WorldWideScience

Sample records for lycopersicon mutant internal

  1. Características fisiológicas de microtomateiros fitocromo-mutantes Physiological characteristics of micro-tomato (Lycopersicon esculentum P. Miller) phytochrome-mutants

    National Research Council Canada - National Science Library

    Hyrandir Cabral de Melo; Evaristo Mauro de Castro; Ângela Maria Soares; Cynthia de Oliveira; Sílvio Júnio Ramos

    2009-01-01

    ... (Lycopersicon esculentum P. Miller cv. Micro-Tom) fitocromo-mutantes. A cultivar Micro-Tom e os mutantes aurea (deficiente na biossíntese do cromóforo dos fitocromos), atroviolacea (atv) e high pigment1 (hp1...

  2. Genetic control of modified genomic region in a firm ripening tomato (Lycopersicon esculentum Mill. mutant

    Directory of Open Access Journals (Sweden)

    Adilson Ricken Schuelter

    2006-01-01

    Full Text Available Studies involving the firm tomato (Lycopersicon esculentum mutant have shown that pleiotropy or geneticlinkage are responsible for modifications in morphological and postharvest traits. The objective of this report was to evaluatethe hypothesis of pleiotropy or genetic linkage linked to morphologic traits and to verify the effect of QTL on fruit firmness.Plants of mutant firm and L. cheesmani were intercrossed; the F2 and F3 generations were analyzed for segregation ofmorphological traits and firmness, and the RAPD technique was used for the F2 population. Results showed that the recessivepleiotropic gene is responsible for the morphological traits, but environmental and/or genetic factors affect the penetranceand expressivity of the mutation. By the RAPD analysis, a QTL was detected in the group represented by the markers AS-08622,AQ-16747 and l-2 that explains 29.77% of the variation to fruit firmness.

  3. Retention of Photoinduction of Cytosolic Enzymes in aurea Mutant of Tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Goud, K. V.; Sharma, R.

    1994-06-01

    The tomato (Lycopersicon esculentum Mill.) aurea (au) mutant has been characterized as a phytochrome-deficient mutant lacking spectrally detectable phytochrome A in etiolated seedlings. Seedlings of au grown under red light (RL) lack phytochrome regulation of nuclear genes encoding plastidic proteins, possess ill-developed chloroplasts, and are slow to de-etiolate. In the present study, the effect of phytochrome deficiency on photoinduction of enzymes in etiolated au seedlings was investigated. The photoinduction of the cytosolic enzymes amylase and nitrate reductase (NR) and of the plastidic enzyme nitrite reductase (NiR) in au was compared with that in the isogenic wild-type (WT) tomato and the high-pigment (hp) mutant with exaggerated phytochrome response. In WT and hp, both brief RL pulses and continuous RL induced amylase, NR, and NiR activities, whereas in au no photoinduction of enzymes was observed with brief RL pulses, and continuous RL induced only amylase and NR activities. The time courses of photoinduction of NR and amylase in au under continuous RL followed patterns qualitatively similar to hp and WT. A blue-light pretreatment prior to continuous RL exposure was ineffective in inducing NiR activity in au. Only continuous white light could elicit a photoinduction of NiR in au seedlings. The norflurazon-triggered loss of photoinduction of NiR in WT and hp indicated that NiR photoinduction depended on chloroplast biogenesis. The results indicate that observed photoinduction of NR and amylase in au may be mediated by a residual phytochrome pool.

  4. Relationships between fruit exocarp antioxidants in the tomato (Lycopersicon esculentum) high pigment-1 mutant during development.

    Science.gov (United States)

    Andrews, Preston K.; Fahy, Deirdre A.; Foyer, Christine H.

    2004-04-01

    Development-dependent changes in fruit antioxidants were examined in the exocarp (epidermal and hypodermal tissues) of the monogenic recessive tomato (Lycopersicon esculentum L.) mutant high pigment (hp-1) and its wild-type parent 'Rutgers' grown under non-stress conditions in a greenhouse. The hp-1 mutant was chosen for this study because the reportedly higher lycopene and ascorbic acid (AsA) contents of the fruit may alter its tolerance to photooxidative stress. Throughout most of fruit development, reduced AsA concentrations in the exocarp of hp-1 were 1.5 to 2.0 times higher than in 'Rutgers', but total glutathione concentrations were similar in both genotypes. Only in ripe red fruit were reduced AsA and total glutathione concentrations lower in hp-1 than in 'Rutgers'. The redox ratios (reduced : reduced + oxidized) of AsA in hp-1 and 'Rutgers' exocarps were similar and usually > 0.9, however, the redox ratio of glutathione was lower in hp-1 than in 'Rutgers' throughout development. Lycopene concentrations in ripe red fruit were about 5 times higher in hp-1 than in 'Rutgers'. Large increases in the specific enzyme activities of superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), and monodehydroascorbate reductase (MDHAR; EC 1.6.5.4) occurred during fruit development in both genotypes, with an inverse relationship between the activities of these enzymes and chlorophyll content. Glutathione reductase (EC 1.6.4.2) and MDHAR-specific activities were higher in hp-1 than 'Rutgers' only at the later stages of fruit development. Dehydroascorbate reductase (EC 1.8.5.1) activities, however, were usually higher in 'Rugters' than in hp-1. Catalase (CAT, EC 1.11.1.6) activities increased with fruit development until the fruit were orange/light red, when CAT was higher in 'Rutgers' than in hp-1, but then declined in the ripe red fruit of both genotypes. These results suggest that elevated AsA in the exocarp of hp-1 fruit early in fruit development may

  5. Características fisiológicas de microtomateiros fitocromo-mutantes Physiological characteristics of micro-tomato (Lycopersicon esculentum P. Miller phytochrome-mutants

    Directory of Open Access Journals (Sweden)

    Hyrandir Cabral de Melo

    2009-10-01

    Full Text Available Objetivou-se, neste trabalho, caracterizar aspectos fisiológicos de microtomateiros (Lycopersicon esculentum P. Miller cv. Micro-Tom fitocromo-mutantes. A cultivar Micro-Tom e os mutantes aurea (deficiente na biossíntese do cromóforo dos fitocromos, atroviolacea (atv e high pigment1 (hp1;ambos superexpressam eventos mediados por fitocromos foram cultivados em condições controladas de luz e temperatura e caracterizados no estágio de floração. O mutante hp1 obteve as maiores taxas de fotossíntese potencial e de conteúdo de carotenóides. O mutante aurea manteve taxas de fotossíntese potencial similares à cultivar Micro-Tom, mesmo expressando o mais baixo conteúdo de clorofilas, e também expressou o maior conteúdo de nitrogênio entre os demais microtomateiros. Os mutantes aurea e hp1 obtiveram os menores conteúdos de açúcares solúveis totais. O mutante atv expressou o maior conteúdo de clorofilas e também a menor razão clorofila a/b.The objective of this work was to characterize physiological aspects of micro-tomato (Lycopersicon esculentum P. Miller cv. Micro-Tom phytochrome-mutants. Plants of Micro-Tom cultivar and aurea (deficient in phytochrome chromophore biosynthesis, high pigment1 (hp1 and atroviolacea (atv (both super express phytochrome events-mediated mutants were cultivated under controlled light and temperature and evaluated in flowering stage. The hp1 mutant expressed the highest rates of potential photosynthesis and also the content of total carotenoids. Aurea mutant maintained similar potential photosynthesis rates as the Micro-Tom cultivar, even containing low chlorophyll content, and expressed the highest content of nitrogen among all micro-tomatoes studied. Total soluble sugars were lower in aurea and hp1 mutants. The atv mutant expressed the highest content of chlorophylls and also the lowest rate of chlorophyll a/b.

  6. Physiological and biochemical responses of fruit exocarp of tomato (Lycopersicon esculentum Mill.) mutants to natural photo-oxidative conditions.

    Science.gov (United States)

    Torres, Carolina A; Andrews, Preston K; Davies, Neal M

    2006-01-01

    Photo-oxidative stress was imposed under natural solar radiation on exposed and shaded sections of detached fruit of immature green tomato (Lycopersicon esculentum Miller = Solanum lycopersicum L.) mutants (anthocyanin absent, beta-carotene, Delta, and high pigment-1) and their nearly isogenic parents ('Ailsa Craig' and 'Rutgers'). After 5 h exposure to high solar irradiance, either with or without ultraviolet (UV) radiation, surface colour changes, pigment composition, photosynthetic efficiency, antioxidant metabolites and enzyme activities, and selected flavonoids and antioxidant proteins in exocarp tissue were evaluated. The imposed photo-oxidative stress reproduced the symptoms observed on attached fruit. Both high temperature and solar irradiance caused fruit surface discoloration with faster degradation of chlorophyll (Chl) than carotenoids (Car), leading to an increase in the Car/Chl ratio. Surface bleaching was mostly caused by visible light, whereas elevated temperatures were mostly responsible for the inactivation of photosynthesis, measured as decreased F(v)/F(m). Ascorbate, glutathione, and total soluble protein concentrations decreased in the exocarp as the duration of exposure increased. Specific activities of superoxide dismutase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), and catalase increased with exposure, suggesting that these proteins were conserved during the imposed stress. GR protein expression remained stable during the imposed stress, whereas, MDHAR protein expression increased. Quercetin and kaempferol concentrations increased rapidly upon exposure, but not to UV radiation, suggesting rapid photo-protection in response to visible light; however, naringenin synthesis was not induced. The apparent increased tolerance of hp-1 fruit is discussed.

  7. Inheritance of fruit color and pigment changes in a yellow tomato (Lycopersicon esculentum Mill. mutant

    Directory of Open Access Journals (Sweden)

    Elizanilda R. do Rêgo

    1999-03-01

    Full Text Available A naturally occurring yellow tomato fruit mutant cv. Santa Clara was reciprocally crossed with the red wild type, after which F1 plants were self pollinated or backcrossed with both parents. Plants from F1 generations produced all fruits with a homogeneous deep red color when ripe. F2 plants showed a 3:1 red:yellow segregation of fruit color, and 100% red when backcrossed with red wild type or 1:1 red:yellow segregation in backcrosses with the yellow mutant; hence, yellow fruit color was determined by a recessive allele. Based on reciprocal crosses, fruit color is unlikely to be determined by maternal genes. Accumulation of lycopene dropped by 99.3% and b-carotene by 77% in ripe yellow fruits, compared to the red wild type. Leaf and flower chlorophyll and total carotenoid concentrations were not affected by the yellow mutation. However, the mutant fruit had a higher rate of chlorophyll degradation during fruit ripening, whilst fruit from the F1 generation showed lower rates of degradation, similar to that observed in red wild type fruits.Neste trabalho avaliou-se a herança da cor do fruto de um mutante natural da cv. Santa Clara, por meio da análise das gerações F1 e segregantes, obtidas mediante cruzamento entre plantas da cv. Santa Clara normal e o mutante amarelo. A caracterização das plantas normais, mutantes e F1 foi feita com base na análise quantitativa dos pigmentos carotenóides e clorofila em flores, folhas e frutos verdes e maduros. Plantas F1 e provenientes do retrocruzamento com o progenitor normal apresentaram 100% de frutos vermelhos. A semelhança entre os F1 recíprocos mostra que há ausência de herança materna para as características avaliadas. Em gerações segregantes, as freqüências observadas foram compatíveis com herança monogênica pelo teste qui-quadrado, com dominância completa para o gene que confere cor vermelha. Os frutos amarelos apresentaram teores reduzidos de b-caroteno e licopeno, enquanto o h

  8. EMMA—mouse mutant resources for the international scientific community

    Science.gov (United States)

    Wilkinson, Phil; Sengerova, Jitka; Matteoni, Raffaele; Chen, Chao-Kung; Soulat, Gaetan; Ureta-Vidal, Abel; Fessele, Sabine; Hagn, Michael; Massimi, Marzia; Pickford, Karen; Butler, Richard H.; Marschall, Susan; Mallon, Ann-Marie; Pickard, Amanda; Raspa, Marcello; Scavizzi, Ferdinando; Fray, Martin; Larrigaldie, Vanessa; Leyritz, Johan; Birney, Ewan; Tocchini-Valentini, Glauco P.; Brown, Steve; Herault, Yann; Montoliu, Lluis; de Angelis, Martin Hrabé; Smedley, Damian

    2010-01-01

    The laboratory mouse is the premier animal model for studying human disease and thousands of mutants have been identified or produced, most recently through gene-specific mutagenesis approaches. High throughput strategies by the International Knockout Mouse Consortium (IKMC) are producing mutants for all protein coding genes. Generating a knock-out line involves huge monetary and time costs so capture of both the data describing each mutant alongside archiving of the line for distribution to future researchers is critical. The European Mouse Mutant Archive (EMMA) is a leading international network infrastructure for archiving and worldwide provision of mouse mutant strains. It operates in collaboration with the other members of the Federation of International Mouse Resources (FIMRe), EMMA being the European component. Additionally EMMA is one of four repositories involved in the IKMC, and therefore the current figure of 1700 archived lines will rise markedly. The EMMA database gathers and curates extensive data on each line and presents it through a user-friendly website. A BioMart interface allows advanced searching including integrated querying with other resources e.g. Ensembl. Other resources are able to display EMMA data by accessing our Distributed Annotation System server. EMMA database access is publicly available at http://www.emmanet.org. PMID:19783817

  9. Callus formation and organogenesis of tomato (Lycopersicon ...

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... In vitro culture response was assessed in tomato (Lycopersicon esculentum Mill. c. v. Omdurman) for ... successful application of plant tissue culture presupposes the establishment of ..... Kino (Pterocarpus marsupium Roxb.) ...

  10. An internal ribosome entry site (IRES mutant library for tuning expression level of multiple genes in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Esther Y C Koh

    Full Text Available A set of mutated Encephalomyocarditis virus (EMCV internal ribosome entry site (IRES elements with varying strengths is generated by mutating the translation initiation codons of 10(th, 11(th, and 12(th AUG to non-AUG triplets. They are able to control the relative expression of multiple genes over a wide range in mammalian cells in both transient and stable transfections. The relative strength of each IRES mutant remains similar in different mammalian cell lines and is not gene specific. The expressed proteins have correct molecular weights. Optimization of light chain over heavy chain expression by these IRES mutants enhances monoclonal antibody expression level and quality in stable transfections. Uses of this set of IRES mutants can be extended to other applications such as synthetic biology, investigating interactions between proteins and its complexes, cell engineering, multi-subunit protein production, gene therapy, and reprogramming of somatic cells into stem cells.

  11. Isolation and characterisation of somatic hybrids between Lycopersicon esculentum and Lycopersicon peruvianum.

    NARCIS (Netherlands)

    Wijbrandi, J.

    1989-01-01

    Several desirable traits, such as disease resistances, have been introduced from more or less related wild Lycopersicon species, into the cultivated tomato, L.esculentum , by classical breeding techniques. Somatic hybridisation by protoplast fusion can enhance the germplasm pool available for tomato

  12. Determination of L-ascorbic acid in Lycopersicon fruits by capillary zone electrophoresis.

    Science.gov (United States)

    Galiana-Balaguer, L; Roselló, S; Herrero-Martínez, J M; Maquieira, A; Nuez, F

    2001-09-15

    This study shows an improved method for the determination of L-ascorbic acid (l-AA) in fruits of Lycopersicon by capillary zone electrophoresis (CZE). Two backgrounds electrolytes (BGEs) have been tested: (i) 400 mM borate at pH 8.0 and 1 x 10(-2)% hexadimethrine bromide, for the separation of Eulycopersicon subgenus species; and (ii) as in BGE(i) but supplemented with 20% (v/v) acetonitrile, for the separation of species of the Eriopersicon subgenus. The present procedures were compared with two routine methods-enzymatic assay and potentiometric titration with 2,6-dichlorophenol-indophenol. While these routine methods presented some difficulties in quantifying l-AA in several Lycopersicon fruits, CZE was successfully applied in all the analyzed samples. The proposed CZE protocols give lower detection limits (<0.4 microg ml(-1)); are cheaper, quicker, and highly reproducible; and can be applied to analyze large series of samples (ca. 50 samples per day) which is utmost importance, not only in screening trials for internal quality and tomato breeding programs, but also in systematic and routine characterization of Lycopersicon fruits.

  13. Gravity-dependent differentiation and root coils in Arabidopsis thaliana wild type and phospholipase-A-I knockdown mutant grown on the International Space Station.

    Science.gov (United States)

    Scherer, G F E; Pietrzyk, P

    2014-01-01

    Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. A major QTL introgressed from wild Lycopersicon hirsutum confers chilling tolerance to cultivated tomato (Lycopersicon esculentum).

    Science.gov (United States)

    John Goodstal, F; Kohler, Glenn R; Randall, Leslie B; Bloom, Arnold J; St Clair, Dina A

    2005-09-01

    Many plants of tropical or subtropical origin, such as tomato, suffer damage under chilling temperatures (under 10 degrees C but above 0 degrees C). An earlier study identified several quantitative trait loci (QTLs) for shoot turgor maintenance (stm) under root chilling in an interspecific backcross population derived from crossing chilling-susceptible cultivated tomato (Lycopersicon esculentum) and chilling-tolerant wild L. hirsutum. The QTL with the greatest phenotypic effect on stm was located in a 28 cM region on chromosome 9 (designated stm 9), and enhanced chilling-tolerance was conferred by the presence of the Lycopersicon hirsutum allele at this QTL. Here, near-isogenic lines (NILs) were used to verify the effect of stm 9, and recombinant sub-NILs were used to fine map its position. Replicated experiments were performed with NILs and sub-NILs in a refrigerated hydroponic tank in the greenhouse. Sub-NIL data was analyzed using least square means separations, marker-genotype mean t-tests, and composite interval mapping. A dominant QTL controlling shoot turgor maintenance under root chilling was confirmed on chromosome 9 using both NILs and sub-NILs. Furthermore, sub-NILs permitted localization of stm 9 to a 2.7 cM interval within the original 28 cM QTL region. If the presence of the L. hirsutum allele at stm 9 also confers chilling-tolerance in L. esculentum plants grown under field conditions, it has the potential to expand the geographic areas in which cultivated tomato can be grown for commercial production.

  15. Induction of streptomycin resistance in the wild tomato Lycopersicon peruvianum

    NARCIS (Netherlands)

    Jansen, C.E.; Snel, E.A.M.; Akerboom, M.J.E.; Nijkamp, H.J.J.; Hille, J.

    1990-01-01

    A protoplast mutagenesis and cell selection system was used for the isolation of streptomycin resistant Lycopersicon peruvianum colonies. Protoplasts were treated with the mutagen N-nitroso-methylurea and could be regenerated into fertile plants, carrying the streptomycin resistant character. Severa

  16. Chloroplast DNA evolution and phylogenetic relationships in Lycopersicon.

    Science.gov (United States)

    Palmer, J D; Zamir, D

    1982-08-01

    Chloroplast DNA was purified from 12 accessions that represent most of the species diversity in the genus Lycopersicon (family Solanaceae) and from 3 closely related species in the genus Solanum. Fragment patterns produced by digestion of these DNAs with 25 different restriction endonucleases were analyzed by agarose gel electrophoresis. In all 15 DNAs, a total of only 39 restriction site mutations were detected among 484 restriction sites surveyed, representing 2,800 base pairs of sequence information. This low rate of base sequence change is paralleled by an extremely low rate of convergent change in restriction sites; only 1 of the 39 mutations appears to have occurred independently in two different lineages. Parsimony analysis of shared mutations has allowed the construction of a maternal phylogeny for the 15 accessions. This phylogeny is generally consistent with relationships based on morphology and crossability but provides more detailed resolution at several places. All accessions within Lycopersicon form a coherent group, with two of the three species of Solanum as outside reference points. Chloroplast DNA analysis places S. pennellii firmly within Lycopersicon, confirming recent studies that have removed it from Solanum. Red-orange fruit color is shown to be a monophyletic trait in three species of Lycopersicon, including the cultivated tomato, L. esculentum. Analysis of six accessions within L. peruvianum reveals a limited amount of intraspecific polymorphism which, however, encompasses all the variation observed in L. chilense and L. chmielewskii. It is suggested that these latter two accessions be relegated to positions within the L. peruvianum complex.

  17. The inheritance of chilling tolerance in tomato (Lycopersicon spp).

    NARCIS (Netherlands)

    Venema, J.H.; Linger, P.; Heusden, van A.W.; Hasselt, van P.R.; Bruggemann, W.

    2005-01-01

    During the past 25 years, chilling tolerance of the cultivated (chilling-sensitive) tomato Lycopersicon esculentum and its wild, chilling-tolerant relatives L. peruvianum and L. hirsutum (and, less intensively studied, L. chilense) has been the object of several investigations. The final aim of thes

  18. Genetic differences in growth within and between Lycopersicon species

    NARCIS (Netherlands)

    Lindhout, Pim; Pet, Gerard; Jansen, Ritsert; Jansen, Hans

    1991-01-01

    Growth analyses were carried out on 88 accessions of five Lycopersicon species. Experiments were conducted in a climate room at 19/14°C day/night temperature which was irradiated at 20 W/m2 for eight hours per day. Large differences in plant weights between wild species and the cultivated tomato wer

  19. The inheritance of chilling tolerance in tomato (Lycopersicon spp.)

    NARCIS (Netherlands)

    Venema, JH; Linger, P; van Heusden, AW; van Hasselt, PR; Brueggemann, W

    2005-01-01

    During the past 25 years, chilling tolerance of the cultivated (chilling-sensitive) tomato Lycopersicon esculentum and its wild, chilling-tolerant relatives L. peruvianum and L. hirsutum (and, less intensively studied, L. chilense) has been the object of several investigations. The final aim of thes

  20. The lack of mitochondrial complex I in a CMSII mutant of Nicotiana sylvestris increases photorespiration through an increased internal resistance to CO2 diffusion.

    Science.gov (United States)

    Priault, P; Tcherkez, G; Cornic, G; De Paepe, R; Naik, R; Ghashghaie, J; Streb, P

    2006-01-01

    The cytoplasmic male sterile II (CMSII) mutant lacking complex I of the mitochondrial electron transport chain has a lower photosynthetic activity but exhibits higher rates of excess electron transport than the wild type (WT) when grown at high light intensity. In order to examine the cause of the lower photosynthetic activity and to determine whether excess electrons are consumed by photorespiration, light, and intercellular CO(2), molar fraction (c(i)) response curves of carbon assimilation were measured at varying oxygen molar fractions. While oxygen is the major acceptor for excess electrons in CMSII and WT leaves, electron flux to photorespiration is favoured in the mutant as compared with the WT leaves. Isotopic mass spectrometry measurements showed that leaf internal conductance to CO(2) diffusion (g(m)) in mutant leaves was half that of WT leaves, thus decreasing the c(c) and favouring photorespiration in the mutant. The specificity factor of Rubisco did not differ significantly between both types of leaves. Furthermore, carbon assimilation as a function of electrons used for carboxylation processes/electrons used for oxygenation processes (J(C)/J(O)) and as a function of the calculated chloroplastic CO(2) molar fraction (c(c)) values was similar in WT and mutant leaves. Enhanced rates of photorespiration also explain the consumption of excess electrons in CMSII plants and agreed with potential ATP consumption. Furthermore, the lower initial Rubisco activity in CMSII as compared with WT leaves resulted from the lower c(c) in ambient air, since initial Rubisco activity on the basis of equal c(c) values was similar in WT and mutant leaves. The retarded growth and the lower photosynthetic activity of the mutant were largely overcome when plants were grown in high CO(2) concentrations, showing that limiting CO(2) supply for photosynthesis was a major cause of the lower growth rate and photosynthetic activity in CMSII.

  1. Impaired recruitment of Grk6 and beta-Arrestin 2 causes delayed internalization and desensitization of a WHIM syndrome-associated CXCR4 mutant receptor.

    Directory of Open Access Journals (Sweden)

    Peter J McCormick

    Full Text Available WHIM (warts, hypogammaglobulinemia, infections, and myelokatexis syndrome is a rare immunodeficiency syndrome linked to heterozygous mutations of the chemokine receptor CXCR4 resulting in truncations of its cytoplasmic tail. Leukocytes from patients with WHIM syndrome display impaired CXCR4 internalization and enhanced chemotaxis in response to its unique ligand SDF-1/CXCL12, which likely contribute to the clinical manifestations. Here, we investigated the biochemical mechanisms underlying CXCR4 deficiency in WHIM syndrome. We report that after ligand activation, WHIM-associated mutant CXCR4 receptors lacking the carboxy-terminal 19 residues internalize and activate Erk 1/2 slower than wild-type (WT receptors, while utilizing the same trafficking endocytic pathway. Recruitment of beta-Arrestin 2, but not beta-Arrestin 1, to the active WHIM-mutant receptor is delayed compared to the WT CXCR4 receptor. In addition, while both kinases Grk3 and Grk6 bind to WT CXCR4 and are critical to its trafficking to the lysosomes, Grk6 fails to associate with the WHIM-mutant receptor whereas Grk3 associates normally. Since beta-Arrestins and Grks play critical roles in phosphorylation and internalization of agonist-activated G protein-coupled receptors, these results provide a molecular basis for CXCR4 dysfunction in WHIM syndrome.

  2. Impaired Recruitment of Grk6 and β-Arrestin2 Causes Delayed Internalization and Desensitization of a WHIM Syndrome-Associated CXCR4 Mutant Receptor

    Science.gov (United States)

    McCormick, Peter J.; Segarra, Marta; Gasperini, Paola; Gulino, A. Virginia; Tosato, Giovanna

    2009-01-01

    WHIM (warts, hypogammaglobulinemia, infections, and myelokatexis) syndrome is a rare immunodeficiency syndrome linked to heterozygous mutations of the chemokine receptor CXCR4 resulting in truncations of its cytoplasmic tail. Leukocytes from patients with WHIM syndrome display impaired CXCR4 internalization and enhanced chemotaxis in response to its unique ligand SDF-1/CXCL12, which likely contribute to the clinical manifestations. Here, we investigated the biochemical mechanisms underlying CXCR4 deficiency in WHIM syndrome. We report that after ligand activation, WHIM-associated mutant CXCR4 receptors lacking the carboxy-terminal 19 residues internalize and activate Erk 1/2 slower than wild-type (WT) receptors, while utilizing the same trafficking endocytic pathway. Recruitment of β-Arrestin 2, but not β-Arrestin 1, to the active WHIM-mutant receptor is delayed compared to the WT CXCR4 receptor. In addition, while both kinases Grk3 and Grk6 bind to WT CXCR4 and are critical to its trafficking to the lysosomes, Grk6 fails to associate with the WHIM-mutant receptor whereas Grk3 associates normally. Since β-Arrestins and Grks play critical roles in phosphorylation and internalization of agonist-activated G protein-coupled receptors, these results provide a molecular basis for CXCR4 dysfunction in WHIM syndrome. PMID:19956569

  3. Water relations of GA- and ABA-deficient tomato mutants during seed and fruit development and their influence on germination

    NARCIS (Netherlands)

    Liu, Y.; Bino, R.J.; Karssen, C.M.; Hilhorst, H.W.M.

    1996-01-01

    To explain the differing germination behaviour of seeds of wild type, gibberellin-deficient (gib1) or abscisic acid-deficient (sitw) mutants of tomato (Lycopersicon esculentum Mill. cv. Moneymaker), growth and water relations of fruit tissues, seeds and embryos were determined during development. Th

  4. Allelopathic potential of Asarum europaeum toward Lycopersicon esculentum

    Directory of Open Access Journals (Sweden)

    Monica MARIAN

    2011-05-01

    Full Text Available Asarum europaeum L. contains water-soluble substances which manifest allelopathic potential. Aqueous extracts from leaves and stems of Asarum europaeum were assayed to determine their allelopathic effects on Lycopersicon esculentum and Zea mays seeds germination and early seedling growth. The germination of the investigated seeds was found to be inhibited with increasing of the Asarum europaeum L. extract concentration. Moreover, the active substances extracted from leaves were found to be more inhibitory on the seeds germination in comparison with those extracted from stems.

  5. Genetics of Hybrid Incompatibility Between Lycopersicon esculentum and L. hirsutum

    Science.gov (United States)

    Moyle, Leonie C.; Graham, Elaine B.

    2005-01-01

    We examined the genetics of hybrid incompatibility between two closely related diploid hermaphroditic plant species. Using a set of near-isogenic lines (NILs) representing 85% of the genome of the wild species Lycopersicon hirsutum (Solanum habrochaites) in the genetic background of the cultivated tomato L. esculentum (S. lycopersicum), we found that hybrid pollen and seed infertility are each based on 5–11 QTL that individually reduce hybrid fitness by 36–90%. Seed infertility QTL act additively or recessively, consistent with findings in other systems where incompatibility loci have largely been recessive. Genetic lengths of introgressed chromosomal segments explain little of the variation for hybrid incompatibility among NILs, arguing against an infinitesimal model of hybrid incompatibility and reinforcing our inference of a limited number of discrete incompatibility factors between these species. In addition, male (pollen) and other (seed) incompatibility factors are roughly comparable in number. The latter two findings contrast strongly with data from Drosophila where hybrid incompatibility can be highly polygenic and complex, and male sterility evolves substantially faster than female sterility or hybrid inviability. The observed differences between Lycopersicon and Drosophila might be due to differences in sex determination system, reproductive and mating biology, and/or the prevalence of sexual interactions such as sexual selection. PMID:15466436

  6. Ex-vivo assessment and non-invasive in vivo imaging of internal hemorrhages in Aga2/+ mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Ermolayev, Vladimir [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Cohrs, Christian M. [Institute for Experimental Genetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Mohajerani, Pouyan; Ale, Angelique [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Hrabé de Angelis, Martin [Institute for Experimental Genetics, Helmholtz Zentrum München, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany); Ntziachristos, Vasilis, E-mail: v.ntziachristos@tum.de [Institute for Biological and Medical Imaging, Helmholtz Zentrum München, Building 56, Ingolstädter Landstraße 1, D-85764 Neuherberg (Germany)

    2013-03-08

    Highlights: ► Aga2/+ mice, model for Osteogenesis imperfecta, have type I collagen mutation. ► Aga2/+ mice display both moderate and severe phenotypes lethal 6–11th postnatal. ► Internal hemorrhages studied in Aga2/+ vs. control mice at 6 and 9 days postnatal. ► Anatomical and functional findings in-vivo contrasted to the ex-vivo appearance. -- Abstract: Mutations in type I collagen genes (COL1A1/2) typically lead to Osteogenesis imperfecta, the most common heritable cause of skeletal fractures and bone deformation in humans. Heterozygous Col1a1{sup Aga2/+}, animals with a dominant mutation in the terminal C-propeptide domain of type I collagen develop typical skeletal hallmarks and internal hemorrhages starting from 6 day after birth. The disease progression for Aga2/+ mice, however, is not uniform differing between severe phenotype lethal at the 6–11th day of life, and moderate-to-severe one with survival to adulthood. Herein we investigated whether a new modality that combines X-ray computer tomography with fluorescence tomography in one hybrid system can be employed to study internal bleedings in relation to bone fractures and obtain insights into disease progression. The disease phenotype was characterized on Aga2/+ vs. wild type mice between 6 and 9 days postnatal. Anatomical and functional findings obtained in-vivo were contrasted to the ex-vivo appearance of the same tissues under cryo-slicing.

  7. The vhs1 mutant form of herpes simplex virus virion host shutoff protein retains significant internal ribosome entry site-directed RNA cleavage activity.

    Science.gov (United States)

    Lu, P; Saffran, H A; Smiley, J R

    2001-01-01

    The virion host shutoff (vhs) protein of herpes simplex virus (HSV) triggers global shutoff of host protein synthesis and accelerated turnover of host and viral mRNAs during HSV infection. As well, it induces endoribonucleolytic cleavage of RNA substrates when produced in a rabbit reticulocyte lysate (RRL) in vitro translation system. The vhs1 point mutation (Thr 214-->Ile) eliminates vhs function during virus infection and in transiently transfected mammalian cells and was therefore previously considered to abolish vhs activity. Here we demonstrate that the vhs1 mutant protein induces readily detectable endoribonuclease activity on RNA substrates bearing the internal ribosome entry site of encephalomyocarditis virus in the RRL assay system. These data document that the vhs1 mutation does not eliminate catalytic activity and raise the possibility that the vhs-dependent endoribonuclease employs more than one mode of substrate recognition.

  8. Características fisiológicas de microtomateiros fitocromo-mutantes

    OpenAIRE

    Melo,Hyrandir Cabral de; Castro,Evaristo Mauro de; Soares,Ângela Maria; Oliveira,Cynthia de; Ramos,Sílvio Júnio

    2009-01-01

    Objetivou-se, neste trabalho, caracterizar aspectos fisiológicos de microtomateiros (Lycopersicon esculentum P. Miller cv. Micro-Tom) fitocromo-mutantes. A cultivar Micro-Tom e os mutantes aurea (deficiente na biossíntese do cromóforo dos fitocromos), atroviolacea (atv) e high pigment1 (hp1;ambos superexpressam eventos mediados por fitocromos) foram cultivados em condições controladas de luz e temperatura e caracterizados no estágio de floração. O mutante hp1 obteve as maiores taxas de fotoss...

  9. Tomato bushy stunt virus (TBSV) infecting Lycopersicon esculentum.

    Science.gov (United States)

    Hafez, El Sayed E; Saber, Ghada A; Fattouh, Faiza A

    2010-01-01

    Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-nm diameter particles, 41-kDa coat protein and the genome of approximately 4800 nt. This is the first TBSV isolate reported in Egypt. Cloning and partial sequencing of the isolate showed that it is more closely related to TBSV-P and TBSV-Ch than TBSV-Nf and TBSV-S strains of the virus. However, it is distinct from the above strains and could be a new strain of the virus which further confirms the genetic diversity of tombusviruses.

  10. Tomato ( Lycopersicon esculentum ) seeds: new flavonols and cytotoxic effect.

    Science.gov (United States)

    Ferreres, Federico; Taveira, Marcos; Pereira, David M; Valentão, Patrícia; Andrade, Paula B

    2010-03-10

    In this study, seeds of Lycopersicon esculentum Mill. were analyzed by HPLC/UV-PAD/MS(n)-ESI. Fourteen flavonoids were identified, including quercetin, kaempferol, and isorhamnetin derivatives, with 13 of them being reported for the first time in tomato seeds. The major identified compounds were quercetin-3-O-sophoroside, kaempferol-3-O-sophoroside, and isorhamnetin-3-O-sophoroside. A significant cell proliferation inhibition (>80%), against rat basophile leukemia (RBL-2H3) cell line, was observed with this extract (IC(50) = 5980 microg/mL). For acetylcholinesterase inhibitory activity, a concentration-dependent effect was verified (IC(20) = 2400 microg/mL). The same behavior was noted regarding antioxidant capacity, evaluated against DPPH (IC(10) = 284 microg/mL), nitric oxide (IC(25) = 396 microg/L), and superoxide radicals (IC(25) = 3 microg/mL).

  11. Ripening Physiology of Fruit from Transgenic Tomato (Lycopersicon esculentum) Plants with Reduced Ethylene Synthesis.

    Science.gov (United States)

    Klee, H. J.

    1993-07-01

    The physiological effects of reduced ethylene synthesis in a transgenic tomato (Lycopersicon esculentum) line expressing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme have been examined. Fruit from the transgenic line 5673 ripen significantly slower than control fruit when removed from the vine early in ripening. In contrast, fruit that remain attached to the plants ripen much more rapidly, exhibiting little delay relative to the control. Ethylene determinations on attached fruit revealed that there was significantly more internal ethylene in attached than detached fruit. The higher ethylene content can fully account for the observed faster on-the-vine ripening. All of the data are consistent with a catalytic role for ethylene in promoting many, although not all, aspects of fruit ripening. Biochemical analyses of transgenic fruit indicated no significant differences from controls in the levels of ACC oxidase or polygalacturonase. Because transgenic fruit are significantly firmer than controls, this last result indicates that other enzymes may have a significant role in fruit softening.

  12. Tomato ( Lycopersicon esculentum prevents lead-induced testicular toxicity

    Directory of Open Access Journals (Sweden)

    Emmanuel O Salawu

    2009-01-01

    Full Text Available Background: Lead, an example of heavy metals, has, for decades, being known for its adverse effects on various body organs and systems such that their functions are compromised. Aim: In the present study, the ability of lead to adversely affect the male reproductive system was investigated and tomato ( Lycopersicon esculentum : Source of antioxidants paste (TP was administered orally to prevent the adverse effects of Pb. Materials and Methods: Fifteen Sprague Dawley rats, randomised into three groups (n = 5, were used for this study. Animals in Group A served as the control and were drinking distilled water. Animals in Groups B and C were drinking 1% Pb (II acetate (LA. Group C animals were, in addition to drinking LA, treated with 1.5 ml of TP/day. All treatments were for 8 weeks. Statistical Analysis Used: A Mann-Whitney U -test was used to analyse the results obtained. Results: The obtained results showed that Pb caused a significant reduction in the testicular weight, sperm count, life-death ratio, sperm motility, normal sperm morphology, and plasma and tissue superoxide dismutase and catalase activity, but a significant increase in plasma and tissue malondialdehyde concentration. But, Pb did not cause any significant change in the serum testosterone level. TP, however, significantly reduced these adverse effects of Pb. Conclusion: These findings lead to the conclusion that TP significantly lowered the adverse effects of Pb exposure on the kidney as well as Pb-induced oxidative stress.

  13. Lycopersicon esculentum seeds: an industrial byproduct as an antimicrobial agent.

    Science.gov (United States)

    Taveira, Marcos; Silva, Luís R; Vale-Silva, Luís A; Pinto, Eugénia; Valentão, Patrícia; Ferreres, Federico; Guedes de Pinho, Paula; Andrade, Paula B

    2010-09-08

    Lycopersicon esculentum (tomato) fruit is a widely studied matrix. However, only few works focus their attention on its seeds, which constitute a major byproduct of the tomato processing industry. In this study the antimicrobial potential of ten different tomato seed extracts from "Bull's heart" and "Cherry" varieties were analyzed against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Enterococcus faecalis and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) bacteria and fungi (Candida albicans, Aspergillus fumigatus and Trichophyton rubrum). Regarding antibacterial capacity, the different extracts were revealed to be active only against Gram-positive bacteria, E. faecalis being the most susceptible one (MIC: 2.5-10 mg/mL). Concerning antifungal activity, "Bull's heart" extracts were the most active. In a general way C. albicans was the most susceptible species (MIC: 5-10 mg/mL). The chemical composition of the extracts was also pursued, concerning organic acids, phenolics and fatty acids, in order to establish a possible relationship with the observed antimicrobial effect.

  14. Effect of textile waste water on tomato plant, Lycopersicon esculentum.

    Science.gov (United States)

    Marwari, Richa; Khan, T I

    2012-09-01

    In this study Sanganer town, Jaipur was selected as study area. The plants of Lycopersicon esculentum var. K 21(Tomato) treated with 20 and 30% textile wastewater were analyzed for metal accumulation, growth and biochemical parameters at per, peak and post flowering stages. Findings of the study revealed that chlorophyll content was most severely affected with the increase in metal concentration. Total chlorophyll content showed a reduction of 72.44% while carbohydrate, protein and nitrogen content showed a reduction of 46.83, 71.65 and 71.65% respectively. With the increase in waste water treatment the root and shoot length, root and shoot dry weight and total dry weight were reduced to 50.55, 52.06, 69.93, 72.42, 72.10% respectively. After crop harvesting, the fruit samples of the plants treated with highest concentration of textile waste water contained 2.570 mg g(-1)d.wt. of Zn, 0.800 mg g(-1) d.wt. Cu, 1.520 mg g(-1) d.wt. Cr and 2.010 mg g(-1) d.wt. Pb.

  15. Desenvolvimento de protocolo para microenxertia do tomateiro Lycopersicon esculentum Mill = Developmental of protocol for micrograffiting to tomato Lycopersicon esculentum Mill

    Directory of Open Access Journals (Sweden)

    Luciano Façanha Marques

    2010-01-01

    Full Text Available A murcha bacteriana, causada por Ralstonia solanacearum, é a principal doença vascular de plantas em todo o mundo. O agente causal é uma bactéria que ocorre em todas as regiões do Brasil, predominando em condições de umidade e temperatura elevadas, fatores propícios aodesenvolvimento do patógeno. Este agente causal é de difícil controle, pois sobrevive nos mais diversos hospedeiros, especialmente Solanaceas, além de outras famílias de importância alimentar, condimentar e medicinal. O uso de espécies do gênero Solanum na enxertia convencional e minienxertia em tomateiro Lycopersicon esculentum é limitada em função da incompatibilidade. Neste trabalho, utilizou-se o método da microenxertia para obtenção de plantas resistentes a doenças como a murcha bacteriana, tendo como cavalo a espécie Solanum palinacanthum Dun. Utilizaram-se dois métodos de microenxertia: convencional em T-invertido e corte em bisel. Foram testados meios de culturas para execução das duas práticas demicropropagação; para isso, realizou-se experimento em diferentes condições ambientais, com presença e ausência de luminosidade e diferentes tratamentos correspondentes a teores de açúcares e sais, submetidos a cinco avaliações com intervalos semanais. Melhor resultado foi encontrado quando se utilizou microenxertia em T-invertido e meio de cultura constituído de sais de MS1/8 de força acrescido de 30 g L-1 de sacarose.The bacterial wilt, caused by Ralstonia solanacearum, is the most important vascular disease among plants in the world. The causal agent is a strain of bacteria found in all regions of Brazil, mainly in places with high humidity and temperature. This bacterium is difficult to control with chemical products, being able to survive in diverse hosts, especially in species of Solanaceae as well as other families of great food, condimental, or medicinal importance. The use of species of the genus Solanum has been attempted, but the

  16. Introgressions of Lycopersicon pennellii improve growth and development of greenhouse tomatoes

    NARCIS (Netherlands)

    Manga Owona, S.

    2005-01-01

    This thesis focused on the possibilities to improve greenhouse tomato (Lycopersicon esculentum cv. Moneymaker) in terms of yield. The domestic tomato has a very narrow genetic base which makes breeding for better performance a difficult task. The wild, crossable relatives of tomato present the possi

  17. Improvement of regeneration of Lycopersicon pennellii protoplasts by decreasing ethylene production

    NARCIS (Netherlands)

    Rethmeier, N.O.M.; Jansen, C.E.; Snel, E.A.M.; Nijkamp, H.J.J.; Hille, J.

    1991-01-01

    Lycopersicon pennellii shoots, cultured in vitro for more than a year (type I plants) produced few viable protoplasts in contrast to shoots cultured in vitro for less than five months (type II plants). Ethylene production of both plant types was compared. The low viability of plant type I protoplast

  18. Attenuated Lead Induced Apoptosis in Rat Hepatocytes in the Presence of Lycopersicon Esculentum

    Directory of Open Access Journals (Sweden)

    Hamidreza Ahmadi Ashtiani

    2016-05-01

    Full Text Available Lead (Pb, has, for decades, being known for its adverse effects on various body organs and systems. In the present study, the damage of Pb on the Liver tissue apoptosis was investigated, and Lycopersicon esculentum as an antioxidants source was administered orally to prevent the adverse effects of Pb. Eighteen Wistar rats, randomized into three groups (n=6, were used for this study. Animals in Group A served as the control and were drinking distilled water. Animals in Groups B and C were drinking 1%Lead acetate (LA. Group C animals were, in addition to drinking LA, treated with 1.5 ml/day of Lycopersicon esculentum. Treatments were for three months. The obtained results showed that lead acetate caused significant reductions in the liver weight, plasma and tissue superoxide dismutase and catalase activity, but a significant increase in plasma and tissue malondialdehyde concentration but Lycopersicon esculentum have an inhibitory effect on LA liver adverse effect. So, it can be concluded that Lycopersicon esculentum have a significant protective effect on liver lead acetate adverse effects as well as, lead acetate -induced oxidative stress.

