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1.
Phytopathology ; 106(8): 890-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27088391

RESUMO

Autofluorescent proteins are frequently applied as visual markers in the labeling of filamentous fungi. Genes gfp and DsRed were transformed into the genome of Fusarium verticillioides via the Agrobacterium tumefaciens-mediated transformation method. The selected transformants displayed a bright green or red fluorescence in all the organelles of the growing fungal mycelia and spores (except for the vacuoles) both in cultures and in the maize (Zea mays) roots they colonized. The results of gene-specific polymerase chain reaction (PCR) analysis and the thermal asymmetrical interlaced (TAIL)-PCR analysis demonstrated that gfp and DsRed were integrated on different chromosomes of the fungus. Reductions in the colony growth on the plates at pH 4.0 and 5.5 was observed for the green fluorescent protein (GFP)-transformant G3 and the DsRed-transformant R4, but transformants G4 and R1 grew as well as the wild-type strain at pH 4.0. The speed of growth of all the transformants was similar to the wild-type strain at pH ≥ 7. The insertion of gfp and DsRed did not alter the production of extracellular enzymes and fumonisin B by F. verticillioides. The transformants expressing GFP and DsRed proteins were able to colonize maize roots. However, the four transformants examined produced fewer CFU in the root samples than the wild-type strain during a sampling period of 7 to 28 days after inoculation.


Assuntos
Fusarium/metabolismo , Proteínas de Fluorescência Verde , Proteínas Luminescentes , Zea mays/microbiologia , DNA Bacteriano , Regulação Fúngica da Expressão Gênica , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia , Transformação Genética
2.
Plant Dis ; 98(2): 278, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30708768

RESUMO

Root rot is a major disease of dry bean and can cause significant yield reductions due to weakened root systems and poor plant stands. An in-depth study on root rot pathogen identification was conducted in 2011 in three commercial dry bean fields from the major production areas in Manitoba. Ten plants, sampled at each of four random sites within each field, were rated for disease severity. Twenty roots were processed for pathogen isolation and identification in the laboratory. Roots were cut into eight sections (~1 cm) and surface-sterilized in a laminar flow bench. Four root sections were placed on potato dextrose agar plates amended with 0.02% streptomycin sulfate (PDA-Strep) and four root sections were placed on peptone-pentachloronitrobenzene agar amended with 0.1% streptomycin sulfate and 0.012% neomycin sulfate. Afterward, 960 monosporic cultures were obtained representing 320 single spore isolates of potential root rot pathogens per commercial field. Common monosporic cultures from each field were subcultured on PDA-Strep and Spezieller Nährstoffarmer Agar (SNA) media. Based on morphological characteristics, 74 isolates were identified as Fusarium cuneirostrum (1). Colonies grew slowly on PDA-Strep with undulated margins, radial cream-grey mycelia, and conidia pustules with a cream-greyish pigmentation. Sporodochial conidia were falcate, mostly 5-septate, with a wedge shape and slightly protruding basal foot cell (56.3 to 71.8 × 4.6 to 6.2 µm on average). Species identity was confirmed for two isolates by sequencing the translation elongation factor 1 alpha (EF1-α) gene (2), the internal transcribed spacer (ITS) region (4), and the ribosomal intergenic spacer (IGS) (3) (GenBank Accession Nos. KF530848, KF530849, and KF025648 to 51). Sequence homology was compared using BLAST analysis and the FUSARIUM-ID database. The F. cuneirostrum isolates were deposited at the Canadian Collection of Fungal Cultures (DAOM 242540 and 242541). Pathogenicity screenings of two isolates was performed using sterilized seed of navy bean cv. Envoy. Seeds were germinated on moist filter paper for 3 days at 25°C and then inoculated by immersion in a prepared conidial suspension (2.5 × 105 conidia/ml) for 5 min. Seeds of the controls were immersed in sterile water. After inoculation, the germinated seeds were planted in 10-cm diameter pots, filled with sterile soilless mix (Sunshine #3). In the greenhouse, the experiment was arranged as a completely randomized design with three replicates with four germinated seeds per isolate, and was repeated twice. Disease assessment was performed 14 days after inoculation. Infected plants displayed dark brown lesions on the hypocotyl and primary root with a disease severity of 4 scored on a 0 to 5 scale. Fusarium cuneirostrum was re-isolated from roots of symptomatic plants. To our knowledge, this is the first report of F. cuneirostrum causing root rot of dry bean in Canada. It has been previously isolated from mung bean (Vigna radiata) in Ontario (1). References: (1) T. Aoki et al. Mycoscience. 46:162, 2005. (2) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (4) H. Wang et al. J. Clin. Microbiol. 49:1890, 2011. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

