin n23 gene promoter in heterologous symbiotic systems.the nodulin n23 gene promoter was analysed in transgenic plants using the chloramphenicol acetyltransferase (cat) coding sequence as a reporter. a 5' flanking region of less than 1 kb was sufficient for the organ-specific expression of a chimeric n23-cat-3'lbc3 gene in root nodules formed on lotus corniculatus and trifolium repens after infection by their respective rhizobium symbionts. expression was regulated at the level of rna in both species of transgenic plants. promoter deletion analysis ...19883340542
the digestion of perennial ryegrass (lolium perenne cv. melle) and white clover (trifolium repens cv. blanca) by grazing cattle.1. pure swards of perennial ryegrass (lolium perenne cv. melle) as a primary growth (may), trimmed primary growth (early june) and regrowth (late june), and white clover (trifolium repens cv. blanca) as a mature primary growth (july) and vegetative regrowth (august), were grazed by twelve friesian steers (mean body-weights throughout experiment 152-231 kg) at daily allocation rates of forage which provided dry matter (dm) intakes ranging from 28 to 36 g/kg body-weight). 2. total nitrogen content ...19883408697
the efficiency of energy utilization in growing cattle consuming fresh perennial ryegrass (lolium perenne cv. melle) or white clover (trifolium repens cv. blanca).1. twenty friesian steers (225 kg live weight) were fed on mid- (m) (june-july) and late- (l) (august-september) season crops of either fresh perennial ryegrass (lolium perenne cv. melle) (g) or white clover (trifolium repens cv. blanca) (c). each of the forage diets was offered at three restricted planes of nutrition above maintenance to compare the effect of forage species on the efficiency of energy utilization. all diets were harvested daily from swards of regrowth forage of intended equival ...19863676184
effect of forage species and season on nutrient digestion and supply in grazing cattle.1. a total of twenty friesian steers were grazed on pure swards of either perennial ryegrass (lolium perenne cv. melle) or white clover (trifolium repens cv. blanca) from may to late august to examine the effect of forage species and season on nutrient digestion and supply. within each forage species, two daily allowances of forage (i.e. 30 and 60 g dry matter (dm)/kg live weight) were given, and nutrient flow into the small intestine was measured on thirteen separate occasions (viz. seven grass ...19863676197
the effect of forage species and stage of harvest on the processes of digestion occurring in the rumen of cattle.1. pure swards of perennial ryegrass (lolium perenne l. cv. melle) or white clover (trifolium repens l. cv. blanca) were harvested daily as either primary growth (may-june) or mid- (july) and late- (august-september) season 4-week regrowths and offered to friesian steers at two levels of feed allowance (18 and 24 g dry matter (dm)/kg live weight), to examine the effect of forage species and stage of harvest on nutrient digestion and supply. 2. the early- and mid-season grasses had low nitrogen ( ...19863676223
the effect of digestibility and forage species on the removal of digesta from the rumen and the voluntary intake of hay by sheep.1. the characteristics of digestion, passage and rumen fill of three hays: early- and late-cut perennial ryegrass (lolium perenne cv. endura) and white clover hay (trifolium repens cv. blanca and pronitro) were studied using six rumen-cannulated sheep fed at a restricted level of intake (18 g dry matter (dm)/kg live weight (lw) per d), in a two 3 x 3 latin square design. 2. voluntary intake of the same diets was measured using a further six non-cannulated sheep in a similar design. 3. rate of di ...19863676225
the role of condensed tannins in the nutritional value of lotus pedunculatus for sheep. 5. effects on the endocrine system and on adipose tissue metabolism.1. three experiments were conducted using lotus pedunculatus containing high concentrations of condensed tannins (ct), and utilizing the principle that polyethylene glycol (peg) application (molecular weight 3350) will irreversibly bind a portion of the ct and thus reduce the dietary reactive (i.e. non-peg bound) ct concentration. lotus diets containing 95, 45 and 14 g total reactive ct/kg dry matter (dm), induced by spraying with three peg rates, were given to sheep at hourly intervals (600 g d ...19863676235
relationships between the cryptic and temperate viruses of alfalfa, beet and white clover.small isometric virus particles containing double-stranded rna have been independently reported in europe and japan from apparently healthy alfalfa (medicago sativa), beet (beta vulgaris), and white clover (trifolium repens). they have been called cryptic viruses in europe and temperate viruses in japan. serological comparison using immunoelectron microscopy, and polyacrylamide gel electrophoresis of the rnas indicate that alfalfa cryptic and temperate viruses are the same, beet cryptic virus is ...19863721811
the use of monensin or formaldehyde to control the digestion of the nitrogenous constituents of perennial ryegrass (lolium perenne cv. melle) and white clover (trifolium repens cv. blanca) in the rumen of cattle.pure swards of perennial ryegrass (lolium perenne cv. melle) and white clover (trifolium repens cv. blanca) were harvested daily as primary growth (grass in may, clover in june) or regrowths (clover only in july) and offered, in the long form, to growing cattle at a feeding rate of 22 g dry matter/kg live weight. with each forage, two treatments were compared with the untreated forage (c): monensin (100 g active ingredient/kg, 250 mg/d) addition to the rumen (treatment m) or formaldehyde (30 g/k ...19873801385
the digestion of fresh perennial ryegrass (lolium perenne l. cv. melle) and white clover (trifolium repens l. cv. blanca) by growing cattle fed indoors.1. pure swards of perennial ryegrass (lolium perenne l. cv. melle) or white clover (trifolium repens l. cv. blanca) were harvested daily at three and two stages of growth respectively, and offered to housed cattle. the grass diets comprised primary growth (may) and two later regrowths of contrasting morphology (i.e. leaf: stem values of 1.54 and 2.84 respectively), and were characterized by high contents of water-soluble carbohydrate and neutral-detergent fibre and comparable in vitro dry matter ...19853870696