  19. Exploring genetic variation in the tomato (Solanum section Lycopersicon) clade by whole-genome sequencing

    NARCIS (Netherlands)

    Aflitos, S.; Schijlen, E.; de Jong, H.; de Ridder, D.; Smit, S.; Finkers, R.; Wang, J.; Zhang, G.; Li, N.; Mao, L.; Bakker, F.; Dirks, R.; Breit, T.; Gravendeel, B.; Huits, H.; Struss, D.; Swanson-Wagner, R.; van Leeuwen, H.; van Ham, R.C.H.J.; Fito, L.; Guignier, L.; Sevilla, M.; Ellul, P.; Ganko, E.; Kapur, A.; Reclus, E.; de Geus, B.; van de Geest, H.; te Lintel Hekkert, B.; van Haarst, J.; Smits, L.; Koops, A.; Sanchez-Perez, G.; van Heusden, A.W.; Visser, R.; Quan, Z.; Min, J.; Liao, L.; Wang, X.; Wang, G.; Yue, Z.; Yang, X.; Xu, N.; Schranz, E.; Smets, E.; Vos, R.; Rauwerda, J.; Ursem, R.; Schuit, C.; Kerns, M.; van den Berg, J.; Vriezen, W.; Janssen, A.; Datema, E.; Jahrman, T.; Moquet, F.; Bonnet, J.; Peters, S.

    2014-01-01

    We explored genetic variation by sequencing a selection of 84 tomato accessions and related wild species representative of the Lycopersicon, Arcanum, Eriopersicon and Neolycopersicon groups, which has yielded a huge amount of precious data on sequence diversity in the tomato clade. Three new referen

  20. Introgressions of Lycopersicon pennellii improve growth and development of greenhouse tomatoes

    NARCIS (Netherlands)

    Manga Owona, S.

    2005-01-01

    This thesis focused on the possibilities to improve greenhouse tomato (Lycopersicon esculentum cv. Moneymaker) in terms of yield. The domestic tomato has a very narrow genetic base which makes breeding for better performance a difficult task. The wild, crossable relatives of tomato present the

  1. Developmental changes in antioxidant metabolites, enzymes, and pigments in fruit exocarp of four tomato (Lycopersicon esculentum Mill.) genotypes: beta-carotene, high pigment-1, ripening inhibitor, and 'Rutgers'.

    Science.gov (United States)

    Torres, C A; Andrews, P K

    2006-01-01

    In surface cell layers of fleshy fruit, antioxidants must limit photooxidative reactions that generate reactive oxygen species (ROS) in high light. Our objective was to measure changes in the concentrations of antioxidant metabolites and pigments, and the activities of enzymes of the Mehler-peroxidase, ascorbate-glutathione cycle in fruit exocarp tissue under non-stress conditions of the following fruit-specific tomato (Lycopersicon esculentum Mill.=Solanum lycopersicum) mutants and their parent: (1) beta-carotene (B), (2) high pigment (hp-1), (3) ripening inhibitor (rin), and (4) the nearly isogenic wild-type 'Rutgers'. Developmental variables included days after anthesis (DAA) and fruit surface color. The highest total ascorbic acid (AsA) concentration was in the exocarp of immature green fruit of hp-1, being 32% higher than 'Rutgers'. The hp-1 mutant also had the highest chlorophyll and total carotenoid concentrations, comprised mostly of lycopene in red ripe fruit; whereas, beta-carotene comprised 90% of the carotenoids in B. Although enzyme activities varied within genotype, they generally increased with development, then decreased as fruit maturity was reached, being coupled with AsA and glutathione (GSH) concentrations. In all mutants, dark-green (DG) exocarp had more chlorophyll and protein, higher concentrations of reduced AsA and GSH, and usually lower enzyme activities than light-green (LG) exocarp taken from the same fruit.

  2. Auxin physiology of the tomato mutant diageotropica

    Science.gov (United States)

    Daniel, S. G.; Rayle, D. L.; Cleland, R. E.

    1989-01-01

    The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

  3. [Bioaccumulation of cadmium and zinc in tomato (Lycopersicon esculentum L.)].

    Science.gov (United States)

    Sbartai, Hana; Djebar, Med Reda; Sbartai, Ibtissem; Berrabbah, Houria

    2012-09-01

    This work aims at evaluating the accumulation of cadmium (Cd) and zinc (Zn) (trace elements) in the organs of young tomato plants (Lycopersicon esculentum L. var. Rio Grande) and their effects on the rate of chlorophyll and enzyme activities involved in the antioxidant system: catalase (CAT), glutathion-S-transferase (GST) and peroxysase ascorbate (APX). Plants previously grown on a basic nutrient solution were undergoing treatment for 7 days, either by increasing concentrations of CdCl(2) or ZnSO(4) (0, 50, 100, 250, 500 μM) or by the combined concentrations of Cd and Zn (100/50, 100/100, 100/250, 100/500 μM). The results concerning the determination of metals in the various compartments of tomato plants as a function of increasing concentrations of Cd or Zn, suggest a greater accumulation of Cd and Zn in the roots compared to leaves. The combined treatment (Cd/Zn) interferes with the absorption of the two elements according to their concentrations in the culture medium. The presence of Zn at low concentrations (50 μM of Zn/100 μM Cd) has little influence on the accumulation of Cd in the roots and leaves, while the absorption of these two elements in the leaves increases and decreases in roots when their concentrations are equivalent (100/100 μM) compared to treatment alone. When the concentration of Zn is higher than that of Cd (500 μM of Zn/100 μM Cd) absorption of the latter is inhibited in the roots while increasing their translocation to the leaves. Meanwhile, the dosage of chlorophylls shows that they tend to decrease in a dose-dependent for both treatments (Cd or Cd/Zn), however, treatment with low concentrations of Zn (50 and 100 μM) stimulates chlorophyll synthesis. However, treatment with different concentrations of Cd seems to induce the activity of the enzymes studied (CAT, APX, GST). It is the same for treatment with different concentrations of Zn and this particularly for the highest concentrations. Finally, the combined treatment (Zn

  4. Somatic hybridization between Lycopersicon esculentum and Solanum tuberosum

    NARCIS (Netherlands)

    Schoenmakers, H.C.H.

    1993-01-01

    This thesis describes an analysis of the possibilities and limitations of asymmetric somatic hybridization between tomato and potato. For this, nitrate reductase-deficient tomato mutants were isolated and characterized. It was shown that two of these mutations could be used as selectable

  5. Características fisiológicas, anatômicas e ultra estruturais de micro-tomateiros fitocromo-mutantes

    OpenAIRE

    Melo,Hyrandir Cabral de

    2014-01-01

    O uso de microtomateiros fitocromo-mutantes é uma estratégia para o estudo do papel dos fitocromos sobre o desenvolvimento das plantas. O objetivo deste trabalho foi caracterizar aspectos fisiológicos, anatômicos e ultra-estruturais em microtomateiros (Lycopersicon esculentum cv. Micro-Tom) fitocromo-mutantes. A cultivar Micro-Tom (MT) e os mutantes aurea (subexpressa fitocromos), atroviolacea (atv) e hp1 (ambos superexpressam eventos mediados por fitocromos) foram cultivados em condições con...

  6. Crescimento e desenvolvimento de frutos do tomateiro 'Santa Clara' e do seu mutante natural 'Firme' Growth and development of 'Santa Clara' tomato fruit and its mutant 'Firme'

    Directory of Open Access Journals (Sweden)

    Marcia Lima Moura

    2004-12-01

    Full Text Available Na região produtora de hortaliças de Viçosa, MG, identificaram-se plantas de tomate da cv. Santa Clara (Lycopersicon esculentum Mill., que apresentam senescência foliar precoce e estigmas amarelados, com frutos de coloração "amarelo-creme" quando imaturos e vermelho quando maduros, de maturação lenta, e mais firmes que o fenótipo normal. Objetivou-se com este trabalho avaliar o crescimento e desenvolvimento dos frutos normais e mutantes. O delineamento experimental foi de blocos casualizados com quatro repetições. Os frutos mutantes apresentaram matéria fresca total e diâmetro transversal e longitudinal menores do que o normal durante todo o seu desenvolvimento. A espessura do pericarpo foi significativamente menor nos frutos mutantes do que nos frutos normais, a partir dos 21 dias após a antese. Folhas medianas e basais de plantas mutantes apresentaram menores teores de clorofila do que o observado em plantas normais. O período de amadurecimento do fruto mutante foi de 14 dias, enquanto dos frutos normais foi de 7 dias, quando ligados à planta-mãe, demonstrando a maior longevidade dos frutos mutantes. Além disso, os frutos mutantes apresentaram atraso na elevação da produção de etileno durante o amadurecimento.'Santa Clara' tomato (Lycopersicon esculentum Mill. plants showing earlier leaf senescence and yellowish stigma, fruits with pale yellow when immature and red when reach full ripe stage, associated to a lower rate of ripening and firmer than the wild type, were found in Viçosa, MG. The objective of this study was to evaluate the fruit growth and development of the mutant and wild type tomatoes. Mutant fruits showed smaller total fresh weight than wild type throughout development and thinner pericarp after 21 days after flowering. Basal and intermediate mutant plant leaves showed lower chlorophyll levels. 'Santa Clara' fruit took 7 days to reach full red ripe stage, while mutant fruits took 14 days. Furthermore

  7. Infection of Cultured Thin Cell Layer Roots of Lycopersicon esculentum by Meloidogyne incognita

    OpenAIRE

    Radin, D. N.; Eisenback, J. D.

    1991-01-01

    A new aseptic culture system for studying interactions between tomato (Lycopersicon esculentum) and Meloidogyne incognita is described. Epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on Murashige &Scoog medium plus kinetin and indole acetic acid. Rooted cultures were transferred to Gamborg's B-5 medium and inoculated with infective second-stage juveniles. Gall formation was apparent 5 days after inoculation and egg prod...

  8. Effect of acclimation to suboptimal temperature on chilling-induced photodamage : comparison between a domestic and a high-altitude wild Lycopersicon species

    NARCIS (Netherlands)

    Venema, JH; Villerius, L; van Hasselt, PR

    2000-01-01

    Plants of a domestic (Lycopersicon esculentum [L.] Mill. cv. Abunda) and a high-altitude wild Lycopersicon species (L. peruvianum Mill. LA 385) were grown at near-optimal (25/20 degrees C) or suboptimal (16/14 degrees C) temperature. Leaf discs from just fully expanded leaves were exposed to an

  9. Effect of acclimation to suboptimal temperature on chilling-induced photodamage : comparison between a domestic and a high-altitude wild Lycopersicon species

    NARCIS (Netherlands)

    Venema, JH; Villerius, L; van Hasselt, PR

    2000-01-01

    Plants of a domestic (Lycopersicon esculentum [L.] Mill. cv. Abunda) and a high-altitude wild Lycopersicon species (L. peruvianum Mill. LA 385) were grown at near-optimal (25/20 degrees C) or suboptimal (16/14 degrees C) temperature. Leaf discs from just fully expanded leaves were exposed to an irra

  10. A molecular linkage map of tomato displaying chromosomal locations of resistance gene analogs based on a Lycopersicon esculentum x Lycopersicon hirsutum cross.

    Science.gov (United States)

    Zhang, L P; Khan, A; Niño-Liu, D; Foolad, M R

    2002-02-01

    A molecular linkage map of tomato was constructed based on a BC1 population (N = 145) of a cross between Lycopersicon esculentum Mill. line NC84173 (maternal and recurrent parent) and Lycopersicon hirsutum Humb. and Bonpl. accession PI126445. NC84173 is an advanced breeding line that is resistant to several tomato diseases, not including early blight (EB) and late blight (LB). PI126445 is a self-incompatible accession that is resistant to many tomato diseases, including EB and LB. The map included 142 restriction fragment length polymorphism (RFLP) markers and 29 resistance gene analogs (RGAs). RGA loci were identified by PCR amplification of genomic DNA from the BC1 population, using ten pairs of degenerate oligonucleotide primers designed based on conserved leucine-rich repeat (LRR), nucleotide binding site (NBS), and serine (threonine) protein kinase (PtoKin) domains of known resistance genes (R genes). The PCR-amplified DNAs were separated by denaturing polyacrylamide gel electrophoresis (PAGE), which allowed separation of heterogeneous products and identification and mapping of individual RGA loci. The map spanned 1469 cM of the 12 tomato chromosomes with an average marker distance of 8.6 cM. The RGA loci were mapped to 9 of the 12 tomato chromosomes. Locations of some RGAs coincided with locations of several known tomato R genes or quantitative resistance loci (QRLs), including Cf-1, Cf-4, Cf-9, Cf-ECP2, rx-1, and Cm1.1 (chromosome 1); Tm-1 (chromosome 2); Asc (chrromosme 3); Pto, Fen, and Prf (chromosome 5); 01-1, Mi, Ty-1, Cm6.1, Cf-2, CF-5, Bw-5, and Bw-1 (chromosome 6); I-1, 1-3, and Ph-1 (chromosome 7); Tm-2a and Fr1 (chromosome 9); and Lv (chromosome 12). These co-localizations indicate that the RGA loci were either linked to or part of the known R genes. Furthermore, similar to that for many R gene families, several RGA loci were found in clusters, suggesting their potential evolutionary relationship with R genes. Comparisons of the present map with

  11. EVALUACIÓN DE LA TOLERANCIA AL CALOR A NIVEL DE PLANTA EN EL GERMOPLASMA DE TOMATE (Solanum L. sección Lycopersicon subsección Lycopersicon) CONSERVADO Ex Situ

    OpenAIRE

    Marilyn Florido; Marta Álvarez; Regla M. Lara; Dagmara Plana; Varela, M.; T. Shagarodsky; Moya, C.

    2009-01-01

    Este trabajo se desarrolló con el objetivo de evaluar la tolerancia al calor en una muestra representativa del germoplasma de tomate (Solanum L. sección Lycopersicon subsección Lycopersicon) conservado ex situ en las colecciones cubanas e identificar las accesiones más tolerantes para su empleo en los programas de mejoramiento genético. Para ello se evaluó el porcentaje de fructificación en los períodos óptimo y estresante (primavera-verano) del cultivo, para calcular los criterios de estrés ...

  12. RELACION ENTRE LA TERMOESTABILIDAD DE LA MEMBRANA, LA VIABILIDAD CELULAR Y LOS CRITERIOS DE TOLERANCIA EN LA EVALUACIÓN DE LA TOLERANCIA AL CALOR EN TOMATE (Solanum L. sección Lycopersicon subsección Lycopersicon)

    OpenAIRE

    Marilyn Florido Bacallao; Marta Álvarez Gil; Mario Varela Nualles; Regla M. Lara Rodríguez; Dagmara Plana Ramos; Tomás Shagarodsky Scull; Carlos Moya López

    2011-01-01

    El presente trabajo se desarrolló con el objetivo deconocer si existe variabilidad en cuanto a tolerancia al calor enuna muestra representativa del germoplasma de tomate (Solanum L. sección Lycopersicon subsección Lycopersicon) conservadoex situ en las colecciones cubanas e identificar las accesionesmás tolerantes para su empleo en los programas de mejoramiento genético. Para ello se calcularon los parámetros estadísticos:media, rango y coeficiente de variación de los caracterestermoestabilid...

  13. Mannosyl- and Xylosyl-Containing Glycans Promote Tomato (Lycopersicon esculentum Mill.) Fruit Ripening.

    Science.gov (United States)

    Priem, B; Gross, K C

    1992-01-01

    The oligosaccharide glycans mannosylalpha1-6(mannosylalpha1-3)mannosylalpha1-6(mannosylalpha1-3) mannosylbeta1-4-N-acetylglucosamine and mannosylalpha1-6(mannosylalpha1-3)(xylosylbeta1-2) mannosylbeta1-4-N-acetylglucosaminyl(fucosylalpha1-3) N-acetylglucosamine were infiltrated into mature green tomato fruit (Lycopersicon esculentum Mill., cv Rutgers). Coinfiltration of 1 nanogram per gram fresh weight of the glycans with 40 micrograms per gram fresh weight galactose, a level of galactose insufficient to promote ripening, stimulated ripening as measured by red coloration and ethylene production.

  14. Chemical analysis of a polysaccharide of unripe (green) tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Chandra, Krishnendu; Ghosh, Kaushik; Ojha, Arnab K; Islam, Syed S

    2009-11-02

    A polysaccharide (PS-I) isolated from the aqueous extract of the unripe (green) tomatoes (Lycopersicon esculentum) consists of D-galactose, D-methyl galacturonate, D-arabinose, L-arabinose, and L-rhamnose. Structural investigation of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments the structure of the repeating unit of the polysaccharide (PS-I) was established as: [structure: see text].

  15. Genealogy and fine mapping of obscuravenosa, a gene affecting the distribution of chloroplasts in leaf veins, and evidence of selection during breeding of tomatoes (Lycopersicon esculentum; Solanaceae).

    Science.gov (United States)

    Jones, Carl M; Rick, Charles M; Adams, Dawn; Jernstedt, Judy; Chetelat, Roger T

    2007-06-01

    In the processes of plant domestication and variety development, some traits are under direct selection, while others may be introduced by indirect selection or linkage. In the cultivated tomato (Lycopersicon esculentum = Solanum lycopersicum), and all other Solanaceae examined, chloroplasts are normally absent from subepidermal and mesophyll cells surrounding the leaf veins, and thus, veins appear clear upon subillumination. The tomato mutant obscuravenosa (obv), in contrast, contains chloroplasts in cells around the vein, and thus, veins appear as dark as the surrounding leaf tissue. Among tomato cultivars, the obv allele is common in processing varieties bred for mechanical harvest, but is otherwise rare. We traced the source of obv in processing tomatoes to the cultivar Earliana, released in the 1920s. The obv locus was mapped to chromosome 5, bin 5G, using introgression lines containing single chromosome segments from the wild species L. pennellii. This region also contains a quantitative trait locus (QTL) for plant height, pht5.4, which cosegregated with SP5G, a paralog of self-pruning (sp), the gene that controls the switch between determinate and indeterminate growth in tomato. The pht5.4 QTL was partially dominant and associated with a reduced percentage of red fruit at harvest. Our data suggest that the prevalence of obv in nearly all processing varieties may have resulted from its tight linkage to a QTL conferring a more compact, and horticulturally desirable, plant habit.

  16. A Temporarily Red Light-Insensitive Mutant of Tomato Lacks a Light-Stable, B-Like Phytochrome.

    Science.gov (United States)

    Van Tuinen, A.; Kerckhoffs, LHJ.; Nagatani, A.; Kendrick, R. E.; Koornneef, M.

    1995-07-01

    We have selected four recessive mutants in tomato (Lycopersicon esculentum Mill.) that, under continuous red light (R), have long hypocotyls and small cotyledons compared to wild type (WT), a phenotype typical of phytochrome B (phyB) mutants of other species. These mutants, which are allelic, are only insensitive to R during the first 2 days upon transition from darkness to R, and therefore we propose the gene symbol tri (temporarily red light insensitive). White light-grown mutant plants have a more elongated growth habit than that of the WT. An immunochemically and spectrophotometrically detectable phyB-like polypeptide detectable in the WT is absent or below detection limits in the tri1 mutant. In contrast to the absence of an elongation growth response to far-red light (FR) given at the end of the daily photoperiod (EODFR) in all phyB-deficient mutants so far characterized, the tri1 mutant responds to EODFR treatment. The tri1 mutant also shows a strong response to supplementary daytime far-red light. We propose that the phyB-like phytochrome deficient in the tri mutants plays a major role during de-etiolation and that other light-stable phytochromes can regulate the EODFR and shade-avoidance responses in tomato.

  17. Optothermal transient emission radiometry for studying the changes in epidermal hydration induced during ripening of tomato fruit mutants

    Science.gov (United States)

    Guo, X.; Bicanic, D.; Imhof, R.; Xiao, P.; Harbinson, J.

    2004-10-01

    Optothermal transient emission radiometry (OTTER) was used to determine the mean surface hydration and the hydration profile of three mutants (beefsteak, slicing and salad) of harvested tomatoes (Lycopersicon esculentum) that were kept under ambient conditions for as long as 51 days. Maximal sensitivity of OTTER to water in the samples was achieved by using 2.94 μm and 13.1 μm as excitation and emission wavelengths, respectively. The surface hydration increases rapidly and reaches a constant level during the remaining period. The hydrolysis of pectic substances that occur in tomatoes while ripening might be a possible cause for the observed change in hydration.

  18. Development of Bemisia tabaci (Gennadius,1889 biotype B on Lycopersicon spp. genotypes

    Directory of Open Access Journals (Sweden)

    Marilene Fancelli

    2002-01-01

    Full Text Available Whiteflies are phytophagous insects, whose nymphs and adults suck the phloem sap, causing direct damage due to host plant weakness. In tomato (Lycopersicon spp. crops, they are important vectors of limiting fitoviruses. The objective of this study was to determine the effects of Lycopersicon spp. genotypes on Bemisia tabaci (Gennadius, 1889 biotype B development under greenhouse conditions. The evaluated genotypes were LA462 (L. peruvianum, LA716 (L. pennellii, LA1584 (L. pimpinellifolium, LA1609 (L. peruvianum, LA1739 (L. hirsutum, P25 (L. esculentum, PI134417 (L. hirsutum f. glabratum and Santa Clara (L. esculentum. LA716 was non-preferred for oviposition by the whitefly, which suggests an antixenotic effect. LA1584 showed an antibiotic resistance because nymphal survival was reduced and nymphal developmental time was increased. Antixenotic resistance was observed in LA1739 and PI134417, based on a reduction of oviposition. PI134417 also reduced nymphal survival, which suggests an antibiotic effect, but LA1739 was suitable for insect development. LA1609 was highly preferred for oviposition, however it reduced insect survival. P25 and Santa Clara (L. esculentum were highly preferred for oviposition.

  19. Ozone sensitivity of currant tomato (Lycopersicon pimpinellifolium), a potential bioindicator species

    Energy Technology Data Exchange (ETDEWEB)

    Iriti, Marcello [Istituto di Patologia Vegetale, Universita di Milano, Via Celoria 2, 20133 Milan (Italy); Belli, Lucia [Istituto di Patologia Vegetale, Universita di Milano, Via Celoria 2, 20133 Milan (Italy); Nali, Cristina [Dipartimento di Coltivazione e Difesa delle Specie Legnose ' G. Scaramuzzi' , Universita di Pisa, Via del Borghetto 80, Pisa (Italy); Lorenzini, Giacomo [Dipartimento di Coltivazione e Difesa delle Specie Legnose ' G. Scaramuzzi' , Universita di Pisa, Via del Borghetto 80, Pisa (Italy); Gerosa, Giacomo [Dipartimento di Matematica e Fisica, Universita Cattolica del Sacro Cuore, Via Musei 41, 25121 Brescia (Italy); Faoro, Franco [CNR, Istituto di Virologia Vegetale, Sezione di Milano, Via Celoria, 2 20133 Milan (Italy)]. E-mail: f.faoro@ivv.cnr.it

    2006-05-15

    The wild tomato species Lycopersicon pimpinellifolium (currant tomato) was exposed to different O{sub 3} concentration, both in controlled environment fumigation facilities and in open-top chambers, to assess its sensitivity and to verify its potential as a bioindicator plant. Plants appeared particularly sensitive to O{sub 3} at an early stage of growth, responding with typical chlorotic spots within 24 h after exposure to a single pulse of 50 ppb for 3 h, and differentiating peculiar symptoms, such as reddish necrotic stipples, bronzing and extensive necrosis, depending on O{sub 3} concentration. Histo-cytochemical investigations with 3,3'-diaminobenzidine, to localize H{sub 2}O{sub 2}, and Evans blue, to detect dead cells, suggested that currant tomato sensitivity to O{sub 3} could be due to a deficiency in the anti-oxidant pools. The combination of these stainings proved to be useful, either to predict visible symptoms, early before their appearance, and to validate leaf ozone injury. - Currant tomato (Lycopersicon pimpinellifolium) was found to be very sensitive to ozone.

  20. Phenotypic response of Lycopersicon chilense to water deficit Respuesta fenotípica de Lycopersicon chilense al deficit hídrico

    Directory of Open Access Journals (Sweden)

    CARLOS MALDONADO

    2003-03-01

    Full Text Available ABSTRACT Environmental-induced phenotypic variation in plants is often considered to be a functional response that maximizes fitness in heterogeneous environments. Lycopersicon chilense, a tomato species endemic to Atacama Desert, shows altitudinal phenotypics variations in their natural environments, which could be due to different soil water availabilities. It is hypothesized that (a seeds coming from populations of different environments, cultivated in the same environment, will have similar phenotypes, if populations are not genetically differentiated, and that (b the different populations subjected to two drought levels should vary their phenotypic constitution with respect to the control groups. The responses of twenty phenotypic traits to different irrigation levels were studied in nine wild populations of Lycopersicon chilense. Seeds were collected from populations along an altitudinal gradient (from 20 m to 3,075 m, transferred to a common environment and grown under three soil water conditions: low (80 % FC, moderate (40 % FC and severe (20 % FC. In spite of the climatic differences in their natural habitat the phenotypic responses of plants growing in the same environment was similar in the nine populations. Significant differences among populations were only observed in three out of twenty traits (fruit fresh weight, fruit volume and number of seeds per fruit. Soil water deficit induced a phenotypic response in twelve characters; among these: root dry weight, cover, number of seeting fruits and number of seeds per fruit showed the highest significance. An interaction between population and drought treatment was found only for fresh weight of fruits, fruit volume and number of seeds per fruit. Our data indicate that the phenotypic response does not differ among populations growing under similar environmental conditions. Probably the phenotypic response of L. chilense in their natural habitats is related to physiological and metabolic

  1. 5alpha-Reductase activity in Lycopersicon esculentum: cloning and functional characterization of LeDET2 and evidence of the presence of two isoenzymes.

    Science.gov (United States)

    Rosati, Fabiana; Bardazzi, Irene; De Blasi, Paola; Simi, Lisa; Scarpi, Dina; Guarna, Antonio; Serio, Mario; Racchi, Milvia L; Danza, Giovanna

    2005-08-01

    The full-length cDNA (LeDET2) encoding a 257 amino acid protein homolog of Arabidopsis DET2 (AtDET2) was isolated in tomato (Lycopersicon esculentum). LeDET2 has 76% similarity with AtDET2 and structural characteristics conserved among plant and mammalian steroid 5alpha-reductases (5alphaRs). LeDET2 is ubiquitously expressed in tomato tissues with higher levels in leaf than in stem, root, seed and callus. When expressed in mammalian cells (COS-7), recombinant LeDET2 was active on substrates typical of mammalian 5alphaRs (progesterone, testosterone, androstenedione), but reduced at very low levels campestenone, the substrate described for AtDET2. Similar results were obtained with the expression in COS-7 of recombinant AtDET2 that showed 5alphaR activity for progesterone and not for campestenone. Recombinant LeDET2 was inhibited by several inhibitors of the human 5alphaRs and the application of an active inhibitor to tomato seedlings induced dwarfism and morphological changes similar to BR-deficient mutants. In tomato tissues, campestenone was 5alpha-reduced in leaf, stem and root homogenates, like progesterone and testosterone, while androstenedione was converted to testosterone, evidencing for the first time a 17beta-hydroxysteroid dehydrogenase activity in plants. Moreover, two separate 5alphaR activities with different kinetic characteristic and response to inhibitors were characterized in tomato tissues. The presence of two 5alphaR isoenzymes was demonstrated also in Arabidopsis using the det2-1 mutant, in which a residual 5alphaR activity for campestenone and progesterone was evidenced and characterized. Therefore, the existence of two isoenzymes of 5alphaR is probably characteristic of the whole plant kingdom highlighting the similarities between the animal and plant steroid biosynthetic pathways.

  2. Impact of suboptimal temperature on growth, photosynthesis, leaf pigments and carbohydrates of domestic and high-altitude wild Lycopersicon species

    NARCIS (Netherlands)

    Venema, J.H.; Posthumus, F.S; van Hasselt, P.R

    1999-01-01

    The impact of near-optimal (25/20 degrees C) and suboptimal (16/14 degrees C) day/night temperatures on growth, photosynthesis, pigment composition and carbohydrate content was compared between domestic and high-altitude wild Lycopersicon species. When related to the relative shoot growth rate

  3. Activation of the cell cycle in tomato (Lycopersicon esculentum Mill.) seeds during osmoconditioning as related to temperature and oxygen

    NARCIS (Netherlands)

    Ozbingöl, N.; Corbineau, F.; Groot, S.P.C.; Bino, R.J.; Côme, D.

    1999-01-01

    Using flow cytometric analyses of the nuclear DNA content, we studied the effects of various conditions of osmopriming on the activation of the cell cycle in embryo root tips of tomato (Lycopersicon esculentum‘Elko’) seeds. In dry untreated seeds, 90.7% of the nuclei revealed 2C signals. Priming of

  4. Nitrogen Requirements for Growth and Early Fruit Development of Drip-Irrigated Processing Tomato (Lycopersicon esculentum Mill.) in Portugal

    Science.gov (United States)

    The effect of continuous application of small quantities of nitrogen (N) in irrigation water and N applied as starter on growth and development of processing tomato (Lycopersicon esculentum Mill.), from transplanting to beginning of fruit set, was studied in two experiments: a pot experiment and a f...

  5. Impact of suboptimal temperature on growth, photosynthesis, leaf pigments and carbohydrates of domestic and high-altitude wild Lycopersicon species

    NARCIS (Netherlands)

    Venema, J.H.; Posthumus, F.S; van Hasselt, P.R

    1999-01-01

    The impact of near-optimal (25/20 degrees C) and suboptimal (16/14 degrees C) day/night temperatures on growth, photosynthesis, pigment composition and carbohydrate content was compared between domestic and high-altitude wild Lycopersicon species. When related to the relative shoot growth rate (RSGR

  6. Activation of the cell cycle in tomato (Lycopersicon esculentum Mill.) seeds during osmoconditioning as related to temperature and oxygen

    NARCIS (Netherlands)

    Ozbingöl, N.; Corbineau, F.; Groot, S.P.C.; Bino, R.J.; Côme, D.

    1999-01-01

    Using flow cytometric analyses of the nuclear DNA content, we studied the effects of various conditions of osmopriming on the activation of the cell cycle in embryo root tips of tomato (Lycopersicon esculentum‘Elko’) seeds. In dry untreated seeds, 90.7% of the nuclei revealed 2C signals. Priming of

  7. Induction of volatile organic compound in the leaves of Lycopersicon esculentum by chitosan oligomer

    Institute of Scientific and Technical Information of China (English)

    He Peiqing; Lin Xuezheng; Shen Jihong; Huang Xiaohang; Chen Kaoshan; Li Guangyou

    2005-01-01

    Induction of VOCs (volatile organic compounds) in the leaves of Lycopersicon esculentum by chitosan oligomer elictor was studied. The results demonstrated that VOCs in chitosan oligomer-treated leaves showed stronger inhibitory activity against Botrytis cinerea than that in water-treated leaves, and the spore germination was reduced by 22.1% in 144h after elicitor treatment at a concentration of 1.0%. A total of 16 constituents were detected in water-treated leaves, and chitosan oligomer treatment increased the amount of VOCs production. Chitosan oligomer at different concentration and different time courses of induction treatment could induce different amount of VOCs. Chitosan oligomer resulted in an optimal production of VOCs in 144h after elicitation at concentration of 0.6%. Chitosan oligomer also enhanced activtity of PAL and LOX. The results showed that the enhancement of VOCs production after chitosan oligomer treatment might be an important agent for L.esculentum acquiring resistance against pathogen.

  8. Amino acid sequences of heterotrophic and photosynthetic ferredoxins from the tomato plant (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Kamide, K; Sakai, H; Aoki, K; Sanada, Y; Wada, K; Green, L S; Yee, B C; Buchanan, B B

    1995-11-01

    Several forms (isoproteins) of ferredoxin in roots, leaves, and green and red pericarps in tomato plants (Lycopersicon esculentum Mill.) were earlier identified on the basis of N-terminal amino acid sequence and chromatographic behavior (Green et al. 1991). In the present study, a large scale preparation made possible determination of the full length amino acid sequence of the two ferredoxins from leaves. The ferredoxins characteristic of fruit and root were sequenced from the amino terminus to the 30th residue or beyond. The leaf ferredoxins were confirmed to be expressed in pericarp of both green and red fruit. The ferredoxins characteristic of fruit and root appeared to be restricted to those tissue. The results extend earlier findings in demonstrating that ferredoxin occurs in the major organs of the tomato plant where it appears to function irrespective of photosynthetic competence.

  9. Infection of Cultured Thin Cell Layer Roots of Lycopersicon esculentum by Meloidogyne incognita.

    Science.gov (United States)

    Radin, D N; Eisenback, J D

    1991-10-01

    A new aseptic culture system for studying interactions between tomato (Lycopersicon esculentum) and Meloidogyne incognita is described. Epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on Murashige &Scoog medium plus kinetin and indole acetic acid. Rooted cultures were transferred to Gamborg's B-5 medium and inoculated with infective second-stage juveniles. Gall formation was apparent 5 days after inoculation and egg production by mature females occurred within 25 days at 25 C in the susceptible genotypes Rutgers and Red Alert. Resistant genotypes LA655, LA656, and LA1022 exhibited a characteristic hypersensitive response. This system provides large numbers of cultured root tips for studies on the molecular basis of the host-parasite relationship.

  10. Introgression of High Yield Genes from Lycopersicon hirsutum acc. LA1777 Using CAPS Marker

    Institute of Scientific and Technical Information of China (English)

    LI Hong; WANG Xiao-xuan; SONG Ming; GAO Jian-chang; GUO Yan-mei; ZHU De-wei; DAI Shan-shu; DU Yong-chen

    2007-01-01

    The idea behind this study is to show that using high yield genes from a wild tomato can enrich tomato breeding resources and accelerate tomato breeding programs. In this study, the near-isogenic line TA1229 containing a 24-cM introgression at the bottom of chromosome 1 from Lycopersicon acc. LA1777, affects several higher yield traits. The TA1229 × 9706 BC1population was analyzed by marker-assisted selection and the traits of the population were evaluated. Twenty-three recombinant individuals that carried a shorter segment than TA1229 were obtained. Among them, 16 lines with the chromosome 1 recombinant segment can increase tomato yield and a QTL affecting yield was found between TG53 and TG158. Sixteen recombinant lines are useful to improve the tomato variety.

  11. Acetylcholine causes rooting in leaf explants of in vitro raised tomato (Lycopersicon esculentum Miller) seedlings.

    Science.gov (United States)

    Bamel, Kiran; Gupta, Shrish Chandra; Gupta, Rajendra

    2007-05-30

    The animal neurotransmitter acetylcholine (ACh) induces rooting and promotes secondary root formation in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby), cultured in vitro on Murashige and Skoog's medium. The roots originate from the midrib of leaf explants and resemble taproot. ACh at 10(-5) M was found to be the optimum over a wide range of effective concentrations between 10(-7) and 10(-3) M. The breakdown products, choline and acetate were ineffective even at 10(-3) M concentration. ACh appears to have a natural role in tomato rhizogenesis because exogenous application of neostigmine, an inhibitor of ACh hydrolysis, could mimic the effect of ACh. Neostigmine, if applied in combination with ACh, potentiated the ACh effect.

  12. INTENSIDAD DE LOS SABORES BÁSICOS DEL TOMATE (Lycopersicon esculentum EN SEIS ESTADOS DE MADUREZ INTENSITY OF BASIC TASTES OF TOMATO (Lycopersicon esculentum IN SIX MATURITY STAGES

    Directory of Open Access Journals (Sweden)

    KATHERIN CASTRO

    2009-06-01

    Full Text Available El tomate (Lycopersicon esculentum, la hortaliza más sembrada en Colombia, es considerada una de las más importantes por su volumen de producción y demanda. La exigencia del consumidor en sus características organolépticas hace necesario un estudio detallado acerca de sus propiedades fisicoquímicas y sensoriales. El análisis sensorial se realizó con un panel entrenado de cinco jueces y las muestras de tomate fueron escogidas de acuerdo con parámetros físicos de color (Cuadro 1 y calidad en los seis estados de madurez del fruto. Se empleó el método de perfil descriptivo, con una escala de respuesta de 0 a 10 puntos, con el fin de cuantificar la intensidad de los sabores básicos (dulce, ácido, amargo, salado y umami. Se realizó un diseño aleatorizado en bloques con seis réplicas por cada tratamiento y un nivel de significancia del 5%. Este indicó la inexistencia de diferencias significativas en las intensidades para cada estado de madurez (p≤ 0,05, y la existencia de diferencias significativas en las intensidades para cada sabor básico evaluado (p>0,05. Mediante el perfil sensorial, se logró establecer que en los estados de madurez 1 y 2, el atributo de mayor intensidad fue el ácido, en los estados de madurez 3, 4 y 5, el atributo que sobresalió fue el dulce y en el estado 6, el atributo percibido en mayor grado fue el umami. Los sabores amargo y salado, se percibieron en una baja intensidad, en los diferentes estados de madurez.The tomato (Lycopersicon esculentum, the vegetable more seeding in the country, is considered one of most important by its volume of production and demand. The exigency of the consumer in sensory characteristics makes necessary a detailed study about its physicochemistry and sensory properties. The sensory analysis was made with a trained panel of five judges and the tomato samples were chosen according to parameters of color and quality in the six ripeness stages of the fruit. Was made using the

  13. Multivariate analysis as a tool for measuring the stability of morphometric traits in Lycopersicon plants from in vitro culture

    Directory of Open Access Journals (Sweden)

    Pratta Guillermo

    2000-01-01

    Full Text Available The phenotypic stability of morphometric traits in Lycopersicon spp. (stem perimeter at the base, middle and top, and number of flowers per cluster was measured by multivariate analysis through a progeny test in order to estimate the genetic stability of these traits. Principal components were calculated for two groups of Lycopersicon spp., non-regenerated plants and the progeny of regenerated plants. Analysis of variance was performed to support principal component analysis. Both groups presented similar eigenvalues and eigenvectors, while no significant differences were found between any of the traits studied. These results indicated that the phenotypic structure was the same among the progeny of regenerated and non-regenerated plants, so that no variation would occur in in vitro culture. Multivariate analysis proved to be an appropriate methodology for the measurement of the stability of morphometric traits after one regeneration cycle.

  14. Effects of Crop Development on the Emission of Volatiles in Leaves of Lycopersicon esculentum and Its Inhibitory Activity to Botrytis cinerea and Fusarium oxysporum

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Volatiles emitted from the leaves of Lycopersicon esculentum at the two-, ten-leaf and anthesis periods were collected by a gas absorbing method and analyzed by gas chromatography (GC)-mass spectrometry. In total, 33 compounds of volatiles emitted from three developmental stage plants were separated and identified, and quantitatively analyzed by the internal standard addition method. All of the samples of volatile were found to be rich in monoterpenes and sesquiterpenes.β-phellandrene and caryophyllene predominated in the volatiles of the leaves of plants at the two- and ten-leaf stages.Furthermore, (E)-2-hexenal were the dominant components in the volatiles emitted from anthesis plants. The results of volatiles analyzed show that the compositions varied depending on the developmental stages. The volatiles emitted from crushed tomato leaves of plants at the anthesis stage had the most strongly inhibitory activity against the spore germination and hyphal growth of Botrytis cinerea and Fusarium oxysporum, followed by ten- and two-leaf plants. However, the activity of volatiles, emitted from the leaves of plants at the two-leaf stage, in inhibiting F. oxysporum was greater than B. cinerea.

  15. Caracterización y evaluación de recursos genéticos del genero Lycopersicon

    OpenAIRE

    Vallejo Cabrera Franco Alirio; Sierra Tulio Alberto; Osorio Erika Rocío

    1993-01-01

    Mediante los descriptores de IBPGR se caracterizaron y evaluaron 118 introducciones del género Lycopersicon, en el Centro Experimental de la Universidad Nacional Sede Palmira. Se utilizó el diseño experimental de Bloques al azar con dos repeticiones; la parcela experimental estuvo constituida por seis plantas. Se estudiaron nueve caracteres relacionados con la planta, diez caracteres relacionados con el fruto, componentes del rendimiento y presencia o ausencia de plagas y enfermedade...

  16. Reduced arbuscular mycorrhizal colonization in tomato ethylene mutants Reduzida formação de micorrízas arbusculares em tomateiros mutantes em etileno

    Directory of Open Access Journals (Sweden)

    Agustin Zsögön

    2008-01-01

    Full Text Available Plant hormones are likely key regulators of arbuscular mycorrhizae (AM development. However, their roles in AM are not well known. Here mutants in five hormone classes introgressed in a single tomato (Lycopersicon esculentum Mill. Syn Solanum lycopersicum L. background (cv. Micro-Tom were used to determine their effects on AM development and the expression of defense-related genes (chitinases and b-1,3-glucanases in roots. Under low P conditions, mutant epinastic (epi and Never ripe (Nr, ethylene overproducer and low sensitivity, respectively, had the intraradical colonization by Glomus clarum highly inhibited, as compared to the control Micro-Tom (MT. No significant alterations in fungal colonization were observed in mutants affecting other hormone classes. Under low P conditions, the steady state levels of transcripts encoding a class I basic chitinase (chi9 were higher in mycorrhizal epi and Nr mutant roots as compared to MT controls. In contrast the steady state levels of a class III acidic b-1,3-glucanase (TomPR-Q'a transcripts in mycorrhizal epi mutant roots were significantly lower than in mycorrhizal MT roots. Root colonization in epi mutants was accompanied by several alterations in fungal morphology, as compared to root colonization in MT controls. The data suggest that ethylene may play an important role in controlling intraradical arbuscular mycorrhizal fungal growth.Os hormônios vegetais são possíveis reguladores chave do desenvolvimento de micorrizas arbusculares (MAS. Contudo, seus papéis em MA são pouco conhecidos. No presente estudo, foram utilizados mutantes em cinco classes hormonais introgredidos em uma única cultivar (cv. Micro-Tom de tomateiro (Lycopersicon esculentum Mill. Syn Solanum lycopersicum L. para determinar seus efeitos no desenvolvimento de MA e expressão de genes relacionados à defesa (quitinases e b-1,3-glucanases em raízes. Sob condição de baixo P, os mutantes epinastic (epi e Never ripe (Nr, os

  17. Natural variation in the Pto pathogen resistance gene within species of wild tomato (Lycopersicon). I. Functional analysis of Pto alleles.