3.
Science ; 169(3948): 880-2, 1970 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-5432584

RESUMO

The principal sterol synthesized by L-cell mouse fibroblasts is desmosterol. Cholesterol was not detected in these cells when they were grown in a sterol-free culture medium. These findings indicate that, in cells, cholesterol can be replaced by desmosterol. Sterol analyses of six other tissue culture cell lines revealed cholesterol synthesis.


Assuntos
Colestanos/biossíntese , Células L/metabolismo , Esteróis/biossíntese , Acetatos/metabolismo , Animais , Isótopos de Carbono , Carcinoma , Colestanos/análise , Colesterol/biossíntese , Cromatografia Gasosa , Cromatografia em Camada Fina , Meios de Cultura , Técnicas In Vitro , Neoplasias Laríngeas , Pulmão , Camundongos , Esteróis/análise
4.
Plant Dis ; 92(2): 312, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30769410

RESUMO

In 2004, rhizome blight of ginger (Zingiber officinale (Willd.) Roscoe) (cv. Yunnanxiaojiang) occurred in the Kunming District of China. The surface of ginger rhizome after harvest was crimpled and covered with white hyphae. Initial symptoms on ginger were wilting on the stem and the color of the rhizome turned from white to light brown with no lesion formation. After 2 weeks, the surface of ginger rhizome was covered with white hyphae and a dry rot set in under humid conditions. The yield loss in ginger almost reached 50% because of the disease. An AG-R tester isolate paired with the unknown 37 isolates of Rhizoctonia spp. from the diseased ginger rhizomes caused a C2 reaction that confirmed their identity. Isolates of AG-R (GenBank Accession Nos. DQ885780 and DQ885781) had 100% sequence similarity with 5.8S rDNA-ITS with the AG-R tester isolate (GenBank Accession No. AF354082). To produce infected soil inoculum, 10 isolates were cultured on potato dextrose agar in a 9-cm petri dish for 3 to 4 days and then covered with approximately 20 g of autoclaved soil and kept at 25°C for 3 to 4 days. Seedlings of ginger (cv, Yunanxiaojiang) were planted in natural potting soil at a density of one plant per vinyl pot (8 cm in diameter, 9 cm high) and grown in the greenhouse for 7 days. Each seedling was inoculated with 7 g of infested soil by placing it around the rhizome. Control plants were inoculated with autoclaved soil. The experiments were carried out three times, each time with three replicates in a growth chamber kept at 25 and 16°C with a 16-h light and 8-h dark photoperiod. After 14 days, the disease severity was recorded based on a scale in which - = no symptoms; + = small lesions on seedlings, no blight; ++ = seedling blight; and +++ = plant dead. All of the 10 tested AG-R isolates caused ginger seedling blight. Rhizoctonia spp. was reisolated from these plants, confirming its pathogenicity. To our knowledge, this is the first report of rhizome blight of ginger caused by Rhizoctonia spp. and binucleate Rhizoctonia AG-R in China. References: (1) B. Sneh et al. Page 135 in: Identification of Rhizoctonia Species. The American Phytopathological Society, St. Paul, MN, 1998.