condensed tannins induce micronuclei in cultured v79 chinese hamster cells.the tannins, delphinidin and procyanidin were isolated from flowers of white clover (trifolium repens) and the leaves of arnot bristly locust (robina fertilis) respectively, and tested for mutagenic properties in a range of systems. there was no evidence for either compound causing significant levels of frameshift or base-pair mutagenesis in bacterial mutagenicity assays, although both were weakly positive in a bacterial dna-repair test. both compounds very slightly increased the frequency of pe ...19853900722
endocrine regulation of metabolism in sheep given kale (brassica oleracea) and ryegrass (lolium perenne)-clover (trifolium repens) fresh-forage diets.diets of fresh kale (brassica oleracea) and ryegrass (lolium perenne)-clover (trifolium repens) herbage were fed to growing sheep in three experiments. in expts 1 and 3 the sheep were confined indoors and fed at hourly intervals, and all were given supplementary iodine to counteract kale goitrogens. lambs grazed the two forages for 24 weeks in expt 2, with and without intramuscular injections of iodized oil. the kale and herbage contained respectively 11 and less than 0.1 g s-methyl-l-cysteine s ...19854063301
the role of condensed tannins in the nutritional value of lotus pedunculatus for sheep. rates of body and wool growth.lotus pedunculatus (cv. grasslands maku) grown on acid low-fertility soil and containing high concentrations of condensed tannin (76-90 g/kg dry matter (dm] was grazed by growing sheep for 31-42 d periods in three experiments. in expt 2 an additional group of lambs grazed areas oversown with white clover (trifolium repens) and red clover (trifolium pratense). lambs were transferred from grazing ryegrass (lolium perenne)-white clover straight on to lotus in all experiments (unconditioned sheep). ...19854063306
[ultrastructural and cytochemical studies of bacteroid differentiation of rhizobium trifolii dangeard in the nodules of trifolium repens l]. 19744138777
studies on the nature of the li locus in trifolium repens l. i. purification and properties of the enzyme components. 19734735021
effect of clover phyllody virus on nodulation of white clover (trifolium repens) by rhizobium trifolii. 19676034037
the physical digestion of perennial ryegrass (lolium perenne) and white clover (trifolium repens) in the foregut of sheep.sheep were fed once daily with 300 or 600 g dried perennial ryegrass (lolium perenne) or white clover (trifolium repens). total rumen contents were sampled once daily at various intervals up to 24 h after feeding for 6 d. total weight of fresh rumen contents and dry matter (dm), organic matter and particulate matter concentrations were measured and the particle size distribution of rumen contents was analysed using a wet sieving technique. there was a similar exponential loss of dm from the rume ...19846089866
copper metabolism in growing sheep given kale (brassica oleracea) and ryegrass (lolium perenne)-clover (trifolium repens) fresh forage diets.kale (brassica oleracea) and ryegrass (lolium perenne)-clover (trifolium repens) pasture grown under similar soil conditions were grazed in the vegetative state by growing lambs of 23.6 kg initial live weight for 24 weeks. forty-eight lambs grazed each forage. the kale and pasture contained respectively 4 and 14 mg copper/kg dry matter (dm), 7.2 and 3.1 g total sulphur/kg dm and 0.4 and 1.1 mg molybdenum/kg dm. subcutaneous injections of cu (12 mg) were given to half the animals grazing each for ...19836311244
transfer of rhizobium meliloti psym genes into agrobacterium tumefaciens: host-specific nodulation by atypical infection.the psym megaplasmid of rhizobium meliloti 2011 mobilized by plasmid rp4, or plasmid pgmi42, an rp4-prime derivative which carries a 290-kilobase psym fragment including nitrogenase and nod genes, was introduced into agrobacterium tumefaciens. the resulting transconjugants induced root deformations specifically on the homologous hosts medicago sativa and melilotus alba and not on the heterologous hosts trifolium pratense and trifolium repens. the root deformations were shown to be genuine nodule ...19846690420
iodine metabolism and thyroid hormone relationships in growing sheep fed on kale (brassica oleracea) and ryegrass (lolium perenne)-clover (trifolium repens) fresh-forage diets. 19836830751
motility of the reticulum and rumen of sheep given juice-extracted pasture.1. sheep were fed on different diets of juice-extracted herbage to determine what effect juice-extraction had on reticulo-rumen motility. 2. the frequency of a and b sequences of contraction of the reticulo-rumen were recorded during eating, rumination and inactivity for continuous periods of 24-72 h by using integrated electromyograms obtained from electrodes implanted in the musculature of the reticulum and cranial dorsal rumen. 3. animals were fed on herbage in which approximately 200 g/kg dr ...19827059570
protein metabolism in growing lambs given fresh ryegrass (lolium perenne)--clover (trifolium repens) pasture ad lib. 2. endocrine changes, glucose production, and their relationship to protein deposition and the partition of absorbed nutrients.1. glucose metabolism and changes in the concentrations of several hormones in jugular plasma were measured in growing lambs fed on fresh pasture ad lib. one group of lambs acted as control while the second received a continuous abomasal infusion supplying 44 g sodium caseinate+0.5 g l-methionine/d. 2. hormone concentrations were determined by radioimmunoassay procedures and glucose irreversible loss measured from continuous infusion of d-[u-14c]glucose. 3. protein infusion increased plasma conc ...19827066291
protein metabolism in growing lambs fed on fresh ryegrass (lolium perenne) -clover (trifolium repens) pasture ad lib. 1. protein and energy deposition in response to abomasal infusion of casein and methionine. 19817317346