    Science.gov (United States)

    Rose, Laura E; Langley, Charles H; Bernal, Adriana J; Michelmore, Richard W

    2005-09-01

    Disease resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) in the cultivated tomato, Lycopersicon esculentum, and the closely related L. pimpinellifolium is triggered by the physical interaction between plant disease resistance protein, Pto, and the pathogen avirulence protein, AvrPto. To investigate the extent to which variation in the Pto gene is responsible for naturally occurring variation in resistance to Pst, we determined the resistance phenotype of 51 accessions from seven species of Lycopersicon to isogenic strains of Pst differing in the presence of avrPto. One-third of the plants displayed resistance specifically when the pathogen expressed AvrPto, consistent with a gene-for-gene interaction. To test whether this resistance in these species was conferred specifically by the Pto gene, alleles of Pto were amplified and sequenced from 49 individuals and a subset (16) of these alleles was tested in planta using Agrobacterium-mediated transient assays. Eleven alleles conferred a hypersensitive resistance response (HR) in the presence of AvrPto, while 5 did not. Ten amino acid substitutions associated with the absence of AvrPto recognition and HR were identified, none of which had been identified in previous structure-function studies. Additionally, 3 alleles encoding putative pseudogenes of Pto were isolated from two species of Lycopersicon. Therefore, a large proportion, but not all, of the natural variation in the reaction to strains of Pst expressing AvrPto can be attributed to sequence variation in the Pto gene.

  18. Natural variation in the Pto disease resistance gene within species of wild tomato (Lycopersicon). II. Population genetics of Pto.

    Science.gov (United States)

    Rose, Laura E; Michelmore, Richard W; Langley, Charles H

    2007-03-01

    Disease resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) in the host species Lycopersicon esculentum, the cultivated tomato, and the closely related L. pimpinellifolium is triggered by the physical interaction between the protein products of the host resistance (R) gene Pto and the pathogen avirulence genes AvrPto and AvrPtoB. Sequence variation at the Pto locus was surveyed in natural populations of seven species of Lycopersicon to test hypotheses of host-parasite coevolution and functional adaptation of the Pto gene. Pto shows significantly higher nonsynonymous polymorphism than 14 other non-R-gene loci in the same samples of Lycopersicon species, while showing no difference in synonymous polymorphism, suggesting that the maintenance of amino acid polymorphism at this locus is mediated by pathogen selection. Also, a larger proportion of ancestral variation is maintained at Pto as compared to these non-R-gene loci. The frequency spectrum of amino acid polymorphisms known to negatively affect Pto function is skewed toward low frequency compared to amino acid polymorphisms that do not affect function or silent polymorphisms. Therefore, the evolution of Pto appears to be influenced by a mixture of both purifying and balancing selection.

  19. Effect of Sodium Chloride on Fruit Ripening of the Nonripening Tomato Mutants nor and rin.

    Science.gov (United States)

    Mizrahi, Y; Zohar, R; Malis-Arad, S

    1982-02-01

    Tomato (Lycopersicon esculentum Mill) plants of the nonripening mutant nor, the ripening-inhibited mutant rin, and the normal cultivar ;Rutgers' were grown in nutrient solution supplemented with 3 grams per liter NaCl from the time of anthesis. In plants treated with NaCl, all the ripening parameters of the fruits of the nor mutant increased, but those of the rin mutant did not. The ripening of the fruits of the NaCl-treated nor plants was characterized by the development of a red color and taste, increased pectolytic activity, and increased evolution of CO(2) and ethylene. These changes do not normally take place in nor under control conditions. The values of these ripening parameters in nor were lower than those of the normal Rutgers fruits. In addition, both in nor and rin and in the normal variety, exposure of the plants to NaCl shortened the developmental period of the fruit, decreased the fruit size, and increased the concentrations of total soluble solids, Na(+), Cl(-), reducing sugars, and titratable acids in the fruit. The role of NaCl in overcoming the inability of nor to ripen is discussed.

  20. Characteristics of fruit ripening in tomato mutant epi

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-feng; YING Tie-jin; BAO Bi-li; HUANG Xiao-dan

    2005-01-01

    The characteristics of fruit ripening and expression of ripening-related genes were investigated in epi, an ethylene overproduction mutant of tomato (Lycopersicon esculentum Mill.). The epi produces apparently more ethylene than its wild type VFN8 at every stage of vegetative and fruit growth and ripening; compared to VFN8, the epi fruit showed higher CO2 evolution,faster descending of chlorophyll, slightly quicker increase of carotenoid and lycopene, and faster reduction in pericarp firmness during maturation and ripening; and the mRNAs of three ripening-related genes including E8, pTOM5 andpTOM6 were at higher levels in epi. The ripening-related characteristics changing of the fruit are consistent with the increase of ethylene production and ripening-related genes expression. These results suggest that epi mutation possibly did not affect the ethylene perception and signaling during fruit ripening, and that the modified characteristics of fruit ripening possibly resulted from the ethylene overproduction and increased expression of ripening-related genes.

  1. Allergenicity assessment of genetically modified cucumber mosaic virus (CMV) resistant tomato (Solanum lycopersicon).

    Science.gov (United States)

    Lin, Chih-Hui; Sheu, Fuu; Lin, Hsin-Tang; Pan, Tzu-Ming

    2010-02-24

    Cucumber mosaic virus (CMV) has been identified as the causal agent of several disease epidemics in most countries of the world. Insect-mediated virus diseases, such as those caused by CMV, caused remarkable loss of tomato (Solanum lycopersicon) production in Taiwan. With expression of the CMV coat protein gene (Cmvcp) in a local popular tomato cultivar L4783, transgenic tomato line R8 has showed consistent CMV resistance through T(0) to T(8). In this report, the allergenicity of the CMV coat protein (CMV cp) expressed in transgenic tomato R8 was assessed by investigation of the expression of the transgene source of protein, sequence similarity with known allergens, and resistance to pepsin hydrolysis. There is no known account for either the CMV or its coat protein being an allergen. The result of a bioinformatic search also showed no significant homology between CMV cp and any known allergen. The pepsin-susceptible property of recombinant CMV cp was revealed by a simulated gastric fluid (SGF) assay. Following the most recent FAO/WHO decision tree, all results have indicated that CMV cp was a protein with low possibility to be an allergen and the transgenic tomato R8 should be considered as safe as its host.

  2. Origin and evolution of tomato production Lycopersicon esculentum in México

    Directory of Open Access Journals (Sweden)

    Tarsicio Medina Saavedra

    Full Text Available ABSTRACT: Lycopersicon esculentum known as tomato, although has an Andean origin is a contribution of Mexico to the world is, being the first agricultural product to be exported. This research aimed to review the literature in relation to the origin and evolution of the production of tomato in Mexico within the historical development of the country. In ancient times, the tomato was cultivated in milpas (open field and chinampas (artificial islands for riparian agriculture using sustainable methods. Spanish colonizers showed the tomato to the rest of the world and diversified its uses. In independent Mexico, haciendas and railroads integrated the different farming regions. Production decreased during the Mexican revolution, and with land reform, the milpa returned. During the Green Revolution (1970, Sinaloa stood out, with the separation of two systems, subsistence, and modern with technology programs. Biotechnological development (1990 emerged parallel to organic production. So actually with this system, we could return to more sustainable pre-Hispanic ecological principles with less environmental impact.

  3. Effects of hydrogen fluoride on plant-pathogen interactions. [Lycopersicon esculentum; Phaseolus vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    McCune, D.C.; Weinstein, L.H.; Mancini, J.F.; van Lueken, P.

    1973-01-01

    Experiments in fumigation chambers with tomato (Lycopersicon esculentum) and pinto bean (Phaseolus vulgaris) plants were performed to assess the effects of hydrogen fluoride on plant-pathogen (fungal and bacterial) interactions. Hydrogen fluoride was found to alter the plant-pathogen interaction, although the kind and consistency of effect caused by HF depended upon the host, pathogen, and several other factors. A reduction in powdery mildew probably indicates that HF was affecting the infectivity of the pathogen itself because reduction in disease was proportional to the length of the exposure period, infection was continuous during the exposure period, and the pathogen itself was epiphytic. The effect of fluoride on bean rust may have been due to accumulated fluoride in the leaf having a direct or indirect effect on the pathogen because both pre- and post-inoculation exposures to HF were effective and additive. Other evidence for an indirect effect of fluoride was found in halo-blight where stem collapse was affected but foliar symptoms were not, and the site affected was spatially removed from the site of fluoride accumulation. Effects on early blight of tomato also indicated an effect of fluoride in the leaf.

  4. Lycopersicon esculentum Extract Enhances Cognitive Function and Hippocampal Neurogenesis in Aged Mice

    Science.gov (United States)

    Bae, Jung-Soo; Han, Mira; Shin, Hee Soon; Shon, Dong-Hwa; Lee, Soon-Tae; Shin, Chang-Yup; Lee, Yuri; Lee, Dong Hun; Chung, Jin Ho

    2016-01-01

    A decrease in adult neurogenesis is associated with the aging process, and this decrease is closely related to memory impairment. Tomato (Lycopersicon esculentum) is a fruit with diverse bioactive nutrients that is consumed worldwide. In this study, we investigated the cognition-enhancing effect of tomato ethanolic extracts (TEE) in aged mice. Six weeks of oral TEE administration in 12-month-old aged mice significantly increased their exploration time of novel objects when compared to vehicle-treated mice. The TEE supplement increased doublecortin (DCX)-positive cells and postsynaptic density-95 (PSD95) expression in mice hippocampus. Moreover, we found an increased expression of brain-derived neurotrophic factor (BDNF) and subsequently-activated extracellular-signal-regulated kinase (ERK)/cAMP response element binding (CREB) signaling pathway in the TEE-supplemented mice hippocampus. In conclusion, the oral administration of TEE exhibits a cognition-enhancing effect, and the putative underlying mechanism is the induction of BDNF signaling-mediated proliferation and synapse formation in the hippocampus. These findings indicate that TEE could be a candidate for treatment of age-related memory impairment and neurodegenerative disorders. PMID:27792185

  5. Mechanisms and genetic control of interspecific crossing barriers in Lycopersicon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mutschler, M.A.

    1997-04-30

    Deficiency of Lycopersicon esculentum allele (E) was observed from the RFLP and isozyme data of the F{sub 2} populations derived from the cross L. esculentum x L. pennellii. The genome composition of the F{sub 2} populations containing L. pennellii cytoplasm (F{sub 2}{sup Lp4}) has a lower proportion of the homozygous L. pennellii (PP) genotypes and a higher proportion of heterozygote (EP) genotypes than that of the F{sub 2} populations containing L. esculentum cytoplasm (F{sub 2}{sup Le}). A lower proportion of the L. pennellii alleles (P) was also observed in F{sub 2}{sup Lp4} as compared to F{sub 2}{sup Le} when each marker locus was tested individually. To study the effects of gametic and zygotic selection on segregation distortion, the expected patterns of segregation at a marker locus were derived for ten selection models with gametic or zygotic selection at a hidden linked locus. Segregation distortion caused by four of the selection models studied can be uniquely identified by the patterns of significance expected for the likelihood ratio tests at the marker loci. Comparison of the chromosomal regions associated with specific selection models across populations (of this experiment and previous publications) indicated that the segregation distortion observed in chromosome 10 is associated with zygotic selection affecting both arms of the chromosome, and cytoplasm substitution has the effect of decreasing the segregation distortion on the long arm of the chromosome.

  6. Morphogenetic Potential of Tomato (Lycopersicon esculentum cv. ‘Arka Ahuti’ to Plant Growth Regulators

    Directory of Open Access Journals (Sweden)

    Kanakapura K. NAMITHA

    2013-05-01

    Full Text Available A highly reproducible in vitro regeneration method for tomato (Lycopersicon esculentum Mill. cultivar ‘Arka Ahuti’ was established by using hypocotyl, leaf and cotyledon explants from in vitro raised seedlings on Murashige and Skoog medium supplemented with different concentrations and combinations of hormones 6-Benzylamino purine (2 to 4 mg/L and Indole-3-acetic acid (0.1 to 1 mg/L. The medium supplemented with 2 mg/L 6-benzylamino purine and 0.1 mg/L indole-3-acetic acid was found to be the best for inducing direct shoot regeneration and multiple shoots per explant from hypocotyl explants. Callus induction was observed in all the explants and regeneration of shoots was also promoted by all these combinations. Shoots were transferred to the elongation medium which also induced 100% rooting. After hardening, plants were transferred to soil. Thus, a tissue culture base line was established for ‘Arka Ahuti’ cultivar of tomato for obtaining direct regeneration using hypocotyl, leaf and cotyledon as explants.

  7. Comparison of polyphenol oxidase expression in glandular trichomes of solanum and lycopersicon species.

    Science.gov (United States)

    Yu, H; Kowalski, S P; Steffens, J C

    1992-12-01

    Tetralobulate glandular trichomes are present on the foliage of many solanaceous species. Resistance of many of these species to insects is conditioned by the ability of trichomes to rupture upon contact and to rapidly polymerize their contents, resulting in entrapment of insects in hardened trichome exudate. In the wild potato, Solanum berthaultii, polymerization of trichome exudate is initiated by a soluble M(r) 59,000 polyphenol oxidase (PPO), which is a dominant protein constituent of the organ. PPOs, although ubiquitous in angiosperms, typically display great heterogeneity in molecular weight and are found at low levels in plant cells. Because of the unusually high accumulation and tissue-specific expression of the M(r) 59,000 PPO in S. berthaultii glandular trichomes, we analyzed trichome proteins of a number of Lycopersicon and Solanum species to assess the extent to which possession of the M(r) 59,000 PPO is conserved. Trichomes were collected manually and examined for PPO activity, immuno-cross-reactivity with S. berthaultiiM(r) 59,000 PPO, and protein content. In addition, N-terminal amino acid sequences were obtained for five trichome PPOs. All species analyzed possessed trichome PPOs similar in structure and level of expression to that of S. berthaultii. The relationship between sequences and structures of these conserved PPOs and the variable PPOs of leaf is discussed.

  8. Shoot regeneration from GUS-transformed tomato (Lycopersicon esculentum) hairy root.

    Science.gov (United States)

    Moghaieb, Reda E A; Saneoka, Hirofumi; Fujita, Kounosuke

    2004-01-01

    To study the influence of genetic background on the transformation and regeneration of cultivated tomato plants, hairy root lines of tomato (Lycopersicon esculentum) were obtained by inoculating the hypocotyl explants of three tomato cultivars with the Agrobacterium rhizogenes strain DCAR-2, which harbors the pBI-121 binary vector. The Ri-T-DNA transformation into the plant DNA was confirmed by both of mikimopine and GUS assay analyses. The regeneration efficiency from hairy root explants was assessed. The data indicated that white embryonic calli were formed within two weeks in the presence of 2 mgl(-1) 2, 4-D plus 0.25 mgl(-1) kinetin. Adventitious shoots emerged from the embryonic callus in the presence of 1 mgl(-1) GA3 along with 0.5 mgl(-1) NAA. The regeneration frequency was higher in the cultivar UC-97, followed by Momotaro and then Edkawi. Molecular confirmation of the integration of the GUS gene into the hairy root-derived plants genomes was done via PCR using GUS-specific primers and also using Southern blotting analysis. Our data shows that regeneration is possible from hairy roots of the cultivated tomato and this system could be used to produce transgenic tomato plants expressing the genes present in Agrobacterium rhizogenes binary vectors.

  9. Phytotoxic effects of a natural bloom extract containing microcystins on Lycopersicon esculentum.

    Science.gov (United States)

    El Khalloufi, Fatima; El Ghazali, Issam; Saqrane, Sana; Oufdou, Khalid; Vasconcelos, Vitor; Oudra, Brahim

    2012-05-01

    The cyanobacterial toxins microcystins (MC) are known to affect many processes in plants. Their presence in the water used for irrigation may have considerable impact on the survivorship, growth and development of plants. In this study, a crude extract of a toxic cyanobacterial bloom from "Lalla Takerkoust" reservoir (Morocco) was used to study the effects of extract containing MC on tomato plants (Lycopersicon esculentum). Five MC variants: MC-LR, MC-FR, MC-LY, MC-(H4)-YR and DMC-LR were identified by HPLC in the cyanobacterial extract. Exposure of the seeds to the crude extract (containing 22.24 μg MC mL(-1)) caused a reduction of germination up to 85%. Experiments showed that 30 days exposure of plant to the cyanobacterial extract containing MC caused inhibition of L. esculentum growth and productivity, as well as harmful effects on photosystem II activity, measured by Fv/Fm fluorescence. An accumulation of nutrients Na(+), K(+) and Ca(2+) was also registered. The activity of peroxidase and phenolic content indicated that the extract caused an oxidative stress. The tissue necrosis of leaves was also a consequence of MC exposure indicating a disorder in the exposed plant metabolism.

  10. EFFECTS OF RADIO FREQUENCY / MICROWAVE ON THE CHEMICAL COMPOSITION AND ANTIOXIDANT POTENTIAL OF LYCOPERSICON ESCULENTUM L.

    Directory of Open Access Journals (Sweden)

    Rammal Marwa

    2013-09-01

    Full Text Available In our work, the effects of radio frequency / microwave on the morphology, chemical composition and the antioxidant power of the plant Lycopersicon esculentum Mill. grown in our laboratory have been accomplished. The obtained results showed that after 10 days of exposure of this plant to electromagnetic fields with high frequency (1250 MHz the stems were long with less leaves than the non exposed plant. However, after 20 days of exposure to this same frequency the stems were long and contain more leaves than the non exposed plant. These leaves were larger and thicker in comparison with those of the non exposed plant. On the other side, the phytochemical screening of the ethanolic extract revealed the presence of flavonoids in the exposed and non exposed plant. Alkaloids, phenols and saponins were only present in non exposed plant. The tannins were absent in the exposed and non exposed plant. Therefore, resins were highly expressed in the exposed plant. On the other side, the x-ray fluorescence indicated the presence of various trace elements more particularly niobium and molybdenum. After exposure, the amount of these elements varies. On the other hand, the DPPH and H2O2 tests showed an important decrease in the antioxidant potential after exposure to studied frequency. This decrease was from 42 % to 18 % at the concentration 0.5 mg/ml. All of these results show that the high frequency emitted by the electromagnetic fields exert a strong effect on the plant and by consequence on human health.

  11. Effects of Lycopersicon esculentum extract on hair growth and alopecia prevention.

    Science.gov (United States)

    Choi, Jae-Suk; Jung, Sung Kyu; Jeon, Min-Hee; Moon, Jin-Nam; Moon, Woi-Sook; Ji, Yi-Hwa; Choi, In Soon; Wook Son, Sang

    2013-01-01

    To evaluate the potential hair growth-promoting activity and the expression of cell growth factors of Lycopersicon esculentum extracts, each 3% (w/w) of ethyl acetate extract (EAE), and supercritical CO2 extract (SCE) of L. esculentum and isolated lycopene Tween 80 solution (LTS) and test hair tonic (THT) containing LTS were applied on the dorsal skin of C57BL/6 mice, once a day for 4 weeks. At week 4, LTS and THT exhibited hair growth-promoting potential similar to that of 3% minoxidil as a positive control (PC). Further, in the LTS group, a significant increase of mRNA expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor, and insulin-like growth factor-1 (IGF-1) was observed than PC, as well as the negative control (NC). In the THT group, increases in IGF-1 and decrease in VEGF and transforming growth factor-β expression were significant over the NC. In a histological examination in the THT group, the induction of anagen stage of hair follicles was faster than that of NC. In the Draize skin irritation study for THT, no observable edema or erythema was observed on all four sectors in the back skin after exposure for 24 or 72 h for any rabbit. Therefore, this study provides reasonable evidence that L. esculentum extracts promote hair growth and suggests that applications could be found in hair loss treatments without skin irritation at moderate doses.

  12. Environmental controls over methanol production, emission, and δ13C values from Lycopersicon esculentum

    Science.gov (United States)

    Oikawa, P.; Giebel, B. M.; Mak, J. E.; Riemer, D. D.; Swart, P. K.; Lerdau, M.

    2009-12-01

    Phytogenic methanol is the dominant source of methanol to the atmosphere, where it is the second most abundant organic compound. Beyond methanol’s role in atmospheric chemistry, it is an indicator of plant function and is linked to plant wound response. Methanol emissions are considered to be a by-product of cell wall expansion and, more specifically, the demethylation of pectin by pectin methylesterase (PME) in cell walls. Production of methanol was investigated in mature and immature tomato Lycopersicon esculentum via measurement of methanol flux, foliar PME activity, and methanol extraction from leaf, root, and stem tissues. δ13C values for mature and immature methanol emissions were also measured using a GC-IRMS system. Environmental control over methanol production and emission was studied by changing temperature and light while holding stomatal conductance constant. As seen previously, mature leaf methanol emissions were significantly less than immature emissions. Surprisingly, preliminary results suggest mature leaf methanol production to be similar to immature leaves, indicating an enhanced metabolic sink for methanol in mature leaves. These data enhance our understanding of methanol production, a term which is not well constrained in current methanol flux models.

  13. Effect of salinity on tomato (Lycopersicon esculentum Mill.) during seed germination stage.

    Science.gov (United States)

    Singh, Jogendra; Sastry, E V Divakar; Singh, Vijayata

    2012-01-01

    A study was conducted using ten genetically diverse genotypes along with their 45F1 (generated by diallel mating) under normal and salt stress conditions. Although, tomato (Lycopersicon esculentum Mill.) is moderately sensitive to salinity but more attention to salinity is yet to be required in the production of tomato. In present study, germination rate, speed of germination, dry weight ratio and Na(+)/K(+) ratio in root and shoot, were the parameters assayed on three salinity levels; control, 1.0 % NaCl and 3.0 % NaCl with Hoagland's solution. Increasing salt stress negatively affected growth and development of tomato. When salt concentration increased, germination of tomato seed was reduced and the time needed to complete germination lengthened, root/shoot dry weight ratio was higher and Na(+) content increased but K(+) content decreased. Among the varieties, Sel-7 followed by Arka Vikas and crosses involving them as a parent were found to be the more tolerant genotypes in the present study on the basis of studied parameters.

  14. Simultaneous ozone fumigation and fluoranthene sprayed as mists negatively affected cherry tomato (Lycopersicon esculentum Mill).

    Science.gov (United States)

    Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

    2010-07-01

    Ozone (O(3)) fumigated at 120 microg L(-1) for 12 hd(-1) was combined with 10 microM fluoranthene, and other treatments, including Mannitol solution to investigate the interaction of the two pollutants on tomato plant (Lycopersicon esculentum Mill). Using ten treatments including Mannitol solution and a control, exposure experiment was conducted for 34 d inside six growth chambers used for monitoring the resulted ecophysiological changes. Visible foliar injury, chlorophyll a fluorescence, leaf pigment contents, CO(2) uptake and water vapor exchange were monitored in tomato. Ozone or fluoranthene independently affected some ecophysiological traits of the tomato. In addition, simultaneous treatments with the duo had increased (additive) negative effects on the photosynthesis rate (A(max)), stomatal conductance (g(s)), chlorophyll pigment contents (Chl a, Chl b and Chl((a+b))) and visible foliar symptoms. Contrarily, alleviation of the negative effects of O(3) on the leaf chlorophyll a fluorescence variables by fluoranthene occurred. Mannitol solution, which functioned as a reactive oxygen species scavenger was able to mitigate some negative effects of the two pollutants on the tomato plants.

  15. Uptake, localization, and speciation of cobalt in Triticum aestivum L. (wheat) and Lycopersicon esculentum M. (tomato).

    Science.gov (United States)

    Collins, Richard N; Bakkaus, Estelle; Carrière, Marie; Khodja, Hicham; Proux, Olivier; Morel, Jean-Louis; Gouget, Barbara

    2010-04-15

    The root-to-shoot transfer, localization, and chemical speciation of Co were investigated in a monocotyledon (Triticum aestivum L., wheat) and a dicotyledon (Lycopersicon esculentum M., tomato) plant species grown in nutrient solution at low (5 muM) and high (20 muM) Co(II) concentrations. Cobalt was measured in the roots and shoots by inductively coupled plasma-mass spectrometry. X-ray absorption spectroscopy measurements were used to identify the chemical structure of Co within the plants and Co distribution in the leaves was determined by micro-PIXE (particle induced X-ray emission). Although the root-to-shoot transport was higher for tomato plants exposed to excess Co, both plants appeared as excluders. The oxidation state of Co(II) was not transformed by either plant in the roots or shoots and Co appeared to be present as Co(II) in a complex with carboxylate containing organic acids. Cobalt was also essentially located in the vascular system of both plant species indicating that neither responded to Co toxicity via sequestration in epidermal or trichome tissues as has been observed for other metals in metal hyperaccumulating plants.

  16. Expression of human coagulation Factor IX in transgenic tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Zhang, Hui; Zhao, Lingxia; Chen, Yuhui; Cui, Lijie; Ren, Weiwei; Tang, Kexuan

    2007-10-01

    In the present study, a plant binary expression vector PG-pRD12-hFIX (where PG is polygalacturonase) harbouring the hFIX (human coagulation Factor IX) gene was constructed and introduced into tomato (Lycopersicon esculentum) via Agrobacterium tumefaciens-mediated transformation. After kanamycin selection, 32 putative independent transgenic tomato plants were regenerated. PCR and Southern-blot analyses confirmed the transgenic status of some plants. RT (reverse transcription)-PCR analysis for the expression of the introduced gene (hFIX) demonstrated that the hFIX gene was expressed specifically in fruits of the tomato. Western-blot analysis confirmed the presence of a 56 kDa band specific to hFIX in the transformed tomatoes. ELISA results showed that the expression of hFIX protein reached a maximum of 15.84 ng/g fresh weight in mature fruit. A blood-clotting assay demonstrated the clotting activity of the expressed hFIX protein in transgenic tomato fruits. This is the first report on the expression of hFIX in plants, and our research provides potentially valuable knowledge for further development of the plant-derived therapeutic proteins.

  17. Hygienic quality of traditional processing and stability of tomato (Lycopersicon esculentum) puree in Togo.

    Science.gov (United States)

    Ameyapoh, Yaovi; de Souza, Comlan; Traore, Alfred S

    2008-09-01

    Microbiological and physicochemical qualities of a tomato (Lycopersicon esculentum) puree production line (ripe tomato, washing, cutting, pounding, bleaching, straining, bottling and pasteurization) and its preservation in Togo, West Africa, were studied using the HACCP method. Samples generated during the steps described previously were analyzed by determining sensory, chemical and microbiological characteristics. Samples were analyzed using MPN for coliform populations and plate count methodology for other bacteria. The microorganisms involved in spoilage of the opened products were moulds of genera Penicillium, Aspergillus, Fusarium, Geotrichum, Mucor and gram-positive Bacillus bacteria. The preserved tomato puree exhibited a pH value of 4.3, 90% water content, 0.98 water activity (aw) and an average ascorbic acid level of 27.3mg/100g. Results showed that the critical control point (CCP) of this tomato puree processing line is the pasteurization stage. The analysis of selected microbiological and physicochemical parameters during the preservation of bottled tomato puree indicated that this product was stable over 22 months at 29 degrees C. But the stability of the opened product stored at 29 degrees C did not exceed two months.

  18. Season-controlled changes in biochemical constituents and oxidase enzyme activities in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Sen, Supatra; Mukherji, S

    2009-07-01

    Season-controlled changes in biochemical constituents viz. carotenoids (carotene and xanthophyll) and pectic substances along with IAA-oxidase and polyphenol oxidase (PPO) enzyme activities were estimated/assayed in leaves of Lycopersicon esculentum Mill. (tomato) in two developmental stages--pre-flowering (35 days after sowing) and post-flowering (75 days after sowing) in three different seasons--summer rainy and winter Carotenoid content along with pectic substances were highest in winter and declined significantly in summer followed by rainy i.e. winter > summer > rainy. Carotenoid content was significantly higher in the pre-flowering as compared to post-flowering in all three seasons while pectic substances increased in the post-flowering as compared to pre-flowering throughout the annual cycle. IAA oxidase and PPO enzyme activities were enhanced in rainy and decreased sharply in summer and winter i.e. rainy > summer > winter. Both the enzymes exhibited higher activity in the post-flowering stage as compared to pre-flowering in all three seasons. These results indicate winter to be the most favourable season for tomato plants while rainy season environmental conditions prove to be unfavourable (stressful) with diminished content of carotenoid and pectic substances and low activities of IAA oxidase and PPO, ultimately leading to poor growth and productivity.

  19. Mechanisms and genetic control of interspecific crossing barriers in Lycopersicon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mutschler, M.A.

    1997-04-30

    Deficiency of Lycopersicon esculentum allele (E) was observed from the RFLP and isozyme data of the F{sub 2} populations derived from the cross L. esculentum x L. pennellii. The genome composition of the F{sub 2} populations containing L. pennellii cytoplasm (F{sub 2}{sup Lp4}) has a lower proportion of the homozygous L. pennellii (PP) genotypes and a higher proportion of heterozygote (EP) genotypes than that of the F{sub 2} populations containing L. esculentum cytoplasm (F{sub 2}{sup Le}). A lower proportion of the L. pennellii alleles (P) was also observed in F{sub 2}{sup Lp4} as compared to F{sub 2}{sup Le} when each marker locus was tested individually. To study the effects of gametic and zygotic selection on segregation distortion, the expected patterns of segregation at a marker locus were derived for ten selection models with gametic or zygotic selection at a hidden linked locus. Segregation distortion caused by four of the selection models studied can be uniquely identified by the patterns of significance expected for the likelihood ratio tests at the marker loci. Comparison of the chromosomal regions associated with specific selection models across populations (of this experiment and previous publications) indicated that the segregation distortion observed in chromosome 10 is associated with zygotic selection affecting both arms of the chromosome, and cytoplasm substitution has the effect of decreasing the segregation distortion on the long arm of the chromosome.

  20. Lycopersicon esculentum Extract Enhances Cognitive Function and Hippocampal Neurogenesis in Aged Mice

    Directory of Open Access Journals (Sweden)

    Jung-Soo Bae

    2016-10-01

    Full Text Available A decrease in adult neurogenesis is associated with the aging process, and this decrease is closely related to memory impairment. Tomato (Lycopersicon esculentum is a fruit with diverse bioactive nutrients that is consumed worldwide. In this study, we investigated the cognition-enhancing effect of tomato ethanolic extracts (TEE in aged mice. Six weeks of oral TEE administration in 12-month-old aged mice significantly increased their exploration time of novel objects when compared to vehicle-treated mice. The TEE supplement increased doublecortin (DCX-positive cells and postsynaptic density-95 (PSD95 expression in mice hippocampus. Moreover, we found an increased expression of brain-derived neurotrophic factor (BDNF and subsequently-activated extracellular-signal-regulated kinase (ERK/cAMP response element binding (CREB signaling pathway in the TEE-supplemented mice hippocampus. In conclusion, the oral administration of TEE exhibits a cognition-enhancing effect, and the putative underlying mechanism is the induction of BDNF signaling-mediated proliferation and synapse formation in the hippocampus. These findings indicate that TEE could be a candidate for treatment of age-related memory impairment and neurodegenerative disorders.

  1. Selenium fertilization alters the chemical composition and antioxidant constituents of tomato (Solanum lycopersicon L.).

    Science.gov (United States)

    Schiavon, Michela; Dall'acqua, Stefano; Mietto, Anna; Pilon-Smits, Elizabeth A H; Sambo, Paolo; Masi, Antonio; Malagoli, Mario

    2013-11-06

    Although selenium (Se) is a known anticarcinogen, little is known regarding how Se affects other nutritional qualities in crops. Tomato ( Solanum lycopersicon ) was supplied with 0-50 μM selenate and analyzed for elemental composition and antioxidant compounds. When supplied at low doses (5 and 10 μM) via the roots, Se stimulated the synthesis of phenolic compounds in leaves and reduced the levels of Mo, Fe, Mn, and Cu in roots. At higher doses (25 and 50 μM Se) leaf glutathione levels were 3-5-fold enhanced. Supply of selenate via foliar spray (0, 2, or 20 mg Se plant(-1)) resulted in Se-biofortified tomato fruits, with Se levels low enough not to pose a health risk. The Se-biofortified fruits showed enhanced levels of the antioxidant flavonoids naringenin chalcone and kaempferol and a concomitant decrease of cinnamic acid derivatives. Thus, tomato fruits can be safely enriched with Se, and Se biofortification may enhance levels of other neutraceutical compounds.

  2. Functional Characterization of Mi, a Root-knot Nematode Resistance Gene from Tomato( Lycopersicon esculentum L.)

    Institute of Scientific and Technical Information of China (English)

    Ru-Gang Chen; Li-Ying Zhang; Jun-Hong Zhang; Wei Zhang; Xue Wang; Bo Ouyang; Han-Xia Li; Zhi-Biao Ye

    2006-01-01

    Root-knot nematodes (Meloidogyne spp.) cause major economic damage to numerous crop species around the world. Plant resistance is the most important attribute that is able to suppress invasion by the rootknot nematodes. In the present study, a candidate root-knot nematode resistance gene (Mi) was isolated from the resistant tomato (Lycopersicon esculentum L.) line RN-1. Expression profiling analysis revealed that this gene was expressed specifically in the roots, stems, and leaves, but not in the flowers or fruits.To verify the real function of this candidate gene, both sense and inteference RNA (RNAi) vectors were constructed. We obtained 31 transgenic plants with between one and seven copies of T-DNA inserts of sense Mi from two nematode-susceptible tomato cultivars as assayed by polymerase chain reaction (PCR)and Southern blotting analysis. Reverse transcription-PCR analysis revealed that expression levels of the Mi gene varied in different transgenic plants. Nematode assays showed that the resistance to root-knot nematodes was significantly improved in some transgenic lines compared with untransformed susceptible controls and that the resistance was heritable in selfed progeny. Loss of function via RNAi further confirmed the role of the Mi gene and the original resistant lines became susceptible to root-knot nematodes.

  3. Comparison of regeneration potentials in tissue cultures of primitive and cultivated tomato species (Lycopersicon sp.

    Directory of Open Access Journals (Sweden)

    M. Lech

    2014-01-01

    Full Text Available Regeneration capacities of two tomato cultivars: Potentat and Rutgers, and of three accessions of wild tomato species: Lycopersicon peruvianum PI 128650, L. peruvianum var. dentatum PI 128655 and L. glandulosum were studied using an universal medium suitable for regeneration of those plants from leaf pieces in tissue culture. Fragments of leaf blades were taken from plants raised in greenhouse conditions and placed on a modified MS medium containing 0.3 mg/l IAA and 3.0 mg/l BAP solidified with 1% agar. The explants were transferred every 4-5 weeks on fresh medium of the same composition. It was shown that all the three primitive tomato species revealed much higher multiplication coefficients than the two cultivars. Appropriate values were: 11 - for L. glandulosum, 8 - for L. peruvianum, 7 - for L. peruvianum var. dentatum, 4 - for L. esculentum cv. Potentat and 2 - cv. Rutgers. Completely regenerated plants were obtained from all the tested species, but organogenesis occurred almost two weeks earlier in wild tomatoes than in the culitivated varieties of L. esculentum.

  4. Adaptive evolution of the water stress-induced gene Asr2 in Lycopersicon species dwelling in arid habitats.

    Science.gov (United States)

    Frankel, Nicolas; Hasson, Esteban; Iusem, Norberto D; Rossi, Maria Susana

    2003-12-01

    The Asr2 gene encodes a putative transcription factor that is up-regulated in leaves and roots of tomato plants exposed to water-deficit stress. This gene was first cloned and characterized in a cultivar of commercial tomato (Lycopersicon esculentum cv. Ailsa Craig). In this work, we report the complete coding sequences of the orthologous Asr2 genes in six wild tomato lineages: L. hirsutum, L. cheesmanii, L. esculentum v. cerasiforme, L. chilense, L. peruvianum v. humifusum and L. peruvianum f. glandulosum. Estimates of the Ka/Ks ratio (omega) in pairwise comparisons within the genus Lycopersicon were equal or greater than 1 (a signature of adaptive evolution) when involving L. chilense and L. peruvianum v. humifusum. Interestingly, these two species are distinct from the others in their adaptation to dry habitats. We also mapped the detected substitutions onto a phylogenetic tree of the genus Lycopersicon. Remarkably, there are two and three amino acid substitutions, which contrast with the absence of synonymous substitutions along the terminal branches leading to L. chilense and L. peruvianum v. humifusum, respectively. Likelihood ratio tests confirmed that omega values in the branches leading to these species are significantly different from the remaining branches of the tree. Moreover, inferred changes in the branches leading to these species that inhabit dry areas are nonconservative and may be associated with dramatic alterations in ASR2 protein conformation. In this work, we demonstrate accelerated rates of amino acid substitutions in the Asr2 gene of tomato lineages living in dry habitats, thus giving support to the hypothesis of adaptive Darwinian evolution.

  5. Characterization of the growth and auxin physiology of roots of the tomato mutant, diageotropica

    Science.gov (United States)

    Muday, G. K.; Lomax, T. L.; Rayle, D. L.

    1995-01-01

    Roots of the tomato (Lycopersicon esculentum, Mill.) mutant (diageotropica (dgt) exhibit an altered phenotype. These roots are agravitropic and lack lateral roots. Relative to wild-type (VFN8) roots, dgt roots are less sensitive to growth inhibition by exogenously applied IAA and auxin transport inhibitors (phytotropins), and the roots exhibit a reduction in maximal growth inhibition in response to ethylene. However, IAA transport through roots, binding of the phytotropin, tritiated naphthylphthalamic acid ([3H]NPA), to root microsomal membranes, NPA-sensitive IAA uptake by root segments, and uptake of [3H]NPA into root segments are all similar in mutant and wild-type roots. We speculate that the reduced sensitivity of dgt root growth to auxin-transport inhibitors and ethylene is an indirect result of the reduction in sensitivity to auxin in this single gene, recessive mutant. We conclude that dgt roots, like dgt shoots, exhibit abnormalities indicating they have a defect associated with or affecting a primary site of auxin perception or action.

  6. EVALUACIÓN DE CALIDAD EN FRUTOS DE SIETE GENOTIPOS NATIVOS DE JITOMATE (Lycopersicon esculentum var. cerasiforme)

    OpenAIRE

    2009-01-01

    El objetivo de este estudio fue evaluar la calidad en frutos de siete genotipos nativos de jitomate (Lycopersicon esculentum var. cerasiforme): JCPRV-05, JCPVR-09, JCPRV-10, JCPRV-43, JCPRV-70, JCPRV-71, y JCPRV-76, cultivados en hidroponía sin recirculación y bajo invernadero. Como testigo se usó un híbrido comercial de jitomate tipo 'cherry' (H-790). Se evaluó firmeza, días para alcanzar 7 % de pérdida de peso (DPP), pH, sólidos solubles totales, acidez titulable, contenido de licopeno, de ...

  7. Antioxidant Activity of Tomato (Lycopersicon esculentum L.) of Low Soluble Solids and Development of a Shelf Stable Spread

    OpenAIRE

    Balaswamy K; Prabhakara Rao PG; Pragati Yadav; Narsing Rao G; Sulochanamma G; Satyanarayana A

    2015-01-01

    Tomato (Lycopersicon esculentum L.) is known to be associated with a reduced risk of developing a certain chronic diseases and cancers due to the presence of lycopene, a bioactive carotenoid. Commercially, the vegetable is used in the preparation of tomato puree or ketchup, but the local varieties with lower total soluble solids was found to be not useful for the same and fetching not enough prices during glut and being wasted without processing. In the present study, the local...

  8. Plant Spacing and Cultivar Affects Yield Components, Qualitative Traits and Early Ripening of Tomato (Lycopersicon esculentum

    Directory of Open Access Journals (Sweden)

    Ebrahim MAMNOIE

    2013-12-01

    Full Text Available Two-year field trial was set up on sandy clay soil in the Jiroft and Kahnouj Agricultural Research Center with the objective to determine the effect of plant spacing and different cultivars on the yield and qualitative characteristics of tomato (Lycopersicon esculentum. This experiment was performed as split plot based on complete randomized block design with 3 replications. The main plots were in – row spacing in 4 levels include 0.3, 0.4, 0.5 and 0.6 m and the subplots were cultivars naming ‘Shef ’, ‘Peto Early CH’ and ‘FDT 202’. The results showed that, fruit length to diameter ratio, total acidity, fruit number per plant, mean fruit weight, yield per plant, total yield and first harvest to total harvests ratio were significantly affected by plant spacing. In addition, cultivars showed significant effect on all traits evaluated (p<0.01. In this experiment, fruit length to diameter ratio and total acidity increased as plant spacing increased, however it had no effect on total soluble solids. In this study, total fruit yield is being increased while the yield per plant, number of fruit per plant and fruit weight is being reduced by increased number of plants per unit area. Although among tomato cultivar, ‘Peto Early CH’ had a higher yield over other cultivars, but cultivar ‘Shef ’ showed higher yield in the first harvest. Generally it seems according to the results collected that plant spacing 0.3 m and ‘Shef ’ cultivar owing to better adaptation and higher commercial yield for production in Jiroft city is suggested.

  9. Two Loci from Lycopersicon hirsutum LA407 Confer Resistance to Strains of Clavibacter michiganensis subsp. michiganensis.

    Science.gov (United States)

    Kabelka, E; Franchino, B; Francis, D M

    2002-05-01

    ABSTRACT We used molecular markers to identify quantitative trait loci (QTL) that contribute to resistance to bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis. Resistance was first identified as a marker-trait association in an inbred backcross (IBC) population derived from crossing Lycopersicon hirsutum accession (LA407) with L. esculentum. Single-marker QTL analysis suggested that at least two loci originating from L. hirsutum LA407, Rcm 2.0 on chromosome 2 and Rcm 5.1 on chromosome 5, contribute to resistance in replicated trials. Two segregating F(2) populations were developed by crossing resistant inbred backcross lines (IBLs) to elite L. esculentum lines and used to confirm QTL associations detected in the IBC population. In these populations, realized heritability estimates were higher for selection based on maximal disease than for selection based on disease progression. Realized heritability in the population carrying Rcm 2.0 was 0.63 and 0.14, respectively, for each selection criteria. Realized heritability estimates were 0.85 for selection based on maximal disease and 0.37 for selection based on disease progression in a population carrying Rcm 5.1. The disease response of F(3) families selected for resistance suggested that both Rcm 2.0 and Rcm 5.1 confer resistance to bacterial strains in the repetitive sequence-based polymerase chain reaction DNA fingerprint classes A and C. Markers linked to Rcm 2.0 explained up to 56% of the total phenotypic variation for resistance in one population, and markers linked to Rcm 5.1 explained up to 73% of the total phenotypic variation for resistance in a separate population.

  10. In vitro and in vivo inoculation of four endophytic bacteria on Lycopersicon esculentum.

    Science.gov (United States)

    Botta, Anna Lucia; Santacecilia, Alessandra; Ercole, Claudia; Cacchio, Paola; Del Gallo, Maddalena

    2013-09-25

    Four bacteria selected on the basis of their capability of fixing atmospheric nitrogen, stimulating plant-growth, and protecting the host plant from pathogens - Azospirillum brasilense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, Burkholderia ambifaria - were inoculated on tomato seeds either singularly, in couple and in a four bacteria mixer. Aim of this research was to evaluate: (1) effect of single and mixed cultures on the inoculated plant - plant growth, dry weight, root length and surface, number of leaves, among others; (2) colonization and interactions of the bacteria inside the host plant; (3) localization inside the host of single bacterial strains marked with the gusA reporter gene. The results obtained indicate that all selected microbial strains have colonized Lycopersicon esculentum but in a different way, depending on the single species. A. brasilense, G. diazotrophicus inoculated in vitro singularly and together were the best plant colonizers. In vivo essays, instead, B. ambifaria and the four-bacteria mixer gave the best results. It was possible to localize both A. brasilense and H. seropedicae inside the plant by the gusA reporter gene. The bacterial strains occur along the root axis from the apical zone until to the basal stem, on the shoot from the base up to the leaves. The four bacteria actively colonize tomato seeds and establish an endophytic community inside the plant. This review gives new information about colonization processes, in particular how bacteria interact with plants and whether they are likely to establish themselves in the plant environment after field application as biofertilizers or biocontrol agents.