5.
Mol Breed ; 38(3): 34, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29568229

RESUMO

Seed hardness trait has a profound impact on cooking time and canning quality in dry beans. This study aims to identify the unknown genetic factors and associated molecular markers to better understand and tag this trait. An F2:7 recombinant inbred line (RIL) population was derived from a cross between the hard and soft seeded black bean parents (H68-4 and BK04-001). Eighty-five RILs and the parental lines were grown at two locations in southern Manitoba during years 2014-2016. Seed samples were harvested manually at maturity to test for seed hardness traits. The hydration capacity and stone seed count were estimated by soaking the seeds overnight at room temperature following AACC method 56-35.01. Seed samples from 2016 tests were also cooked to determine effect of seed hardness on cooking quality. For mapping of genomic regions contributing to the traits, the RIL population was genotyped using the genotype by sequencing (GBS) approach. The QTL mapping revealed that in addition to the major QTL on chromosome 7 at a genomic location previously reported to affect seed-hydration, two novel QTL with significant effects were also detected on chromosomes 1 and 2. In addition, a major QTL affecting the visual appeal of cooked bean was mapped on chromosome 4. This multi-year-site study shows that despite large environmental effects, seed hardness is an oligo-genic and highly heritable trait, which is inherited independently of the cooking quality scored as visual appeal of cooked beans. The identification of the QTLs and development of SNP markers associated with seed hardness can be applied for common bean variety improvement and genetic exploitation of these traits.

6.
Plant Dis ; 91(11): 1516, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30780765

RESUMO

During July, 2003, damping-off of Swiss chard (Beta vulgaris subsp. cicla L.) was observed in a seedling (approximately 1 month after germination) field (approximately 2 ha) in Yuanmou County in the Cuxiong District of Yunnan, China. More than 80% of the seedlings showed symptoms of the disease. Symptoms on newly emerged plants consisted of wilting, a brown necrosis of the lower taproot, and eventual death of seedlings. Among the 15 isolates of Rhizoctonia spp. isolated from Swiss chard with damping-off symptoms, 12 isolates of Rhizoctonia solani with dark brown sclerotia on potato dextrose agar (PDA) anastomosed with tester isolates of each subgroup AG-4 HG I, AG-4 HG II, and AG-4 HG III, giving a C2 hyphal fusion (1) reaction at a high frequency. The other three binucleate Rhizoctonia spp. (BNR) isolates whose mycelia were white with floccose aerial hyphae on PDA anastomosed freely with two BNR AG-A tester isolates producing a C2 hyphal reaction. The 5.8S rDNA-ITS of a single isolate of R. solani and a single isolate of BNR was sequenced. The sequence of the AG-4 isolate (GenBank Accession No. EF679777) exhibited 99 to 100% homology with isolates of R. solani AG-4, subgroup 4HG I (GenBank Accession No. AY154307). The sequence from the AG-A isolate (GenBank Accession No. EF679778) exhibited 98% homology with BNR AG-A (GenBank Accession Nos. AB000040 and AF354092). Swiss chard (cv. Baijin) seedlings (approximately 5 cm high) were planted in potting soil at a density of one seedling per vinyl pot (8 cm diameter, 9 cm high). Two isolates each of R. solani and BNR were used in pathogenicity testing. Each seedling was inoculated in the root zone with approximately 7 g of artificially infested soil. Control plants were inoculated with autoclaved soil. The experiments were conducted three times, each time with three replicates, in a greenhouse with a photoperiod of 16 h of light and 8 of h dark at 30 and 16°C, respectively. After 7 days, disease severity was measured based on a scale in which 0 = no symptom; 1 = small lesions on seedlings, no blight; 2 = leaves blight, no stem blight; 3 = stem blight; and 4 = plant dead. The two AG-4 and two of AG-A isolates were pathogenic on the Swiss chard seedlings and caused damping-off symptoms with a disease index 1.7 to 4.0, and there were no significant differences (P = 0.05) among them. We reisolated and confirmed the presence of R. solani and BNR AG-A from diseased plants. AG-3 isolates were reported to cause the damping-off of Swiss chard in the United States (2). To our knowledge, this is the first report of damping-off of Swiss chard caused by Rhizoctonia solani AG-4 HG I and BNR AG-A. References: (1) D. E. Carling. Page 37 in: Grouping in Rhizoctonia solani by Hyphal Anastomosis Reaction. Kluwer Academic Publishers, Dordecht, the Netherlands, 1996. (2) S. T. Koike and K. V. Subbarao. Plant Dis. 83:695, 1999.