in vitro digestion of bloat-safe and bloat-causing legumes by rumen microorganisms: gas and foam production.leaves of three bloat-safe legumes -- birdsfoot trefoil (lotus corniculatus l.), sainfoin (onobrychis viciaefolia scop.), and cicer milkvetch (astralagus cicer l.) -- and of three bloat-causing legumes -- alfalfa (medicago sativa l.), red clover (trifolium pratense l.), and white clover (trifolium repens l.) -- were incubated with strained rumen fluid or with mixed rumen fluid and solids. gas released was measured during the early period (0 to 22 h) of this in vitro digestion. gas volume was gre ...19807419778
expression of the pea albumin 1 gene in transgenic white clover and tobacco.in order to improve the quality of pasture protein for ruminant animal nutrition, we are introducing genes encoding rumen-protected proteins, rich in essential amino acids, into white clover (trifolium repens l.). we have introduced a chimaeric gene transcribed from the 35s camv promoter, and encoding the pea albumin 1 (pa1) protein, rich in sulphur amino acids, into the white clover genotype wr8 by agrobacterium-mediated transformation. a transgenic plant with high levels of pa1 mrna was crosse ...19948000431
expression of the symbiotic plasmid from rhizobium leguminosarum biovar trifolii in sphingobacterium multivorum.an inoculant strain of rhizobium leguminosarum biovar trifolii containing a tn5 marked symbiotic plasmid transferred this plasmid by conjugation to sphingobacterium multivorum, an organism that can be found in soil. the transconjugant bacteria nodulated the roots of white clover (trifolium repens) seedlings but did not fix atmospheric nitrogen. microscopic examination revealed abnormal nodule structures. bacteria isolated from the nodules were shown to be closely related to the recipient s. mult ...19948000966
influence of grazing cattle and sheep together and separately on animal performance and forage quality.cattle and sheep grazed together and separately from april to october during 3 yr. initial forage composition was 29% kentucky bluegrass (poa pratensis l.), 11% white clover (trifolium repens l.), and 60% weeds. there were six angus cow-calf pairs or six ewes (1/2 dorset x 1/4 finn x 1/4 rambouillet) with 11 lambs per each of three pasture replications for single animal species. six cow-calf pairs plus six ewes and 11 lambs grazed in each of three replications of the mixed animal species treatme ...19948014135
flavone-enhanced accumulation and symbiosis-related biological activity of a diglycosyl diacylglycerol membrane glycolipid from rhizobium leguminosarum biovar trifolii.rhizobium leguminosarum bv. trifolii is the bacterial symbiont which induces nitrogen-fixing root nodules on the leguminous host, white clover (trifolium repens l.). in this plant-microbe interaction, the host plant excretes a flavone, 4',7-dihydroxyflavone (dhf), which activates expression of modulation genes, enabling the bacterial symbiont to elicit various symbiosis-related morphological changes in its roots. we have investigated the accumulation of a diglycosyl diacylglycerol (bf-7) in wild ...19948021221
forage systems for beef production from conception to slaughter: iii. finishing systems.fall-weaned angus calves grazed or were fed different forages during winter followed by 1) n-fertilized tall fescue (festuca arundinacea schreb.) grazed alone, 2) bluegrass (poa pratensis l.)-white clover (trifolium repens l.) sequence grazed with tall fescue-red clover (trifolium pratense l.), or 3) bluegrass-white clover sequence grazed with alfalfa (medicago sativa l.)-orchardgrass (dactylis glomerata l.). heifers were supplemented with grain at 1% of bw from april until slaughter in july. on ...19968707721
identification of soil bacteria expressing a symbiotic plasmid from rhizobium leguminosarum bv. trofolii.a hundred strains of non-nodulating, gram-negative, rod-shaped bacteria were isolated from clover-ryegrass pastures on three different soil types and from a sandy loam under lupins. when crossed with escherichia coli pn200 containing the cointegrate plasmid ppn1, 11 transconjugants gained the ability to form nodules on the roots of white clover (trifolium repens cv. grasslands huia). a noda probe indicated that they had gained nodulation genes. the identities of these 11 strains and 4 others der ...19979090106
infestation of sheep dung by nematophagous fungi and implications for the control of free-living stages of gastro-intestinal nematodes.a field trial was conducted to assess the rate at which dung becomes infested by fungi which parasitise nematodes (nematophagous fungi) after deposition. sheep dung was placed on field plots of bare ground, ryegrass (lolium perenne), browntop (agrostis capillaris) and white clover (trifolium repens) in summer (february) and autumn (april), and subsamples were examined at intervals for the presence of nematophagous fungi. nematophagous fungi occurred in 71% of 129 samples recovered in february an ...19979211650
structural requirements of rhizobium chitolipooligosaccharides for uptake and bioactivity in legume roots as revealed by synthetic analogs and fluorescent probes.rhizobium chitolipooligosaccharides (closs) are heterogeneous fatty acylated n-acetyl glucosamine oligomers with variations in both the polar (hydrophilic) oligosaccharide head group and the non-polar (hydrophobic) fatty acyl chain. they trigger root hair deformation and cortical cell divisions in legume roots during development of the nitrogen-fixing root-nodule symbiosis. it has been proposed that only certain unique molecular species of closs made by a particular rhizobia can elicit these res ...19979215550
host-root exudates increase gene expression of asparagine synthetase in the roots of a hemiparasitic plant triphysaria versicolor (scrophulariaceae).triphysaria is a facultative root parasite in the scrophulariaceae family. similar to other related parasites, the development of the parasitic life cycle is initiated by molecular signals released from appropriate host roots. using a differential display, we isolated cdnas preferentially abundant in t. versicolor roots exposed to trifolium repens (white clover) root exudates in vitro. sequence analysis indicated that one of the differentially expressed cdnas had significant homology to the nitr ...19989831643