  11. Salt tolerance in Lycopersicon species. IV. Efficiency of marker-assisted selection for salt tolerance improvement.

    Science.gov (United States)

    Monforte, A J; Asíns, M J; Carbonell, E A

    1996-10-01

    The usefulness of marker-assisted selection (MAS) to develop salt-tolerant breeding lines from a F2 derived from L. esculentum x L. pimpinellifolium has been studied. Interval mapping methodology of quantitative trait locus (QTL) analysis was used to locate more precisely previously detected salt tolerance QTLs. A new QTL for total fruit weight under salinity (TW) near TG24 was detected. Most of the detected QTLs [3 for TW, 5 for fruit number, (FN) and 4 for fruit weight (FW)] had low R (2) values, except the FW QTL in the TG180-TG48 interval, which explains 36.6% of the total variance. Dominant and overdominant effects were detected at the QTLs for TW, whereas gene effects at the QTLs for FJV and FW ranged from additive to partial dominance. Phenotypic selection of F2 familes and marker-assisted selection of F3 families were carried out. Yield under salinity decreased in the F2 generation. F3 means were similar to those of the F1 as a consequence of phentoypic selection. The most important selection response for every trait was obtained from the F3 to F4 where MAS was applied. While F3 variation was mainly due to the within-family component, in the F4 the FN and FW between-family component was larger than the within-family one, indicating an efficient compartmentalization and fixation of QTLs into the F4 families. Comparison of the yield of these families under control versus saline conditions showed that fruit weight is a key trait to success in tomato salt-tolerance improvement using wild Lycopersicon germplasm. The QTLs we have detected under salinity seem to be also working under control conditions, although the interaction family x treatment was significant for TW, thereby explaining the fact that the selected families responded differently to salinity.

  12. Production and characterisation of monoclonal antibodies to phytoene synthase of Lycopersicon esculentum.

    Science.gov (United States)

    Fraser, P D; Misawa, N; Sandmann, G; Johnson, J; Schuch, W; Bramley, P M

    1998-10-01

    Monoclonal antibodies have been prepared against the tomato (Lycopersicon esculentum Mill.) fruit ripening-enhanced phytoene synthase (PSY1). The antigen was prepared as a beta-galactosidase fusion protein by cloning a 1.13 kb fragment of Psy1 cDNA into pUR291, followed by transformation of E. coli. The fusion protein, induced by IPTG, was purified by preparative SDS-PAGE and used to elicit an immune response. The cell lines were screened for cross-reactivity against beta-galactosidase-phytoene synthase fusion protein in E. coli extracts using western blotting and ELISA detection procedures. Positive clones were further screened for their ability to cross-react with the mature phytoene synthase protein on western blots as well as their ability to inhibit enzyme activity. Eleven monoclonal lines were obtained. Nine of these, all of the IgM isotype, exhibited strong responses to phytoene synthase of ripe tomato fruit on western blots, but did not inhibit enzyme activity effectively. The other two lines (IgG/la 2 isotypes) inhibited phytoene synthase activity in ripe tomato stroma, but produced a poor response to the protein on western blots. The monoclonals identified a ripe fruit phytoene synthase of 38 kDa, exclusively located in the chromoplast. In contrast, antibodies were unable to detect microbial phytoene synthases, nor phytoene synthase of maize leaf, tomato chloroplast or mango fruit extracts, either on western blots or from inhibition of phytoene synthase activity. However, they did cross-react with a 44 kDa protein from carrot leaf stroma and with three different proteins (44, 41, and 37 kDa) in carrot root. Cross-reactivity was also found with a 37 kDa protein from pumpkin fruit stroma.

  13. Cloning of tomato (Lycopersicon esculentum Mill.) arginine decarboxylase gene and its expression during fruit ripening.

    Science.gov (United States)

    Rastogi, R; Dulson, J; Rothstein, S J

    1993-11-01

    Arginine decarboxylase (ADC) is the first enzyme in one of the two pathways of putrescine biosynthesis in plants. The genes encoding ADC have previously been cloned from oat and Escherichia coli. Degenerate oligonucleotides corresponding to two conserved regions of ADC were used as primers in polymerase chain reaction amplification of tomato (Lycopersicon esculentum Mill.) genomic DNA, and a 1.05-kb fragment was obtained. This genomic DNA fragment encodes an open reading frame of 350 amino acids showing about 50% identity with the oat ADC protein. Using this fragment as a probe, we isolated several partial ADC cDNA clones from a tomato pericarp cDNA library. The 5' end of the coding region was subsequently obtained from a genomic clone containing the entire ADC gene. The tomato ADC gene contains an open reading frame encoding a polypeptide of 502 amino acids and a predicted molecular mass of about 55 kD. The predicted amino acid sequence exhibits 47 and 38% identify with oat and E. coli ADCs, respectively. Gel blot hybridization experiments show that, in tomato, ADC is encoded by a single gene and is expressed as a transcript of approximately 2.2 kb in the fruit pericarp and leaf tissues. During fruit ripening the amount of ADC transcript appeared to peak at the breaker stage. No significant differences were seen when steady-state ADC mRNA levels were compared between normal versus long-keeping Alcobaca (alc) fruit, although alc fruit contain elevated putrescine levels and ADC activity at the ripe stage. The lack of correlation between ADC activity and steady-state mRNA levels in alc fruit suggests a translational and/or posttranslational regulation of ADC gene expression during tomato fruit ripening.

  14. Phytochemical and nutrient/antinutrient interactions in cherry tomato (Lycopersicon esculentum) fruits.

    Science.gov (United States)

    Oyetayo, Folake Lucy; Ibitoye, Muyiwa Femi

    2012-07-01

    The fruit of the cherry tomato (Lycopersicon esculentum (Solanaceae)) was analysed for mineral and antinutrient composition. Phosphorus (33.04 ± 0.21 mg/100g) was the most abundant mineral in the fruit, followed by calcium (32.04 ± 0.06 mg/100 g), and potassium (11.9 ± 0.1 mg/100 g) and manganese (9.55 ± 0.28 mg/100 g) were also present in appreciable quantities. Antinutrients, including phytate, glycoside, saponin and tannin, were screened and quantified. Phytate (112.82 ± 0.1 mg/100 g), glycoside (2.33 ± 0.00 mg/100 g), saponin (1.31 ± 0.00 mg/100g) and tannin (0.21 ± 0.00 mg/100 g) were present in the fruit but phlobatanin and glycosides with steroidal rings were not found. The calculated calcium:phytate ratio of the fruits was below the critical value and the calculated [calcium] [phytate]:[zinc] molar ratio was less than the critical value. The calcium:phosphorus ratio (0.97 mg/100 g) shows the fruit to be a good source of food nutrients, while the sodium:potassium value was less than 1. Ca/P ratio below 0.5 indicates deficiency of these minerals while Na/K ratio above 1 is detrimental because of excessive sodium levels. The results of the study generally revealed the fruit to be rich in minerals but containing insufficient quantities of antinutrients to result in poor mineral bioavailability.

  15. Padrão de identidade e qualidade do tomate (Lycopersicon esculentum Mill. de mesa

    Directory of Open Access Journals (Sweden)

    Ferreira Sila Mary Rodrigues

    2004-01-01

    Full Text Available O valor comercial do tomate, Lycopersicon esculentum Mill., é definido pelas características de identidade e qualidade presentes no fruto que podem ser avaliadas pela classificação do produto. A presente revisão de literatura teve como objetivo descrever o padrão de identidade e qualidade do tomate de mesa, através da classificação. O tomate de mesa é classificado em grupos, subgrupos, classes e tipos. De acordo com o formato do fruto, o tomate é classificado em dois grupos: oblongo, quando o diâmetro longitudinal é maior que o transversal e redondo, quando o diâmetro longitudinal é menor ou igual ao transversal. Em função do estádio de maturação, o tomate é classificado em cinco subgrupos: verde maduro, pintado, rosado, vermelho e vermelho maduro. A classe é definida em função do maior diâmetro transversal do fruto em relação ao grupo a que pertença. O tomate oblongo é classificado em três classes: grande, médio e pequeno. O tomate redondo é classificado em quatro classes: gigante, grande, médio e pequeno. De acordo com os índices de ocorrência de defeitos graves e leves presentes nos frutos, o tomate é classificado também em tipo: extra, especial ou selecionado e comercial. São considerados defeitos graves: podridão, passado, queimado, dano por geada, podridão apical, e defeitos leves: dano, mancha, ocado, deformado e imaturo. A amostra de tomate que ultrapasse os índices de defeitos previstos pela legislação do Ministério da Agricultura é classificada como fora do padrão.

  16. Exploring genetic variation in the tomato (Solanum section Lycopersicon) clade by whole-genome sequencing.

    Science.gov (United States)

    Aflitos, Saulo; Schijlen, Elio; de Jong, Hans; de Ridder, Dick; Smit, Sandra; Finkers, Richard; Wang, Jun; Zhang, Gengyun; Li, Ning; Mao, Likai; Bakker, Freek; Dirks, Rob; Breit, Timo; Gravendeel, Barbara; Huits, Henk; Struss, Darush; Swanson-Wagner, Ruth; van Leeuwen, Hans; van Ham, Roeland C H J; Fito, Laia; Guignier, Laëtitia; Sevilla, Myrna; Ellul, Philippe; Ganko, Eric; Kapur, Arvind; Reclus, Emannuel; de Geus, Bernard; van de Geest, Henri; Te Lintel Hekkert, Bas; van Haarst, Jan; Smits, Lars; Koops, Andries; Sanchez-Perez, Gabino; van Heusden, Adriaan W; Visser, Richard; Quan, Zhiwu; Min, Jiumeng; Liao, Li; Wang, Xiaoli; Wang, Guangbiao; Yue, Zhen; Yang, Xinhua; Xu, Na; Schranz, Eric; Smets, Erik; Vos, Rutger; Rauwerda, Johan; Ursem, Remco; Schuit, Cees; Kerns, Mike; van den Berg, Jan; Vriezen, Wim; Janssen, Antoine; Datema, Erwin; Jahrman, Torben; Moquet, Frederic; Bonnet, Julien; Peters, Sander

    2014-10-01

    We explored genetic variation by sequencing a selection of 84 tomato accessions and related wild species representative of the Lycopersicon, Arcanum, Eriopersicon and Neolycopersicon groups, which has yielded a huge amount of precious data on sequence diversity in the tomato clade. Three new reference genomes were reconstructed to support our comparative genome analyses. Comparative sequence alignment revealed group-, species- and accession-specific polymorphisms, explaining characteristic fruit traits and growth habits in the various cultivars. Using gene models from the annotated Heinz 1706 reference genome, we observed differences in the ratio between non-synonymous and synonymous SNPs (dN/dS) in fruit diversification and plant growth genes compared to a random set of genes, indicating positive selection and differences in selection pressure between crop accessions and wild species. In wild species, the number of single-nucleotide polymorphisms (SNPs) exceeds 10 million, i.e. 20-fold higher than found in most of the crop accessions, indicating dramatic genetic erosion of crop and heirloom tomatoes. In addition, the highest levels of heterozygosity were found for allogamous self-incompatible wild species, while facultative and autogamous self-compatible species display a lower heterozygosity level. Using whole-genome SNP information for maximum-likelihood analysis, we achieved complete tree resolution, whereas maximum-likelihood trees based on SNPs from ten fruit and growth genes show incomplete resolution for the crop accessions, partly due to the effect of heterozygous SNPs. Finally, results suggest that phylogenetic relationships are correlated with habitat, indicating the occurrence of geographical races within these groups, which is of practical importance for Solanum genome evolution studies.

  17. Evaluation of the Effect of Ecologic on Root Knot Nematode, Meloidogyne incognita, and Tomato Plant, Lycopersicon esculenum

    Directory of Open Access Journals (Sweden)

    Gary W. Lawrence

    2008-06-01

    Full Text Available Nonchemical methods and strategies for nematode management including cultural methods and engineered measures have been recommended as an alternative to methyl bromide (a major soil fumigant, due to its role in the depletion of the ozone layer. Hence, an international agreement has recently been reached calling for its reduced consumption and complete phasing out. This present research evaluates the potential of Ecologic, a biological, marine shell meal chitin material, as a soil amendment management agent for root knot nematode, Meloidogyne incognita, control, and its effect on the growth of Floradel tomato plant, Lycopersicon esculentum. To accomplish this goal, studies were conducted during which, experimental pots were set up in greenhouse environments using sterilized soil inoculated with 5,000 root-knot eggs per 1500 g soil. There were 4 treatments and 5 replications. Treatments were: No chitin; 50 g chitin; 100 g chitin; and 200 g chitin. A two-week wait period following Ecologic amendment preceded Floradel tomato planting to allow breakdown of the chitin material into the soil. Fresh and dry weights of shoot and root materials were taken as growth end-points. A statistically significant difference (p ≤ 0.05 was obtained with regard to the growth rate of L. esculentum at 100 g chitin treatment compared to the control with no chitin. Mean fresh weights of Floradel tomato were 78.0 ± 22.3g, 81.0 ± 20.3g, 109.0 ± 25.4g and 102.0 ± 33.3g at 0, 50, 100 and 200g chitin, respectively. The analysis of root knot nematode concentrations indicated a substantial effect on reproduction rate associated with chitin amendment. Study results showed a significant decrease in both root knot nematode eggs and juveniles (J2 at 100g and 200g Ecologic chitin levels, however, an increase in nematode concentrations was recorded at the 50g Ecologic chitin level (p ≤ 0.05. The mean amounts of J2 population, as

  18. Connexin mutants and cataracts

    Directory of Open Access Journals (Sweden)

    Eric C Beyer

    2013-04-01

    Full Text Available The lens is a multicellular, but avascular tissue that must stay transparent to allow normal transmission of light and focusing of it on the retina. Damage to lens cells and/or proteins can cause cataracts, opacities that disrupt these processes. The normal survival of the lens is facilitated by an extensive network of gap junctions formed predominantly of connexin46 and connexin50. Mutations of the genes that encode these connexins (GJA3 and GJA8 have been identified and linked to inheritance of cataracts in human families and mouse lines. In vitro expression studies of several of these mutants have shown that they exhibit abnormalities that may lead to disease. Many of the mutants reduce or modify intercellular communication due to channel alterations (including loss of function or altered gating or due to impaired cellular trafficking which reduces the number of gap junction channels within the plasma membrane. However, the abnormalities detected in studies of other mutants suggest that they cause cataracts through other mechanisms including gain of hemichannel function (leading to cell injury and death and formation of cytoplasmic accumulations (that may act as light scattering particles. These observations and the anticipated results of ongoing studies should elucidate the mechanisms of cataract development due to mutations of lens connexins and abnormalities of other lens proteins. They may also contribute to our understanding of the mechanisms of disease due to connexin mutations in other tissues.

  19. Altered Phytochrome Regulation of Greening in an aurea Mutant of Tomato.

    Science.gov (United States)

    Ken-Dror, S; Horwitz, B A

    1990-04-01

    A brief pulse of red light accelerates chlorophyll accumulation upon subsequent transfer of dark-grown tomato (Lycopersicon esculentum) seedlings to continuous white light. Such potentiation of greening was compared in wild type and an aurea mutant W616. This mutant has been the subject of recent studies of phytochrome phototransduction; its dark-grown seedlings are deficient in phytochrome, and light-grown plants have yellow-green leaves. The rate of greening was slower in the mutant, but the extent (relative to the dark control) of potentiation by the red pulse was similar to that in the wild type. In the wild type, the fluence-response curve for potentiation of greening indicates substantial components in the VLF (very low fluence) and LF (low fluence) ranges. Far-red light could only partially reverse the effect of red. In the aurea mutant, only red light in the LF range was effective, and the effect of red was completely reversed by far-red light. When grown in total darkness, aurea seedlings are also deficient in photoconvertible PChl(ide). Upon transfer to white light, the aurea mutant was defective in both the abundance and light regulation of the light-harvesting chlorophyll a/b binding polypeptide(s) [LHC(II)]. The results are consistent with the VLF response in greening being mediated by phytochrome. Furthermore, the data support the hypothesis that light modulates LHC(II) levels through its control of the synthesis of both chlorophyll and its LHC(II) apoproteins. Some, but not all, aspects of the aurea phenotype can be accounted for by the deficiency in photoreception by phytochrome.

  20. RESISTÊNCIA DE TOMATEIRO (Lycopersicon esculentum Mill. A Stemphylium solani Weber RESISTANCE OF TOMATO (Lycopersicon esculentum Mill. TO THE Stemphylium solani Weber

    Directory of Open Access Journals (Sweden)

    Reinaldo Soares de Paula

    2007-09-01

    ="justify">In the climate conditions of the Brazilian central west regions, tomato can be cultivated the whole year. However, the production is low and quite onerous in function of different factors Besides, different diseases affect the crop. Among the most being the fungal important is the fungi Stemphylium solani, responsible for damages of qualitative and quantitative nature in tomato. With the objective of finding a way to minimize the effect of these pathogen, an experiment was conduced at the experimental fields of the Federal University of Goiás, Goiânia-GO, Brazil. It is located at an altitude of 730 m, latitude of 16° 41’S and longitude of 49° 17’W, with temperature varying among 20 to for 40ºC, relative humidity (average of the month of 80% in August, 83% in September and 85% in October. Precipitation in August, September and October of 1999 was respectively 0.0 mm, 69.6 mm, and 118.4 mm. The main objectives were to test levels of resistance of commercial varieties, genotypes belonging to the bank of germoplasm of Embrapa-CNPH and F1 generations of tomato Lycopersicon esculentum in field conditions to S. solani. The evaluations were accomplished at the 36, 43, 50, 57, 64, 71, 78 and 85 days after the seedlings planting combining diagramatic scale and grades. Was considered the percentage of infected area on the leaf (PIAL and the also grades: 1 – without symptoms; 2 – spraid lesions; 3 – gathering lesions; 4 – partial dryness of the leaf; 5 – death of the leaf and 6 – death of the plant. The differentiation among genotypes was made through analysis of variance of the values of area under disease progress curve and by of Tukey’s test at the level of 5% of probability and also the logistic model. Regarding resistance to S. solani, Ohio 4013, Yoshimatusu and TSW-10 behaved as resistant, among the indeterminate. Among the determined ones, F1 (Hawaii 7998 x Monense showed higher resistance. The genotypes Ohio 4013 and

  1. Differential response of domestic and wild Lycopersicon species to chilling under low light : Growth, carbohydrate content, photosynthesis and the xanthophyll cycle

    NARCIS (Netherlands)

    Venema, JH; Posthumus, F; van Hasselt, PR; de Vries, Michal

    1999-01-01

    The response of five Lycopersicon species to 14 days moderate chilling at 10 degrees C under low light (75 mu mol m(-2) s(-1)) and subsequent recovery was examined by measurements on relative shoot growth rate, leaf dry matter and carbohydrate content, CO2-exchange and pigment composition. In additi

  2. Low-temperature-related growth and photosynthetic performance of alloplasmic tomato (Lycopersicon esculentum Mill.) with chloroplasts from L-hirsutum Humb. & Bonpl.

    NARCIS (Netherlands)

    Dolstra, O; Venema, JH; Groot, PJ; van Hasselt, PR

    2002-01-01

    Growth and photosynthetic performance were analyzed in alloplasmic tomato at a high- (25/17degreesC; HTR) and low-temperature regime (12/6degreesC; LTR) in order to establish the role of cytoplasmic variation on low-temperature tolerance of tomato ( Lycopersicon esculentum Mill.). Four alloplasmic t

  3. Secretos de Mutantes

    OpenAIRE

    Marín, Martha; Muñoz, Germán; Serrano, Rafael

    2017-01-01

    Apartándose de enfoques que consideran las culturas juveniles como ‘desviaciones sociales', ‘tribus urbanas' o ‘nuevos movimientos políticos', Secretos de mutantes bucea en culturas juveniles urbanas como la Skinhead, el Punk, el Metal, el Hardcore, el Grunge y el Hip Hop, explorándolas desde un punto de vista inédito: su dimensión de creación, para percibir los cruciales y casi desconocidos procesos que sus miembros llevan a cabo en estos vastos universos de experimentación. Esta obra se nut...

  4. Salt-mediated changes in leaf mesophyll cells of Lycopersicon esculentum Mill. plants

    Directory of Open Access Journals (Sweden)

    Magdalena Gapinska

    2014-09-01

    Full Text Available Five-week-old tomato plants (Lycopersicon esculentum cv. Perkoz grown in pots containing garden soil in a growth chamber were submitted to 50 or 150 mM NaCl for 1 h, 2 and 5 days. Tomato leaf anatomy generally did not change after short time salinity, except 5-day-treatment with 150 mM NaCl, where changed cell shape (shrunk and deformed simultaneously with increased volume of intercellular spaces (IS were observed. Although leaf hydration (H depleted only 1 h after 150 mM NaCl treatment both salt concentrations generated two coexisting populations of salt-affected mesophyll cells: (i slightly-affected (Sl-A which showed incipient plasmolysis or slightly changed shapes, and (ii severely-affected (Sv-A which showed severe plasmolysis; serious deformation of cell shape or disorganization including cell degeneration. In Sl-A cells salinity changed location and shape of chloroplasts which were: more rounded, with oversized starch grains (SG (2d or more flat (5d. Salt-mediated changes were becoming more distinguished and pronounced with length of 150 mM NaCl treatment. The amount of salt-affected cells was changing during the experiment and depended on the salt concentration. In 50 mM-treated plants salt-affected cells appeared 1 h after treatment (~40% and raised up to 78% on 2nd day, however the population of Sl-A cells dominated. In 150 mM NaCl-treated plants the percentage of affected cells raised during the experiment from 75% to 99%. Firstly Sl-A cells dominated, but on the 5th day the majority was Sv-A. Salt-affected cells were distributed quite evenly in palisade or spongy mesophyll, except 2 d after treatment with 50 mM NaCl, when their number was higher in the palisade mesophyll. Sv-A cells in the spongy mesophyll were located mostly near the bundle while in the palisade mesophyll more irregularly. Different susceptibility of cells to salt stress might be the consequence of an unequal distribution of osmotic stress and subsequent ionic

  5. Capítulo V: evaluación de especies silvestres de Lycopersicon sp. como fuente de resistencia al insecto plaga Scrobipalpula absoluta (Meyrick y su intento de transferencia a Lycopersicon esculentum Mill

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    1994-12-01

    Full Text Available

    En condiciones de campo, se evaluaron 32 introducciones silvestres de Lycopersicon sp. y una de la especie cultivada, L. esculentum Mill, con el fin de determinar la resistencia a Scrobipalpula absoluta (Meyrick. Se utilizó el diseño experimental bloques completos al azar con 4 repeticiones. Como bordes se colocaron tres variedades comerciales susceptibles al insecto (Chonto "Mata Verde", Napoli Y Chonto "Santa Cruz Kada" con el fin de tener una fuente de infestación natural y permanente del cogollero dentro del experimento. Se evaluaron los caracteres número de cogollos afectados, número de hojas dañadas, número de ampollas e intensidad de daño. Todas las introducciones de L. hirsutum y L. peruvianum fueron altamente resistentes. Las introducciones 1406 y 1407 de L. pimpinellifolium también fueron altamente resistentes. La introducción 1759 de L. esculentum y L. esculentum var. ceraciforme fueron muy susceptibles. Las introducciones de L. pimpinellifolium y L. hirsutum no tuvieron dificultad para hibridarse con L. esculentum var. Tropic. El cruzamiento L. esculentum x L. peruvianum no presentó semilla híbrida y se requirió efectuar cultivo de embriones inmaduros, in vitro, utilizando el medio Murashige & Skoog pero sin lograrse resultados positivos.

    Thirty two (32 wild accessions of Lycopersicon sp. and one (1 cultivated accession of Lycopersicon esculentum Mill were evaluated to determinate the resistance to Scrobipalpula absoluta (Meyrick. The experiment was conducted with a complete random design and four repetitions. Three (3 susceptibles cultivated accessions of L. esculentum (Chonto "Mata Verde", Napoli and Chonto "Santa Cruz Kada" were sowed to have natural infestation of S. absoluta. Damage intensity, number of buds damaged, number of leaves demaged and number of "blister" in the leaves were evaluated, All evaluated accessions of L. peruvianum showed heigh resistence. 1406 and 1407 accessions of L. pimpinellifolium

  6. In vitro selection of NaCl-tolerant mutant of Lycopersicon esculentum Mill%栽培番茄耐盐突变体的离体筛选

    Institute of Scientific and Technical Information of China (English)

    陈火英; 张建华; 张晓宁

    2002-01-01

    栽培番茄品种"矮黄"的子叶作为外植体诱导愈伤组织,用NaCl进行直接高盐胁迫筛选.结果表明,225 mmol/LNaCl直接高盐胁迫获得了耐盐突变体,10株完整的再生耐盐植株,在150 mmol/LNaCl的盐胁迫下,成活率可达70%,而未经胁迫筛选过的原始株成活率则为零.其中,1株耐盐突变株能正常开花、结果.对其后代离体培养的茎尖和下胚轴外植体耐盐性进行比较,表明其后代仍然保持耐盐性.%To obtain salt-tolerant tomato plants, NaCl at a different level was added into the culture medium. Cotyledon-derived calli tolerant to 225mmol/L NaCl were selected in vitro and regenerated into plants. The 10 plants regenerated from salt-tolerant calli obtained by a direct use of 225mmol/L NaCl showed high tolerance when subjected to NaCl stress. Plants retained tolerance following transplant to containers filled with a mixture of peat and vermiculite (3∶1) and watered with 150 mmol/L NaCl. But only one salt-tolerant regenerants flowered and fruited, and transferred tolerance to their progeny following self-pollination.

  7. ECB deacylase mutants

    Science.gov (United States)

    Arnold, Frances H.; Shao, Zhixin; Zhao, Huimin; Giver, Lorraine J.

    2002-01-01

    A method for in vitro mutagenesis and recombination of polynucleotide sequences based on polymerase-catalyzed extension of primer oligonucleotides is disclosed. The method involves priming template polynucleotide(s) with random-sequences or defined-sequence primers to generate a pool of short DNA fragments with a low level of point mutations. The DNA fragments are subjected to denaturization followed by annealing and further enzyme-catalyzed DNA polymerization. This procedure is repeated a sufficient number of times to produce full-length genes which comprise mutants of the original template polynucleotides. These genes can be further amplified by the polymerase chain reaction and cloned into a vector for expression of the encoded proteins.

  8. EVALUACIÓN DE LA TOLERANCIA AL CALOR A NIVEL DE PLANTA EN EL GERMOPLASMA DE TOMATE (Solanum L. sección Lycopersicon subsección Lycopersicon CONSERVADO Ex Situ

    Directory of Open Access Journals (Sweden)

    Marilyn Florido

    2009-01-01

    Full Text Available Este trabajo se desarrolló con el objetivo de evaluar la tolerancia al calor en una muestra representativa del germoplasma de tomate (Solanum L. sección Lycopersicon subsección Lycopersicon conservado ex situ en las colecciones cubanas e identificar las accesiones más tolerantes para su empleo en los programas de mejoramiento genético. Para ello se evaluó el porcentaje de fructificación en los períodos óptimo y estresante (primavera-verano del cultivo, para calcular los criterios de estrés siguientes: índice de susceptibilidad al estrés (ISE, valor de tolerancia al estrés (TOL, índice de tolerancia al estrés (ITE, fructificación geométrica del estrés (FGE e índice de tolerancia relativo (IT. Se clasificaron las 122 accesiones por su tolerancia al calor a nivel de planta en base al porcentaje de fructificación en siembras de primavera-verano y la relación entre los índices de tolerancia evaluados se efectuó mediante análisis Biplot. Se pudo comprobar que en el germoplasma evaluado existieron accesiones con altos porcentajes de fructificación en el período de primavera-verano, lo cual indica que en el germoplasma que se conserva ex situ en Cuba existen accesiones tolerantes al calor, que pueden ser explotadas en los programas de mejoramiento genético para obtener variedades e híbridos con buen comportamiento en estas condiciones.

  9. RELACION ENTRE LA TERMOESTABILIDAD DE LA MEMBRANA, LA VIABILIDAD CELULAR Y LOS CRITERIOS DE TOLERANCIA EN LA EVALUACIÓN DE LA TOLERANCIA AL CALOR EN TOMATE (Solanum L. sección Lycopersicon subsección Lycopersicon

    Directory of Open Access Journals (Sweden)

    Marilyn Florido Bacallao

    2011-01-01

    Full Text Available El presente trabajo se desarrolló con el objetivo deconocer si existe variabilidad en cuanto a tolerancia al calor enuna muestra representativa del germoplasma de tomate (Solanum L. sección Lycopersicon subsección Lycopersicon conservadoex situ en las colecciones cubanas e identificar las accesionesmás tolerantes para su empleo en los programas de mejoramiento genético. Para ello se calcularon los parámetros estadísticos:media, rango y coeficiente de variación de los caracterestermoestabilidad de la membrana celular (TMC y viabilidadcelular (VC, evaluados a nivel de tejido, así como de los caracteresy criterios de tolerancia: fructificación potencial (FP, fructificaciónen condiciones de estrés (FE, fructificación geométrica del estrés(FGE, tolerancia (TOL, índice de susceptibilidad al estrés (ISE,índice de tolerancia al estrés (ITE e índice de tolerancia relativo(ITR, evaluados a nivel de planta. Se evaluó, asimismo, la relaciónexistente entre estos, mediante estimaciones del índice de coincidencia de las mejores y peores accesiones, y la correlaciónexistente entre ellos. Se pudo comprobar que las evaluaciones anivel de tejido, especialmente la TMC, tuvo altos índices de coincidencia y correlación positiva con los criterios de toleranciaa nivel de planta, sobre todo con ITE o FGE, determinándose 18accesiones que coincidentemente se clasificaron como tolerantes al calor por todos los indicadores evaluados, las cuales seproponen como progenitores en los programas de mejoramientopara tolerancia al calor en el cultivo.

  10. Nicotine promotes rooting in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

    Science.gov (United States)

    Bamel, Kiran; Gupta, Rajendra; Gupta, Shrish C

    2015-11-01

    Nicotine promotes rooting in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby). Nicotine at 10(-9) to 10(-3) M concentrations was added to the MS basal medium. The optimum response (three-fold increase in rooting) was obtained at 10(-7) M nicotine-enriched MS medium. At the same level i.e. 10(-7) M Nicotine induced dramatic increase (11-fold) in the number of secondary roots per root. We have shown earlier that exogenous acetylcholine induces a similar response in tomato leaves. Since nicotine is an agonist of one of the two acetylcholine receptors in animals, its ability to simulate ACh action in a plant system suggests the presence of the same molecular mechanism operative in both, animal and plant cells. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Phytochrome-mediated induction of phenylalanine ammonia-lyase in the cotyledons of tomato (Lycopersicon esculentum Mill.) plants.

    Science.gov (United States)

    Lercari, B; Sodi, F; Fastami, C

    1982-01-01

    Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5.) induction in cotyledons from 96-h dark-grown Lycopersicon esculentum Mill. was studied in response to continuous light and hourly light pulses (blue, red, far red). The increases of PAL promoted by blue and red pulses are reversed completely by immediately following 758 nm irradiations. The response to continuous red light could be substituted for by hourly 6-min red light pulses. The effect of continuous red treatments is mainly due to a multiple induction effect of phytochrome. In contrast to red light, hourly light pulses with far red and blue, light can only partially substitute for continuous irradiation. The continuous blue response could be due to a combination of a multiple induction response and of a high irradiance response of phytochrome. The continuous far red response, could represent a high irradiance response of phytochrome. Dichromatic irradiations indicate that phytochrome is the photoreceptor controlling the light response (PAL) in tomato seedlings.

  12. Effect of Heat Shock Treatment and Aloe Vera Coating to Chilling Injury Symptom in Tomato (Lycopersicon asculantum Mill.

    Directory of Open Access Journals (Sweden)

    Sutrisno

    2012-04-01

    Full Text Available This research was undertaken to determine the effect of length in heat shock and edible coating as pre-storage treatment to Chilling Injury (CI symptom reflected by ion leakage induced and quality properties in tomato (Lycopersicon asculantum Mill.. Heat Shock Treatment (HST was conducted at three different levels of length, which were, 20; 40 and 60 min. Edible coating was conducted using aloe vera gel. The result showed that HST and Aloe Vera Coating (AVC were more effective to reduce CI symptom at lower chilling storage. Prolong exposure to heated water may delay climacteric peak. The length of heat shock, AVC treatment and low temperature storage significantly affected the tomato quality parameter but not significantly different for each treatment except weight loss. HST for 20 min at ambient temperature was significantly different to other treatment.

  13. Caracterización y evaluación de recursos genéticos del genero Lycopersicon

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    1993-12-01

    Full Text Available

    Mediante los descriptores de IBPGR se caracterizaron y evaluaron 118 introducciones del género Lycopersicon, en el Centro Experimental de la Universidad Nacional Sede Palmira. Se utilizó el diseño experimental de Bloques al azar con dos repeticiones; la parcela experimental estuvo constituida por seis plantas. Se estudiaron nueve caracteres relacionados con la planta, diez caracteres relacionados con el fruto, componentes del rendimiento y presencia o ausencia de plagas y enfermedades. Se encontró gran variabilidad para la mayoría de los caracteres. Las variedades de la especie cultivada, L. esculentum, presentaron las mayores producciones por planta y el mayor tamaño de fruto. Las especies silvestres; presentaron mayor resistencia a plagas y enfermedades. Se destacaron los siguientes variedades de L. esculentum por presentar altas producciones y tolerancia a plagas y enfermedades: ADB 18, ADB 400, 1600, 1601 Y Rio Fuego.

    118 accessions of the genus Lycopersicon were characterized and evaluated to determinate the genetic potential, using the IBPGR descriptors. The experiment was conducted, using a complete random design and two repetitions. Characteristics concerned to the plant, fruit, yield components and resistence to insects and disease was studied. Important fenotipic differences were founded. The varieties of the cultivated specie L. esculentum, showed heigh productions per plant and heigh average fruit weight. The wild accessions showed heigh resistence to the insects and pathogens. ADBI8, ADB 400, 1600, 1601 and Rio Fuego accessions of the L. esculentum showd heigh productions per plant and heigh resistence to the insects and pathogens.

  14. Influence of manganese on yielding of tomato (Lycopersicon esculentum Mill. cultivated in rockwool

    Directory of Open Access Journals (Sweden)

    Tomasz Kleiber

    2014-06-01

    Full Text Available The aim of the conducted studies was to determine the effect of different concentrations of manganese in nutrient solution on yielding of tomato (Lycopersicon esculentum Mill. cvs. ‘Alboney F1’ and ‘Emotion F1’ for optimization of the nutrition (experiment I and to determine the threshold of tolerance of plants on the mentioned nutrient (experiment II. Plants were grown in rockwool using a nutrient solution with the differentiated contents of manganese (mg·dm-3: experiment I, 2008-2011 – control (0.06, 0.3, 0.6, 1.2 (described as Mn-0, Mn-0.3, Mn-0.6, Mn-1.2, experiment II, 2012 – 2.4, 4.8, 9.6, 19.2 (described as Mn-2.4, Mn-4.8, Mn-9.6, Mn-19.2. For plant fertigation was used standard nutrient solution with the following chemical composition (mg·dm-3: N-NH4 – 2.2, N-NO3 – 230, P – 50, K – 430, Ca – 145, Mg – 65, Cl – 35, S-SO4 – 120, Fe – 2.48, Zn – 0.50, Cu – 0.07. pH value was 5.50, and EC – 3.00 mS·cm-1. The earliest symptoms of manganese poisoning plants were observed in case of Mn-19.2 – a month and a half after the beginning of the cultivation, and in the case of Mn-9.6 – after 2.5 months of exposure to the nutrient solution. Initial signs of plants poisoning applying manganese Mn-4.8 were observed after a 3-month use of the nutrient solution. To the level of Mn-1.2 there was a significant effect of manganese on the tomatoes yield of class I, III, IV and VI. The variety affected the average yield of class I and V, only. The highest marketable fruit yield of ‘Alboney F1’ was obtained using nutrient solutions with manganese content of 0.3 and 0.6 mg·dm-3. In the case of ‘Emotion F1’ the yield by using Mn-0 and Mn-0.3 was significantly lower than in the case of Mn-0.6. In the application of the nutrient solution containing 1.2 mg Mn per 1 dm3 significant reducing of yielding was found while the plants were not observed for symptoms resulting from excessive manganese nutrition. In range of

  15. Studies on Internal Physiological and Biochemical Changes of Xantha Mutant in Melon Leaves%叶色黄化突变体甜瓜叶片内部生理生化变化的研究

    Institute of Scientific and Technical Information of China (English)

    邵勤; 于泽源; 李兴国; 李为; 高艳娟

    2013-01-01

      Xantha mutant 9388-1,a spontaneous mutant,was screened out from a normal green leaf melon(Cucumis melo L.)variety‘Baishami No.1’.Its contents of photosynthetic pigment and Chl synthesis precursors,chlorophyll fluorescence kinetic parameters and ultra-structure of chloroplasts were studied with mutant parent‘Baishami No.1’as contrast.The results showed that photosynthetic pigment content in mutant leaves was significantly lower than that in‘Baishami No.1’,while the ratio between chlorophyll a and chlorophyll b was significantly higher than in‘Baishami No.1’.Chlorophyll biosynthesis was hampered at conversion from prophobilinogen(PBG)into uroporphyrinogen (Urogen Ⅲ).Compared with chlorophyll fluorescence kinetic parameters of‘Baishami No.1’,F0, Pn,ФPS Ⅱ and ETR were significantly lower,while qN and NPQ were notably higher than that of‘Baishami No.1’.There were no significant differences in Fm,FV/Fm and qP .Under transmission electron microscopy,9388-1 leaves were found with underdeveloped chloroplast,containing aberrant thylakiods,fewer graum and starch grains than that of‘Baishami No.1’.Grana lamellae were deranged with a line shape and less stacked,but grana lamellae was crowed together in normal one.These results indicated that the biosynthesis chlorophyll was hampered,leading to aberrant chloroplast and the photosynthetic pigments content changed,and then affected their stability.The mutant kept a higher heat dissipation capacity,which could prevent photosynthetic apparatus from damaged by excessive light energy and maintain the normal growth of plant.%  从薄皮甜瓜白莎蜜1号中筛选出一个生长发育正常的自发型叶色黄化突变体9388-1,以突变亲本白莎蜜1号为对照,对其光合色素含量、叶绿素生物合成前体物质含量、叶绿素荧光参数以及叶绿体超微结构进行研究。结果显示:9388-1光合色素含量显著低于白莎蜜1号,而叶绿素a与叶绿素b

  16. Proteínas antifúngicas contra p. infestans en los espacios intercelulares de hojas de tomate (lycopersicon esculentum cerasiforme) posibles defensinas de plantas

    OpenAIRE

    Luz Dary Riaño; Humberto Miguel Zamora

    2008-01-01

    Se aislaron y caracterizaron parcialmente proteínas antifúngicas de los espacios intercelulares de hojas de tomate Lycopersicon esculentum cerasiforme, variedad que ha mostrado resistencia en campo a Phytophthora Infestans; se observó quedespués de inoculación con el patógeno dichas proteínas se acumularon sistémicamente en la planta. Las proteínas identificadasmostraron características de Defensinas de plantas, una nueva f...

  17. Mutant prevention concentrations of pradofloxacin for susceptible and mutant strains of Escherichia coli with reduced fluoroquinolone susceptibility.

    Science.gov (United States)

    Marcusson, Linda L; Komp Lindgren, Patricia; Olofsson, Sara K; Hughes, Diarmaid; Cars, Otto

    2014-10-01

    Pharmacodynamic and mutant prevention properties of the fluoroquinolone pradofloxacin (PRA) were measured against a set of 17 Escherichia coli strains carrying no, one or two known mutations conferring reduced fluoroquinolone susceptibility. The strains included susceptible wild-types, isogenic constructed mutants, isogenic selected mutants and clinical isolates. The effectiveness of PRA was determined with regard to preventing the selection of resistant mutants, using static and changing concentrations of drug. Ciprofloxacin was used as a reference drug. Minimum inhibitory concentrations (MICs) and mutant prevention concentrations (MPCs) of PRA for the susceptible wild-type strains were in the range 0.012-0.016mg/L and 0.2-0.3mg/L, respectively, giving a mean±standard deviation mutant prevention index (MPI=MPC/MIC) of 17.7±1.1. The mean MPI PRA of the 14 mutant strains was 19.2±12, and the mean MPI across all 17 strains was 18.9±10.8. In an in vitro kinetic model in which PRA was diluted with a half-life of 7h to mimic in vivo conditions, an initial concentration of PRA of 1.6-2.4mg/L (8-10× MPC), giving a PRA AUC/MPC ratio of 73-92, and a T>MPC of 21-23h was sufficient to prevent the selection of resistant mutants from the three susceptible wild-type strains. Dosing to reduce selection for antibiotic resistance in veterinary therapy has a role in reducing the reservoir of resistant mutants. We conclude that a level of dosing that prevents the selection of resistant mutants during therapy should be achievable in vivo. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  18. Métodos de remoção da mucilagem e qualidade fisiológica de sementes de tomate (Lycopersicon esculentum, Mill. Methods of mucilage remotion and physiological quality of tomato (Lycopersicon sculentum Mill. seeds

    Directory of Open Access Journals (Sweden)

    C. Cavariani

    1994-04-01

    Full Text Available Objetivando estudar diferentes métodos de remoção da mucilagem e a qualidade de sementes de tomate (Lycopersicon esculentum Mill., conduziu-se um experimento, em delineamento inteiramente casualizado com quatro repetições. Após extração manual, sementes e mucilagens foram submetidas aos seguintes tratamentos de remoção: lavagem imediata, fermentação por três dias, ácido clorídrico a 2,5% (25 ml/kg, durante 2 horas, ácido acético a 10% (25 ml/kg de material e hidróxido de amônia a 2,5% (25 ml/kg, durante 2 horas. Seguiu-se a avaliação da qualidade fisiológica das sementes através das determinações de porcentagem de germinação e vigor, pela porcentagem de emergência em areia, condutividade elétrica e pesos das matérias verde e seca de plântulas. Os resultados permitiram concluir que os métodos de remoção por lavagem imediata, fermentação, ácido clorídrico e ácido acético comercial não afetaram a qualidade fisiológica de sementes de tomate; a porcentagem de germinação não foi afetada pelos diferentes métodos de remoção e o método hidróxido de amônia prejudica o vigor das sementes.Different methods of mucilage remotion and quality of tomato (Lycopersicon esculentum Mill. seeds were studied, in a complete randomized design experiment with four replications. After manual extraction, seeds and slimes were submitted to the following remotion treatments: immediate washing, three-day fermentation, hydrochloric acid at 2,5% (25 mg/kg for 2 hrs., acetic acid at 10% (25 ml/kg of material, and ammonia hydroxide at 2,5% (25 ml/kg, for 2 hrs.. A physiological quality evaluation of seeds was carried out through the percentage of germination and vigor, percentage of in-sand emergence, electrical conductivity, and weight of fresh and dry matters of seedlings. The results showed that the methods of immediate washing, fermentation, commercial hydrochloric and acetic acids do not affect the physiological quality of

  19. EFEITO DE TRICOMAS, ALELOQUÍMICOS E NUTRIENTES NA RESISTÊNCIA DE LYCOPERSICON HIRSUTUM À TRAÇA-DO-TOMATEIRO EFFECT OF TRICHOMES, ALELLOCHEMICALS AND MINERALS ON THE RESISTANCE OF LYCOPERSICON HIRSUTUM TO TOMATO LEAF MINER

    Directory of Open Access Journals (Sweden)

    GERMANO LEÃO DEMOLIN LEITE

    1999-11-01

    Full Text Available Estudos foram conduzidos com o objetivo de verificar o efeito de tricomas, aleloquímicos e nutrientes nas folhas de partes do dossel das plantas na resistência de Lycopersicon hirsutum à traça- do-tomateiro, Tuta absoluta (Lepidoptera: Gelechiidae. Foram quantificados os teores de 2-tridecanona (2-TD, 2-undecanona (2-UD, N, P, K, Ca e Mg, densidade e tipos de tricomas e tamanho das folhas nos terços apical, mediano e basal do dossel de plantas de L. hirsutum e de L. esculentum e estudaram- se os efeitos destes fatores sobre características biológicas de T. absoluta. Observou-se elevação no teor de 2-TD da base para o ápice do dossel. Não se detectou diferença significativa quanto ao número de ovos de T. absoluta ao longo do dossel de L. hirsutum, constatando-se em L. esculentum maior oviposição nos terços apical e mediano do que no basal. As folhas do terço apical de L. hirsutum apresentaram maior efeito deletério sobre as larvas de traça.The objective of this work was to study the effect of trichomes, alellochemicals and minerals in the leaves of different canopy heights on the resistance of Lycopersicon hirsutum to tomato leaf miner, Tuta absoluta (Lepidoptera: Gelechiidae. Effects of 2-tridecanone (2-TD, 2-undecanone (2-UD, N, P, K, Ca and Mg levels, density and types of trichomes and leaf area on apical, medium and basal parts of plant dossel of L. hirsutum and L. esculentum on the oviposition and mines number of T. absoluta was studied. Production of 2-TD increased from the bottom to the top of the canopy. The apical part of plants of L. hirsutum showed more antibiotic effect on the caterpillar. T. absoluta oviposited more on leaves of the apical and medium portion of the plants than in the basal parts of L. esculentum.