7.
Plant Dis ; 91(10): 1271-1276, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30780518

RESUMO

To facilitate early diagnosis and improve control of bean anthracnose, a rapid, specific, and sensitive polymerase chain reaction (PCR)-based method was developed to detect the causal agent, Colletotrichum lindemuthianum, in bean (Phaseolus vulgaris) seed. Based on sequence data of the rDNA region consisting of the 5.8S gene and internal transcribed spacers (ITS) 1 and 2 of four C. lindemuthianum races and 17 Colletotrichum species downloaded from GenBank, five forward primers were designed and evaluated for their specificity. Among them, one forward primer was selected for use in combination with ITS4 to specifically detect C. lindemuthianum. A 461-bp specific band was amplified from the genomic DNA template of 16 representative isolates of C. lindemuthianum, but not from 58 representative isolates of 17 other Colletotrichum species or 10 bean pathogens. Moreover, to enhance the sensitivity of detection, nested PCR was applied, which allowed the detection of as little as 10 fg of C. lindemuthianum genomic DNA and 1% infected seed powder, which was mixed with 99% healthy seed powder. The diagnostic analysis can be completed within 24 h, compared with about 2 weeks required for culturing. Furthermore, this method can be performed and interpreted by personnel with no specialized taxonomic expertise.

8.
Plant Dis ; 91(4): 368-374, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30781176

RESUMO

High yield potential and the wide adaptability of wheat-rye T1BL·1RS translocation lines are attractive to breeders. The wheat-rye lines Lankao 1, 3, 4, and 5 were resistant to a wide spectrum of wheat powdery mildew (Blumeria graminis f. sp. tritici) isolates from both China and Canada. They also were resistant to a mixture of wheat stem rust (Puccinia graminis f. sp. tritici) pathotypes (98WSR) and wheat stripe rust (P. striiformis f. sp. tritici) races from western Canada and China. Colonization of wheat curl mite (WCM) (Aceria tosichella) resulted in slower development of rolling and trapping leaves in the Lankao lines than in the WCM-susceptible check cultivars. The delayed development of Wheat streak mosaic (WSM) symptoms on Lankao lines was observed when transmitted by viruliferous WCM, even though they were susceptible to Wheat streak mosaic virus (WSMV). This effect of Lankao lines on limiting the spread of WSM was comparable with other known sources of WCM resistance. Sequential C-banding and genomic in situ hybridization analyses revealed the presence of a pair of T1BL·1RS translocated chromosomes in the Lankao lines. Segregation analysis of the F2 progeny plants derived from crosses between Lankao 4 and the susceptible wheat cvs. Mingxian 169 and Lovrin 13 indicated that a single dominant gene was responsible for the isolate-specific resistance against wheat powdery mildew in Lankao 4. Polymerase chain reaction analysis using an STS marker amplified rye chromatin in powdery mildew-resistant and -susceptible F2 plants of the Mingxian 169 × Lankao 4 cross demonstrated that the resistance of Lankao 4 was not controlled by a gene or genes located on the rye chromosome arm of T1BL·1RS. The resistance of the Lankao lines to diseases and limitation of the spread of WSMV, in combination with good quality and high yield potential, makes them useful for wheat improvement and production.

9.
Biochim Biophys Acta ; 398(2): 209-16, 1975 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-810159

RESUMO

Cultures of Tetrahymena pyriformis W respond to isovalerate supplementation by an increase in odd-numbered saturated, unsaturated and alpha-hydroxy iso-fatty acids and by a decrease in even-numbered normal fatty acids in the glycerolipids and sphingolipids. Supplementation, however, did not alter the relative amount of unsaturated fatty acids found in the polar lipids. The unsaturated acids 17 : 1(i) and 19 : 1(i) were isolated from cells grown with [1-14C]isovalerate and found to have a higher specific activity than the monoenes of the normal series. Isotopic and gas-chromatographic analyses also indicated the presence of dienoic and trienoic acids of the iso-acid series. The iso-fatty acid content was elevated with isovalerate levels up to 5.0 mM and an inhibition of growth was noted. At higher concentrations of the short chain precursor, no further increase in total cellular iso-acids was detected although growth inhibition was more pronounced. The alpha-hydroxy iso-fatty acids of the sphingolipids, however, were elevated in a fashion that paralleled the external concentration of isovalerate; thus, the amount of alpha-hydroxy iso-acids and the degree of growth inhibition show a direct relationship. The increase in alpha-hydroxy iso-acid content of the sphingolipids was at the expense of the saturated normal and iso-acid components. The impact on the physiology of the cells can be envisaged as the result of changes in membrane fluidity due to the presence of high levels of iso-fatty acids without an accompanying reduction in unsaturated acids.