production, faecal egg counts and worm burdens of ewe lambs which grazed six contrasting forages.lambs were grazed on monospecific swards of one of six forages, some containing condensed tannins (ct); sulla (hedysarum coronarium), lotus corniculatus and l. pedunculatus and some without ct (lucerne (medicago sativa), plantain (plantago lanceolata) and a ryegrass/white clover pasture (lolium perenne/trifolium repens)) to evaluate effects of forage type on gastrointestinal nematode burdens, faecal egg count as well as liveweight gain (lwg), wool growth and dag formation over a 42-day period. a ...19989877067
expression of 1-aminocyclopropane-1-carboxylate oxidase during leaf ontogeny in white clover.we examined the expression of three distinct 1-aminocyclopropane-1-carboxylic acid oxidase genes during leaf ontogeny in white clover (trifolium repens). significant production of ethylene occurs at the apex, in newly initiated leaves, and in senescent leaf tissue. we used a combination of reverse transcriptase-polymerase chain reaction and 3'-rapid amplification of cdna ends to identify three distinct dna sequences designated traco1, traco2, and traco3, each with homology to 1-aminocyclopropane ...199910318691
influence of an elevated atmospheric co2 content on soil and rhizosphere bacterial communities beneath lolium perenne and trifolium repens under field conditions.> abstract the increase in atmospheric co2 content alters c3 plant photosynthetic rate, leading to changes in rhizodeposition and other root activities. this may influence the activity, the biomass, and the structure of soil and rhizosphere microbial communities and therefore the nutrient cycling rates and the plant growth. the present paper focuses on bacterial numbers and on community structure. the rhizospheres of two grassland plants, lolium perenne (ryegrass) and trifolium repens (white clo ...199910384008
ileal amino acid digestibilities in pigs of barley-based diets with inclusion of lucerne (medicago sativa), white clover (trifolium repens), red clover (trifolium pratense) or perennial ryegrass (lolium perenne).two experiments were performed with post-valve t-cannulated growing pigs, using five animals in each experiment in a change-over design to evaluate the effect of inclusion of four different dried forage meals on ileal crude protein (cp) and amino acid (aa) digestibilities. the control diets (c1 and c2) were barley-based and the experimental diets were formulated by replacing the barley with 100 or 200 g/kg of either lucerne (medicago sativa) or white clover (trifolium repens) meal in expt 1 and ...199910743486
the effect of breed slaughter weight and nutritional management on cholesterol content of lamb carcasses.this study was carried out to assess the effect of breed, sex, post-weaning nutrition, live weight at slaughter and their interactions on the cholesterol content in carcass fat of lambs. the carcasses were obtained from lambs of three indigenous greek dairy breeds of sheep, the boutsko (b), serres (s) and karagouniko (k) breed. after weaning (at approximately 42 days), the lambs of the three breeds had been reared under different conditions of housing and nutritional management in three consecut ...200010781744
effect of breed and age on the voluntary intake and the micromineral status of non-pregnant sheep. 1. estimation of voluntary intake.twenty-four sheep were used to test breed and age differences in voluntary intake (vi). the sheep were divided into four groups of six animals each: suffolk mature ewes (sm), suffolk yearlings (sy), rambouillet mature ewes (rm), and rambouillet yearlings (ry). the animals grazed alternatively two mixed pastures containing trifolium repens latum, lolium perenne and pennisetum clandestinum from 07:00 to 16:30 hours and remained penned overnight. voluntary intake was estimated using chromic sesquio ...200010867320
effect of breed and age on the voluntary intake and the micromineral status of non-pregnant sheep. ii. micromineral status.twenty-four non-pregnant sheep, divided into four groups of six animals each, were used to test breed (suffolk and rambouillet) and age (mature (six years old) and yearling (16 months old) ewes) differences in micromineral status. the animals grazed alternatively two mixed pastures containing trifolium repens latum, lolium perenne and pennisetum clandestinum from 07:00 to 16:30hours, and remained penned overnight. hand-plucked forage samples, blood and wool samples were collected on days 1 (exce ...200010867321
engineering the active center of the 6-phospho-beta-galactosidase from lactococcus lactis.several amino acids in the active center of the 6-phospho-beta-galactosidase from lactococcus lactis were replaced by the corresponding residues in homologous enzymes of glycosidase family 1 with different specificities. three mutants, w429a, k435v/y437f and s428d/ k435v/y437f, were constructed. w429a was found to have an improved specificity for glucosides compared with the wild-type, consistent with the theory that the amino acid at this position is relevant for the distinction between galacto ...200010906347
forage systems for production of stocker steers in the upper south.the southern states produce large numbers of beef calves that are generally weaned and sold in autumn. keeping calves in this region beyond weaning to graze high-quality forages through a stocker cattle phase could improve profitability. autumn-weaned angus crossbred steers were allocated by breeding and weight to four forage systems that began in mid-november and continued through mid-october as follows: system 1, tall fescue (festuca arundinacea schreb.) and kentucky bluegrass (poa pratensis l ...200010907841
transgenic trifolium repens with foliage accumulating the high sulphur protein, sunflower seed albumin.with the aim of increasing the rumen-protected level of the sulphur amino acids cysteine and methionine in trifolium repens, we introduced the coding sequence of the sunflower seed albumin (ssa) into t. repens by agrobacterium tumefaciens-mediated transformation. the ssa gene was modified such that the protein would be localised to the endoplasmic reticulum (er). four different t-dna constructions all containing the ssa gene driven by either the promoter of a gene encoding the small subunit of r ...200010951694