  20. The altered gravitropic response of the lazy-2 mutant of tomato is phytochrome regulated.

    Science.gov (United States)

    Gaiser, J C; Lomax, T L

    1993-06-01

    Shoots of the lazy-2 (lz-2) gravitropic mutant of tomato (Lycopersicon esculentum Mill.) have a normal gravitropic response when grown in the dark, but grow downward in response to gravity when grown in the light. Experiments were undertaken to investigate the nature of the light induction of the downward growth of lz-2 shoots. Red light was effective at causing downward growth of hypocotyls of lz-2 seedlings, whereas treatment with blue light did not alter the dark-grown (wild-type) gravity response. Downward growth of lz-2 seedlings is greatest 16 h after a 1-h red light irradiation, after which the seedlings begin to revert to the dark-grown phenotype. lz-2 seedlings irradiated with a far-red light pulse immediately after a red light pulse exhibited no downward growth. However, continuous red or far-red light both resulted in downward growth of lz-2 seedlings. Thus, the light induction of downward growth of lz-2 appears to involve the photoreceptor phytochrome. Fluence-response experiments indicate that the induction of downward growth of lz-2 by red light is a low-fluence phytochrome response, with a possible high-irradiance response component.

  1. Polyamine metabolism in ripening tomato fruit. I. Identification of metabolites of putrescine and spermidine. [Lycopersicon esculentum Mill

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, R.; Davies, P.J. (Cornell Univ., Ithaca, NY (USA))

    1990-11-01

    The metabolism of (1,4-{sup 14}C)putrescine and (terminal methylene-{sup 3}H)spermidine was studied in the fruit pericarp (breaker stage) discs of tomato (Lycopersicon esculentum Mill.) cv Rutgers, and the metabolites identified by high performance liquid chromatography and gas chromatography-mass spectrometry. The metabolism of both putrescine and spermidine was relatively slow; in 24 hours about 15% of each amine was metabolized. The {sup 14}C label from putrescine was incorporated into spermidine, {gamma}-aminobutyric acid (GABA), glutamic acid, and a polar fraction eluting with sugars and organic acids. In the presence of gabaculine, a specific inhibitor of GABA:pyruvate transminase, the label going into glutamic acid, sugars and organic acids decreased by 80% while that in GABA increased about twofold, indicating that the transamination reaction is probably a major fate of GABA produced from putrescine in vivo. ({sup 3}H)Spermidine was catabolized into putrescine and {beta}-alanine. The conversion of putrescine into GABA, and that of spermidine into putrescine, suggests the presence of polyamine oxidizing enzymes in tomato pericarp tissues. The possible pathways of putrescine and spermidine metabolism are discussed.

  2. ACTIVIDAD BIOLÓGICA DEL PECTIMORF EN LA MORFOGÉNESIS In Vitro DEL TOMATE (Lycopersicon esculentum, Mill VAR. AMALIA

    Directory of Open Access Journals (Sweden)

    Dagmara Plana

    2003-01-01

    Full Text Available Diferentes investigaciones realizadas en el Laboratorio de Biotecnología de las plantas del Instituto Nacional de Ciencias Agrícolas (INCA, han demostrado el papel de los oligogalacturónidos como biorreguladores del crecimiento y desarrollo in vitro. En este trabajo se estudió la actividad biológica de diferentes concentraciones de la mezcla de oligogalacturónidos conocida como Pectimorf, en la respuesta morfogenética in vitro del tomate (Lycopersicon esculentum, Mill. En los ensayos realizados se emplearon como explantes segmentos apicales de hipocótilos y cotiledones provenientes de plántulas del cultivar Amalia, cultivadas en medio basal complementado con diferentes concentraciones de Pectimorf (1, 5, 10 y 15 mg.L-1 enpresencia o no de bajas concentraciones de BAP (0.25, 0.5 y 1 mg.L-1. Se puso de manifiesto la acción favorable del producto sobre la regeneración in vitro de los explantes estudiados, siendo la dosis de 10 mg.L-1 de Pectimorf la que favoreció la regeneración de plantas a partir de hipocótilos. En el caso de los cotiledones, las mejores combinaciones fueron aquellas donde se emplearon 10 mg.L-1 de Pectimorf con 0.25 y 0.5 mg.L-1 de BAP como complemento del medio de cultivo.

  3. Products Released from Enzymically Active Cell Wall Stimulate Ethylene Production and Ripening in Preclimacteric Tomato (Lycopersicon esculentum Mill.) Fruit.

    Science.gov (United States)

    Brecht, J K; Huber, D J

    1988-12-01

    Enzymically active cell wall from ripe tomato (Lycopersicon esculentum Mill.) fruit pericarp release uronic acids through the action of wall-bound polygalacturonase. The potential involvement of products of wall hydrolysis in the induction of ethylene synthesis during tomato ripening was investigated by vacuum infiltrating preclimacteric (green) fruit with solutions containing pectin fragments enzymically released from cell wall from ripe fruit. Ripening initiation was accelerated in pectin-infiltrated fruit compared to control (buffer-infiltrated) fruit as measured by initiation of climacteric CO(2) and ethylene production and appearance of red color. The response to infiltration was maximum at a concentration of 25 micrograms pectin per fruit; higher concentrations (up to 125 micrograms per fruit) had no additional effect. When products released from isolated cell wall from ripe pericarp were separated on Bio-Gel P-2 and specific size classes infiltrated into preclimacteric fruit, ripening-promotive activity was found only in the larger (degree of polymerization >8) fragments. Products released from pectin derived from preclimacteric pericarp upon treatment with polygalacturonase from ripe pericarp did not stimulate ripening when infiltrated into preclimacteric fruit.

  4. Olive mill wastewater triggered changes in physiology and nutritional quality of tomato (Lycopersicon esculentum mill) depending on growth substrate.

    Science.gov (United States)

    Ouzounidou, G; Asfi, M; Sotirakis, N; Papadopoulou, P; Gaitis, F

    2008-10-30

    We have studied the changes in the physiology and nutritional quality of Lycopersicon esculentum exposed to olive mill wastewater (OMW) with regard to cultivation in sand and soil. Tomato plant performance decreased with increasing concentration of OMW to both substrates. Root was more sensitive to OMW than the upper parts of the plants, grown either in sand or in soil for 10 days and 3 months, respectively, probably due to the direct OMW toxicity on roots as compared to other parts. Significant restriction on uptake and translocation of nutrients (K, Na, Fe, Ca and Mg) under OMW application was found. The decrease in the photochemical efficiency of PSII photochemistry in the light adapted state and the big decrease in photochemical quenching, indicate that OMW resulted in diminished reoxidation of Q(A)(-) and started to inactivate the reaction centers of PSII. The OMW supply on soil and sand, resulted in leaf water stress and lesser water use efficiency. Plants treated with high OMW concentration, produced fewer but bigger tomatoes as compared to plants treated with lower OMW concentration. Generally, fruit yield and nutritional value was inhibited under OMW application.

  5. Characterization and quantification of phenolic compounds in four tomato (Lycopersicon esculentum L.) farmers' varieties in northeastern Portugal homegardens.

    Science.gov (United States)

    Barros, Lillian; Dueñas, Montserrat; Pinela, José; Carvalho, Ana Maria; Buelga, Celestino Santos; Ferreira, Isabel C F R

    2012-09-01

    Tomato (Lycopersicon esculentum L.) is one of the most widely consumed fresh and processed vegetables in the world, and contains bioactive key components. Phenolic compounds are one of those components and, according to the present study, farmers' varieties of tomato cultivated in homegardens from the northeastern Portuguese region are a source of phenolic compounds, mainly phenolic acid derivatives. Using HPLC-DAD-ESI/MS, it was concluded that a cis p-coumaric acid derivative was the most abundant compound in yellow (Amarelo) and round (Batateiro) tomato varieties, while 4-O-caffeolyquinic acid was the most abundant in long (Comprido) and heart (Coração) varieties. The most abundant flavonoid was quercetin pentosylrutinoside in the four tomato varieties. Yellow tomato presented the highest levels of phenolic compounds (54.23 μg/g fw), including phenolic acids (43.30 μg/g fw) and flavonoids (10.93 μg/g fw). The phenolic compounds profile obtained for the studied varieties is different from other tomato varieties available in different countries, which is certainly related to genetic features, cultivation conditions, and handling and storage methods associated to each sample.

  6. Negative effects of fluoranthene on the ecophysiology of tomato plants (Lycopersicon esculentum Mill) Fluoranthene mists negatively affected tomato plants.

    Science.gov (United States)

    Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

    2010-02-01

    Cherry tomato plants (Lycopersicon esculentum Mill) were sprayed with fluoranthene and mixture of fluoranthene and mannitol solutions for 30d. The exposure was carried out in growth chambers in field conditions, and the air was filtered through charcoal filters to remove atmospheric contaminants. Plants were sprayed with 10microM fluoranthene as mist until they reached the fruiting stage, and the eco-physiological parameters were measured to determine the effects of the treatments. We measured CO(2) uptake and water vapour exchange, chlorophyll fluorescence, leaf pigment contents, visual symptoms and biomass allocation. Fluoranthene which was deposited as mist onto leaves negatively affected both growth and the quality of tomato plants, while other treatments did not. The photosynthetic rate measured at saturated irradiance was approximately 37% lower in fluoranthene-treated plants compared with the control group. Other variables, such as stomata conductance, the photochemical efficiency of PSII in the dark, Chl a, Chl b, and the total chlorophyll contents of the tomato leaves were significantly reduced in the fluoranthene-treated plants. Tomato plants treated with fluoranthene showed severe visible injury symptoms on the foliage during the exposure period. Mannitol (a reactive oxygen scavenger) mitigated effects of fluoranthene; thus, reactive oxygen species generated through fluoranthene may be responsible for the damaged tomato plants. It is possible for fluoranthene to decrease the aesthetic and hence the economic value of this valuable crop plant.

  7. Growth and development of tomato plants Lycopersicon Esculentum Mill. under different saline conditions by fertirrigation with pretreated cheese whey wastewater.

    Science.gov (United States)

    Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse

    2013-01-01

    Pretreated cheese whey wastewater (CWW) has been used at different salinity levels: 1.75, 2.22, 3.22, 5.02 and 10.02 dS m(-1) and compared with fresh water (1.44 dS m(-1)). Two cultivars (cv.) of the tomato plant Lycopersicon Esculentum Mill. (Roma and Rio Grande) were exposed to saline conditions for 72 days. Salinity level (treatment) had no significant effects on the fresh weight and dry matter of the leaves, stems and roots. Similar results were found when specific leaf area, leaflet area, ramifications number of 1st order/plant, stem diameter and length, nodes number/stem and primary root length were considered. Conversely, the salinity level significantly influenced the Soil Plant Analysis Development (SPAD) index and the distance between nodes in the plant stem. In the first case, an increase of 21% was obtained in the salinity levels of 5.02 and 10.02 dS m(-1) for cv. Rio Grande, compared with the control run. The results showed that the pretreated CWW can be a source of nutrients for tomato plants, with reduced effects on growth and development.

  8. Characterization of endophytic Bacillus strains from tomato plants (Lycopersicon esculentum) displaying antifungal activity against Botrytis cinerea Pers.

    Science.gov (United States)

    Kefi, Asma; Ben Slimene, Imen; Karkouch, Ines; Rihouey, Christophe; Azaeiz, Sana; Bejaoui, Marwa; Belaid, Rania; Cosette, Pascal; Jouenne, Thierry; Limam, Ferid

    2015-12-01

    Eighty endophytic bacteria were isolated from healthy tissues of roots, stems, leaves and fruits of tomato plants (Lycopersicon esculentum). Four strains, named BL1, BT5, BR8 and BF11 were selected for their antagonism against Botrytis cinerea, a phytopathogenic fungus responsible of gray mold in several important crops, with growth inhibitory activity ranging from 27 to 53%. Morphological, biochemical, and molecular parameters as 16S rDNA sequencing demonstrated that the selected bacterial strains were related to Bacillus species which are known to produce and secrete a lot of lipopeptides with strong inhibitory effect against pathogen mycelial growth. Electrospray mass spectrometry analysis showed that these strains produced heterogeneous mixture of antibiotics belonging to fengycin and surfactin for BL1 and BT5, to iturin and surfactin for BR8, to bacillomycin D, fengycin and surfactin for BF11. Furthermore, these bacteria exhibited biocontrol potential by reducing the disease severity when tested on detached leaflets. Based on their antifungal activity against Botrytis cinerea, these strains could be used for biological control of plant diseases.

  9. Enhanced biosynthesis of quercetin occurs as A photoprotective measure in Lycopersicon esculentum mill. under Acute UV-B exposure

    Directory of Open Access Journals (Sweden)

    Abhilasha Shourie

    2014-06-01

    Full Text Available Lycopersicon esculentum respond to UV-B by enhanced synthesis of flavonoid quercetin, a strong antioxidant that helps the plants to well acclimatize to UV-B stress. Three weeks old plants of L. esculentum were subjected to acute UV-B irradiation for 20, 40 and 60 minutes daily until 28 days and analyzed for the morphological and biochemical changes. UV-B exposure for 40 and 60 minutes considerably affected the growth and biomass of L. esculentum. The leaves were deformed, developed chlorosis and abscised early as compared to the unexposed plants. Biomass declined by 35% and total chlorophyll decreased by 24.7% due to disintegration of chloroplasts. Enhancement was seen in the content of carotenoids, anthocyanins and total flavonoids by 15, 33.3 and 22.8%, respectively, which was attributed to the photoprotective role of these compounds as potential quenchers of excess excitation energy. Quercetin content decreased on UV-B exposure to 20 and 40 min, and thereafter increased significantly by 5.19% on 60 min of exposure. This pattern probably indicated that the over-expression of genes involved in its biosynthesis such as phenylalanine ammonia lyase (PAL, chalcone synthase (CHS, flavanone 3-hydroxylase (F3H and dihydroflavonol 4-reductase (DFR occurred only after certain threshold exposure (60 min, which could be the strategy for developing tolerance against UV-B stress in L. esculentum.

  10. Quantitative genetic analysis indicates natural selection on leaf phenotypes across wild tomato species (Solanum sect. Lycopersicon; Solanaceae).

    Science.gov (United States)

    Muir, Christopher D; Pease, James B; Moyle, Leonie C

    2014-12-01

    Adaptive evolution requires both raw genetic material and an accessible path of high fitness from one fitness peak to another. In this study, we used an introgression line (IL) population to map quantitative trait loci (QTL) for leaf traits thought to be associated with adaptation to precipitation in wild tomatoes (Solanum sect. Lycopersicon; Solanaceae). A QTL sign test showed that several traits likely evolved under directional natural selection. Leaf traits correlated across species do not share a common genetic basis, consistent with a scenario in which selection maintains trait covariation unconstrained by pleiotropy or linkage disequilibrium. Two large effect QTL for stomatal distribution colocalized with key genes in the stomatal development pathway, suggesting promising candidates for the molecular bases of adaptation in these species. Furthermore, macroevolutionary transitions between vastly different stomatal distributions may not be constrained when such large-effect mutations are available. Finally, genetic correlations between stomatal traits measured in this study and data on carbon isotope discrimination from the same ILs support a functional hypothesis that the distribution of stomata affects the resistance to CO2 diffusion inside the leaf, a trait implicated in climatic adaptation in wild tomatoes. Along with evidence from previous comparative and experimental studies, this analysis indicates that leaf traits are an important component of climatic niche adaptation in wild tomatoes and demonstrates that some trait transitions between species could have involved few, large-effect genetic changes, allowing rapid responses to new environmental conditions.

  11. Nif- Hup- mutants of Rhizobium japonicum.

    OpenAIRE

    Moshiri, F; Stults, L; Novak, P.; Maier, R J

    1983-01-01

    Two H2 uptake-negative (Hup-) Rhizobium japonicum mutants were obtained that also lacked symbiotic N2 fixation (acetylene reduction) activity. One of the mutants formed green nodules and was deficient in heme. Hydrogen oxidation activity in this mutant could be restored by the addition of heme plus ATP to crude extracts. Bacteroid extracts from the other mutant strain lacked hydrogenase activity and activity for both of the nitrogenase component proteins. Hup+ revertants of the mutant strains...

  12. Efectos genéticos y heterosis de tomate (Lycopersicon esculentum Mill. en campo e invernadero para rendimiento y calidad Genetic effects and heterosis in tomato (Lycopersicon esculentum Mill. in field and greenhouse for yield and quality

    Directory of Open Access Journals (Sweden)

    David Sánchez Aspeytia

    Full Text Available El cultivo de tomate (Lycopersicon esculentum Mill. ocupa el segundo lugar de importancia en México, por su gran producción de 2.22 millones de toneladas que alcanzo en el año 2007, con un rendimiento promedio de 35.54 t ha-1. Para la región noreste de México este cultivo representa una alternativa agrícola bajo condiciones de agricultura protegida debido a la poca disponibilidad de agua y a las temperaturas extremas que llegan a ser hasta 48 ºC en verano. El conocimiento de la habilidad combinatoria general y específica de materiales genéticos es esencial para lograr diversos objetivos en un programa de mejoramiento tales como: desarrollar híbridos y variedades, incrementar variabilidad genética y evitar erosión genética. El objetivo de la presente investigación fue evaluar los efectos genéticos de cuatro progenitores y seis cruzas directas posibles, evaluados en campo e invernadero bajo el análisis de variables de rendimiento y de calidad. En el análisis de varianza combinado hubo diferencias altamente significativas (p≤ 0.01 entre ambientes para peso promedio de fruto y rendimiento así como diferencias significativas (p≤ 0.05 para días a primer corte, donde las condiciones ambientales de cada localidad fueron diferentes para los genotipos en general, incluyendo progenitores e híbridos, peso promedio de fruto y rendimiento, indicándonos que los genotipos se comportaron diferente y que los híbridos difirieron en su comportamiento debido a la diversidad genética de los progenitores.Tomato cultivation (Lycopersicon esculentum Mill. ranks second place of importance in Mexico, for its big production of 2.22 million tons that reached in year 2007, with an average yield of 35.54 t ha-1. For northeast region of Mexico this crop represents an agricultural alternative under protected agriculture conditions due to little water availability and to extreme temperatures that rise up to 48 ºC in summer. Knowledge of general and

  13. Ciclo de maturação e produção de etileno de tomates (Lycopersicon esculentum, Mill. transgênicos Ripening cycle and ethylene production of transgenic tomatoes (Lycopersicon esculentum, Mill.

    Directory of Open Access Journals (Sweden)

    Ana Lúcia CHAVES

    1998-04-01

    Full Text Available Objetivou-se estudar o comportamento fisiológico de frutos de tomateiro (Lycopersicon esculentum, Mill., da cv. Kadá, transformados geneticamente, via Agrobacterium tumefaciens, com o clone de DNA pMEL1, em orientação antisenso, e de frutos desta mesma cultivar, não transformados. O estudo fisiológico foi realizado avaliando-se a duração do ciclo de maturação dos frutos, amadurecidos na planta e após a colheita no estádio verde-maduro, e sua produção de etileno. Os frutos transformados amadurecidos na planta tiveram um ciclo total médio de 27 dias, enquanto os amadurecidos após a colheita, tiveram este intervalo prolongado a 50 dias. Ao contrário, os tomates não transformados apresentaram um ciclo de maturação mais acelerado quando colhidos no estádio verde-maduro, em relação aos frutos amadurecidos nas plantas. Os valores foram, em média, de 20 e 30 dias, respectivamente. Estes resultados estão correlacionados com as variações na produção de etileno observada nos dois genótipos. Frutos não transformados produziram, em média, 10,46 nL de etileno.g-1.h-1, enquanto os transgênicos tiveram sua produção de etileno diminuída para 0,13 nL.g-1.h-1. Pode-se concluir, então, que a redução da produção de etileno, verificada nos tomates transformados, é necessária, mas não é suficiente para prolongar o ciclo de maturação e aumentar a durabilidade dos frutos. Para que isto ocorra, é necessário que se proceda à colheita dos tomates no estádio verde-maduro.This work was carried out to study the physiological behaviour of tomato fruits (Lycopersicon esculentum, Mill., var. Kada, geneticaly transformed, via Agrobacterium tumefaciens, with the pMEL1 DNA clone, in antisense orientation, and nontransformed ones, from the same variety, growth in a greenhouse. The physiological study was conducted for evaluating the ripening cycle of fruits, ripened attached and detached from the plants in the mature-green stage

  14. Temporal regulation of polygalacturonase gene expression in fruits of normal, mutant, and heterozygous tomato genotypes.

    Science.gov (United States)

    Biggs, M S; Handa, A K

    1989-01-01

    Molecular cloning of polygalacturonase (PG; EC 3.2. 1.15) from fruits of tomato (Lycopersicon esculentum Mill cv Rutgers) was accomplished by constructing a cDNA library from turning stage poly(A)(+) RNA in lambdagtll and immunoscreening with polyclonal antibodies raised against purified PG2. Both PG cDNA and antibody probes were used to quantify changes in PG gene expression in pericarp from normal, mutant, and heterozygous genotypes. Results show that PG mRNA, protein, and enzyme activity sequentially peak at the turning, ripe, and red ripe stages of Rutgers pericarp ripening, respectively. PG gene expression was attenuated greatly (0-15% of normal on a gram fresh weight basis) for PG mRNA, protein, and enzyme activity in five ripening-impaired mutants (rin, nor, Nr, Gr, and Long Keeper) tested. Maximum expression of the PG gene in heterozygotes of rin, nor, Nr, Gr, and Long Keeper (crosses with Rutgers) at the mRNA level was about 25, 13, 17, 5, and 62% of the Rutgers turning stage, at the protein level was about 166, 110, 15, 6, and 104% of the Rutgers ripe stage, and at the enzyme activity level was about 69, 37, 4, 1, and 50% of the Rutgers red ripe stage, respectively. No PG gene expression was found in preclimacteric fruits or vegetative tissues. PG mRNA was localized on both free and membrane-bound polyribosomes of ripening pericarp. In addition to transcriptional regulation, mechanisms contributing to mRNA stability, delayed protein accumulation, and posttranslational modifications may play important roles in the overall accumulation of PG activity during fruit ripening.

  15. Wild Accessions and Mutant Resources

    DEFF Research Database (Denmark)

    Kawaguchi, Masayoshi; Sandal, Niels Nørgaard

    2014-01-01

    Lotus japonicus, Lotus burttii, and Lotus filicaulis are species of Lotus genus that are utilized for molecular genetic analysis such as the construction of a linkage map and QTL analysis. Among them, a number of mutants have been isolated from two wild accessions: L. japonicus Gifu B-129...

  16. Absisik asit (ABA) uygulamalarının domates (Lycopersicon esculentum Mill.) Fidelerinde bazı fizyolojik ve morfolojik özellikler ile kök gelişim değerlerine etkisi

    OpenAIRE

    2011-01-01

           Çalışma ile farklı doz ve sürelerde uygulanan absisik asit (ABA)'in domates (Lycopersicon esculentum Mill.) fidelerde oluşturduğu stresin; fizyolojik, morfolojik ve gelişim parametrelerine etkisi tespit edilmiş, ABA'nın domates fide yetiştiriciliğinde kullanılabilecek optimum doz ve uygulama süresi belirlenmiştir. Lycopersicon esculentum cv....

  17. Light-regulated expression of the nitrate-reductase and nitrite-reductase genes in tomato and in the phytochrome-deficient aurea mutant of tomato.

    Science.gov (United States)

    Becker, T W; Foyer, C; Caboche, M

    1992-08-01

    The phytochrome-deficient aurea mutant of tomato (Lycopersicon esculentum (L.) Mill) was used to investigate if phytochrome plays a role in the regulation of nitrate-reductase (NR, EC 1.6.6.1) and nitrite-reductase (NiR, EC 1.7.7.1) gene expression. We show that the expression of the tomato NR and NiR genes is stimulated by light and that this light response is mediated by the photoreceptor phytochrome. The red-light response of the NR and NiR genes was reduced in etiolated aurea seedlings when compared to isogenic wild-type cotyledons. The relative levels of NR mRNA and NiR transcripts and their diurnal fluctuations were identical in mature white-light-grown leaves of the wild-type and of the aurea mutant. The transcript levels for cab and RbcS (genes for the chlorophyll-a/b-binding protein of PSII and the small subunit of the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase, respectively) in aurea leaves grown in white light were indistinguishable from the respective transcript levels in the leaves of the wildtype grown under the same conditions. Despite a severe reduction in the chlorophyll content, the rate of net CO2 uptake by leaves of the aurea mutant was only slightly reduced when compared to the rate of net photosynthesis of wild-type leaves. This difference in the photosynthetic performances of wild-type and aurea mutant plants disappeared during aging of the plants. The increase in zeaxanthin and the concomitant decrease in violaxanthin in leaves of the aurea mutant compared with the same pigment levels in leaves of the wild-type indicate that the activity of the xanthophyll cycle is increased in aurea leaves as a consequence of the reduced CO2-fixation capacity of the mutant leaves.

  18. EVALUACIÓN DE CARACTERÍSTICAS DE INTERÉS AGRONÓMICO DE SIETE GENOTIPOS NATIVOS DE JITOMATE (Lycopersicon esculentum Mill.) CULTIVADOS EN HIDROPONÍA

    OpenAIRE

    2012-01-01

    México es considerado el centro de domesticación del jitomate (Lycopersicon esculentum Mill.). Sin embargo, existe escasa información que permita el aprovechamiento de las formas nativas de esta especie. El objetivo de la presente investigación fue evaluar algunas características de interés agronómico de siete genotipos provenientes de los estados de Guerrero y Puebla, cultivados en invernadero e hidroponía, y compararlos con un híbrido comercial de jitomate cherry (H-790). Se evaluaron día...

  19. Capítulo III: caracterización y evaluación de recursos genéticos del género Lycopersicon

    OpenAIRE

    Sierra Tulio Alberto; Osorio Erika Rocío; Vallejo Cabrera Franco Alirio

    1994-01-01

    Con el fin de determinar el potencial genético de 118 introducciones del género Lycopersicon se realizó la caracterización y evaluación, en el Centro Experimental de la Universidad Nacional Sede Palmira, utilizando los descriptores recomendados por el IBPGR (1981). Se utilizó el diseño experimental de Bloques al azar con dos repeticiones. La parcela experimental estuvo constituida por seis plantas. Se estudiaron nueve caracteres relacionados con la planta, diez caracteres relacionado...

  20. Effects of Different Sources of Nutrition on Quantitative and Qualitative Characteristics of Lycopersicon esculentum under Ecological Cropping System

    Directory of Open Access Journals (Sweden)

    M.B. Amiri

    2016-02-01

    Full Text Available Introduction: Increasing usage of chemical fertilizers imposes irreparable damages to the environment. Disadvantages of chemical fertilizers has led to more attention to the application of organic fertilizers and manures. The use of organic fertilizers and livestock, especially in nutrient poor soils, it is necessary to maintain soil quality. Plant growth promoting rhizobacteria (PGPR occupy the rhizosphere of many plant species and have beneficial effects on the host plant. They may influence the plant in a direct or indirect manner. A direct mechanism would be to increase plant growth by supplying the plant with nutrients and hormones. Indirect mechanisms on the otherhand, include, reduced susceptibility to diseases, and activing a form of defese referred to as induces systematic resistance. Examples of bacteria which have been found to enhance plant growth, include Pseudomonas, Enterobacter and Arthrobacter. Biofertilizers contain organic compounds that increase soil fertility either directly or as a result of their decay (9, 10. Tomato (Lycopersicon esculentum L. belongs to the nightshade family, Solanaceae. The plant typically grow 1-3 meters in height and a weak stem. It is a perennial in its native habitat, although often grown outdoors in temperate climates as an annual. An average common tomato weighs approximately 100 grams. Tomatoes contain the carotene lycopene, one of the most powerful natural antioxidants. In some studies, lycopene, especially in cooked tomatoes, has been found to help prevent prostate cancer. Lycopene has also been shown to improve the skin’s ability to protect against harmful UV rays. Tomatoes might help in managing human neurodegenerative diseases. The lycopene has no effect on the risk of developing diabetes, but may help relieve the oxidative stress of people who already have diabetes. The purpose of this study was the possibility of replacing chemical fertilizers with biofertilizers, reducing production

  1. Aftereffect conditions of prolonged space flight on physiological and biochemical processes and plant resistance Lycopersicon esculentum Mill. to pathogens

    Science.gov (United States)

    Mishchenko, Lidiya

    2016-07-01

    Tomatoes (Lycopersicon esculentum Mill.) - one of the most popular vegetables in Ukraine, they are a valuable product of therapeutic and dietetic foods because they contain a significant amount of nutrients and essential to the human body minerals and vitamins, but by the content of carotenoids - lycopene and β-carotene - is a powerful antioxidant. Therefore, tomato plants can be used successfully to astronauts on long space flights. We aftereffect was studied factors of space flight on the variety of tomato seeds Mir-1, which lasted (6 years) were on an orbital space station "Mir". Then, also after long-term storage in 2011, seeds were sown in the laboratory and received seedlings grown in field conditions Kiev region. The resulting seeds of the tomato crop in 2011 ("Space" and still) we used in our subsequent field studies in Kyiv and Poltava regions. We have previously shown that the "space" seeds had shown in 2011-2012 increased resistance to viruses PVY and PVM natural infectious background. Therefore, it is necessary continue the investigation and started to observe in future years, including 2015 and to analyze the results obtained. Because plants grown constantly in the field natural infectious background, there was a high probability of their defeat pathogens of different nature, including viruses. The works of many authors proved reduce the concentration of carotene and lycopene in tomatoes with the defeat of viruses (Raithak, 2012). In addition, the control plants were observed symptoms of such that is a viral infection, namely in 2011 - leaves curl in 2012 - except leaves curl and even mosaics. The research results were confirmed in 2013, namely on the plants of "space" seed no symptoms of, and in control - detection of potato virus Y (method RT-PCR) and symptoms of leaf curl and mosaic. During the bearing samples were taken leaves of the options and experiment conducted determination of photosynthetic pigments. It should be emphasized that in plant

  2. Effect of 1-methylcyclopropene post-harvest treatment on ripening process in cherry tomato fruit (Lycopersicon esculentum var. cerasiforme).

    Science.gov (United States)

    Opiyo, Arnold M; Ying, Tie-Jin

    2005-02-01

    The responses of cherry tomato (Lycopersicon esculentum var. cerasiforme) fruits to post-harvest treatment with 1-MCP were investigated. The maturity stage at which 1-MCP application is most effective in delaying the ripening process was determined, and then the effects of different concentrations (0, 0.035, 0.07 and 0.11 microL/L) of 1-MCP on ethylene production, fruit softening, chlorophyll, lycopene and carotenoids contents of mature green (MG) cherry tomato fruits were assessed. 1-MCP at 0.07 and 0.11 microL/L reduced fruit C(2)H(4) production, delayed the C(2)H(4) peak at ambient temperature. Although 1-MCP at 0.035 microL/L was effective in retarding fruit ripening, it did not suppress endogenous ethylene production. Fruit softening was suppressed by 1-MCP, but its initiation was not affected by 1-MCP. The rate of chlorophyll degradation and its pattern of change with time, and the initiation of lycopene biosynthesis as well as its accumulation were all affected by 1-MCP, but only the accumulation of carotenoids was suppressed. Accumulation of lycopene and carotenoids was almost permanently hampered by 1-MCP at 0.07 microL/L or higher concentrations, and fruit color could not reach the control level even 2 weeks after 1-MCP treatment, indicating the close association of the metabolism of these pigments with ethylene perception. Since the concentration of 0.11 microL/L of 1-MCP was so high that it did not elicit additional response very much than 0.07 microL/L, these concentrations were considered to be practically effective concentrations for cherry tomato at MG stage. The effective 1-MCP concentrations might provide a useful reference to the levels of ethylene receptors as well as ethylene sensitivity in a specific fruit at given development stage.

  3. Effect of Simulated Acid Rain on the Germination, Growth, Elements, Protein and Photosynthetic Pigments Contents in Tomato (Lycopersicon esculentum

    Directory of Open Access Journals (Sweden)

    M. Askary

    2014-04-01

    Full Text Available Uncontrolled use of fossil fuels in industries and the transport sector has led to an increase in concentrations of gaseous pollutants such as sulphur dioxide (SO2, nitrogen dioxide (NO2 and their derivatives and ozone (O3. In addition to dry and wet deposition of these gases has been the major route of influx in ionic form into the ecosystem. This investigation was evaluated the effects of simulated acid rain (SAR with different pH (6.8 as control, 6.5, 6, 5.5, 5, 4.5, 4, 3.5, 3 and 2.5 on germination, growth, elements, protein, photosynthetic pigments contents of Lycopersicon esculentum in hydroponic culture. Experiments were conducted at research laboratory of arak university in summer of 1391. Results were showed that from pH=6.8 until pH=5/5 significantly increased P and K and protein content, root and shoot dry and wet weight. SAR exposure with high acidity (pH=5/5 until pH=2.5 significantly suppressed germination, growth index, measured elements as P and K, protein and photosynthetic pigments, while significant increased sulphur contect from 150% to 550% compared to controls. Maximal amounts sulphur were measured in pH=2/5. Acid rain in low pH were decrease plant growth and make protein and incearsed sulphur content in leaf. As regards, low acidity promoted the growth of tomato plants and high acidity inhibit, Therefore, it is recommended that tomato plants cultures in soils with low acidity.

  4. Induction of Volatile Organic Compounds of Lycopersicon esculentum Mill. and Its Resistance to Botrytis cinerea Pers. by Burdock Oligosaccharide

    Institute of Scientific and Technical Information of China (English)

    Pei-Qing He; Li Tian; Kao-Shan Chen; Lin-Hua Hao; Guang-You Li

    2006-01-01

    In the present study, we investigated the induction of volatile organic compounds (VOCs) of Lycopersicon esculentum Mill. and its resistance to Botrytis cinerea Pers. by burdock oligosaccharide. The disease severity of L. esculentum was evaluated 48 h after treatment with 0.6% burdock oligosaccharide, followed by inoculation with a spore suspension of B. cinerea. The formation of O()2, the activity of lipoxygenases (LOX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), and the quantity and quality of changes in VOCs were determined a period of time after treatment with 0.6% burdock oligosaccharide. The results demonstrated that the disease index in treated plants was decreased by 42.5% compared with control 96 h after inoculation. The production of O()2 reached a maximum 6 h after treatment (1.36-fold compared with control). There was an increase in LOX, POD, CAT and SOD activity in response to burdock oligosaccharide treatment and the enzymes showed different trends in the time-course of induction. At 120 h after treatment,(E)-2-hexenal was increased by 92% compared with control, whereas methyl salicylate showed a gradual increase with induction period. Previous results had demonstrated that chitosan elicitor enhanced the production VOCs of L. esculentum and decreased plant susceptibility towards B. cinerea. Together, these findings suggest that increasing the production of VOCs in response to burrdock oligosaccharide may be an important mechanism for L. esculentumin its defense against pathogens. In addition, burrdock oligosaccharide may act as a potent elicitor of resistance to disease in L. esculentum.

  5. Hypoglycaemic Effects of Dietary Intake of Ripe and Unripe Lycopersicon esculentum (Tomatoes on Streptozotocin-Induced Diabetes Mellitus in Rats

    Directory of Open Access Journals (Sweden)

    A. M. Akinnuga

    2010-01-01

    Full Text Available Ripe and unripe tomatoes have been implicated in prevention of chronic diseases such as cancer probably due to their antioxidant, antibiotic, antifungal and anti-inflammatory properties. Problem statement: This study was designed to investigate whether ripe and unripe tomatoes will have hypoglycaemic effect in a chronic disease such as diabetes mellitus that has been characterized with hyperglycaemia. Approach: Twenty albino Wistar rats were divided into 4 groups (2 control and 2 test groups of 5 rats each. The normal and diabetic control groups were given citrate buffer (intraperitoneally and normal rat chow and 65 mg kg-1 streptozotocin (intraperitoneally and normal rat chow respectively. The test groups were given 65 mg kg-1 streptozotocin via intraperitoneal route and either a mixture of ripe or unripe tomato and normal rat chow. In all groups, the blood samples were obtained at the tail vein of the animals and the fasting blood glucose level were monitored and determined on the 1st, 3rd and 14th day of consumption of different feed combinations. Results: There was significant difference in blood glucose level in animals fed on ripe and unripe Lycopersicon esculentum (tomato compared to the normal and diabetic control groups on the 3rd and 14th day without significant difference on the 1st day. Conclusion: Both high-lycopene ripe tomato and high-tomatine unripe tomato have hypoglycaemic effect in diabetic mellitus at short period of dietary intake therefore this suggest that consumers may benefit by not only eating high-lycopene ripe tomatoes, but also high-tomatine unripe tomatoes.

  6. Effects of the Lycopersicon chmielewskii sucrose accumulator gene (sucr) on fruit yield and quality parameters following introgression into tomato.

    Science.gov (United States)

    Chetelat, R T; Deverna, J W; Bennett, A B

    1995-07-01

    A gene controlling fruit sucrose accumulation, sucr, was introgressed from the wild tomato species Lycopersicon chmielewskii into the genetic background of a hexose-accumulating cultivated tomato, L. esculentum. During introgression, the size of the L. chmielewskii chromosomal segment containing sucr was reduced by selection for recombination between RFLP markers for the sucr gene and flanking loci. The effects of sucr on soluble solids content, fruit size, yield and other fruit parameters were studied in the genetic background of the processing tomato cultivar 'Huntl00'. In a segregating BC5F2 generation, the smallest introgression containing sucr-associated markers was necessary and sufficient to confer high-level sucrose accumulation, the effects of which were completely recessive. Fruit of sucr/sucr genotypes were smaller than those of +/sucr or +/+ genotypes at all stages of development. The timing of sugar accumulation and total sugar concentration were unaffected by sugar composition. No differences in total fruit biomass (fresh weight of red and green fruit) at harvest were observed between the genotypes, and sucrose accumulators produced greater numbers of fruit than hexose accumulators in one family. However, the proportion of ripe fruit at harvest, and hence yield of ripe fruit, as well as average ripe fruit weight and seed set were reduced in sucr/sucr genotypes. Sucrose accumulation was also associated with increased soluble solids content, consistency, serum viscosity, predicted paste yield and acidity, and decreased color rating. In the first backcross to L. chmielewskii, hexose accumulators (+/sucr) had larger fruit than sucrose accumulators (sucr/sucr), while no difference in soluble solids was detected.

  7. Effect of Different Doses of NK Chemical Fertilizers and Compost on Growth and Yield Attributes of Tomato (Lycopersicon esculentum Mill.

    Directory of Open Access Journals (Sweden)

    Thayamini Harold Seran

    2016-07-01

    Full Text Available This study was conducted to evaluate the effect of NK chemical fertilizers in combination with compost on the growth and yield attributes of tomato (Lycopersicon esculentum Mill.. The pot experiment was done in a complete randomized block design possessing eight treatments with four replicates. Fruit weight, pulp weight, seed weight, total soluble solid, leaf area and dry weights of plat parts were taken and fruit yield was calculated. All the collected data were subjected to statistical analysis. The results revealed that there were significant differences in fruit and seed weights, total soluble solid, pulp weight, 100 seed weight, pulp consistency, leaf area and crop residue. In these parameters, higher mean values were recorded in chemical fertilizers (7.5 g N + 6 g K2O + 15 g P2O5 per m2 with compost (2 kg per m2 than those in the chemical fertilizers applied alone (9.0 g N + 8 g K2O + 15 g P2O5 per m2as standard control. Total soluble solid and fruit yield were 5.73 obrix and 3.21 kg/m2 respectively in the chemical fertilizers with compost (7.5 g N + 6 g K2O + 15 g P2O5 +2 kg compost per m2 treated plants and these were statically on par with the standard control which gave 4.36 obrix total soluble solid and 3.05 kg/m2 fruit yield. The result could be concluded that application of chemical fertilizers (7.5 g N + 6 g K2O + 15 g P2O5 per m2 with compost (2 kg per m2 could increase the total soluble solid and fruit yield as well as reduce the usage of chemical fertilizers in tomato cultivation over the standard control in sandy regosol.

  8. Efficiency of local Indonesia honey bees (Apis cerana L.) and stingless bee (Trigona iridipennis) on tomato (Lycopersicon esculentum Mill.) pollination.