Assuntos
Ácidos Graxos/metabolismo , Tetrahymena pyriformis/metabolismo , Valeratos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Hidroxiácidos/metabolismo , Fosfatidilgliceróis/metabolismo , Esfingolipídeos/metabolismo , Relação Estrutura-Atividade , Tetrahymena pyriformis/crescimento & desenvolvimento
10.
Biochim Biophys Acta ; 575(3): 475-8, 1979 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-117840

RESUMO

Cultures of Tetrahymena pyriformis W incorporate exogenous 3-[14C]-cilienic acid and gamma-[1(-14)C] linolenic acid, terminal products of unsaturated fatty acid synthesis, into glycerophosphatides without randomization of the radiolabel. There was no difference in the rate of loss of each of the two acids at 15 or 28.5 degrees C. Differential turnover of these fatty acids, therefore, does not appear to be the cause of the shift in fatty acid pattern observed with temperature reduction.


Assuntos
Ácidos Graxos Insaturados/metabolismo , Tetrahymena pyriformis/metabolismo , Temperatura Alta , Ácidos Linoleicos/metabolismo , Ácidos Linolênicos/metabolismo
11.
Biochim Biophys Acta ; 663(1): 121-33, 1981 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-6783106

RESUMO

Tetrahymena pyriformis W cells were grown with short- and long-chain, odd and even normal fatty acid supplements. Tris acetate addition had no effect on the fatty acyl composition of the glycerophospholipids or sphingolipids, while Tris propionate supplementation led to a marked increase in odd normal fatty acids at the expense of even normal acids in both classes of complex lipids. This enhancement of odd normal acids permitted the identification of 17:1 delta 9(n), 17:2 delta 6,9(n), 17:2 delta 9,12(n), 17:3 delta 6,9,12(n), 19:1 delta 9(n), 19:2 delta 9,12(n) and 19:3 delta 6,9,12(n) by oxidation with periodate-permanganate and examination of the short-chain fragments. Supplementation with pentadecanoic acid (15:0(n)) led to an increase in the proportions of normal C15, C17 and C19 acids. The increase in C15 acids primarily reflected a rise in 15:0(n), whereas the rise in the levels of C17 and C19 acids was accounted for by an elevation of unsaturated acids. Growth with heptadecanoic acid (17:0(n)) resulted in substantial increases in unsaturated normal C17 and C19 fatty acids, while nonadecanoic acid (19:0(n)) addition led only to an increase in the proportion of unsaturated C19 acids. Retroconversion of these saturated, odd normal long chain fatty acid supplements was limited. Supplementation with arachidic acid (20:0(n)) resulted in only a marginal increase (1.4%) in normal C20 fatty acids of both the glycerophospholipids and the mild alkali labile neutral lipids and provided no evidence that desaturation occurred. The release of 14CO2 from [1-14C]arachidic acid when incubated with the ciliates indicated that this long-chain saturate is accumulated, activated and degraded. Normal C16-C19 saturated fatty acids are substrates for the delta 9 desaturase. The delta 11 isomers arise by chain elongation. Normal C16-C19 delta 9 monoenoic acids are substrates for the delta 12 desaturase. Normal C16-C18 delta 9 monoenes, normal C16-C19 delta 9,12 dienes and 18:1 delta 11(n) are desaturated at the C-6,7 position.