portal net appearance of amino acids in growing pigs fed a barley-based diet with inclusion of three different forage meals.the net absorption of amino acids (aa) in young pigs fed a barley-based control diet (c) and diets where barley was replaced by 200 g/kg fresh weight of dried lucerne (medicago sativa; l20), white clover (trifolium repens; w20) or perennial ryegrass (lolium perenne; pr20) meal was studied. castrated male pigs were fitted with permanent catheters in the hepatic portal vein and mesenteric artery, and the hepatic portal net absorption of aa was estimated from the porto-arterial plasma concentration ...200011103219
the effect of birdsfoot trefoil (lotus corniculatus) and white clover (trifolium repens) in mixed pasture swards on incoming and established nematode infections in young lambs.lotus corniculatus l., a leguminous plant containing condensed tannins, is now being evaluated in sweden as a component of mixed pastures. this is because of its high nutritive value, palatability, modest requirement for water, calcium and phosphorous and particularly because it has the ability to survive harsh weather conditions that typify northern scandinavia. this trial was undertaken to assess the possible parasitological benefits of using l. corniculatus when fed as a minor component in a ...200011234969
cloning and expression of a down-regulated gene (trenoddr1) of white clover responded by the nod genes derived from rhizobium leguminosarum bv. trifolii strain 4s.the nodulation genes of rhizobium leguminosarum bv. trifolii 4s (strain 4s) were cloned into cosmid vector plafr1 named pc4s8 which was contained nodnmlfedabcij and a part of nodt as an insert. the pc4s8 was transferred to strain h1, sym plasmid (prt4sa) cured strain of strain 4s, and isolated as tc resistant and nodulation restored mutant, strain h1(pc4s8). during infection process of this strain, visible symbiotic features, such as root hair curling (hac), root hair deformation (had) and infec ...200111290421
flavonoids induced in cells undergoing nodule organogenesis in white clover are regulators of auxin breakdown by peroxidase.it was tested whether flavonoids that specifically accumulate in cells undergoing early nodule organogenesis could affect auxin turnover by a peroxidase to explain local changes in auxin distribution that occur during nodule formation in white clover (trifolium repens cv. haifa). a fluorometric assay was developed to determine the kinetics of indoleacetic acid (iaa) breakdown rates by a horseradish peroxidase in vitro. three flavonoid compounds, which had previously been localized and identified ...200111326048
direct amplification of nodd from community dna reveals the genetic diversity of rhizobium leguminosarum in soil.sequences of nodd, a gene found only in rhizobia, were amplified from total community dna isolated from a pasture soil. the polymerase chain reaction (pcr) primers used, y5 and y6, match nodd from rhizobium leguminosarum biovar trifolii, r. leguminosarum biovar viciae and sinorhizobium meliloti. the pcr product was cloned and yielded 68 clones that were identified by restriction pattern as derived from biovar trifolii [11 restriction fragment length polymorphism (rflp) types] and 15 clones ident ...200111472501
transgenic white clover. studies with the auxin-responsive promoter, gh3, in root gravitropism and lateral root development.we report improved method for white clover (trifolium repens) transformation using agrobacterium tumefaciens. high efficiencies of transgenic plant production were achieved using cotyledons of imbibed mature seed. transgenic plants were recovered routinely from over 50% of treated cotyledons. the bar gene and phosphinothricin selection was shown to be a more effective selection system than nptii (kanamycin selection) or aada (spectinomycin selection). white clover was transformed with the soybea ...199611539555
spatial and time distribution of dairy cattle excreta in an intensive pasture system.this study determined distribution of feces and urine from 36 lactating dairy cattle (bos taurus) managed in a rotationally grazed 0.74-ha endophyte-free tall fescue (festuca arundinacea schreb.)-white clover (trifolium repens l.) pasture. cows were observed for 24 h five times from july 1997 to april 1998, and for 13.5 h in september 1997. during each 24-h observation period, the first grazing period (12 h) used 54% of the paddock and the second grazing period (8 h) used the entire paddock. tim ...200111790030
influence of flavor on goat feeding preferences.goat feeding preferences for straw pellets flavored with ryegrass (lolium perenne, cv. belida) or white clover (trifolium repens, cv. huia) aromatic extracts, obtained by means of a cold aromatic extraction method, were assessed with cafeteria trials. prior to the trials, odor differences between the two plant species, the two aromatic extracts, and the straw pellets sprayed with the two aromatic extracts were verified using sensory analysis performed by 30 human panelists. since odor difference ...200211925067
the effect of diet fed to lambs on subsequent development of trichostrongylus colubriformis larvae in vitro and on pasture.contrasting herbage diets were fed to lambs to evaluate their effect on subsequent development of trichostrongylus colubriformis larvae in faeces and on pasture. the diets had either no condensed tannin (ct), lucerne (medicago sativa cv. otaio), white clover (trifolium repens cv. tahora), or had moderate to high concentrations of ct, sulla (hedysarum coronarium cv. grassland aokau), lotus corniculatus (cv. grasslands goldie), l. pedunculatus (cv. grassland maku), dorycnium pentophyllum, and dory ...200211983303
the white clover enod40 gene family. expression patterns of two types of genes indicate a role in vascular function.enod40 is one of the genes associated with legume nodule development and has a putative role in general plant organogenesis. we have isolated a small enod40 gene family from white clover (trifolium repens), with three genes designated trenod40-1, trenod40-2, and trenod40-3, all containing the conserved enod40 regions i and ii. trenod40-1 and trenod40-2 share over 90% homology in the transcribed regions and high levels of similarity in their upstream regulatory sequences. trenod40-1 and trenod40- ...200212114565