    Science.gov (United States)

    Putra, Ramadhani Eka; Kinasih, Ida

    2014-01-01

    Tomato (Lycopersicon esculentum Mill.) is considered as one of major agricultural commodity of Indonesia farming. However, monthly production is unstable due to lack of pollination services. Common pollinator agent of tomatoes is bumblebees which is unsuitable for tropical climate of Indonesia and the possibility of alteration of local wild plant interaction with their pollinator. Indonesia is rich with wild bees and some of the species already domesticated for years with prospect as pollinating agent for tomatoes. This research aimed to assess the efficiency of local honey bee (Apis cerana L.) and stingless bee (Trigona iridipennis), as pollinator of tomato. During this research, total visitation rate and total numbers of pollinated flowers by honey bee and stingless bee were compared between them with bagged flowers as control. Total fruit production, average weight and size also measured in order to correlated pollination efficiency with quantity and quality of fruit produced. Result of this research showed that A. cerana has slightly higher rate of visitation (p>0.05) and significantly shorter handling time (p tomato flowers. However, honey bee pollinated tomato flowers more efficient pollinator than stingless bee (80.3 and 70.2% efficiency, respectively; p tomatoes were similar (p>0.05). Based on the results, it is concluded that the use of Apis cerana and Trigona spp., for pollinating tomatoes in tropical climates could be an alternative to the use of non-native Apis mellifera and bumblebees (Bombus spp.). However, more researches are needed to evaluate the cost/benefit on large-scale farming and greenhouse pollination using both bees against other bee species and pollination methods.

  9. The effect of the lenght of storage on the amount of lycopene in the fruits of tomato (Lycopersicon esculentum L.

    Directory of Open Access Journals (Sweden)

    Anton Uher

    2008-01-01

    Full Text Available We focused on tomatoes for industrial processing due to its economical importance for its lycopene content. The objective of our research is to find the variation of lycopene content in tomato fruits depending upon the length of after harvest storage and thermic treatment, which is inevitable when being industrialy processed. From the point of view of nutritional qualities the most relevant contentual substance of tomatos are carotenoids, included lycopene.At average for tree following experimental years we learnt significant differences regarding the content of lycopene and the length of storage of tomato fruits. Immediately after the harvest and proccesing tomato fruits contained, at average for tree years, 103.24 mg of lycopene. After 14 days the content of lycopene declined to 46.76 mg . kg−1 of fresh mass. After 30 days the average value dropped to 29.26 mg . kg−1. This fact comfirms that boiling respectively thermic treatment increases the content of lycopene in tomato fruits, particulary in our experiment to the value 83.33 mg . kg−1. At varieties Ladislav, Peto 86, Prémium, Salus the content of lycopene has even risen in comparison with its content up to 48 hours after the harvest. Tomato (Lycopersicon esculentum L. belongs to the most signifficant vegetable varieties either for its exploitation in processing industry as well as for its nutritional value with extraordinary beneficial effect for human organism.Although the content of lycopene is genetically stable attribute, its content in our experiment ranged from 45.39 mg . kg−1 (Prémium variety to 77.98 mg . kg−1 (Zámčan variety, which are significant differences.

  10. NUTRIÇÃO DO TOMATEIRO (Lycopersicon esculentum EM FUNÇÃO DE DOSES DE FERTILIZANTES ORGÂNICOS

    Directory of Open Access Journals (Sweden)

    José André Custódio da Silva

    2009-01-01

    Full Text Available The study aimed to evaluate the effect of two doses of organic material in the nutrition of tomato (Lycopersicon esculentum, cv Santa Cruz, grown in pots in an Oxisol Ultisol Distrocoeso the municipality of Rio Largo - AL. The design was in randomized blocks in factorial 2 X 4 (two and four fertilizer doses with 5 replicates. The experimental unit consisted of a vessel with capacity for 12 dm3 containing 15 kg of soil. The fertilizer materials were: 1 fertilizer - manure from corral + chicken manure + fertilizer and the filter cake of 2 - to corral manure + chicken manure + sugar cane bagasse, in doses 0, 5, 10 and 15 t ha-1. The applications were split in the following way: 10% at the time of transplantation, and 15% at 20, 34, 48, 62, 76 and 90 days after transplanting (DAT in coverage. The seedlings were produced in the tomato seed, on March 10, 2008, in polystyrene trays with 128 cells, after transplantation and were selected for the vessel on April 02, 2008, leaving two plants per pot . The plants were conducted in mentoring and single stem, and where, therefore, all cultural and treatment plant. There was a collection of leaves 4 + from the apex of the plant, to assess nutritional status at the beginning of flowering. Among the nutrients, the nitrogen was absorbed the most, followed by: potassium, calcium, sulfur, magnesium and phosphorus, whereas among the micronutrients, in increasing order of absorption was the following: boron, zinc, copper, manganese and iron. According to analysis of variance and regression analysis of the fertilizer did not affect the levels of nutrients in the plant, with only difference between the doses.

  11. Quality perception of organically grown tomatoes (Lycopersicon esculentum Mill. in Vienna, Austria

    Directory of Open Access Journals (Sweden)

    PK Ng’ang’a

    2015-12-01

    Full Text Available Austria is one of the major organic tomato producing countries for local and export marketing. These tomatoes are produced in parts of Austria especially around Vienna where their production system has to meet stringent organic quality standards in both local and international markets. These quality standards may put considerable strain on farmers and are normally formulated without famers’ participation so may not be wholly representative of the farmers’ quality interpretation. The aim of this paper is therefore to determine the Austrian organic tomatoes growers’ perception and practice of quality and challenges. Qualitative semi-structured interviews were carried out among 28 organic tomatoes farmers in Vienna, Austria. Findings suggest that quality of organic tomatoes is mainly perceived in terms of both informal values (big fruit size, long shelf life, food security and amount of income received from tomato sales as well as formal norms (non- application of chemicals, human health, damage free, sweet taste, red colour, and juiciness. There were no gendered differences in quality perception among the growers. High costs of production inputs were identified as the main challenge to attaining quality in organic tomatoes. Following these findings, there is need for effective participation of growers in formulation of standards as well as subsidizing of production inputs by the government. The Austrian tomato growers as well as local and international retailers should work closely to increase the price received by the Austrian organic tomato growers so that it more adequately covers their production costs.

  12. Maintenance of Chloroplast Components during Chromoplast Differentiation in the Tomato Mutant Green Flesh.

    Science.gov (United States)

    Cheung, A. Y.; McNellis, T.; Piekos, B.

    1993-04-01

    During ripening of tomato (Lycopersicon esculentum) fruit, chloroplasts develop into chromoplasts. The chloroplast-chromoplast transition is marked by the accumulation of carotenoids and the disappearance of chlorophyll, the degradation of the highly structured thylakoid membrane system, and a reduction in the levels of proteins and mRNAs associated with photosynthesis. In the tomato mutant green flesh (gf), detectable amounts of chlorophyll remain in the ripe, mutant fruit, giving rise to a rusty red fruit color and suggesting that at least chlorophyll degradation is defective in the mutant. We show here that the ultrastructure of the plastids in the ripe gf fruit maintained significant amouonts of the chloroplast thylakoid grana along with structures characteristic of tomato chromoplasts. The maintenance of chloroplast structure in the gf ripe fruit was paralleled on the molecular level by the retention of plastid photosynthetic components that normally decline significantly in ripening tomato fruits. These included the light-harvesting chlorophyll a/b-binding proteins of photosystem II, the second electron accepting plastoquinone of photosystem II binding protein, the large and small subunits of ribulose bisphosphate carboxylase/oxygenase, the 33-kD oxygen evolution protein, and cytochrome b559. Similarly, photosynthetic transcripts, cab, psbA, rbcL, rbcS, and psbE mRNAs, also accumulated to higher levels in ripening gf fruit than wild type. It is interesting that the levels of some of these transcripts, especially cab mRNA, were noticeably higher in the mature gf green fruit than in the corresponding wild-type fruit. This suggests that the onset of the effect from the gf mutation might be earlier than fruit ripening. We also observed that when chloroplast formation was blocked during the development and ripening of gf fruit, these mutant fruits were bright red and their chromoplasts were indistinguishable from those found in wild-type ripe fruits grown and

  13. Inhibition of volatile compounds derived from fatty acid oxygenation with chilling and heating treatments and their influences on the oxylipin pathawy gene expression and enzyme activity levels in tomato (Solanum lycopersicon

    Science.gov (United States)

    Hexanal, Z-3-hexenal, E-2-hexenal, hexanol and Z-3-hexenol are major tomato (Solanum Lycopersicon) volatile aromas derived from oxygenation of unsaturated fatty acids. Chilling or heating treatments suppress production of these C6 volatiles. The objective of this research was to determine the respon...

  14. Bacterial mutants for enhanced succinate production

    NARCIS (Netherlands)

    Baart, G.J.E.; Beauprez, J.J.R.; Foulquie, M.M.R.; Heijnen, J.J.; Maertens, J.

    2010-01-01

    The present invention relates to a method for obtaining enhanced metabolite production in micro-organisms, and to mutants and/or transformants obtained with said method. More particularly, it relates to bacterial mutants and/or transformants for enhanced succinate production, especially mutants and/

  15. Problem-Solving Test: Tryptophan Operon Mutants

    Science.gov (United States)

    Szeberenyi, Jozsef

    2010-01-01

    This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

  16. Polyuronides in Avocado (Persea americana) and Tomato (Lycopersicon esculentum) Fruits Exhibit Markedly Different Patterns of Molecular Weight Downshifts during Ripening.

    Science.gov (United States)

    Huber, D. J.; O'Donoghue, E. M.

    1993-01-01

    Avocado (Persea americana) fruit experience a rapid and extensive loss of firmness during ripening. In this study, we examined whether the chelator solubility and molecular weight of avocado polyuronides paralleled the accumulation of polygalacturonase (PG) activity and loss in fruit firmness. Polyuronides were derived from ethanolic precipitates of avocado mesocarp prepared using a procedure to rapidly inactivate endogenous enzymes. During ripening, chelator (cyclohexane-trans-1,2-diamine tetraacetic acid [CDTA])-soluble polyuronides increased from approximately 30 to 40 [mu]g of galacturonic acid equivalents (mg alcohol-insoluble solids)-1 in preripe fruit to 150 to 170 [mu]g mg-1 in postclimacteric fruit. In preripe fruit, chelator-extractable polyuronides were of high molecular weight and were partially excluded from Sepharose CL- 2B-300 gel filtration media. Avocado polyuronides exhibited marked downshifts in molecular weight during ripening. At the postclimacteric stage, nearly all chelator-extractable polyuronides, which constituted from 75 to 90% of total cell wall uronic acid content, eluted near the total volume of the filtration media. Rechromatography of low molecular weight polyuronides on Bio-Gel P-4 disclosed that oligomeric uronic acids are produced in vivo during avocado ripening. The gel filtration behavior and pattern of depolymerization of avocado polyuronides were not influenced by the polyuronide extraction protocol (imidazole versus CDTA) or by chromatographic conditions designed to minimize interpolymeric aggregation. Polyuronides from ripening tomato (Lycopersicon esculentum) fruit extracted and chromatographed under conditions identical with those used for avocado polyuronides exhibited markedly less rapid and less extensive downshifts in molecular weight during the transition from mature-green to fully ripe. Even during a 9-d period beyond the fully ripe stage, tomato fruit polyuronides exhibited limited additional depolymerization and

  17. Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings.

    Science.gov (United States)

    Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

    2017-01-01

    Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H2O2) under chilling stress conditions using tomato seedlings [(Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 24 h), the application of spermidine (Spd) and spermine (Spm) elevated NO and H2O2 levels, enhanced nitrite reductase (NR), nitric oxide synthase (NOS)-like, and polyamine oxidase activities, and upregulated LeNR relative expression, but did not influence LeNOS1 expression. In contrast, putrescine (Put) treatment had no obvious impact. During the recovery period (25/15°C, 10 h), the above-mentioned parameters induced by the application of PAs were restored to their control levels. Seedlings pretreated with sodium nitroprusside (SNP, an NO donor) showed elevated Put and Spd levels throughout the treatment period, consistent with increased expression in leaves of genes encoding arginine decarboxylase (LeADC. LeADC1), ornithine decarboxylase (LeODC), and Spd synthase (LeSPDS) expressions in tomato leaves throughout the treatment period. Under chilling stress, the Put content increased first, followed by a rise in the Spd content. Exogenously applied SNP did not increase the expression of genes encoding S-adenosylmethionine decarboxylase (LeSAMDC) and Spm synthase (LeSPMS), consistent with the observation that Spm levels remained constant under chilling stress and during the recovery period. In contrast, exogenous Put significantly increased the ABA content and the 9-cis-epoxycarotenoid dioxygenase (LeNCED1) transcript level. Treatment with ABA could alleviate the electrolyte leakage (EL) induced by D-Arg (an inhibitor of Put). Taken together, it is concluded that, under chilling

  18. Effect of Organic and Biological Fertilizers on Growth and Yield of Tomatoes (Lycopersicon esculentum Mill. and Bacterial Colonization

    Directory of Open Access Journals (Sweden)

    H. Makarian

    2016-02-01

    Full Text Available Introduction: In recent decades, excessive use of chemical fertilizers causes environmental problems such as water resource pollution and decrease in soil fertility. Organic matters are excellent sources of plant-available nutrients and their addition to soil could maintain high microbial populations and activities. In crop studies, Prabha et al. (2007 reported that there was excellent plant growth as well as yield in garlic plants that received vermicompost as nutrient in the field (28. Recent studies confirmed that, a number of bacterial species mostly associated with the plant rhizosphere, are found to be beneficial for plant growth, yield and crop quality. Therefore, the objective of this study is to investigate the growth promoting effects of organic and bio-fertilizers on tomato growth and yield. Materials and Methods: A factorial experiment in randomized complete block design with three replications was conducted at the College of Agricultural, University of Shahrood in 2011. Geographically, the site is located in Bastam (36° 25’E, 54° 58’N, 1349 m a.s.l..The climate of this region is semi-arid. Treatments included three levels of organic fertilizers: vermicompost (1300 kgha-1, cow manure (3350 kgha-1, and control, biological fertilizer in four levels (Pseudomonas putyda, Pseudomonas fluorescens, Azotobacter chrococcum and control. The bacterial suspension for each species was applied at a rate of 3 liters per hectare. Metribuzin herbicide (wettable 80% powder was used at a rate of 1000 gr. ha-1. Petopride No. 2' variety of tomato (Lycopersicon esculentum Mill. was used in the present experiment. At the time of harvesting, the plant characteristics namely lengths and diameter of stem, number and weight of fruit, weight of stem and leaf were also registered. Statistical analyses of data were performed with statistical software Mstatc. Significant differences between means refer to the probability level of 0.05 by LSD test. Results

  19. Nif- Hup- mutants of Rhizobium japonicum.

    Science.gov (United States)

    Moshiri, F; Stults, L; Novak, P; Maier, R J

    1983-01-01

    Two H2 uptake-negative (Hup-) Rhizobium japonicum mutants were obtained that also lacked symbiotic N2 fixation (acetylene reduction) activity. One of the mutants formed green nodules and was deficient in heme. Hydrogen oxidation activity in this mutant could be restored by the addition of heme plus ATP to crude extracts. Bacteroid extracts from the other mutant strain lacked hydrogenase activity and activity for both of the nitrogenase component proteins. Hup+ revertants of the mutant strains regained both H2 uptake ability and nitrogenase activity. Images PMID:6874648

  20. Identification of a Long Rice Spikelet Mutant

    Institute of Scientific and Technical Information of China (English)

    WU Xian-jun; WANG Bin; HAN Zan-ping; XIE Zhao-hui; MOU Chun-hong; WANG Xu-dong

    2004-01-01

    A spontaneously occurring rice (Oryza sativa L. ) mutant, characterized by homeotic conversion in glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes and glumaceous lodicules and morphological transformation of stamens into pistils. Mutant florets consisted of 1 to 3 completely developed pistils, some pistilloid stamens with filaments, but tipped by bulged tissue and 0 to 3 stigmas. It seens that the mutant phenotype of the homeotic conversions in glumes and stamens is similar to that of the B loss-of-function mutants in Arabidopsis and Antirrhinum. The mutant is controlled by a single recessive gene as a segregation ratio of 3:1 (wild type to mutant plants) was observed in the F2 generation.

  1. The auxin-resistant diageotropica mutant of tomato responds to gravity via an auxin-mediated pathway

    Science.gov (United States)

    Rice, M. S.; Lomax, T. L.

    2000-01-01

    Hypocotyls of the diageotropica (dgt) mutant of tomato (Lycopersicon esculentum Mill.) do not elongate in response to exogenous auxin, but can respond to gravity. This appears paradoxical in light of the Cholodny-Went hypothesis, which states that shoot gravicurvature results from asymmetric stimulation of elongation by auxin. While light-grown dgt seedlings can achieve correct gravitropic reorientation, the response is slow compared to wild-type seedlings. The sensitivity of dgt seedlings to inhibition of gravicurvature by immersion in auxin or auxin-transport inhibitors is similar to that of wild-type plants, indicating that both an auxin gradient and auxin transport are required for the gravitropic response and that auxin uptake, efflux, and at least one auxin receptor are functional in dgt. Furthermore, dgt gravicurvature is the result of asymmetrically increased elongation as would be expected for an auxin-mediated response. Our results suggest differences between elongation in response to exogenous auxin (absent in dgt) and elongation in response to gravistimulation (present but attenuated in dgt) and confirm the presence of two phases during the gravitropic response, both of which are dependent on functional auxin transport.

  2. The Tomato Fruit Cell Wall : II. Polyuronide Metabolism in a Nonsoftening Tomato Mutant.

    Science.gov (United States)

    Koch, J L; Nevins, D J

    1990-03-01

    A nonsoftening tomato (Lycopersicon esculentum L.) variety, dg, was examined to assess the physiological basis for its inability to soften during ripening. Total uronic acid levels, 18 milligrams uronic acid/100 milligrams wall, and the extent of pectin esterification, 60 mole%, remained constant throughout fruit development in this mutant. The proportion of uronic acid susceptible to polygalacturonase in vitro also remained constant. Pretreatment of heat-inactivated dg fruit cell walls with tomato pectinmethylesterase enhances polygalacturonase susceptibility at all ripening stages. Pectinesterase activity of cell wall protein extracts from red ripe dg fruit was half that in extracts from analogous tissue of VF145B. Polygalacturonase activities of cell wall extracts, however, were similar in both varieties. Diffusion of uronic acid from tissue discs of both varieties increased beginning at the turning stage to a maximum of 2.0 milligrams uronic acid released/gram fresh weight at the ripe stage. The increased quantity of hydrolytic products released during ripening suggests the presence of in situ polygalacturonase activity. Low speed centrifugation was employed to induce efflux of uronide components from the cell wall tree space. In normal fruit, at the turning stage, 2.1 micrograms uronic acid/gram fresh weight was present in the eluant after 1 hour, and this value increased to a maximum of 8.2 micrograms uronic acid/gram fresh weight at the red ripe stage. However, centrifuge-aided extraction of hydrolytic products failed to provide evidence for in situ polygalacturonase activity in dg fruit. We conclude that pectinesterase and polygalacturonase enzymes are not active in situ during the ripening of dg fruit. This could account for the maintenance of firmness in ripe fruit tissue.

  3. Gibberellins regulate seed germination in tomato by endosperm weakening: a study with gibberellin-deficient mutants.

    Science.gov (United States)

    Groot, S P; Karssen, C M

    1987-08-01

    The germination of seeds of tomato [Lycopersicon esculentum (L.) Mill.] cv. Moneymaker has been compared with that of seeds of the gibberellin-deficient dwarf-mutant line ga-1, induced in the same genetic background. Germination of tomato seeds was absolutely dependent on the presence of either endogenous or exogenous gibberellins (GAs). Gibberellin A4+7 was 1000-fold more active than commercial gibberellic acid in inducing germination of the ga-1 seeds. Red light, a preincubation at 2°C, and ethylene did not stimulate germination of ga-1 seeds in the absence of GA4+7; however, fusicoccin did stimulate germination independently. Removal of the endosperm and testa layers opposite the radicle tip caused germination of ga-1 seeds in water. The seedlings and plants that develop from the detipped ga-1 seeds exhibited the extreme dwarfy phenotype that is normal to this genotype. Measurements of the mechanical resistance of the surrounding layers showed that the major action of GAs was directed to the weakening of the endosperm cells around the radicle tip. In wild-type seeds this weakening occurred in water before radicle protrusion. In ga-1 seeds a similar event was dependent on GA4+7, while fusicoccin also had some activity. Simultaneous incubation of de-embryonated endosperms and isolated axes showed that wild-type embryos contain and endosperm-weakening factor that is absent in ga-1 axes and is probably a GA. Thus, an endogenous GA facilitates germination in tomato seeds by weakening the mechanical restraint of the endosperm cells to permit radicle protrusion.

  4. Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

    Science.gov (United States)

    Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C

    2016-06-02

    We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10(-4) M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10(-5) M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants.

  5. Evaluation of biological nematicides on the control of root-knot nematode (Meloidogyne incognita Chitwood at protected crops house in tomato (Lycopersicon esculentum Mill.

    Directory of Open Access Journals (Sweden)

    Pedro Fidel Fuentes Chaviano

    2011-06-01

    Full Text Available This research was carried out on Tomato (Lycopersicon esculentum Mill. variety HA 3105 at the protected crops houses in Empresa Azucarera Melanio Hernández of Sancti Spiritus, located at the southwest of Tuinucú, from November 2009 to May 2010 with the objective of evaluating the effectiveness of biological nematicides on the control of the root-knot nematode, Meloidogyne incognita Chitwood. Three treatments were used: Agrocelhone, biological nematicide HeberNem and HeberNem + Trichoderma. Biological nematicides showed better results than Agrocelhone regarding the length of the leaf, the height of the plant, the yield of tomato and the control of nematodes HeberNem showed the best results in the control of the nematode, decreasing the infestation from degree V to degree II.

  6. Factors affecting the production of seeds in fully fertile tomatoes (Lycopersicon esculentum L. Mill. and those showing a tendency to parthenocarpy

    Directory of Open Access Journals (Sweden)

    Barbara Gabara

    2014-01-01

    Full Text Available Comparative studies on the development of the female gametophyte, pollination and fertilization in two lines of Lycopersicon esculentum, Kholodostoykye (Kh, fertile and A33 (with a tendency to parthenocarpy have revealed that seed production is affected by disturbances in embryo sac formation but mainly by its degeneration after anthesis, which is especially visible in line A33. Moreover, delayed development of some embryo sacs and incomplete pollination due to various stigma levels seem to be responsible for the diminution of seed number in line A33. Deep fluorescence of numerous pollen grains as well as whole pollen tubes in 83.3 per cent of A33 stigmas and only 24.1 per cent in the Kh line points to the heterogeneity of pollen. This could be one more reason for reduced fertility. The results of application of plant growth regulators (auxin, PCIB which affect seed production in tomato of line A33 remain inconclusive.

  7. Capítulo III: caracterización y evaluación de recursos genéticos del género Lycopersicon

    Directory of Open Access Journals (Sweden)

    Sierra Tulio Alberto

    1994-12-01

    Full Text Available

    Con el fin de determinar el potencial genético de 118 introducciones del género Lycopersicon se realizó la caracterización y evaluación, en el Centro Experimental de la Universidad Nacional Sede Palmira, utilizando los descriptores recomendados por el IBPGR (1981. Se utilizó el diseño experimental de Bloques al azar con dos repeticiones. La parcela experimental estuvo constituida por seis plantas. Se estudiaron nueve caracteres relacionados con la planta, diez caracteres relacionados con el fruto, componentes del rendimiento y  presencia o ausencia de plagas y enfermedades. Se encontró una gran variabilidad para la mayoría de los caracteres estudiados. Las variedades de la especie cultivada, L. esculentum, presentaron las mayores producciones por planta y el mayor tamaño de fruto, en comparación con las especies silvestres; sin embargo, estas últimas presentaron mayor resistencia a plagas y enfermedades. Se destacaron los siguientes variedades de L. esculentum por presentar altas producciones y tolerancia a plagas y enfermedades: ADB 18, ADB 400, 1600, 1604  y Río Fuego.

    118 accessions of the genus Lycopersicon were characterized and evaluated to determinate the genetic potential, using the IBPGR descriptors. The experiment was conducted, using a complete random design and two repetitions. Characteristics concerned to the plant, fruit yield components and resistence to insects and disease was studied. Important fenotipic differences, for the evaluated characters, were founded. The varieties of the cultivated specie L. esculentum, showed heigh productions per plant and heigh average fruit weight. The wild accessions showed heigh resistence to the insects and pathogens. ADB18,  ADB 400, 1600, 1601 and Rio Fuego accessions of the L. esculentum  showd heigh productions per plant and heigh resistence to the insects and pathogens.

  8. Régénération in vitro de plantes de tomate Lycopersicon esculenteum Mill. adaptées au NaCl

    Directory of Open Access Journals (Sweden)

    Abir, M.

    2006-01-01

    Full Text Available In vitro Regeneration of NaCl-adapted Tomato Plants (Lycopersicon esculenteum Mill.. In vitro growth seedlings of tomato (Lycopersicon esculentum Mill. Var. Sabra were used as source of explants: internode segment and leaf fragment. These explants were cultivated into a MS-based medium containing 0.2 mg.l-1ANA and 2 mg.l-1 BAP, supplemented or not with NaCl at 3 and 6 g.l-1 in order to regenerate salt-tolerant plants. Results show that internode's segment and leaf fragment formed callus both in the control and in the saline media (3 and 6 g.l-1. However NaCl affected calli growth and mineral uptake. The callus growth was stimulated by NaCl at 3 g.I-1, but reduced at 6 g.I-1. Na+ and Cl- content of calli increased in saline media with respect to the control. K+ content decreased slightly with salinity, but Ca2+ content did not change. Leaf callus showed higher K+ and Ca2+ contents both in the control and saline media and were more salt tolerant than internodes callus. Latest ones regenerated shoots only on control medium. Leaf callus adapted to 3 g.l-1 NaCl were able to regenerate shoots, but with high percentage of hyperhydricity. Regenerated plants were rooted and acclimatized successfully and they tolerated 3 g.l-1 NaCl added to irrigation solution, when cultivated on peat under glasshouse.

  9. Modelo de producción de tomate Lycopersicon esculentum Mill usando como sustrato la mezcla cachaza-carbonilla en diferentes dosis de fertilización

    Directory of Open Access Journals (Sweden)

    Bruzón C. Serapio F.

    1996-12-01

    Full Text Available

    The industrial subproducts filter cake press and botton fly ash were used in mixtures (3:1 like sustratum for the tomato Lycopersicon esculentum Mill (Celebrity HF1 production. The trial constituted six treatments each one repeated three times. Half of treatments were sowed in the mixture and the other half in the soil, using three fertilization levels: 0, 300 and 600 kg/ha 18-18*-18. There were productions of 140, 158 and 178 ton/ha for the three fertilization levels using the filter press cake substate and 140, 143 and 160 t/ha tor the three fertilization levels in the soil. Such results are showing the excellent quality of the mixture filter cake press: coal dust (3:1 because of the similar results, which were obtained in one soil with excellent physics and chemical properties.

    Los subproductos industriales cachaza y carbonilla se utilizaron en mezcla (3:1 como sustrato para producción de tomate Lycopersicon esculentum Mili, Celebrity HF1. El experimento se diseñó en bloques completos al azar con arreglo factorial; constó de seis tratamientos y tres repeticiones cada uno, la mitad de los tratamientos se sembró en la mezcla y la otra mitad en suelo, utilizándose tres niveles de fertilización: 0, 300 y 600 kg/Ha 18-18-18. Se obtuvieron producciones de 140, 158 y 178 ton/ha de tomate para los tres niveles de fertilización en el sustrato cachaza y 140, 143 y 160 para los tres niveles de fertilización en el suelo, lo que demuestra la excelente calidad de la mezcla cachaza: carbonilla (3:1, al obtenerse resultados similares al suelo de excelentes propiedades físicas y químicas.

     

  10. Evaluation of volatile metabolites as markers in Lycopersicon esculentum L. cultivars discrimination by multivariate analysis of headspace solid phase microextraction and mass spectrometry data.

    Science.gov (United States)

    Figueira, José; Câmara, Hugo; Pereira, Jorge; Câmara, José S

    2014-02-15

    To gain insights on the effects of cultivar on the volatile metabolomic expression of different tomato (Lycopersicon esculentum L.) cultivars--Plum, Campari, Grape, Cherry and Regional, cultivated under similar edafoclimatic conditions, and to identify the most discriminate volatile marker metabolites related to the cultivar, the chromatographic profiles resulting from headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-qMS) analysis, combined with multivariate analysis were investigated. The data set composed by the 77 volatile metabolites identified in the target tomato cultivars, 5 of which (2,2,6-trimethylcyclohexanone, 2-methyl-6-methyleneoctan-2-ol, 4-octadecyl-morpholine, (Z)-methyl-3-hexenoate and 3-octanone) are reported for the first time in tomato volatile metabolomic composition, was evaluated by chemometrics. Firstly, principal component analysis was carried out in order to visualise data trends and clusters, and then, linear discriminant analysis in order to detect the set of volatile metabolites able to differentiate groups according to tomato cultivars. The results obtained revealed a perfect discrimination between the different Lycopersicon esculentum L. cultivars considered. The assignment success rate was 100% in classification and 80% in prediction ability by using "leave-one-out" cross-validation procedure. The volatile profile was able to differentiate all five cultivars and revealed complex interactions between them including the participation in the same biosynthetic pathway. The volatile metabolomic platform for tomato samples obtained by HS-SPME/GC-qMS here described, and the interrelationship detected among the volatile metabolites can be used as a roadmap for biotechnological applications, namely to improve tomato aroma and their acceptance in the final consumer, and for traceability studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Muscle cells and motoneurons differentially remove mutant SOD1 causing familial amyotrophic lateral sclerosis.

    Science.gov (United States)

    Onesto, Elisa; Rusmini, Paola; Crippa, Valeria; Ferri, Nicola; Zito, Arianna; Galbiati, Mariarita; Poletti, Angelo

    2011-07-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motoneuronal disease which occurs in sporadic or familial forms, clinically indistinguishable. About 15% of familial ALS cases are linked to mutations of the superoxide dismutase 1 (SOD1) gene that may induce misfolding in the coded protein, exerting neurotoxicity to motoneurons. However, other cell types might be target of SOD1 toxicity, because muscle-restricted expression of mutant SOD1 correlates with muscle atrophy and motoneurons death. We analysed the molecular behaviour of mutant SOD1 in motoneuronal NSC34 and muscle C2C12 cells. We found that misfolded mutant SOD1 clearance is much more efficient in muscle C2C12 than in motoneuronal NSC34 cells. Mutant SOD1 forms aggregates and impairs the proteasome only in motoneuronal NSC34 cells. Interestingly, NSC34 cells expressing mutant SOD1 are more sensitive to a superoxide-induced oxidative stress. Moreover, in muscle C2C12 cells mutant SOD1 remains soluble even when proteasome is inhibited with MG132. The higher mutant SOD1 clearance in muscle cells correlates with a more efficient proteasome activity, combined with a robust autophagy activation. Therefore, muscle cells seem to better manage misfolded SOD1 species, not because of an intrinsic property of the mutant protein, but in function of the cell environment, indicating also that the SOD1 toxicity at muscle level may not directly depend on its aggregation rate. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

  12. Biochemical and histological characterization of tomato mutants

    Directory of Open Access Journals (Sweden)

    Carolina C. Monteiro

    2012-06-01

    Full Text Available Biochemical responses inherent to antioxidant systems as well morphological and anatomical properties of photomorphogenic, hormonal and developmental tomato mutants were investigated. Compared to the non-mutant Micro-Tom (MT, we observed that the malondialdehyde (MDA content was enhanced in the diageotropica (dgt and lutescent (l mutants, whilst the highest levels of hydrogen peroxide (H2O2 were observed in high pigment 1 (hp1 and aurea (au mutants. The analyses of antioxidant enzymes revealed that all mutants exhibited reduced catalase (CAT activity when compared to MT. Guaiacol peroxidase (GPOX was enhanced in both sitiens (sit and notabilis (not mutants, whereas in not mutant there was an increase in ascorbate peroxidase (APX. Based on PAGE analysis, the activities of glutathione reductase (GR isoforms III, IV, V and VI were increased in l leaves, while the activity of superoxide dismutase (SOD isoform III was reduced in leaves of sit, epi, Never ripe (Nr and green flesh (gf mutants. Microscopic analyses revealed that hp1 and au showed an increase in leaf intercellular spaces, whereas sit exhibited a decrease. The au and hp1 mutants also exhibited a decreased in the number of leaf trichomes. The characterization of these mutants is essential for their future use in plant development and ecophysiology studies, such as abiotic and biotic stresses on the oxidative metabolism.Neste trabalho, analisamos as respostas bioquímicas inerentes ao sistema antioxidante, assim como propriedades morfológicas e anatômicas de mutantes fotomorfogenéticos e hormonais de tomateiro. Comparados ao não mutante Micro-Tom (MT, observamos que o conteúdo de malondialdeído (MDA aumentou nos mutantes diageotropica (dgt e lutescent (l, enquanto os maiores níveis de H2O2 foram encontrados nos mutantes high pigment 1 (hp1 e aurea (au. Análises de enzimas antioxidantes mostraram que todos os mutantes reduziram a atividade de catalase (CAT quando comparado a MT. A

  13. Response of superoxide dismutase isoenzymes in tomato plants (Lycopersicon esculentum) during thermo-acclimation of the photosynthetic apparatus.

    Science.gov (United States)

    Camejo, Daymi; Martí, María del C; Nicolás, Emilio; Alarcón, Juan J; Jiménez, Ana; Sevilla, Francisca

    2007-11-01

    Seedlings of Lycopersicon esculentum Mill. var. Amalia were grown in a growth chamber under a photoperiod of 16 h light at 25 degrees C and 8 h dark at 20 degrees C. Five different treatments were applied to 30-day-old plants: Control treatment (plants maintained in the normal growth conditions throughout the experimental time), heat acclimation (plants exposed to 35 degrees C for 4 h in dark for 3 days), dark treatment (plants exposed to 25 degrees C for 4 h in dark for 3 days), heat acclimation plus heat shock (plants that previously received the heat acclimation treatment were exposed to 45 degrees C air temperature for 3 h in the light) and dark treatment plus heat shock (plants that previously received the dark treatment were exposed to 45 degrees C air temperature for 3 h in the light). Only the heat acclimation treatment increased the thermotolerance of the photosynthesis apparatus when the heat shock (45 degrees C) was imposed. In these plants, the CO(2) assimilation rate was not affected by heat shock and there was a slight and non-significant reduction in maximum carboxylation velocity of Rubisco (V(cmax)) and maximum electron transport rate contributing to Rubisco regeneration (J(max)). However, the plants exposed to dark treatment plus heat shock showed a significant reduction in the CO(2) assimilation rate and also in the values of V(cmax) and J(max). Chlorophyll fluorescence measurements showed increased thermotolerance in heat-acclimated plants. The values of maximum chlorophyll fluorescence (F(m)) were not modified by heat shock in these plants, while in the dark-treated plants that received the heat shock, the F(m) values were reduced, which provoked a significant reduction in the efficiency of photosystem II. A slight rise in the total superoxide dismutase (SOD) activity was found in the plants that had been subjected to both heat acclimation and heat shock, and this SOD activity was significantly higher than that found in the plants subjected to

  14. Lycopersicon esculentum Mill.

    African Journals Online (AJOL)

    HP

    2015-06-03

    Jun 3, 2015 ... clusters were monogenotypic and cluster I possessed highest number of genotypes numbering 25. Out ... be used to compare the genetic dis-similarity between different species ... order to maintain the native flavour and taste.

  15. Study on culturing Trichodema mutants

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-ai; WANG Wei-ming

    2004-01-01

    @@ Trichodema mutants strains T5, T0803, T1010, T1003were cultured in different conditions and media, also in the presence of fungicides at 40 mg/kg (CK or procymidone + chlorothalonil, or maneb or phosethyl-Al) . The pH values of media were 5, 6, 7 and 8 and hyphae were grown at temperatures of 15, 20, 25 and 30 ℃. After being cultured for 3, 4, 5, or 6 days, the strains were transferred at a lower temperature to sporulate (20℃) Obtained data were analyzed statistically, with the orthogonal array and ranges (R) differing dependes on the treatments (R = 40.0,42.4, 48.0, 62.8,107.0). The results indicated that the most important factor was the nature of the strain (R =107.0), while the change in temperature and time of cultivation produced the lowest effect (R =40.0). Each factor variance was significant and A3B4C2D1E3 was the optimum combined condition, in which strain T1010 grew more quickly and sporulated most.

  16. CMPD: cancer mutant proteome database.

    Science.gov (United States)

    Huang, Po-Jung; Lee, Chi-Ching; Tan, Bertrand Chin-Ming; Yeh, Yuan-Ming; Julie Chu, Lichieh; Chen, Ting-Wen; Chang, Kai-Ping; Lee, Cheng-Yang; Gan, Ruei-Chi; Liu, Hsuan; Tang, Petrus

    2015-01-01

    Whole-exome sequencing, which centres on the protein coding regions of disease/cancer associated genes, represents the most cost-effective method to-date for deciphering the association between genetic alterations and diseases. Large-scale whole exome/genome sequencing projects have been launched by various institutions, such as NCI, Broad Institute and TCGA, to provide a comprehensive catalogue of coding variants in diverse tissue samples and cell lines. Further functional and clinical interrogation of these sequence variations must rely on extensive cross-platforms integration of sequencing information and a proteome database that explicitly and comprehensively archives the corresponding mutated peptide sequences. While such data resource is a critical for the mass spectrometry-based proteomic analysis of exomic variants, no database is currently available for the collection of mutant protein sequences that correspond to recent large-scale genomic data. To address this issue and serve as bridge to integrate genomic and proteomics datasets, CMPD (http://cgbc.cgu.edu.tw/cmpd) collected over 2 millions genetic alterations, which not only facilitates the confirmation and examination of potential cancer biomarkers but also provides an invaluable resource for translational medicine research and opportunities to identify mutated proteins encoded by mutated genes.

  17. Gamma radiation effects of Cobalt-60 on tomatoes (Lycopersicon esculentum Mill.) stored at room temperature and under refrigerated conditions; Efeito da radiacao gama do Cobalto-60 em tomates (Lycopersicon esculentum Mill.) armazenados em temperatura ambiente e refrigeracao

    Energy Technology Data Exchange (ETDEWEB)

    Penna, Raquel Medeiros de Almeida

    1994-07-01

    This work was carried out in two distinct experiments. Tomatoes (Lycopersicon esculentum Mill.) of the variety 'Santa Clara in the 'turning' stage (first experiment) and of the variety 'Santa Cruz' in the 'mature-green' stage (second experiment), were irradiated in a Cobalt-60 source with doses of 0.0; 0.5; 1.0; 1.5 e 2.0 kGy, and stored at room temperature (20{+-}2 deg C) and under refrigeration (9 deg C). The aim of the experiments was to verify the effects of the gamma-radiation on the extension of the market life of tomatoes stored under two different temperatures. The following types of analysis were carried out: physical (weight and skin resistance), chemical (brix, pH), sensorial (general appearance, external coloration and firmness) and organoleptic (aroma and flavor), during 30 days of storage, with four evaluations. At the end of the experiment microbiologic and microscopic analyses of histological sections were also performed. In both experiments, occurred a greater loss of weight in the irradiated tomatoes in relation to the controls proportional to the increase in the period of storage, but not to the increase of doses. This effect was more pronounced in fruits stored at room temperature. Concerning the resistance, the fruits of the first experiment showed that irradiation causes softening of the fruit skin. This softening was proportional to the increase of doses, in the 1, 10 e 30th day, and also the fruits irradiated with 1.0, 1.5 and 2.0 kGy showed a higher softening on both temperatures. In the second experiment, on both temperatures, the fruits showed an increase of skin resistance until the 10th day, which diminished until the 30th day. The content of soluble solids was altered by irradiation in the first experiment, and this resulted in a decrease of Brix proportional to the increase of dose. In the second experiment, the radiation induced a maximum Brix value at the 10th day in the fruits maintained under

  18. Effect of temperature on the occurrence of O/sub 2/ and CO/sub 2/ insensitive photosynthesis in field grown plants. [Phaseolus vulgaris; Capsicum annum; Lycopersicon esculentum, Scrophularia desertorum; Cardaria draba, Populus fremontii

    Energy Technology Data Exchange (ETDEWEB)

    Sage, R.F.; Sharkey, T.D.

    1987-07-01

    The sensitivity of photosynthesis to O/sub 2/ and CO/sub 2/ was measured in leaves from field grown plants of six species (Phaseolus vulgaris, Capsicum annuum, Lycopersicon esculentum, Scrophularia desertorum, Cardaria draba, and Populus fremontii) from 5/sup 0/C to 35/sup 0/C using gas-exchange techniques. In all species but Phaseolus, photosynthesis was insensitive to O/sub 2/ in normal air below a species dependent temperature. CO/sub 2/ insensitivity occurred under the same conditions that resulted in O/sub 2/ insensitivity. A complete loss of O/sub 2/ sensitivity occurred up to 22/sup 0/C in Lycopersicon but only up to 6/sup 0/C in Scrophularia. In Lycopersicon and Populus, O/sub 2/ and CO/sub 2/ insensitivity occurred under conditions regularly encountered during the cooler portions of the day. Because O/sub 2/ insensitivity is an indicator of feedback limited photosynthesis, these results indicate that feedback limitations can play a role in determining the diurnal carbon gain in the field. At higher partial pressures of CO/sub 2/ the temperature at which O/sub 2/ insensitivity occurred was higher, indicating that feedback limitations in the field will become more important as the CO/sub 2/ concentration in the atmosphere increases.

  19. Muscle development in mdx mutant mice.

    Science.gov (United States)

    Dangain, J; Vrbova, G

    1984-01-01

    Mechanical and contractile properties of tibialis anterior (TA) muscles from X-linked muscular dystrophic (mdx) mutant mice at different stages of development are compared to those of muscles from normal control animals. There is no difference between the tension output, speeds of contraction and relaxation, and weight of TA muscles from mutant adults and normal control animals. However, it is found that in 3-4-week-old mutant animals, tension output and muscle weight are very much reduced, and half relaxation time is prolonged. Thus, during this stage of development, muscles from mdx mice do not function properly. Histological examination of these muscles provides further evidence that, in these animals, rapid muscle destruction occurs at a particular time of development and that it is followed by complete recovery. This new mutant therefore presents an interesting case of muscle destruction and rapid regeneration. However, it is not an adequate model for Duchenne muscular dystrophy.