Assuntos
Ácidos Graxos não Esterificados/metabolismo , Tetrahymena pyriformis/metabolismo , Animais , Dióxido de Carbono/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Cinética , Oxirredução , Relação Estrutura-Atividade , Especificidade por Substrato
12.
Theor Appl Genet ; 104(2-3): 315-320, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12582703

RESUMO

Stripe rust resistance was identified in Triticum vavilovii( T. vaviloviiAus22498)-derived Russian wheat aphid (RWA)-resistant germplasm. Inheritance studies indicated monogenic control of resistance. The resistance gene was tentatively designated as Yrvav and was located on chromosome 1B by monosomic analysis. A close association (1.5+/-0.9% recombination) of Yrvav with a T. vavilovii-derived gliadin allele ( Gli-B1vav) placed it in chromosome arm 1BS. Yrvavwas allelic with Yr10. Tests with Yr10 avirulent and virulent pathotypes showed that Yrvav and Yr10 possess identical pathogenic specificity. Yrvav and Yr10 showed close genetic associations with alternate alleles at the Xpsp3000(microsatellite marker), Gli-B1 and Rg1 loci. Based on these observations Yrvav was named as Yr10vav. The close association between Xpsp3000 and Gli-B1 was also confirmed. The Yr10vav-linked Xpsp3000 allele (285 bp) was not present in 65 Australian cultivars, whereas seven Australian wheats lacking Yr10 carried the same Xpsp3000 allele (260 bp) as Yr10carrying wheat cultivar Moro. Xpsp3000 and/or Gli-B1 could be used in marker-assisted selection for pyramiding Yr10vavor Yr10 with other stripe rust resistance genes. Yr10vav was inherited independently of the T. vavilovii-derived RWA resistance.

13.
Pharmacol Biochem Behav ; 33(3): 533-7, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2587594

RESUMO

The relationship between opioids and social behavior was examined by administering morphine (an opioid agonist) and naloxone (an opioid antagonist) to juvenile dogs and measuring various social behaviors (e.g., tail wagging) in a large room. Drugs were administered following social deprivation and nondeprivation. It was hypothesized that morphine would ease effects of social deprivation while naloxone would result in behavior typical of untreated socially-deprived dogs. Social deprivation (24 hr) resulted in more contact with the experimenter and increased tail wagging relative to nondeprivation. Morphine (0.25 mg/kg) resulted in more contacts with the experimenter and entrances into the "experimenter's area" relative to vehicle injections. Further, morphine decreased and naloxone increased tail wagging in the dog's area and there was a significant social condition X drug interaction for that measure. Naloxone (0.25 mg/kg) increased wagging following nondeprivation while morphine decreased wagging following deprivation. These data support the hypotheses that social deprivation can increase social behaviors, and that social behavior is regulated by activity in brain opioid systems.


Assuntos
Comportamento Animal/efeitos dos fármacos , Morfina/farmacologia , Naloxona/farmacologia , Apego ao Objeto , Comportamento Social , Isolamento Social , Animais , Comportamento Animal/fisiologia , Cães , Feminino , Masculino
14.
Lipids ; 19(4): 285-8, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6717257

RESUMO

The ciliate, Tetrahymena, was provided a supplement of the fatty acid [1-14 C]18:2 delta 6.9. After a period of growth the cells were claimed, the lipids extracted, the polar lipids recovered and the mild alkali-labile fatty acid methyl esters generated. The fatty acids were resolved by high pressure liquid chromatography (HPLC), the 18:3 delta 6.9,12(gamma-linolenic acid) was recovered and its identity verified by high pressure liquid chromatography (HPLC), gas liquid chromatography (GLC), hydrogenation and oxidation. Fifty-three percent of the cell-associated label was found in gamma-linolenic acid; thus, a delta 12 fatty acid desaturase converts the 6,9 octadecadienoic acid to the 6,9,12 derivative. No carboxyl or methyl terminus restriction appears on delta 9 monoenoic or dienoic fatty acid desaturation in this cell as is found in higher plants and animals.