phytoremediation of subarctic soil contaminated with diesel fuel.the effects of several plant species, native to northern latitudes, and different soil amendments, on diesel fuel removal from soil were studied. plant treatments included scots pine (pinus sylvestris), poplar (populus deltoides x wettsteinii), a grass mixture (red fescue, fesuca rubra; smooth meadowgrass, poa pratensis and perennial ryegrass, lolium perenne) and a legume mixture (white clover, trifolium repens and pea, pisum sativum). soil amendments included npk fertiliser, a compost extract a ...200212118697
a simple model of feedback regulation for nitrate uptake and n2 fixation in contrasting phenotypes of white clover.a simple three equation model is proposed for the feedback regulation of nitrate uptake and n2 fixation, based on the concentration of the organic n substrate pool within the plant and two parameters denoting the n substrate concentrations at which half-maximal inhibition occurs. this model simulated three contrasting phenotypes of white clover (trifolium repens l.) inbred lines with (1) normal rates of nitrate uptake and n2 fixation (nnu); (2) low rates of nitrate uptake (lnu); and (3) very low ...200212125767
arbuscular mycorrhizal community composition associated with two plant species in a grassland ecosystem.arbuscular mycorrhizal (am) fungi are biotrophic symbionts colonizing about two-thirds of land plant species and found in all ecosystems. they are of major importance in plant nutrient supply and their diversity is suggested to be an important determinant of plant community composition. the diversity of the am fungal community composition in the roots of two plant species (agrostis capillaris and trifolium repens) that co-occurred in the same grassland ecosystem was characterized using molecular ...200212144674
the effects of altitude, aspect, grazing and time on the proportion of cyanogenics in neighbouring populations of trifolium repens l. (white clover).the proportion of cyanogenic individuals of white clover amongst 200 individuals in each of 32 neighbouring populations in northumberland, uk were recorded. sites differed for four altitude zones, two aspects, and were either sheep pasture or ungrazed meadow. the proportion of cyanogenics showed a striking reduction with increasing altitude. below 100 m, north-facing sites contained more cyanogenics than south-facing sites, but aspect did not affect higher sites. grassland management had no effe ...200212180084
hazards of insecticides to the bumble bees bombus impatiens (hymenoptera: apidae) foraging on flowering white clover in turf.insecticides used on turf are sometimes applied to areas with flowering weeds that attract honey bees and native pollinators. we tested residual effects of such treatments on colony vitality and behavior of the bumble bees bombus impatiens cresson foraging on turf containingwhite clover, trifolium repens l. imidacloprid, a syst emic chloronicotinyl used for preventive control of root-feeding grubs, was applied as granules, followed by irrigation, or sprayed as a wettable powder, with or without ...200212216812
differential localization of carbohydrate epitopes in plant cell walls in the presence and absence of arbuscular mycorrhizal fungi.two monoclonal antibodies (mcabs) generated against rhamnogalacturonan i and characterized as specific for a terminal [alpha]-(1->2)-linked fucosyl-containing epitope (ccrc-m1) and for an arabinosylated [beta]-(1,6)-galactan epitope (ccrc-m7) were used in immunogold experiments to determine the distribution of the epitopes in four plants. allium porrum, zea mays, trifolium repens, and nicotiana tabacum plants were chosen as representatives of monocots and dicots with different wall structures. a ...199612226286
oxygen-induced membrane depolarizations in legume root nodules (possible evidence for an osmoelectrical mechanism controlling nodule gas permeability).various stresses trigger rapid and reversible decreases in the o2 permeability (po) of legume root nodules. several possible mechanisms have been proposed, but no supporting data have previously been presented that meet the requirements for both rapidity and reversibility. stomatal regulation of gas permeability in leaves involves electrically driven fluxes of inorganic osmoticants, so we investigated the possibility of a somewhat similar mechanism in nodules. we used microelectrodes to monitor ...199512228468
sugar-binding activity of pea lectin expressed in white clover hairy roots.introduction of the pea (pisum sativum l.) lectin (psl) gene into white clover (trifolium repens l.) hairy roots facilitates nodulation by the nitrogen-fixing bacterium rhizobium leguminosarum biovar viciae, which normally nodulates pea and not white clover (c.l. diaz, l.s. melchers, p.j.j. hooykaas, b.j.j. lugtenberg, and j.w. kijne [1989] nature 338: 579-581). here, we show that psl is functionally expressed in transgenic white clover hairy roots transformed with the psl gene. psl could be iso ...199512228660
effects of grazing undrenched weaner deer on chicory or perennial ryegrass/white clover pasture on the viability of gastrointestinal nematodes and lungworms.this study determined the in vitro effects on the viability of internal parasites of grazing undrenched weaner deer on either chicory (cichorium intybus) or perennial ryegrass (lolium perenne)/white clover (trifolium repens) pasture. one experiment investigated the hatching and development of gastrointestinal nematode eggs and larvae, and the development and motility of l1 lungworm (dictyocaulus eckerti) larvae, and a second experiment used larval migration inhibition assays to test the viabilit ...200212371691
biomarkers of exposure to cyanogens in horses with grass sickness.to test the hypothesis that equine grass sickness may be associated with the ingestion of cyanogenic glycosides from white clover (trifolium repens), the concentrations of whole blood cyanide, and plasma and urinary thiocyanate, the main metabolite of cyanide, were measured in 12 horses with acute grass sickness and 10 horses with subacute grass sickness, and in 43 control horses, of which 21 were co-grazing with cases of acute grass sickness, 12 grazed pastures where grass sickness had not been ...200212408327