  20. Targeting ESR1-Mutant Breast Cancer

    Science.gov (United States)

    2015-09-01

    AWARD NUMBER: W81XWH-14-1-0359 TITLE: Targeting ESR1-Mutant Breast Cancer PRINCIPAL INVESTIGATOR: Dr. Sarat Chandarlapaty CONTRACTING...31 Aug 2015 4. TITLE AND SUBTITLE Targeting ESR1-Mutant Breast Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0359 5c. PROGRAM ELEMENT...mutations found in breast cancer using both structural and cell based assays. We have now have evidence for the effects of the most recurrent

  1. Targeting ESR1-Mutant Breast Cancer

    Science.gov (United States)

    2015-09-01

    Introduction Approximately 70% of ER+ breast cancers harbor expression of the estrogen receptor and are dependent upon its activity for various aspects of the...resistance to current FDA approved ER antagonists, but that more potent and selective estrogen receptor antagonists will be sufficiently active to...antagonists and their potency against ER mutants both in vitro and in vivo . Targeting ESR1-Mutant Breast Cancer W81XWH-14-1-0359 9 4. Impact A) Impact

  2. A fluorescence-activated cell sorting-based strategy for rapid isolation of high-lipid Chlamydomonas mutants.

    Science.gov (United States)

    Terashima, Mia; Freeman, Elizabeth S; Jinkerson, Robert E; Jonikas, Martin C

    2015-01-01

    There is significant interest in farming algae for the direct production of biofuels and valuable lipids. Chlamydomonas reinhardtii is the leading model system for studying lipid metabolism in green algae, but current methods for isolating mutants of this organism with a perturbed lipid content are slow and tedious. Here, we present the Chlamydomonas high-lipid sorting (CHiLiS) strategy, which enables enrichment of high-lipid mutants by fluorescence-activated cell sorting (FACS) of pooled mutants stained with the lipid-sensitive dye Nile Red. This method only takes 5 weeks from mutagenesis to mutant isolation. We developed a staining protocol that allows quantification of lipid content while preserving cell viability. We improved separation of high-lipid mutants from the wild type by using each cell's chlorophyll fluorescence as an internal control. We initially demonstrated 20-fold enrichment of the known high-lipid mutant sta1 from a mixture of sta1 and wild-type cells. We then applied CHiLiS to sort thousands of high-lipid cells from a pool of about 60,000 mutants. Flow cytometry analysis of 24 individual mutants isolated by this approach revealed that about 50% showed a reproducible high-lipid phenotype. We further characterized nine of the mutants with the highest lipid content by flame ionization detection and mass spectrometry lipidomics. All mutants analyzed had a higher triacylglycerol content and perturbed whole-cell fatty acid composition. One arbitrarily chosen mutant was evaluated by microscopy, revealing larger lipid droplets than the wild type. The unprecedented throughput of CHiLiS opens the door to a systems-level understanding of green algal lipid biology by enabling genome-saturating isolation of mutants in key genes.

  3. PROTEÍNAS ANTIFÚNGICAS CONTRA P. INFESTANS EN LOS ESPACIOS INTERCELULARES DE HOJAS DE TOMATE (Lycopersicon esculentum cerasiforme POSIBLES DEFENSINAS DE PLANTAS

    Directory of Open Access Journals (Sweden)

    Luz Dary Riaño

    2008-03-01

    Full Text Available Se aislaron y caracterizaron parcialmente proteínas antifúngicas de los espacios intercelulares de hojas de tomate Lycopersicon esculentum cerasiforme, variedad que ha mostrado resistencia en campo a Phytophthora Infestans; se observó quedespués de inoculación con el patógeno dichas proteínas se acumularon sistémicamente en la planta. Las proteínas identificadasmostraron características de Defensinas de plantas, una nueva familia de proteínas con bajo peso molecular, carga positiva a pH fisiológico y actividad antifúngica evaluada in vitro contra P. infestans.Los análisis electroforéticos en geles de poliacrilamida con SDS-Tricina en condiciones reductoras y no reductoras, sugirieron que están asociadas en trímeros y tetrámeros y poseen pesos moleculares de 5,2 kDa.

  4. Antioxidant-enzyme reaction to the oxidative stress due to alpha-cypermethrin, chlorpyriphos, and pirimicarb in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Chahid, Karim; Laglaoui, Amin; Zantar, Said; Ennabili, Abdeslam

    2015-11-01

    Tomato (Lycopersicon esculentum Mill.) becomes one of the world's foremost vegetables, and its world production and consumption have increased fairly quickly. The capacity to induce oxidative stress in tomato plant, exposed to three xenobiotics such as alpha-cypermethrin, chlorpyriphos, and pirimicarb, was investigated by the evaluation of lipid peroxidation by measuring malondialdehyde (MDA) rate; also, we studied the response of tomato to this stress by assessing the response of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione-s-transferase (GST), and glutathione reductase (GR). The effect of the insecticides was observed using four concentrations (25, 50, 75, and 100%) for germinating seeds and only the recommended concentration in agriculture (100%) for growing plants. Our results show an important accumulation of MDA, demonstrating the increase of lipid peroxidation in consequence of the excessive reactive oxygen species (ROS) production due to insecticide treatment. In response to this oxidative stress in tomato seedlings and plants, the activities of antioxidant-enzyme system were generally enhanced. The electrophoretic analysis showed also the apparition of new isoenzymes as the case for CAT and POD.

  5. The role of cow dung and kitchen manure composts and their non-aerated compost teas in reducing the incidence of foliar diseases of Lycopersicon esculentum (Mill

    Directory of Open Access Journals (Sweden)

    A. Ngakou

    2014-06-01

    Full Text Available Compost teas are fermented watery extracts of composted materials used for their beneficial effect on plants. A study was conducted in the field to compare the efficacy of cow dung and kitchen manure composts and their derived non-aerated compost teas on disease symptoms expression and severity of Lycopersicon esculentum. The experimental layout was a complete randomised block design comprising six treatments, each of which was repeated three times: the negative control plot (Tm-; the positive control or fungicide plot (Tm+; the cow dung compost plot (Cpi; the kitchen manure compost plot (Cpii; the compost tea derived cow dung plot (Tci; and the compost tea derived kitchen manure plot (Tcii. Compost tea derived cow dung was revealed to be richer in elemental nutrients (N, P, K than compost tea from kitchen manure, and significantly (p < 0.0001 enhanced fruit yield per plant. Similarly, the two composts and their derived compost teas significantly (p < 0.0001 reduced the incidence and severity of disease symptoms compared to the controls, with the highest efficacy accounting for cow dung compost and compost tea. Although the non-aerated compost teas were not amended with micro-organisms, these results suggest that the two compost teas in use were rich enough in microbial pathogen antagonists, and therefore, are perceived as potential alternatives to synthetic chemical fungicides. Future work will attempt to identify these microbial antagonists with highly suppressive activity in the non-aerated compost teas.

  6. Polyhydroxyalcanoates of strains of Azospirillum spp. isolated of roots of Lycopersicon esculentum Mill. “tomato” and Oryza sativa L. “rice” in Lambayeque

    Directory of Open Access Journals (Sweden)

    Katty Baca

    2010-12-01

    Full Text Available In this work was determined the concentration of polyhydroxyalkanoates (PHAs of Azospirillum strains isolated from roots of Lycopersicon esculentum Mill "tomato" and Oryza sativa L. "rice" as an alternative to accumulation of petroleum-based plastics. Previously disinfected root were plated in Nfb semisolid medium where nitrogen-fixing bacteria were recognized by a whitish film on the surface and turn from green to blue. The genus Azospirillum was identified in Congo red agar medium, obtained 96 isolates of A. lipoferum and A. brasilense on tomato and rice. Batch fermentation was performed with broth Azotobacter modified feeding a saturated solution of malic acid every 12 hours and were stained with Sudan Black B. Strains were selected with the greatest number of PHAs granules (in tomato, 18 of A. lipoferum and 2 of A. brasilense; in rice, 10 of A. lipoferum and 10 of A. brasilense and quantified the biomass and PHAs. PHAs concentration reached 0.661 gL-1 in A. lipoferum KM(T-73 and 0.738 gL-1 in A. brasilense KM(T-19, both isolated from tomato. Strains of A. lipoferum and A. brasilense isolated from tomato reached a higher concentration of biomass and PHAs against the strains of rice.

  7. Caracterización de germoplasma de tomate (Lycopersicon esculentum, Mill con vistas a la implementación de un programa de fitomejoramiento participativo

    Directory of Open Access Journals (Sweden)

    A. Solís

    2001-01-01

    Full Text Available En las áreas de la Estación Territorial de Investigaciones Agropecuarias de Holguín (ETIAH, sobre un suelo Pardo sin carbonato, se realizó un estudio con 18 líneas de tomate (Lycopersicon esculentum, Mill obtenidas por el campesino Jorge Pupo1, con el objetivo de caracterizarlas y establecer una estrategia de mejora que permita alcanzar genotipos con características varietales adaptadas a las condiciones del territorio. La información disponible fue sometida a variados análisis de la estadística descriptiva y multivariada, ambos procederes adecuados para este tipo de trabajo, a fin de profundizar en la caracterización de la población. Los resultados indicaron una alta variabilidad y segregación genética en los materiales evaluados, por lo que se recomienda continuar el proceso de evaluación y selección hasta alcanzar la estabilidad varietal; no obstante, los de mayores perspectivas fueron la J10-87, J4-90, J4-92 y J6-93, que mostraron características agrícolas favorables y mayores potencialidades que las variedades más comúnmente cultivadas en el territorio.

  8. Surface-enhanced Raman spectroscopy of genomic DNA from in vitro grown tomato (Lycopersicon esculentum Mill.) cultivars before and after plant cryopreservation

    Science.gov (United States)

    Muntean, Cristina M.; Leopold, Nicolae; Tripon, Carmen; Coste, Ana; Halmagyi, Adela

    2015-06-01

    In this work the surface-enhanced Raman scattering (SERS) spectra of five genomic DNAs from non-cryopreserved control tomato plants (Lycopersicon esculentum Mill. cultivars Siriana, Darsirius, Kristin, Pontica and Capriciu) respectively, have been analyzed in the wavenumber range 400-1800 cm-1. Structural changes induced in genomic DNAs upon cryopreservation were discussed in detail for four of the above mentioned tomato cultivars. The surface-enhanced Raman vibrational modes for each of these cases, spectroscopic band assignments and structural interpretations of genomic DNAs are reported. We have found, that DNA isolated from Siriana cultivar leaf tissues suffers the weakest structural changes upon cryogenic storage of tomato shoot apices. On the contrary, genomic DNA extracted from Pontica cultivar is the most responsive system to cryopreservation process. Particularly, both C2‧-endo-anti and C3'-endo-anti conformations have been detected. As a general observation, the wavenumber range 1511-1652 cm-1, being due to dA, dG and dT residues seems to be influenced by cryopreservation process. These changes could reflect unstacking of DNA bases. However, not significant structural changes of genomic DNAs from Siriana, Darsirius and Kristin have been found upon cryopreservation process of tomato cultivars. Based on this work, specific plant DNA-ligand interactions or accurate local structure of DNA in the proximity of a metallic surface, might be further investigated using surface-enhanced Raman spectroscopy.

  9. Characterization of native strains of Azotobacter spp. and its effect on growth of Lycopersicon esculentum Mill. “tomato” in Lambayeque

    Directory of Open Access Journals (Sweden)

    Cynthia Escobar

    2011-03-01

    Full Text Available The objective of this research was characterize and determine the effect of native strains of Azotobacter spp. on the vegetative growth of Lycopersicon esculentum Mill. "Tomato" as an alternative to the indiscriminate use of chemical fertilizers. Samples were taken from roots and rhizosphere soil of vegetables from which dilutions (10-4 in Ashbysucrose broth and incubated at 30 ° C to observe a yellow color, turbidity and surface film. The genus Azotobacter was identified in mineral agar without nitrogen and Ashby-benzoate, obtaining 96 strains with a yield of 7.10 to 57.99 mgL-1 indoleacetic acid, 0.13 to 1.64 mgL-1 of fixed nitrogen as ammonium and up to 1.61% efficiency in the solubilization of phosphate Bayovar rock. It obtained a cell suspension (10 8 of each of the four strains with the highest values and inoculated independently and in consortium, as well as a combination with 50% urea-100 % phosphate rock in the rhizosphere of Rio Grande tomato, in a completely randomized design. The entire native strains increased height, root volume, total dry matter, shoot and root, compared with absolute control.

  10. Soluble Proteins, Proline, Carbohydrates and Na+/K+ Changes in Two Tomato (Lycopersicon esculentum Mill. Cultivars under in vitro Salt Stress

    Directory of Open Access Journals (Sweden)

    Fariba Amini

    2005-01-01

    Full Text Available The effect of NaCl stress on soluble proteins, proline, carbohydrates and Na+/K+ of two tomato (Lycopersicon esculentum Mill. cultivars Isfahani and Shirazy were studied. Seeds were germinated on medium containing only water agar, then transferred to MS medium supplemented with different concentrations of NaCl (0, 40, 80, 120 and 160 mM for 21 days. Increasing of salinity resulted in increasing of soluble proteins in stem & leaf of cv. Isfahani but decreasing in cv. Shirazy. Soluble proteins in roots of both cultivars showed some variations. When concentration of NaCl in the medium was increased proline contents of stem-leaf and roots in both cultivars increased significantly. However, cv. Shirazy showed higher amount of proline level. Proline content in stem-leaf in comparing with roots was higher in two cultivars. In response to increasing of salt concentration of the medium, the average amount of total carbohydrate in stem-leaf of cv. Shirazy increased but, in cv. Isfahani level of carbohydrate decreased. When explants form both cultivars were exposed to the higher concentration of salt the level of carbohydrate in roots increased. High-level salinity decreased the reduced sugars in both cv. either in stem-leaf or roots. Salt stress increased Na+ and decreased K+ content in both cultivars significantly.

  11. The impact of enhanced atmospheric carbon dioxide on yield, proximate composition, elemental concentration, fatty acid and vitamin C contents of tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Khan, Ikhtiar; Azam, Andaleeb; Mahmood, Abid

    2013-01-01

    The global average temperature has witnessed a steady increase during the second half of the twentieth century and the trend is continuing. Carbon dioxide, a major green house gas is piling up in the atmosphere and besides causing global warming, is expected to alter the physico-chemical composition of plants. The objective of this work was to evaluate the hypothesis that increased CO(2) in the air is causing undesirable changes in the nutritional composition of tomato fruits. Two varieties of tomato (Lycopersicon esculentum) were grown in ambient (400 μmol mol(-1)) and elevated (1,000 μmol mol(-1)) concentration of CO(2) under controlled conditions. The fruits were harvested at premature and fully matured stages and analyzed for yield, proximate composition, elemental concentration, fatty acid, and vitamin C contents. The amount of carbohydrates increased significantly under the enhanced CO(2) conditions. The amount of crude protein and vitamin C, two important nutritional parameters, decreased substantially. Fatty acid content showed a mild decrease with a slight increase in crude fiber. Understandably, the effect of enhanced atmospheric CO(2) was more pronounced at the fully matured stage. Mineral contents of the fruit samples changed in an irregular fashion. Tomato fruit has been traditionally a source of vitamin C, under the experimental conditions, a negative impact of enhanced CO(2) on this source of vitamin C was observed. The nutritional quality of both varieties of tomato has altered under the CO(2) enriched atmosphere.

  12. Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Saha, Sujoy; Purath, Ahammed Shabeer Thekkum; Jadhav, Manjusha R; Loganathan, M; Banerjee, Kaushik; Rai, A B

    2014-01-01

    This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

  13. The never ripe mutant provides evidence that tumor-induced ethylene controls the morphogenesis of agrobacterium tumefaciens-induced crown galls on tomato stems

    Science.gov (United States)

    Aloni; Wolf; Feigenbaum; Avni; Klee

    1998-07-01

    We confirm the hypothesis that Agrobacterium tumefaciens-induced galls produce ethylene that controls vessel differentiation in the host stem of tomato (Lycopersicon esculentum Mill.). Using an ethylene-insensitive mutant, Never ripe (Nr), and its isogenic wild-type parent we show that infection by A. tumefaciens results in high rates of ethylene evolution from the developing crown galls. Ethylene evolution from isolated internodes carrying galls was up to 50-fold greater than from isolated internodes of control plants when measured 21 and 28 d after infection. Tumor-induced ethylene substantially decreased vessel diameter in the host tissues beside the tumor in wild-type stems but had a very limited effect in the Nr stems. Ethylene promoted the typical unorganized callus shape of the gall, which maximized the tumor surface in wild-type stems, whereas the galls on the Nr stems had a smooth surface. The combination of decreased vessel diameter in the host and increased tumor surface ensured water-supply priority to the growing gall over the host shoot. These results indicate that in addition to the well-defined roles of auxin and cytokinin, there is a critical role for ethylene in determining crown-gall morphogenesis.

  14. Molecular flexibility of Mycobacterium tuberculosis ribosome recycling factor and its functional consequences: An exploration involving mutants

    Indian Academy of Sciences (India)

    M Selvaraj; A Govindan; A Seshadri; B Dubey; U Varshney; M Vijayan

    2013-12-01

    Internal mobility of the two domain molecule of ribosome recycling factor (RRF) is known to be important for its action. Mycobacterium tuberculosis RRF does not complement E. coli for its deficiency of RRF (in the presence of E. coli EF-G alone). Crystal structure had revealed higher rigidity of the M. tuberculosis RRF due to the presence of additional salt bridges between domains. Two inter-domain salt bridges and one between the linker region and the domain containing C-terminal residues were disrupted by appropriate mutations. Except for a C-terminal deletion mutant, all mutants showed RRF activity in E. coli when M. tuberculosis EF-G was also co-expressed. The crystal structures of the point mutants, that of the C-terminal deletion mutant and that of the protein grown in the presence of a detergent, were determined. The increased mobility resulting from the disruption of the salt bridge involving the hinge region allows the appropriate mutant to weakly complement E. coli for its deficiency of RRF even in the absence of simultaneous expression of the mycobacterial EF-G. The loss of activity of the C-terminal deletion mutant appears to be partly due to the rigidification of the molecule consequent to changes in the hinge region.

  15. Phanerochaete mutants with enhanced ligninolytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Kakar, S.N.; Perez, A.; Gonzales, J.

    1993-06-01

    In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organopollutants in soils and aqueous media. Although some of the organic compounds are degraded under nonligninolytic conditions, most are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, biopulping, biobleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated or are hyperproducers or supersecretors of key enzymes under enriched conditions. Through ultraviolet-light and gamma-rays mutagenesis we have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants produced 272 units (U) of lignin peroxidases enzyme activity per liter after nine days under high nitrogen. The mutant and the parent strains produced up to 54 U/L and 62 U/L, respectively, of the enzyme activity under low-nitrogen growth conditions during this period. In some experiments the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 days.

  16. The phenotype of a phospholipase C (plc-1) mutant in a filamentous fungus, Neurospora crassa.

    Science.gov (United States)

    Lew, Roger R; Giblon, Rachel E; Lorenti, Miranda S H

    2015-09-01

    In the filamentous fungus Neurospora crassa, phospholipase C may play a role in hyphal extension at the growing tips as part of a growth-sensing mechanism that activates calcium release from internal stores to mediate continued expansion of the hyphal tip. One candidate for a tip-localized phospholipase C is PLC-1. We characterized morphology and growth characteristics of a knockout mutant (KO plc-1) and a RIP mutated strain (RIP plc-1) (missense mutations and a nonsense mutation render the gene product non-functional). Growth and hyphal cytology of wildtype and KO plc-1 were similar, but the RIP plc-1 mutant grew slower and exhibited abnormal membrane structures at the hyphal tip, imaged using the fluorescence dye FM4-64. To test for causes of the slower growth of the RIP plc-1 mutant, we examined its physiological poise compared to wildtype and the KO plc-1 mutant. The electrical properties of all three strains and the electrogenic contribution of the plasma membrane H(+)-ATPase (identified by cyanide inhibition) were the same. Responses to high osmolarity were also similar. However, the RIP plc-1 mutant had a significantly lower turgor, a possible cause of its slower growth. While growth of all three strains was inhibited by the phospholipase C inhibitor 3-nitrocoumarin, the RIP plc-1 mutant did not exhibit hyphal bursting after addition of the inhibitor, observed in both wildtype and the KO plc-1 mutant. Although the plc-1 gene is not obligatory for tip growth, the phenotype of the RIP plc-1 mutant - abnormal tip cytology, lower turgor and resistance to inhibitor-induced hyphal bursting - suggest it does play a role in tip growth. The expression of a dysfunctional plc-1 gene may cause a shift to alternative mechanism(s) of growth sensing in hyphal extension. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Enhanced cellulase production in mutants of Thermomonospora

    Energy Technology Data Exchange (ETDEWEB)

    Fennington, G.; Lupo, D.; Stutzenberger, F.

    1982-01-01

    Thermomonospora curvata, a thermophilic actinomycete, secretes multiple forms of endo-beta, 1-4-glucanase (EG) when grown on cellulose-mineral salts liquid medium. The EG activity (measured as carboxymethyl cellulose hydrolysis) was separated by ion exchange chromatography into three distinct components which differed in their kinetic properties. Exposure of T. curvata to ultraviolet light, N-nitrosoguanidine, or ethane methyl sulfonate produced mutants with enhanced EG production. Selection of colonies which cleared cellulose agar plants containing 2-deoxyglucose or glycerol yielded mutants having 1.5 to 2.6 times the extracellular EG and saccharifying activity (measured by filter-paper and cotton-fiber hydrolysis). The secretion of extracellular protein was increased proportionally in mutant cultures. (Refs. 40).

  18. High Persister Mutants in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Heather L Torrey

    Full Text Available Mycobacterium tuberculosis forms drug-tolerant persister cells that are the probable cause of its recalcitrance to antibiotic therapy. While genetically identical to the rest of the population, persisters are dormant, which protects them from killing by bactericidal antibiotics. The mechanism of persister formation in M. tuberculosis is not well understood. In this study, we selected for high persister (hip mutants and characterized them by whole genome sequencing and transcriptome analysis. In parallel, we identified and characterized clinical isolates that naturally produce high levels of persisters. We compared the hip mutants obtained in vitro with clinical isolates to identify candidate persister genes. Genes involved in lipid biosynthesis, carbon metabolism, toxin-antitoxin systems, and transcriptional regulators were among those identified. We also found that clinical hip isolates exhibited greater ex vivo survival than the low persister isolates. Our data suggest that M. tuberculosis persister formation involves multiple pathways, and hip mutants may contribute to the recalcitrance of the infection.

  19. Escherichia coli mutants with a temperature-sensitive alcohol dehydrogenase.

    OpenAIRE

    Lorowitz, W; Clark, D.

    1982-01-01

    Mutants of Escherichia coli resistant to allyl alcohol were selected. Such mutants were found to lack alcohol dehydrogenase. In addition, mutants with temperature-sensitive alcohol dehydrogenase activity were obtained. These mutations, designated adhE, are all located at the previously described adh regulatory locus. Most adhE mutants were also defective in acetaldehyde dehydrogenase activity.

  20. Native Mutant Huntingtin in Human Brain

    Science.gov (United States)

    Sapp, Ellen; Valencia, Antonio; Li, Xueyi; Aronin, Neil; Kegel, Kimberly B.; Vonsattel, Jean-Paul; Young, Anne B.; Wexler, Nancy; DiFiglia, Marian

    2012-01-01

    Huntington disease (HD) is caused by polyglutamine expansion in the N terminus of huntingtin (htt). Analysis of human postmortem brain lysates by SDS-PAGE and Western blot reveals htt as full-length and fragmented. Here we used Blue Native PAGE (BNP) and Western blots to study native htt in human postmortem brain. Antisera against htt detected a single band broadly migrating at 575–850 kDa in control brain and at 650–885 kDa in heterozygous and Venezuelan homozygous HD brains. Anti-polyglutamine antisera detected full-length mutant htt in HD brain. There was little htt cleavage even if lysates were pretreated with trypsin, indicating a property of native htt to resist protease cleavage. A soluble mutant htt fragment of about 180 kDa was detected with anti-htt antibody Ab1 (htt-(1–17)) and increased when lysates were treated with denaturants (SDS, 8 m urea, DTT, or trypsin) before BNP. Wild-type htt was more resistant to denaturants. Based on migration of in vitro translated htt fragments, the 180-kDa segment terminated ≈htt 670–880 amino acids. If second dimension SDS-PAGE followed BNP, the 180-kDa mutant htt was absent, and 43–50 kDa htt fragments appeared. Brain lysates from two HD mouse models expressed native full-length htt; a mutant fragment formed if lysates were pretreated with 8 m urea + DTT. Native full-length mutant htt in embryonic HD140Q/140Q mouse primary neurons was intact during cell death and when cell lysates were exposed to denaturants before BNP. Thus, native mutant htt occurs in brain and primary neurons as a soluble full-length monomer. PMID:22375012

  1. Aging Kit mutant mice develop cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Lei Ye

    Full Text Available Both bone marrow (BM and myocardium contain progenitor cells expressing the c-Kit tyrosine kinase. The aims of this study were to determine the effects of c-Kit mutations on: i. myocardial c-Kit(+ cells counts and ii. the stability of left ventricular (LV contractile function and structure during aging. LV structure and contractile function were evaluated (echocardiography in two groups of Kit mutant (W/Wv and W41/W42 and in wild type (WT mice at 4 and 12 months of age and the effects of the mutations on LV mass, vascular density and the numbers of proliferating cells were also determined. In 4 month old Kit mutant and WT mice, LV ejection fractions (EF and LV fractional shortening rates (FS were comparable. At 12 months of age EF and FS were significantly decreased and LV mass was significantly increased only in W41/W42 mice. Myocardial vascular densities and c-Kit(+ cell numbers were significantly reduced in both mutant groups when compared to WT hearts. Replacement of mutant BM with WT BM at 4 months of age did not prevent these abnormalities in either mutant group although they were somewhat attenuated in the W/Wv group. Notably BM transplantation did not prevent the development of cardiomyopathy in 12 month W41/W42 mice. The data suggest that decreased numbers and functional capacities of c-Kit(+ cardiac resident progenitor cells may be the basis of the cardiomyopathy in W41/W42 mice and although defects in mutant BM progenitor cells may prove to be contributory, they are not causal.

  2. Behavioral characterization of system xc- mutant mice.

    Science.gov (United States)

    McCullagh, Elizabeth A; Featherstone, David E

    2014-05-15

    The slc7a11 gene encodes xCT, an essential component of 'system xc-', a plasma membrane exchanger that imports cystine and exports glutamate. Slc7a11 is expressed primarily in the brain, but its role there is not clear. We performed behavioral tests on two different strains of homozygous slc7a11 mutant mice ('sut' and 'xCT'), as well as heteroallelic offspring of these two strains ('xCT/sut') and their associated genetic backgrounds. Homozygous sut mutant males showed reduced spontaneous alternation in spontaneous alternation tasks as well as reduced movement in an open field maze, but xCT and xCT/sut strains did not show significant changes in these tasks compared to appropriate controls. Neither xCT nor sut mutants showed differences from controls in rotarod tests. Female behavioral phenotypes were independent of estrus cycle stage. To ensure that homozygous xCT, sut, and xCT/sut strains all represent protein null alleles, we measured whole brain xCT protein levels using immunoblots. xCT, sut and xCT/sut strains showed no detectable xCT protein expression, confirming them as null alleles. Previously published microdialysis experiments showed reduced striatal glutamate in xCT mutants. Using the same methods, we measured reduced interstitial glutamate levels in the striatum but not cerebellum of sut mutants. However, we detected no glutamate change in the striatum or cerebellum of sut/xCT mice. We detected no changes in whole brain EAAT-1, -2, or -3 expression. We conclude that the behavioral and chemical differences exist between slc7a11 mutant strains, but we were unable to definitively attribute any of these differences to loss of system xc-.

  3. Targeting ESR1-Mutant Breast Cancer

    Science.gov (United States)

    2015-09-01

    cell line, biochemical and structural biology techniques to uncover the best candidate drugs for the clinical targeting of these mutants. Targeting...ESR1-­‐Mutant  Breast  Cancer   W81XWH-­‐14-­‐1-­‐0360   4   2. Keywords Estrogen Receptor Acquired Drug Resistance Metastatic Breast...preparations for publication: 1) “ESR1 Somatic Mutations Y537S and D538G Confer Breast Cancer Endocrine Resistance by Stabilizing the Active AF-2 conformation

  4. Endocytosis of Ubiquitylation-Deficient EGFR Mutants via Clathrin-Coated Pits is Mediated by Ubiquitylation.

    Science.gov (United States)

    Fortian, Arola; Dionne, Lai K; Hong, Sun H; Kim, Woong; Gygi, Steven P; Watkins, Simon C; Sorkin, Alexander

    2015-11-01

    Signaling by epidermal growth factor receptor (EGFR) is controlled by endocytosis. However, mechanisms of EGFR endocytosis remain poorly understood. Here, we found that the EGFR mutant lacking known ubiquitylation, acetylation and clathrin adaptor AP-2-binding sites (21KRΔAP2) was internalized at relatively high rates via the clathrin-dependent pathway in human duodenal adenocarcinoma HuTu-80 cells. RNA interference analysis revealed that this residual internalization is strongly inhibited by depletion of Grb2 and the E2 ubiquitin-conjugating enzyme UbcH5b/c, and partially affected by depletion of the E3 ubiquitin ligase Cbl and ubiquitin-binding adaptors, indicating that an ubiquitylation process is involved. Several new ubiquitin conjugation sites were identified by mass spectrometry in the 21KRΔAP2 mutant, suggesting that cryptic ubiquitylation may mediate endocytosis of this mutant. Total internal reflection fluorescence microscopy imaging of HuTu-80 cells transfected with labeled ubiquitin adaptor epsin1 demonstrated that the ubiquitylation-deficient EGFR mutant was endocytosed through a limited population of epsin-enriched clathrin-coated pits (CCPs), although with a prolonged CCP lifetime. Native EGFR was recruited with the same efficiency into CCPs containing either AP-2 or epsin1 that were tagged with fluorescent proteins by genome editing of MDA-MD-231 cells. We propose that two redundant mechanisms, ubiquitylation and interaction with AP-2, contribute to EGFR endocytosis via CCPs in a stochastic fashion.

  5. Chloroplast ultrastructure in leaves of Cucumis sativus chlorophyll mutant

    Directory of Open Access Journals (Sweden)

    Irena Palczewska

    2014-02-01

    Full Text Available The developing and young leaves of Cucumis sativus chlorophyll mutants are yellow, when mature they become green and do not differ in their colour from those of control plants. The mesophyll of yellow leaves contains a diversiform plastid population with a varying degree of defectiveness, which is mainly manifested in the reduction or disorganization of the typical thylakoid system. DNA areas, ribosome-like particles and aggregates of electron-dense material are preserved in the stroma of mutated plastids. Starch grains are deficient. Apart from mutated plastids, chloroplasts with a normal structure, as in control plants, were also observed.The leaf greening process is accompanied by a reconstruction and rearrangement of the inner chloroplast lamellar system and an ability to accumulate starch. However, in the mutant chloroplasts as compared with control-plant ones, an irregular arrangement of grana and reduced number of inter-grana thylakoids can be seen. An osmiophilic substance stored in the stroma of mutated plastids and the vesicles formed from an internal plastid membrane take part in restoration of the membrane system.

  6. Rapid Antibiotic Resistance Evolution of GASP Mutants

    Science.gov (United States)

    Zhang, Qiucen; Kim, Hyunsung; Pourmand, Nader; Austin, Robert

    2012-02-01

    The GASP phenotype in bacteria is due to a mutation which enables the bacteria to grow under high stress conditions where other bacteria stop growing. We probe using our Death Galaxy microenvironment how rapidly the GASP mutant can evolve resistance to mutagenic antibiotics compared to wild-type bacteria, and explore the genomic landscape changes due to the evolution of resistance.

  7. Generation and characterization of pigment mutants of ...

    African Journals Online (AJOL)

    acer

    deleterious effects on living organisms (Shigaeva et al.,. 1994); they are also ... It was cultured at 25±0.5°C with a fluorescent light intensity of approximately 6 ... mutants) resulted in three new colonies characterized by different green colors ...

  8. A dominant semi dwarf mutant in rice

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ In the winter of 1997, a semi dwarf mutant was found in the F6 population of M9056/ R8018 xuan in Hainan Province. In the spring of 1998, the seeds were sown in Hefei, Anhui Province and the plant height of the population was measured at maturity.

  9. Nicotinamide ribosyl uptake mutants in Haemophilus influenzae.

    Science.gov (United States)

    Herbert, Mark; Sauer, Elizabeta; Smethurst, Graeme; Kraiss, Anita; Hilpert, Anna-Karina; Reidl, Joachim

    2003-09-01

    The gene for the nicotinamide riboside (NR) transporter (pnuC) was identified in Haemophilus influenzae. A pnuC mutant had only residual NR uptake and could survive in vitro with high concentrations of NR, but could not survive in vivo. PnuC may represent a target for the development of inhibitors for preventing H. influenzae disease.

  10. Mutant PTEN in Cancer : Worse Than Nothing

    NARCIS (Netherlands)

    Leslie, Nick R; den Hertog, Jeroen

    2014-01-01

    Tumor suppressors block the development of cancer and are often lost during tumor development. Papa et al. show that partial loss of normal PTEN tumor suppressor function can be compounded by additional disruption caused by the expression of inactive mutant PTEN protein. This has significant

  11. Colored HOMFLY polynomials can distinguish mutant knots

    CERN Document Server

    Nawata, Satoshi; Singh, Vivek Kumar

    2015-01-01

    We illustrate from the viewpoint of braiding operations on WZNW conformal blocks how colored HOMFLY polynomials with multiplicity structure can detect mutations. As an example, we explicitly evaluate the (2,1)-colored HOMFLY polynomials that distinguish a famous mutant pair, Kinoshita-Terasaka and Conway knot.

  12. Identification of QTLs for early blight ( Alternaria solani) resistance in tomato using backcross populations of a Lycopersicon esculentum x L. hirsutum cross.

    Science.gov (United States)

    Foolad, R.; Zhang, P.; Khan, A. A.; Niño-Liu, D.; Lin, Y.

    2002-05-01

    Most commercial cultivars of tomato, Lycopersicon esculentum Mill., are susceptible to early blight (EB), a devastating fungal ( Alternaria solani Sorauer) disease of tomato in the northern and eastern parts of the U.S. and elsewhere in the world. The disease causes plant defoliation, which reduces yield and fruit quality, and contributes to significant crop loss. Sources of resistance have been identified within related wild species of tomato. The purpose of this study was to identify and validate quantitative trait loci (QTLs) for EB resistance in backcross populations of a cross between a susceptible tomato breeding line (NC84173; maternal and recurrent parent) and a resistant Lycopersicon hirsutum Humb. and Bonpl. accession (PI126445). Sixteen hundred BC(1) plants were grown to maturity in a field in 1998. Plants that were self-incompatible, indeterminant in growth habit, and/or extremely late in maturity, were discarded in order to eliminate confounding effects of these factors on disease evaluation, QTL mapping, and future breeding research. The remaining 145 plants (referred to as the BC(1) population) were genotyped for 141 restriction fragment length polymorphism (RFLP) markers and 23 resistance gene analogs (RGAs), and a genetic linkage map was constructed. BC(1) plants were evaluated for disease symptoms throughout the season, and the area under the disease progress curve (AUDPC) and the final percent defoliation (disease severity) were determined for each plant. BC(1) plants were self-pollinated and produced BC(1)S(1) seed. The BC(1)S(1) population, consisting of 145 BC(1)S(1) families, was grown and evaluated for disease symptoms in replicated field trials in two subsequent years (1999 and 2000) and AUDPC and/or final percent defoliation were determined for each family in each year. Two QTL mapping approaches, simple interval mapping (SIM) and composite interval mapping (CIM), were used to identify QTLs for EB resistance in the BC(1) and BC(1)S(1

  13. Caracterización de cepas nativas de Azotobacter spp. y su efecto en el desarrollo de Lycopersicon esculentum Mill. “tomate” en Lambayeque

    Directory of Open Access Journals (Sweden)

    Cynthia Escobar

    2011-01-01

    Full Text Available El objetivo de la presente investigación fue caracterizar y determinar el efecto de cepas nativas de Azotobacter spp. en el desarrollo vegetativo de Lycopersicon esculentum Mill. “tomate”, como una alternativa al uso indiscriminado de fertilizantes químicos. Se tomaron muestras de raíces y suelo rizosférico de hortalizas con las que se realizaron diluciones (10-4 en caldo Ashby-Sacarosa y se incubaron a 30 ºC hasta observar un color amarillo, turbidez y película superficial. El género Azotobacter se identificó en agar mineral sin nitrógeno y Ashby-Benzoato, obteniéndose 96 cepas con una producción de 7.10 a 57.99 mgL-1 de ácido indolacético, 0.13 a 1.64 mgL-1 de nitrógeno fijado como amonio y hasta 1.61 % de eficiencia en la solubilización de roca fosfórica de Bayóvar. Se obtuvo una suspensión celular (108 de cada una de las cuatro cepas con los mayores valores y se inocularon independientemente y en consorcio, así como una combinación con 50 % de urea-100 % de roca fosfórica, en la rizósfera de tomate cv. Río Grande, en un diseño experimental completamente aleatorio. Todas las cepas nativas incrementaron la altura, volumen radicular, materia seca total, parte aérea y radicular frente al testigo absoluto.

  14. Polihidroxialcanoatos de cepas de Azospirillum spp. aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz” en Lambayeque

    Directory of Open Access Journals (Sweden)

    Katty Baca

    2010-01-01

    Full Text Available En este trabajo se determinó la concentración de polihidroxialcanoatos (PH As de cepas de Azospirillum aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz”, como una alternativa ante la acumulación de plásticos derivados del petróleo. R aíces previamente desinfectadas se sembraron en medio Nfb se misólido, donde las bacterias fijadoras de nitrógeno se reconocieron por una película blanquecina bajo la superficie y el viraje del indicador al azul. El género Azospirillum se identificó en medio rojo de Congo, obteniéndose 96 cepas de A. lipoferum y A. brasilense en tomate y arroz. Se realizó una fermentación discontinua con caldo Azotobacter modificado, alimentando con una solución saturada de ácido málico cada 12 horas y se realizaron tinciones con Sudán Negro B. Se seleccionaron las cepas con mayor nú mero de gránulos de PHAs (en tomate , 18 de A. lipoferum y 2 de A. brasilense y en arroz, 10 de A. lipoferum y 10 de A. brasilense y se cuantificó la biomasa y PHAs. La concentración de PHAs alcanzó 0 . 661 gL - 1 en A. lipoferum KM(T - 73 y 0 . 738 gL - 1 en A. br asilense KM(T - 19. Las cepas de A. lipoferum y A. brasilense aisladas de tomate alcanzaron una mayor concentración de biomasa y PHAs frente a las cepas aisladas de arroz.

  15. β(1,3 GLUCANASAS DE LOS ESPACIOS INTERCELULARES DE HOJAS DE TOMATE LYCOPERSICON ESCULENTUM CERACIFORME DESPUES DE INFECCIÓN CON PHYTOPHTHORA INFESTANS.

    Directory of Open Access Journals (Sweden)

    Humberto M. Zamora

    2009-06-01

    Full Text Available Análisis en líquido de lavado intercelular de Lycopersicon esculentum ceraciforme L1568 perteneciente al germoplasma nacional con resistencia en campo a P. infestans mostró la presencia de cuatro   β (1,3 glucanasas después de infección con el patógeno. Las plantas se inocularon con el patógeno para inducir aumento en la concentración de las proteínas PR. Después de 15 días de inoculadas, se extrajo el líquido de lavado intercelular de los foliolos de la planta utilizando agua destilada. Las proteínas extraídas se liofilizaron, se  resuspendieron en buffer, se purificaron utilizando cromatografía de intercambio iónico y electroforesis preparativa,  esto permitió la  caracterización parcial de una β (1,3  glucanasa básica con peso molecular  de 36,8 kDa y PI  9,2 y tres ácidas de  35.4, 30.1 y 7.2 kDa  con puntos isoeléctricos de 3.8; 3.6 y 5.0 respectivamente. Además se determinaron las propiedades cinéticas de cada enzima, KM, Vmax, Eo y K3 encontrando que la proteína básica no ha sido reportada en la literatura hasta ahora.

  16. Exposure of Lycopersicon esculentum to microcystin-LR: effects in the leaf proteome and toxin translocation from water to leaves and fruits.

    Science.gov (United States)

    Gutiérrez-Praena, Daniel; Campos, Alexandre; Azevedo, Joana; Neves, Joana; Freitas, Marisa; Guzmán-Guillén, Remédios; Cameán, Ana María; Renaut, Jenny; Vasconcelos, Vitor

    2014-06-11

    Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR) toxicity in Lycopersicon esculentum and the toxin accumulation in this horticultural crop. Adult plants (2 month-old) grown in a greenhouse environment were exposed for 2 weeks to either pure MC-LR (100 μg/L) or Microcystis aeruginosa crude extracts containing 100 μg/L MC-LR. Chlorophyll fluorescence was measured, leaf proteome investigated with two-dimensional gel electrophoresis and Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF)/TOF, and toxin bioaccumulation assessed by liquid chromatography-mass spectrometry (LC-MS)/MS. Variations in several protein markers (ATP synthase subunits, Cytochrome b6-f complex iron-sulfur, oxygen-evolving enhancer proteins) highlight the decrease of the capacity of plants to synthesize ATP and to perform photosynthesis, whereas variations in other proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit and ribose-5-phosphate isomerase) suggest an increase of carbon fixation and decrease of carbohydrate metabolism reactions in plants exposed to pure MC-LR and cyanobacterial extracts, respectively. MC-LR was found in roots (1635.21 μg/kg fw), green tomatoes (5.15-5.41 μg/kg fw), mature tomatoes (10.52-10.83 μg/kg fw), and leaves (12,298.18 μg/kg fw). The results raise concerns relative to food safety and point to the necessity of monitoring the bioaccumulation of water toxins in agricultural systems affected by cyanotoxin contamination.

  17. Genetic diversity analysis based on molecular marker and quantitative traits of the response of different tomato (Lycopersicon esculentum Mill. cultivars to drought stress

    Directory of Open Access Journals (Sweden)

    Metwali Ehab M.R.

    2016-01-01

    Full Text Available The drought tolerance of tomato (Lycopersicon esculentum Mill. is a trait needing urgent improvement due to recent climate changes and limited water availability. We therefore conducted a greenhouse screening experiment to identify tomato cultivars with improved drought tolerance. Several sensitivity and tolerance indices were computed based on morphological markers. With the aim of establishing a correlation to these markers, a total of 16 inter-simple sequence repeat (ISSR primers were used, the genetic diversity among cultivars was elucidated and clustering the cultivars into groups based on their molecular profiles was performed. The obtained results indicated that selection indices, such as geometric mean productivity (GMP, mean productivity (MP, tolerance index (TOL,and stress tolerance index (STI, represented suitable indices for screening the drought tolerance of tomato cultivars. An interesting correlation of the ISSR analyses to these morphological findings was established according to 83 detectable fragments derived from 10 primers. The highest value of the effective multiplex ratio (EMR and marker index (MI was detected for primer INC7 followed by INC1. Based on Jaccard's similarity coefficients, the genetic distance of the genotypes varied from 0.702 to 0.942 with a mean value of 0.882. The results showed a clear-cut separation of the 15 tomato cultivars due to their genetic variability, making them a valuable genetic source for their incorporation into potential breeding programs. Molecular data were in good agreement with the results as regards selection indices, and both of them will be useful tools for improvement of the tomato germplasm.

  18. Long-distance signals regulating stomatal conductance and leaf growth in tomato (Lycopersicon esculentum) plants subjected to partial root-zone drying.