Assuntos
Ácidos Graxos Dessaturases/metabolismo , Tetrahymena/enzimologia , Cromatografia Líquida de Alta Pressão , Ácidos Graxos Insaturados/metabolismo , Especificidade por Substrato
15.
Lipids ; 17(3): 257-62, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6806558

RESUMO

The delta 5-sterol, androst-5-en-3 beta-ol, which has no side chain at C-17, did not permit molting of the insect Heliothis zea, growth of either the protozoan Tetrahymena pyriformis, or the yeast Saccharomyces cerevisiae adapted to anaerobic conditions, nor was the sterol esterified by a mammalian microsomal ACAT preparation. However, the sterol did form a liposome with egg lecithin and, when fed to mice, did inhibit hepatic cholesterol synthesis. 21-Isopentylcholesterol also formed a liposome but neither supported the growth of the yeast nor was metabolized by the protozoan. When sterols, 20(R)-n-alkylpregn-5-en-3 beta-ols, with side chains of varying lengths were added to the medium of the protozoan, maximal esterification with fatty acids occurred with the 20(R)-n-pentyl derivative, and maximal inhibition of tetrahymanol formation occurred with the n-butyl, n-pentyl, and n-hexyl derivatives. In all of the assays cholesterol showed a positive response, either permitting molting or growth, being metabolized, inhibiting sterol or tetrahymanol synthesis, or forming a liposome.


Assuntos
Androstenóis/farmacologia , Colesterol/análogos & derivados , Colesterol/farmacologia , Pregnenos/farmacologia , Animais , Bioensaio , Colesterol/biossíntese , Lipossomos/metabolismo , Fígado/metabolismo , Camundongos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Tetrahymena pyriformis/efeitos dos fármacos , Tetrahymena pyriformis/crescimento & desenvolvimento
16.
J Exp Anal Behav ; 10(6): 555-63, 1967 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-4295216

RESUMO

Rats were conditioned to avoid shock on a free-operant avoidance schedule in which no exteroceptive stimulus signaled impending shock. Injections of adrenocorticotropic hormone (ACTH) or dexamethasone raised blood levels of glucocorticoids. These increases were accompanied by changes in avoidance performance: there was a higher frequency of long-duration interresponse times, a greater stability among them, and fewer short interresponse times, total responses, and shocks.


Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Dexametasona/farmacologia , Glucocorticoides/sangue , Animais , Condicionamento Operante , Eletrochoque , Ratos , Tempo de Reação/efeitos dos fármacos
17.
Plant Dis ; 86(4): 423-428, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30818719

RESUMO

Wheat curl mite (WCM), Aceria tosichella, is the vector of Wheat streak mosaic virus (WSMV), a destructive viral pathogen in wheat (Triticum aestivum). Genetic resistance to WCM colonization can reduce the incidence of wheat streak mosaic. Chromosome 6V in Hay-naldia villosa is a new source of WCM resistance. We compared variation in resistance among different sources of H. villosa chromosome 6V and 6VS lines to WCM and WSMV and their effectiveness in controlling the incidence of WSMV following exposure to viruliferous WCM. WCM resistance varied among the 6V and 6VS lines depending on the H. villosa parent. The 6V substitution lines Yi80928, GN21, and GN22 derived from an accession of H. villosa from China, and the 6VS translocation lines 92R137, 92R178, and Sub6V from an H. villosa accession collected from the United Kingdom were uniformly resistant to WCM colonization. In contrast, the 6V substitution line RW15 and a 6VS translocation line Pm33 developed from an H. villosa collection from the former Union of Soviet Socialist Republics were susceptible to WCM. All 6V and 6VS lines were susceptible to WSMV when manually inoculated. However, symptom expression was delayed in the WCM-resistant 6V and 6VS lines after exposure to viruliferous WCM. The 6V and 6VS lines differed in their ability to control WSMV infection. WCM-susceptible lines RW15 and Pm33 had no effect on controlling the infection by WSMV. Lines GN21 and GN22 were the most effective of the three H. villosa sources in limiting the spread of WSMV. Their high yield potential and protein content, in combination with resistance to stripe rust (Puccinia striiformis f. sp. tritici) and powdery mildew (Erysiphe graminis f. sp. tritici), make GN21 and GN22 promising sources of WCM resistance.

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