the influence of phosphorus deficiency on growth and nitrogen fixation of white clover plants.the effects of p deficiency on growth, n(2)-fixation and photosynthesis in white clover (trifolium repens l.) plants were investigated using three contrasting relative addition rates of p, or following abrupt withdrawal of the p supply. responses to a constant below-optimum p supply rate consisted of a decline in n(2)-fixation per unit root weight and a small reduction in the efficiency with which electrons were allocated to the reduction of n(2) in nodules. abrupt removal of p arrested nodule g ...200212451030
lotus corniculatus condensed tannins decrease in vivo populations of proteolytic bacteria and affect nitrogen metabolism in the rumen of sheep.condensed tannins in forage legumes improve the nutrition of sheep by reducing ruminal degradation of plant protein and increasing crude protein flow to the intestine. however, the effects of condensed tannins in forage legumes on rumen bacterial populations in vivo are poorly understood. the aim of this study was to investigate the specific effects of condensed tannins from lotus corniculatus on four proteolytic rumen bacteria in sheep during and after transition from a ryegrass (lolium perenne ...200212489781
headspace solid-phase microextraction--comprehensive two-dimensional gas chromatography of wound induced plant volatile organic compound emissions.plant emissions of volatile organic compounds from mechanically wounded agrostis stolonifera, pennisetum clandestinum, eucalyptus leucoxylon and trifolium repens have been sampled by headspace-solid phase microextraction (hs-spme) and analysed by using comprehensive two-dimensional gas chromatography (gcxgc) for measurement of the plant emissions. gcxgc produces a fingerprint of the volatile organic compounds in a 2d separation space that may be approximately interpreted as a boiling point-polar ...200212537367
[responses of agricultural crops of free-air co2 enrichment].over the past decade, free-air co2 enrichment (face) experiments have been conducted on several agricultural crops: wheat(triticum aestivum l.), perennial ryegrass (lolium perenne), and rice(oryza sativa l.) which are c3 grasses; sorghum (sorghum bicolor (l.) möench), a c4 grass; white clover (trifolium repens), a c3 legume; potato (solanum tuberosum l.), a c3 forb with tuber storage; and cotton (gossypium hirsutum l.) and grape (vitis vinifera l.) which are c3 woody perennials. using reports fr ...200212557686
the effect of birdsfoot trefoil (lotus corniculatus) and chicory (cichorium intybus) on parasite intensities and performance of lambs naturally infected with helminth parasites.conventionally, farmers rely upon the routine use of anthelmintics to control helminth parasites and their use has proved highly cost-effective. however, several factors, including the emergence of helminths resistant to pharmaceutical anthelmintics, are forcing farmers to seek alternative approaches to parasite control. studies in new zealand have shown that some alternative forages may reduce parasitic infestation in sheep. in the current study, it was found that under uk environmental conditi ...200312581592
a preliminary rapd-pcr analysis of cimicifuga species and other botanicals used for women's health.traditional taxonomic methods of botanical identification that rely primarily on morphological observations cannot be used efficiently when only powdered plant materials are available. thus, our objectives were to determine if we could apply a molecular approach to: a) produce unique dna profiles that are characteristic of the species, and b) determine if the geographical area or time of collection influences these dna profiles. towards this end, random amplified polymorphic dna (rapd) analyses ...200212587700
selection of appropriate host plants used in trap culture of arbuscular mycorrhizal fungi.arbuscular mycorrhizal (am) fungi in coalmine spoil, island forest and saline soils were enriched in pot culture with maize (zea mays l.), tobacco (nicotiana tabacum l.), white clover (trifolium repens linn.) and silverweed cinquefoil (potentilla anserina l.). based on spores, there were more species of am fungi in the coalmine spoil (15 species, 3 genera), than in the forest soil (11 species, 4 genera) and the saline soil (5 species, 2 genera). in the trap cultures, the total of 28 species in a ...200312687445
relationship between resistance and growth of trifolium repens plants and their disease history.17 healthy host clones and 14 clones originally diseased with the annual rust, uromyces trifolii-repentis, were sampled from the natural population of trifolium repens, which were used as the experimental plant materials. 10 rust strains of uromyces trifolii-repentis were collected for the experimental inoculation. two greenhouse and two field experiments were done, with three treatments as inoculated with one rust strain, inoculated with ten rust strains and controls, respectively. the results ...200312722435
a novel family in medicago truncatula consisting of more than 300 nodule-specific genes coding for small, secreted polypeptides with conserved cysteine motifs.transcriptome analysis of medicago truncatula nodules has led to the discovery of a gene family named ncr (nodule-specific cysteine rich) with more than 300 members. the encoded polypeptides were short (60-90 amino acids), carried a conserved signal peptide, and, except for a conserved cysteine motif, displayed otherwise extensive sequence divergence. family members were found in pea (pisum sativum), broad bean (vicia faba), white clover (trifolium repens), and galega orientalis but not in other ...200312746522
effects of earthworms and organic litter distribution on plant performance and aphid reproduction.human management practices and large detritivores such as earthworms incorporate plant litter into the soil, thereby forming a heterogeneous soil environment from which plant roots extract nutrients. in a greenhouse experiment we investigated effects of earthworms and spatial distribution of (15)n-labelled grass litter on plants of different functional groups [ lolium perenne (grass), plantago lanceolata (forb), trifolium repens (legume)]. earthworms enhanced shoot and root growth in l. perenne ...200312844255
morphological compatibility of white clover and perennial ryegrass cultivars grown under two nitrate levels in flowing solution culture.the effects of nitrate (no3-) supply on shoot morphology, vertical distribution of shoot and root biomass and total nitrogen (n) acquisition by two perennial ryegrass (lolium perenne l.) cultivars (aberelan and preference) and two white clover (trifolium repens l.) cultivars (grasslands huia and aberherald) were studied in flowing nutrient culture. cultivars were grown from seed as monocultures and the clovers inoculated with rhizobium. the 6-week measurement period began on day 34 (grasses) and ...200312876188
whole-body fluxes and partitioning of amino acids to the mammary gland of cows fed fresh pasture at two levels of intake during early lactation.the utilisation of essential amino acids (eaa) by the mammary gland of lactating dairy cows fed fresh forages was studied to provide basic information useful in designing strategies to increase the production of milk protein from pasture-fed dairy cows. the relationship between the flux of eaa in the whole body and their uptake by the mammary gland was determined in four cows in early lactation (length of time in milk 44 (sd 14.5) d) producing 21 (sd 4.0) kg milk/d. the cows were maintained in m ...200312908887
symbiotic efficiency of autochthonous arbuscular mycorrhizal fungus (g. mosseae) and brevibacillus sp. isolated from cadmium polluted soil under increasing cadmium levels.the effect of inoculation with indigenous naturally occurring microorganisms (an arbuscular mycorrhizal (am) fungus and rhizosphere bacteria) isolated from a cd polluted soil was assayed on trifolium repens growing in soil contaminated with a range of cd. one of the bacterial isolate showed a marked pgpr effect and was identified as a brevibacillus sp. mycorrhizal colonization also enhanced trifolium growth and n, p, zn and ni content and the dually inoculated (am fungus plus brevibacillus sp.) ...200312927489
ability of cold-tolerant plants to grow in hydrocarbon-contaminated soil.phytoremediation of hydrocarbons in soil involves plants and their associated microorganisms. differences in environmental conditions and restrictions on species importation mean that each country may need to identify indigenous plants to use for phytoremedation. screening plants for hydrocarbon tolerance before screening for degradation ability may prove more economical than screening directly for degradation. thirty-nine cold-tolerant plants native, or exotic and naturalized, in western canada ...200312929494
inhibition of populations of haemonchus contortus in sheep fed on white clover (trifolium repens) high in lotaustralin. 195313036873
flavonoid-related regulation of auxin accumulation in agrobacterium tumefaciens-induced plant tumors.agrobacterium tumefaciens-induced plant tumors accumulate considerable concentrations of free auxin. to determine possible mechanisms by which high auxin concentrations are maintained, we examined the pattern of auxin and flavonoid distribution in plant tumors. tumors were induced in transformants of trifolium repens (l.), containing the beta-glucuronidase ( gus)-fused auxin-responsive promoter ( gh3) or chalcone synthase ( chs2) genes, and in transformants of arabidopsis thaliana (l.) heynh., c ...200314523649
frameshift mutation events in beta-glucosidases.compensated frameshift mutation is a modification of the reading frame of a gene that takes place by way of various molecular events. it appears to be a widespread event that is only observed when homologous amino acid and nucleodotide sequences are compared. to identify these mutation events, the sequence analysis rationale was based on the search for short regions that would have much lower degrees of conservation in protein, but not in dna, in well-conserved beta-glucosidase families. we have ...200314527732
the effect of dietary forage on the development and survival of helminth parasites in ovine faeces.studies in new zealand and the uk have shown that lambs grazing birdsfoot trefoil (lotus corniculatus) or chicory (cichorium intybus) have reduced parasite intensities compared to lambs grazing ryegrass swards. however, data in the literature on the influence of forages on helminth parasites is equivocal and the underlying mechanisms by which different forage diets may affect these parasites have not been fully determined. the aim of the experiments reported here was to investigate the hypothesi ...200314651879
determination of acaulospora longula and glomus subgroup aa in plant roots from grassland using new primers against the large subunit ribosomal dna.molecular techniques have become increasingly important for the identification of arbuscular mycorrhizal fungi (amf). in this work acaulospora longula and glomus mosseae have been detected in plant roots from pastures using specific nucleotide primers for the two species. part of the 5' end of the large subunit of the ribosomal rna gene was amplified by nested pcr and sequenced. the distribution of the fungi within three different plant species, plantago lanceolata, trifolium repens, and holcus ...200415035508
the effect of heavy metals on dinitrogen fixation by rhizobium-white clover in a range of long-term sewage sludge amended and metal-contaminated soils.an investigation was conducted to determine whether effective strains of rhizobium leguminosarum biovar. trifolii capable of symbiotic n2 fixation with white clover (trifolium repens) were present in a range of metal-contaminated soils. a number of historically sewage-amended sites (including experimental, pasture grassland and arable sites) were selected and compared with highly contaminated samples from abandoned heavy metal mines. many sites had metal concentrations above the limits establish ...199315091894
ntzip antisense plants show reduced chlorophyll levels.we have isolated and characterized a new photosynthetic tissue-specific gene ntzip (nicotiana tabacum leucine zipper) from tobacco (n. tabacum). its deduced amino acid sequence has two highly conserved regions, leucine zipper and [ex(n)dexrh](2) motifs, which are related to the gene's biochemical functions. ntzip was expressed in leaves and stems, but was not detected in roots or flowers, suggesting that its physiological functions might be associated with photosynthesis. northern blot analysis ...200415120117
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