    Science.gov (United States)

    Sobeih, Wagdy Y; Dodd, Ian C; Bacon, Mark A; Grierson, Donald; Davies, William J

    2004-11-01

    Tomato (Lycopersicon esculentum Mill. cv. Ailsa Craig) plants were grown with roots split between two soil columns. After plant establishment, water was applied daily to one (partial root-zone drying-PRD) or both (well-watered control-WW) columns. Water was withheld from the other column in the PRD treatment, to expose some roots to drying soil. Soil and plant water status were monitored daily and throughout diurnal courses. Over 8 d, there were no treatment differences in leaf water potential (psileaf) even though soil moisture content of the upper 6 cm (theta) of the dry column in the PRD treatment decreased by up to 70%. Stomatal conductance (gs) of PRD plants decreased (relative to WW plants) when of the dry column decreased by 45%. Such closure coincided with increased xylem sap pH and did not require increased xylem sap abscisic acid (ABA) concentration ([X-ABA]). Detached leaflet ethylene evolution of PRD plants increased when of the dry column decreased by 55%, concurrent with decreased leaf elongation. The physiological significance of enhanced ethylene evolution of PRD plants was examined using a transgenic tomato (ACO1AS) with low stress-induced ethylene production. In response to PRD, ACO1AS and wild-type plants showed similar xylem sap pH, [X-ABA] and gs, but ACO1AS plants showed neither enhanced ethylene evolution nor significant reductions in leaf elongation. Combined use of genetic technologies to reduce ethylene production and agronomic technologies to sustain water status (such as PRD) may sustain plant growth under conditions where yield would otherwise be significantly reduced.

  19. Identification and quantification of stilbenes in fruits of transgenic tomato plants (Lycopersicon esculentum Mill.) by reversed phase HPLC with photodiode array and mass spectrometry detection.

    Science.gov (United States)

    Nicoletti, Isabella; De Rossi, Antonella; Giovinazzo, Giovanna; Corradini, Danilo

    2007-05-02

    Reversed-phase high-performance liquid chromatography (RP-HPLC) with photodiode array (PDA) and mass spectrometry (MS) detection was employed to study the accumulation of stilbenes and other naturally occurring polyphenol intermediates of flavonoid pathway in tomato fruits of plants genetically modified to synthesize resveratrol. The transgenic tomato fruits were obtained by overexpression of a grapevine gene encoding the enzyme stilbene synthase in tomato plants (Lycopersicon esculentum Mill.). Stilbenes and flavonoids, either glycosylated or free, were simultaneosly identified by electrospray interface (ESI)-MS in negative ionization mode and were quantified by PDA detection at the wavelength corresponding to their maximum absorbance. The two detectors were coupled online with an HPLC system utilizing a narrow-bore C18 reversed-phase column, which was eluted by a multistep gradient of increasing concentration of acetonitrile in water containing 0.5% (v/v) formic acid. The results of these analysis revealed that the genetic modification of the tomato plants originated different levels of accumulation of four stilbenes (i.e., trans- and cis-piceid and trans- and cis-resveratrol) in their fruit depending on the stages of ripening. Either at immature or at mature stages of ripening the stilbenes were preferentially accumulated in the fruit peel as the glycosylated form. The highest amount of trans-piceid and trans-resveratrol were found in the peel of fruits harvested at mature stage of ripening. The variations in the levels of rutin, naringenin, and chlorogenic acid found in the samples extracted from the fruits of transgenic tomato plants, in comparison to that determined in the control lines, seemed to be related to the genetic transformation, whose effect on the flavonoid biosynthetic pathway needs to be elucidated by additional studies.

  20. Exposure of Lycopersicon Esculentum to Microcystin-LR: Effects in the Leaf Proteome and Toxin Translocation from Water to Leaves and Fruits

    Directory of Open Access Journals (Sweden)

    Daniel Gutiérrez-Praena

    2014-06-01

    Full Text Available Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR toxicity in Lycopersicon esculentum and the toxin accumulation in this horticultural crop. Adult plants (2 month-old grown in a greenhouse environment were exposed for 2 weeks to either pure MC-LR (100 μg/L or Microcystis aeruginosa crude extracts containing 100 μg/L MC-LR. Chlorophyll fluorescence was measured, leaf proteome investigated with two-dimensional gel electrophoresis and Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF/TOF, and toxin bioaccumulation assessed by liquid chromatography-mass spectrometry (LC-MS/MS. Variations in several protein markers (ATP synthase subunits, Cytochrome b6-f complex iron-sulfur, oxygen-evolving enhancer proteins highlight the decrease of the capacity of plants to synthesize ATP and to perform photosynthesis, whereas variations in other proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit and ribose-5-phosphate isomerase suggest an increase of carbon fixation and decrease of carbohydrate metabolism reactions in plants exposed to pure MC-LR and cyanobacterial extracts, respectively. MC-LR was found in roots (1635.21 μg/kg fw, green tomatoes (5.15–5.41 μg/kg fw, mature tomatoes (10.52–10.83 μg/kg fw, and leaves (12,298.18 μg/kg fw. The results raise concerns relative to food safety and point to the necessity of monitoring the bioaccumulation of water toxins in agricultural systems affected by cyanotoxin contamination.

  1. GAMPMS: Genetic algorithm managed peptide mutant screening.

    Science.gov (United States)

    Long, Thomas; McDougal, Owen M; Andersen, Tim

    2015-06-30

    The prominence of endogenous peptide ligands targeted to receptors makes peptides with the desired binding activity good molecular scaffolds for drug development. Minor modifications to a peptide's primary sequence can significantly alter its binding properties with a receptor, and screening collections of peptide mutants is a useful technique for probing the receptor-ligand binding domain. Unfortunately, the combinatorial growth of such collections can limit the number of mutations which can be explored using structure-based molecular docking techniques. Genetic algorithm managed peptide mutant screening (GAMPMS) uses a genetic algorithm to conduct a heuristic search of the peptide's mutation space for peptides with optimal binding activity, significantly reducing the computational requirements of the virtual screening. The GAMPMS procedure was implemented and used to explore the binding domain of the nicotinic acetylcholine receptor (nAChR) α3β2-isoform with a library of 64,000 α-conotoxin (α-CTx) MII peptide mutants. To assess GAMPMS's performance, it was compared with a virtual screening procedure that used AutoDock to predict the binding affinity of each of the α-CTx MII peptide mutants with the α3β2-nAChR. The GAMPMS implementation performed AutoDock simulations for as few as 1140 of the 64,000 α-CTx MII peptide mutants and could consistently identify a set of 10 peptides with an aggregated binding energy that was at least 98% of the aggregated binding energy of the 10 top peptides from the exhaustive AutoDock screening.

  2. Phanerochaete mutants with enhanced ligninolytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Kakar, S.N.; Perez, A.; Gonzales, J. (Argonne National Lab., IL (United States))

    In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organopollutants in soils and aqueous media. Most of the organic compounds are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, biopulping, biobleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated, or are hyperproducers or supersectors of key enzymes under enriched conditions. Through UV-light and [gamma]-ray mutagenesis, the authors have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants, 76UV, produced 272 U of lignin peroxidases enzyme activity/L after 9 d under high nitrogen (although the parent strain does not produce this enzyme under these conditions). The mutant and the parent strains produced up to 54 and 62 U/L, respectively, of the enzyme activity under low-nitrogen growth conditions during this period. In some experiments, the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 d. 17 refs., 1 fig., 3 tabs.

  3. BRED: a simple and powerful tool for constructing mutant and recombinant bacteriophage genomes.

    Directory of Open Access Journals (Sweden)

    Laura J Marinelli

    Full Text Available Advances in DNA sequencing technology have facilitated the determination of hundreds of complete genome sequences both for bacteria and their bacteriophages. Some of these bacteria have well-developed and facile genetic systems for constructing mutants to determine gene function, and recombineering is a particularly effective tool. However, generally applicable methods for constructing defined mutants of bacteriophages are poorly developed, in part because of the inability to use selectable markers such as drug resistance genes during viral lytic growth. Here we describe a method for simple and effective directed mutagenesis of bacteriophage genomes using Bacteriophage Recombineering of Electroporated DNA (BRED, in which a highly efficient recombineering system is utilized directly on electroporated phage DNA; no selection is required and mutants can be readily detected by PCR. We describe the use of BRED to construct unmarked gene deletions, in-frame internal deletions, base substitutions, precise gene replacements, and the addition of gene tags.

  4. Spontaneous Remission in an Older Patient with Relapsed FLT3 ITD Mutant AML

    Directory of Open Access Journals (Sweden)

    Pankit Vachhani

    2016-01-01

    Full Text Available Spontaneous remission (SR of acute myeloid leukemia (AML is a very rare phenomenon. AML characterized by FLT3 internal tandem duplication (FLT3 ITD is typically associated with an aggressive clinical course with rapid progression, relapse, and short overall survival in the absence of transplantation. We report here the first case of SR of FLT3 ITD mutant AML in the literature. Our patient was an elderly woman with relapsed NPM1 and FLT3 ITD mutant AML whose disease underwent SR for a brief duration without precipitating cause. We review the potential immune mechanisms underlying SR in AML and discuss the implications for novel immunotherapeutic approaches for FLT3 mutant AML.

  5. Internalization of cholera toxin by different endocytic mechanisms

    National Research Council Canada - National Science Library

    Torgersen, M L; Skretting, G; van Deurs, B; Sandvig, K

    2001-01-01

    The mechanism of cholera toxin (CT) internalization has been investigated using Caco-2 cells transfected with caveolin to induce formation of caveolae, HeLa cells with inducible synthesis of mutant dynamin (K44A...

  6. Isolation and characterisation of a dwarf rice mutant exhibiting defective gibberellins biosynthesis.

    Science.gov (United States)

    Ji, S H; Gururani, M A; Lee, J W; Ahn, B-O; Chun, S-C

    2014-03-01

    We have isolated a severe dwarf mutant derived from a Ds (Dissociation) insertion mutant rice (Oryza sativa var. japonica c.v. Dongjin). This severe dwarf phenotype, has short and dark green leaves, reduced shoot growth early in the seedling stage, and later severe dwarfism with failure to initiate flowering. When treated with bioactive GA3 , mutants are restored to the normal wild-type phenotype. Reverse transcription PCR analyses of 22 candidate genes related to the gibberellin (GA) biosynthesis pathway revealed that among 22 candidate genes tested, a dwarf mutant transcript was not expressed only in one OsKS2 gene. Genetic analysis revealed that the severe dwarf phenotype was controlled by recessive mutation of a single nuclear gene. The putative OsKS2 gene was a chromosome 4-located ent-kaurene synthase (KS), encoding the enzyme that catalyses an early step of the GA biosynthesis pathway. Sequence analysis revealed that osks2 carried a 1-bp deletion in the ORF region of OsKS2, which led to a loss-of-function mutation. The expression pattern of OsKS2 in wild-type cv Dongjin, showed that it is expressed in all organs, most prominently in the stem and floral organs. Morphological characteristics of the dwarf mutant showed dramatic modifications in internal structure and external morphology. We propose that dwarfism in this mutant is caused by a point mutation in OsKS2, which plays a significant role in growth and development of higher plants. Further investigation on OsKS2 and other OsKS-like proteins is underway and may yield better understanding of the putative role of OsKS in severe dwarf mutants.

  7. Thermostability of photosynthesis in two new chlorophyll b-less rice mutants

    Institute of Scientific and Technical Information of China (English)

    LIN; Zhifang; PENG; Changlian; Xu; Xinlan; LIN; Guizhu; ZH

    2005-01-01

    Leaves of the two new chlorophyll b-less rice mutants VG28-1, VG30-5 and the wild type rice cv. Zhonghua 11 were subjected to temperatures 28, 36, 40, 44 and 48℃ in the dark for 30 min or gradually elevated temperature from 30℃ to 80℃ at 0.5℃/min. The thermostability of photosynthetic apparatus was estimated by the changes in chlorophyll fluorescence parameters, photosynthetic rate and pigment content, chloroplast ultrastructure and tissue location of H2O2 accumulation. There were different patterns of Fo-temperature curves between the Chl b-less mutants and the wild type plant, and the temperature of Fo rising threshold was shifted 3℃ lower in the Chl b-less mutants (48℃) than in the wild type (51℃). At temperature up to about 45℃, chloroplasts were swollen and thylakoid grana became misty accompanied with the complete loss of photosynthetic oxygen evolution in the two Chl b-less mutants, but chloroplast ultrastructure in the wild type showed no obvious alteration. After 55℃ exposure, the disordered thylakoid and significant H2O2 accumulation in leaves were found in the two Chl b-less mutants, whereas in the wild type plant, less H2O2 was accumulated and the swollen thylakoid still maintained a certain extent of stacking. A large extent of the changes in qP, NPQ and Fv/Fm was consistent with the Pn decreasing rate in the Chl b-less mutants during high temperature treatment as compared with the wild type. The results indicated that the Chl b-less mutants showed a tendency for higher thermosensitivity, and loss of Chl b in LHC II could lead to less thermostability of PSII structure and function. Heat damage to photosynthetic apparatus might be partially attributed to the internal oxidative stress produced at severely high temperature.

  8. Long-lived mitochondrial (Mit) mutants of Caenorhabditis elegans utilize a novel metabolism.

    Science.gov (United States)

    Butler, Jeffrey A; Ventura, Natascia; Johnson, Thomas E; Rea, Shane L

    2010-12-01

    The Caenorhabditis elegans mitochondrial (Mit) mutants have disrupted mitochondrial electron transport chain (ETC) functionality, yet, surprisingly, they are long lived. We have previously proposed that Mit mutants supplement their energy needs by exploiting alternate energy production pathways normally used by wild-type animals only when exposed to hypoxic conditions. We have also proposed that longevity in the Mit mutants arises as a property of their new metabolic state. If longevity does arise as a function of metabolic state, we would expect to find a common metabolic signature among these animals. To test these predictions, we established a novel approach monitoring the C. elegans exometabolism as a surrogate marker for internal metabolic events. Using HPLC-ultraviolet-based metabolomics and multivariate analyses, we show that long-lived clk-1(qm30) and isp-1(qm150) Mit mutants have a common metabolic profile that is distinct from that of aerobically cultured wild-type animals and, unexpectedly, wild-type animals cultured under severe oxygen deprivation. Moreover, we show that 2 short-lived mitochondrial ETC mutants, mev-1(kn1) and ucr-2.3(pk732), also share a common metabolic signature that is unique. We show that removal of soluble fumarate reductase unexpectedly increases health span in several genetically defined Mit mutants, identifying at least 1 alternate energy production pathway, malate dismutation, that is operative in these animals. Our study suggests long-lived, genetically specified Mit mutants employ a novel metabolism and that life span may well arise as a function of metabolic state.

  9. Immobilization of tomato (Lycopersicon esculentum) pectinmethylesterase in calcium alginate beads and its application in fruit juice clarification.

    Science.gov (United States)

    Bogra, Pushpa; Kumar, Ashwani; Kuhar, Kalika; Panwar, Surbhi; Singh, Randhir

    2013-11-01

    Clarity of fruit juices is desirable to maintain an aesthetically pleasing quality and international standards. The most commonly used enzymes in juice industries are pectinases. A partially-purified pectinmethylesterase from tomato was entrapped in calcium alginate beads and used for juice clarification. The activity yield was maximum at 1 % (w/v) CaCl2 and 2.5 % (w/v) alginate. The immobilized enzyme retained ~55 % of its initial activity (5.7 × 10(-2) units) after more than ten successive batch reactions. The Km, pH and temperature optima were increased after immobilization. The most effective clarification of fruit juice (%T620 ~60 %) by the immobilized enzyme was at 4 °C with a holding time of 20 min. The viscosity dropped by 56 % and the filterability increased by 260 %. The juice remains clear after 2 months of storage at 4 °C.

  10. pnp4a Is the Causal Gene of the Medaka Iridophore Mutant guanineless

    Directory of Open Access Journals (Sweden)

    Tetsuaki Kimura

    2017-04-01

    Full Text Available See-through medaka lines are suitable for observing internal organs throughout life. They were bred by crossing multiple color mutants. However, some of the causal genes for these mutants have not been identified. The medaka has four pigment cell types: black melanophores, yellow xanthophores, white leucophores, and silvery iridophores. The causal genes of melanophore, xanthophore, and leucophore mutants have been elucidated, but the causal gene for the iridophore mutant remains unknown. Here, we describe the iridophore mutant, guanineless (gu, which exhibits a strong reduction in visible iridophores throughout its larval to adult stages. The gu locus was previously mapped to chromosome 5, but was located near the telomeric region, making it difficult to integrate into the chromosome. We sought the causal gene of gu using synteny analysis with the zebrafish genome and found a strong candidate, purine nucleoside phosphorylase 4a (pnp4a. Gene targeting and complementation testing showed that pnp4a is the causal gene of gu. This result will allow the establishment of inbred medaka strains or other useful strains with see-through phenotypes without major disruption in the genetic background of each strain.

  11. Amuvatinib has cytotoxic effects against NRAS-mutant melanoma but not BRAF-mutant melanoma.

    Science.gov (United States)

    Fedorenko, Inna V; Fang, Bin; Koomen, John M; Gibney, Geoffrey T; Smalley, Keiran S M

    2014-10-01

    Effective targeted therapy strategies are still lacking for the 15-20% of melanoma patients whose melanomas are driven by oncogenic NRAS. Here, we report on the NRAS-specific behavior of amuvatinib, a kinase inhibitor with activity against c-KIT, Axl, PDGFRα, and Rad51. An analysis of BRAF-mutant and NRAS-mutant melanoma cell lines showed the NRAS-mutant cohort to be enriched for targets of amuvatinib, including Axl, c-KIT, and the Axl ligand Gas6. Increasing concentrations of amuvatinib selectively inhibited the growth of NRAS-mutant, but not BRAF-mutant melanoma cell lines, an effect associated with induction of S-phase and G2/M-phase cell cycle arrest and induction of apoptosis. Mechanistically, amuvatinib was noted to either inhibit Axl, AKT, and MAPK signaling or Axl and AKT signaling and to induce a DNA damage response. In three-dimensional cell culture experiments, amuvatinib was cytotoxic against NRAS-mutant melanoma cell lines. Thus, we show for the first time that amuvatinib has proapoptotic activity against melanoma cell lines, with selectivity observed for those harboring oncogenic NRAS.

  12. EVALUACIÓN DEL GERMOPLASMA DE TOMATE (Solanum L. sección Lycopersicon CONSERVADO Ex Situ EN CUBA UTILIZANDO PRUEBA In Vitro PARA PREDECIR LAS RESPUESTAS A ALTAS TEMPERATURAS

    Directory of Open Access Journals (Sweden)

    Marilyn Florido

    2009-01-01

    Full Text Available El presente trabajo se desarrolló con el objetivo de evaluar la tolerancia al calor a nivel de tejido en una muestra representativa del germoplasma de tomate (Solanum L. sección Lycopersicon subsección Lycopersicon conservado ex situ en Cuba e identificar las accesiones más tolerantes para su empleo en los programas de mejoramiento genético. Para ello, se midió la viabilidad celular por reducción del cloruro de trifenil tetrazolio a formazán mediante la acción de enzimas deshidrogenadas en 122 accesiones de tomate, que se clasificaron por su tolerancia al calor atendiendo a tres controles de comportamiento conocido: Nagcarlang, Amalia y AN-104-1. Se pudo comprobar que en el germoplasma que se conserva ex situ en Cuba existen accesiones tolerantes al calor, fundamentalmente de S. lycopersicum variedad Cerasiforme y S. pimpinellifollium, que pueden ser explotadas en los programas de mejoramiento genético, para obtener variedades e híbridos con buen comportamiento en estas condiciones.

  13. Characterization of a Legionella micdadei mip mutant

    DEFF Research Database (Denmark)

    O'Connell, W A; Bangsborg, Jette Marie; Cianciotto, N P

    1995-01-01

    The pathogenesis of Legionella micdadei is dependent upon its ability to infect alveolar phagocytes. To better understand the basis of intracellular infection by this organism, we examined the importance of its Mip surface protein. In Legionella pneumophila, Mip promotes infection of both human m...... into the phagocyte. Similarly, the mutant was less able to parasitize Hartmannella amoebae. Taken together, these data argue that Mip specifically potentiates intracellular growth by L. micdadei....

  14. Some Mutant Forms of Quantum Mechanics

    CERN Document Server

    Takeuchi, Tatsu; Lewis, Zachary; Minic, Djordje

    2013-01-01

    We construct a `mutant' form of quantum mechanics on a vector space over the finite Galois field GF(q). We find that the correlations in our model do not violate the Clauser-Horne-Shimony-Holt (CHSH) version of Bell's inequality, despite the fact that the predictions of this discretized quantum mechanics cannot be reproduced with any hidden variable theory. An alternative `mutation' is also suggested.

  15. Spontaneous Nif- mutants of Rhodopseudomonas capsulata.

    OpenAIRE

    Wall, J D; Love, J.; Quinn, S P

    1984-01-01

    Revertible, spontaneous Nif- mutants of Rhodopseudomonas capsulata have been shown to accumulate in cultures growing photosynthetically with an amino acid as the nitrogen source such that H2 is maximally produced. The majority of such strains carry mutations which are clustered in a short region of the chromosome, probably representing one or two genes. Because this cluster includes temperature-sensitive mutations, it is also likely that it identifies the structural gene of a polypeptide. The...

  16. El efecto de la disponibilidad de agua durante el crecimiento de Lycopersicon chilense sobre la capacidad de sus semillas para germinar a distintas temperaturas y concentraciones de manitol y NaCl Effect of water availability during the growth of Lycopersicon chilense on the capacity of their seeds to germinate at different temperatures and concentrations of manitol and NaCl

    Directory of Open Access Journals (Sweden)

    CARLOS MALDONADO

    2002-12-01

    Full Text Available El número de semillas producidas por una planta puede estar limitada por factores ambientales adversos, los cuales también pueden afectar el desarrollo, originando semillas no viables. En la Primera Región de Chile hemos observado que Lycopersicon chilense, una especie de tomate endémica del Desierto de Atacama, presenta una alta producción de frutos y de semillas, sin embargo se observa una escasa regeneración de nuevos individuos. Se plantea que esto se debe a dos factores: (a las plantas madres, producto de las condiciones adversas donde crecen desarrollan semillas no viables o (b las semillas son viables pero las condiciones ambientales son desfavorables para la germinación. Se estudió la capacidad germinativa de semillas de Lycopersicon chilense sometidas a distintas temperaturas y concentraciones de manitol y NaCl, provenientes de plantas madres que crecieron con buen abastecimiento hídrico (+H2O y de otro grupo que creció con un abastecimiento hídrico deficiente (-H2O. El nivel de riego tuvo un efecto sobre el número de semillas germinadas y sobre el tiempo que necesitan las semillas para germinar frente a distintas temperaturas y diferentes potenciales hídricos. Las semillas de plantas -H2O fueron capaces de germinar a potenciales hídricos más negativos y en menor tiempo que las semillas provenientes de plantas +H2O en el caso de manitol. Una relación inversa ocurrió respecto a NaCl, en que un mayor porcentaje de germinación y un menor tiempo de germinación se presentó en las semillas provenientes de plantas +H2O. La germinación de L. chilense disminuye progresivamente a potenciales hídricos menores de -0,5 MPa siendo esta disminución más notoria con NaCl, en ambos casos se observó un retraso en la germinación. El óptimo de temperatura para la germinación se encontró entre los 15 y los 25 °C. Lycopersicon chilense no germinó a temperaturas menores de 8 °C y mayores de 35 °C. Los datos mostraron que las

  17. Mutant chaperonin proteins: new tools for nanotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y [SETI Institute, 515 N Whisman Road, Mountain View, CA 94043 (United States); Paavola, C D [NASA Ames Research Center, Bioengineering Branch, Mail Stop 239-15, Moffett Field, CA 94035 (United States); Kagawa, H [SETI Institute, 515 N Whisman Road, Mountain View, CA 94043 (United States); Chan, S L [SETI Institute, 515 N Whisman Road, Mountain View, CA 94043 (United States); Trent, J D [NASA Ames Research Center, Bioengineering Branch, Mail Stop 239-15, Moffett Field, CA 94035 (United States)

    2007-11-14

    Much effort has gone into finding peptides that bind potentially useful nanoparticles, but relatively little effort has focused on the scaffolds that organize these peptides into useful nanostructures. Chaperonins are protein complexes with 14-18 protein subunits that self-assemble into double-ring complexes and function as scaffolds for peptides or amino acids that bind metallic and semiconductor quantum dots. The utility of chaperonins as scaffolds depends on their structure and their ability to self-assemble into double-rings and higher-order structures, such as filaments and two-dimensional arrays. To better understand the structure of chaperonins, we constructed a model of a group II chaperonin and, based on this model, genetically constructed five mutant subunits with significant deletions. We expressed these mutants as recombinant proteins and observed by native polyacrylamide gel electrophoresis (PAGE) and transmission electron microscopy (TEM) that they all self-assembled into double rings. Our model predicted and TEM confirmed that these deletions did not significantly change the 17 nm diameter of the wild-type double rings, but decreased their height and opened their central cavities. Four of the five mutants formed higher-order structures: chains of rings, bundles of chains or filaments, and two-dimensional arrays, which we suggest can be useful nanostructures.

  18. Isolation of a novel mutant from Bacillus subtilis natto.

    Science.gov (United States)

    Yoshida, Kazuo

    2006-01-01

    For the construction of strains with full probiotics function in intestines, deoxycholate resistant mutants were isolated from Bacillus subtilis natto. The partial characterization of the mutants was carried out and described.

  19. Inducement and identification of an endosperm mutant in maize

    African Journals Online (AJOL)

    ajl yemi

    2011-11-30

    Nov 30, 2011 ... “super sweet” phenotype were derived from the mutated offspring. ... characteristics and distinguished molecular mechanism to the previous mutants of gene sh2, these three mutant lines are ...... Physical association of starch biosynthetic ... reduced seedling mutant in oilseed rape, Brassica napus, for.

  20. Internal and International Corruption

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Mario Antinucci

    2015-06-01

    Full Text Available This subject, whence the name of this paper originates from, must be addressed with courage and intellectual integrity by all of us, the different parts of the civil society, the public institutions, the entrepreneurs and the legal professionals, the youth and the new generations. All the public policies of the European governments share the belief of a direct correlation between the criminal density connected to corruption of States political and economic protagonists and the lack of availability of investments on young talents, new generations, both in the entrepreneurial and in the professional fields. In most Member States, anticorruption policies have gained an increased prominence in government agendas and the financial crisis has drawn attention to the integrity and accountability of policy-makers. Most Member States that are currently in serious financial difficulties have acknowledged the seriousness of issues related to corruption and have created (or are planning anticorruption programs in order to deal with the risks deriving from this issue and with the diversion of public funds. In some Member States, the economic adjustment programs provide for explicit obligations related to anti-corruption policies. Even when not formally connected to adjustment programs, anticorruption policies complement the adjustment measures, especially in those countries in which corruption is a serious issue.  During the European Semester of economic policy coordination, recommendations for efficiently fighting corruption have been laid out; Among the most vulnerable sectors, urban development and building projects are certainly very exposed to corruption risks and to infiltration of internal and transnational organized crime.

  1. International arbejdsdeling

    DEFF Research Database (Denmark)

    Henten, Anders

    1998-01-01

    Article dealing with the implications of informátion and communication technologies on the international division of labour.......Article dealing with the implications of informátion and communication technologies on the international division of labour....

  2. Internal Bleeding

    Science.gov (United States)

    ... in Paralyzed Monkeys Additional Content Medical News Internal Bleeding By Amy H. Kaji, MD, PhD, Associate Professor, ... Emergency First Aid Priorities Cardiac Arrest Choking Internal Bleeding Wounds Soft-Tissue Injuries Severed or Constricted Limbs ...

  3. Mutant prevention concentration and mutant selection window for 10 antimicrobial agents against Rhodococcus equi.

    Science.gov (United States)

    Berghaus, Londa J; Giguère, Steeve; Guldbech, Kristen

    2013-10-25

    The objectives of this study were to determine the mutant prevention concentration (MPC), time above the MPC and mutant selection window for 10 antimicrobial agents against Rhodococcus equi and to determine if the combination of a macrolide with rifampin would decrease emergence of resistant mutants. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, and doxycycline) were selected based on in vitro activity and frequency of use in foals or people infected with R. equi. Each antimicrobial agent or combination of agents was evaluated against four virulent strains of R. equi. MPC were determined using an agar plate assay. Pharmacodynamic parameters were calculated using published plasma and pulmonary pharmacokinetic variables. There was a significant (Pequi. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Characterisation of cuticular mutants in Arabidopsis thaliana

    OpenAIRE

    Faust, Andrea

    2006-01-01

    Plants are protected by the extracellular cuticle, which is made up of cutin, cutan and waxes. The cutin composition of a variety of plants has been known and models of the biosynthesis of cutin monomers exist but not many enzymes have been identified. It is generally accepted that a defect in the cuticle leads to an organ fusion phenotype. In the model plant A. thaliana many fusion mutants have been identified but the identification of genes involved have not lead to a complete picture of th...

  5. Using of AFLP to evaluate gamma-irradiated amaranth mutants

    Directory of Open Access Journals (Sweden)

    Labajová Mária

    2013-01-01

    Full Text Available To determine which of several gamma-irradiated mutants of amaranth Ficha cultivar and K-433 hybrid are most genetically similar to their non-irradiated control genotypes, we performed amplified fragment length polymorphism (AFLP based analysis. A total of 40 selective primer combinations were used in reported analyses. First analyses of gamma-irradiated amaranth mutant lines were done used the AFLP. In the study, primers with the differentiation ability for all analysed mutant lines are reported. The very specific changes in the mutant lines´ non-coding regions based on AFLP length polymorphism were analysed. Mutant lines of the Ficha cultivar (C15, C26, C27, C82, C236 shared a genetic dissimilarity of 0,11 and their ISSR profiles are more similar to the Ficha than those of K-433 hybrid mutant lines. The K-433 mutant lines (D54, D279, D282 shared genetic dissimilarity of 0,534 but are more distinct to their control plant as a whole, as those of the Ficha mutant lines. Different AFLP fingerprints patters of the mutant lines when compared to the Ficha cultivar and K-433 hybrid AFLP profiles may be a consequence of the complex response of the intergenic space of mutant lines to the gamma-radiance. Although a genetic polymorphism was detected within accessions, the AFLP markers successfully identified all the accessions. The AFLP results are discussed by a combination of biochemical characteristics of mutant lines and their control genotypes.

  6. Distribution of soluble amino acids in maize endosperm mutants

    Directory of Open Access Journals (Sweden)

    Toro Alejandro Alberto

    2003-01-01

    Full Text Available For human nutrition the main source of vegetable proteins are cereal and legume seeds. The content of total soluble amino acids in mature endosperm of wild-type, opaque and floury maize (Zea mays L. mutants were determined by HPLC. The total absolute concentration of soluble amino acids among the mutants varied depending on the mutant. The o11 and o13 mutants exhibited the highest average content, whereas o10, fl3 and fl1 exhibited the lowest average content. In general, the mutants exhibited similar concentrations of total soluble amino acids when compared to the wild-type lines, with the clear exception of mutants o11 and fl1, with the o11 mutant exhibiting a higher concentration of total soluble amino acids when compared to its wild-type counterpart W22 and the fl1 mutant a lower concentration when compared to its wild-type counterpart Oh43. For methionine, the mutants o2 and o11 and wild-type Oh43 exhibited the highest concentrations of this amino acid. Significant differences were not observed between mutants for other amino acids such as lysine and threonine. The high lysine concentrations obtained originally for these mutants may be due to the amino acids incorporated into storage proteins, but not those present in the soluble form.

  7. Analysis of low-temperature tolerance of a tomato (Lycopersicon esculentum) cybrid with chloroplasts from a more chilling-tolerant L-hirsutum accession

    NARCIS (Netherlands)

    Venema, JH; Eekhof, M; van Hasselt, PR

    2000-01-01

    Growth and photosynthesis of an alloplasmic tomato (cybrid), i.e. line AH47, containing the nuclear genome of the chilling-sensitive cytoplasmic albino mutant of L. esculentum Mill. 'Large Red Cherry' (LRC) and the plastome of a more chilling-tolerant high-altitude accession of the related wild spec

  8. Indy mutants: live long and prosper

    Directory of Open Access Journals (Sweden)

    Stewart eFrankel

    2012-02-01

    Full Text Available Indy encodes the fly homologue of a mammalian transporter of di and tricarboxylatecomponents of the Krebs cycle. Reduced expression of fly Indy or two of the C. elegansIndy homologs leads to an increase in life span. Fly and worm tissues that play key roles inintermediary metabolism are also the places where Indy genes are expressed. One of themouse homologs of Indy (mIndy is mainly expressed in the liver. It has been hypothesizedthat decreased INDY activity creates a state similar to caloric restriction (CR. Thishypothesis is supported by the physiological similarities between Indy mutant flies on highcalorie food and control flies on CR, such as increased physical activity and decreases inweight, egg production, triglyceride levels, starvation resistance, and insulin signaling. Inaddition, Indy mutant flies undergo changes in mitochondrial biogenesis also observed inCR animals. Recent findings with mIndy knockout mice support and extend the findingsfrom flies. mIndy-/- mice display an increase in hepatic mitochondrial biogenesis, lipidoxidation and decreased hepatic lipogenesis. When mIndy-/- mice are fed high calorie foodthey are protected from adiposity and insulin resistance. These findings point to INDY as apotential drug target for the treatment of metabolic syndrome, type 2 diabetes and obesity.

  9. Mutants of Saccharomyces cerevisiae with defects in acetate metabolism: isolation and characterization of Acn- mutants.

    Science.gov (United States)

    McCammon, M T

    1996-09-01

    The two carbon compounds, ethanol and acetate, can be oxidatively metabolized as well as assimilated into carbohydrate in the yeast Saccharomyces cerevisiae. The distribution of acetate metabolic enzymes among several cellular compartments, mitochondria, peroxisomes, and cytoplasm makes it an intriguing system to study complex metabolic interactions. To investigate the complex process of carbon catabolism and assimilation, mutants unable to grow on acetate were isolated. One hundred five Acn- ("ACetate Nonutilizing") mutants were sorted into 21 complementation groups with an additional 20 single mutants. Five of the groups have defects in TCA cycle enzymes: MDH1, CIT1, ACO1, IDH1, and IDH2. A defect in RTG2, involved in the retrograde communication between the mitochondrion and the nucleus, was also identified. Four genes encode enzymes of the glyoxylate cycle and gluconeogenesis: ICL1, MLS1, MDH2, and PCK1. Five other genes appear to be defective in regulating metabolic activity since elevated levels of enzymes in several metabolic pathways, including the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism, were detected in these mutants: ACN8, ACN9, ACN17, ACN18, and ACN42. In summary, this analysis has identified at least 22 and as many as 41 different genes involved in acetate metabolism.

  10. Defective kernel mutants of maize. I. Genetic and lethality studies.

    Science.gov (United States)

    Neuffer, M G; Sheridan, W F

    1980-08-01

    A planting of 3,919 M(1) kernels from normal ears crossed by EMS-treated pollen produced 3,461 M(1) plants and 3,172 selfed ears. These plants yielded 2,477 (72%) total heritable changes; the selfed ears yielded 2,457 (78%) recessive mutants, including 855 (27%) recessive kernel mutants and 8 (0.23%) viable dominant mutants. The ratio of recessive to dominant mutants was 201:1. The average mutation frequency for four known loci was three per 3,172 genomes analyzed. The estimated total number of loci mutated was 535 and the estimated number of kernel mutant loci mutated was 285. Among the 855 kernel mutants, 432 had a nonviable embryo, and 59 germinated but had a lethal seedling. A sample of 194 of the latter two types was tested for heritability, lethality, chromosome arm location and endosperm-embryo interaction between mutant and nonmutant tissues in special hyper-hypoploid combinations produced by manipulation of B-A translocations. The selected 194 mutants were characterized and catalogued according to endosperm phenotype and investigated to determine their effects on the morphology and development of the associated embryo. The possibility of rescuing some of the lethal mutants by covering the mutant embryo with a normal endosperm was investigated. Ninety of these 194 mutants were located on 17 of the 18 chromosome arms tested. Nineteen of the located mutants were examined to determine the effect of having a normal embryo in the same kernel with a mutant endosperm, and vice versa, as compared to the expression observed in kernels with both embryo and endosperm in a mutant condition. In the first situation, for three of the 19 mutants, the mutant endosperm was less extreme (the embryo helped); for seven cases, the mutant endosperm was more extreme (the embryo hindered); and for nine cases, there was no change. In the reverse situation, for four cases the normal endosperm helped the mutant embryo; for 14 cases there was no change and one case was inconclusive.

  11. Mutants of downy mildew resistance in Lactuca sativa (lettuce).

    Science.gov (United States)

    Okubara, P A; Anderson, P A; Ochoa, O E; Michelmore, R W

    1994-07-01

    As part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to Bremia lactucae, the casual fungus of downy mildew. Using a rapid and reliable screen, we identified 16 distinct mutants of Latuca sativa that have lost activity of one of four different downy mildew resistance genes (Dm). In all mutants, only a single Dm specificity was affected. Genetic analysis indicated that the lesions segregated as single, recessive mutations at the Dm loci. Dm3 was inactivated in nine of the mutants. One of five Dm 1 mutants was selected from a population of untreated seeds and therefore carried a spontaneous mutation. All other Dm1, Dm3, Dm5/8 and Dm7 mutants were derived from gamma- or fast neutron-irradiated seed. In two separate Dm 1 mutants and in each of the eight Dm3 mutants analyzed, at least one closely linked molecular marker was absent. Also, high molecular weight genomic DNA fragments that hybridized to a tightly linked molecular marker in wild type were either missing entirely or were truncated in two of the Dm3 mutants, providing additional evidence that deletions had occurred in these mutants. Absence of mutations at loci epistatic to the Dm genes suggested that such loci were either members of multigene families, were critical for plant survival, or encoded components of duplicated pathways for resistance; alternatively, the genes determining downy mildew resistance might be limited to the Dm loci.

  12. Forward genetic screen for auxin-deficient mutants by cytokinin.

    Science.gov (United States)

    Wu, Lei; Luo, Pan; Di, Dong-Wei; Wang, Li; Wang, Ming; Lu, Cheng-Kai; Wei, Shao-Dong; Zhang, Li; Zhang, Tian-Zi; Amakorová, Petra; Strnad, Miroslav; Novák, Ondřej; Guo, Guang-Qin

    2015-07-06

    Identification of mutants with impairments in auxin biosynthesis and dynamics by forward genetic screening is hindered by the complexity, redundancy and necessity of the pathways involved. Furthermore, although a few auxin-deficient mutants have been recently identified by screening for altered responses to shade, ethylene, N-1-naphthylphthalamic acid (NPA) or cytokinin (CK), there is still a lack of robust markers for systematically isolating such mutants. We hypothesized that a potentially suitable phenotypic marker is root curling induced by CK, as observed in the auxin biosynthesis mutant CK-induced root curling 1 / tryptophan aminotransferase of Arabidopsis 1 (ckrc1/taa1). Phenotypic observations, genetic analyses and biochemical complementation tests of Arabidopsis seedlings displaying the trait in large-scale genetic screens showed that it can facilitate isolation of mutants with perturbations in auxin biosynthesis, transport and signaling. However, unlike transport/signaling mutants, the curled (or wavy) root phenotypes of auxin-deficient mutants were significantly induced by CKs and could be rescued by exogenous auxins. Mutants allelic to several known auxin biosynthesis mutants were re-isolated, but several new classes of auxin-deficient mutants were also isolated. The findings show that CK-induced root curling provides an effective marker for discovering genes involved in auxin biosynthesis or homeostasis.

  13. Neurobehavioral Mutants Identified in an ENU Mutagenesis Project

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Melloni N. [University of Memphis; Dunning, Jonathan P [University of Memphis; Wiley, Ronald G [Vanderbilt University and Veterans Administration, Nashville, TN; Chesler, Elissa J [ORNL; Johnson, Dabney K [ORNL; Goldowitz, Daniel [University of Tennessee Health Science Center, Memphis

    2007-01-01

    We report on a behavioral screening test battery that successfully identified several neurobehavioral mutants among a large-scale ENU-mutagenized mouse population. Large numbers of ENU mutagenized mice were screened for abnormalities in central nervous system function based on abnormal performance in a series of behavior tasks. We developed and employed a high-throughput screen of behavioral tasks to detect behavioral outliers. Twelve mutant pedigrees, representing a broad range of behavioral phenotypes, have been identified. Specifically, we have identified two open field mutants (one displaying hyper-locomotion, the other hypo-locomotion), four tail suspension mutants (all displaying increased immobility), one nociception mutant (displaying abnormal responsiveness to thermal pain), two prepulse inhibition mutants (displaying poor inhibition of the startle response), one anxiety-related mutant (displaying decreased anxiety in the light/dark test), and one learning and memory mutant (displaying reduced response to the conditioned stimulus) These findings highlight the utility of a set of behavioral tasks used in a high throughput screen to identify neurobehavioral mutants. Further analysis (i.e., behavioral and genetic mapping studies) of mutants is in progress with the ultimate goal of identification of novel genes and mouse models relevant to human disorders as well as the identification of novel therapeutic targets.

  14. Effects of super absorbent with different application methods on soil moisture, soil salinity and Lycopersicon esculentum growth%保水剂施用方式对土壤水盐及番茄生长的影响

    Institute of Scientific and Technical Information of China (English)

    耿桂俊; 白岗栓; 杜社妮; 于健; 李曼

    2011-01-01

    In order to determine the effects of BJ2101-L super absorbent with various application methods, field experiments were conducted to investigate their effects on soil moisture, soil salinity and Lycopersicon esculentum growth in Hetao irrigation district, Inner Mongolia.In this paper, BJ2101-L super absorbent was applied with four treatments of furrowing, mixing, holing and broadcasting.The results showed that furrowing, holing, mixing significantly increased soil moisture in 0 -80 cm soil layer,particularly there were significant effects during Lycopersicon esculentum fruit-setting stage, and soil moisture in furrowing, mixing and holing treatments increased by 12.66% , 9.40% and 7.50% in 0 -80 cm soil layer compared to the control respectively.BJ2101-L super absorbent inhibited the accumulation of soil salinity and could improve the survival rate of Lycopersicon esculentum seedlings.The yields in furrowing, mixing, holing and broadcasting treatments increased by 37.70% , 30.93% , 26.35% and 12.87% compared to the control, and water use efficiency increased by 56.58% , 44.98%, 32.58%and 24.05% against the control respectively.Optimum application method of BJ2101-L super absorbent should be furrowing application in Hetao irrigation district in Lycopersicon esculentum production.%为探讨保水剂不同施用方式的应用效果,在河套灌区,以不施为对照,开展撒施、穴施、沟施和混施BJ2101-L保水剂对土壤水分、盐分和番茄生长影响的田间试验.结果表明:1)沟施、穴施和混施均显著提高0~80 cm土层土壤水分,特别在番茄坐果期较对照提高了12.66%、9.40%和7.50%;2)保水剂可有效抑制土壤盐分的积累,提高番茄幼苗成活率,沟施、穴施、混施和撒施番茄产量较对照提高了37.70%、30.93%、26.35%和12.87%,水分利用效率提高了56.58%、44.98%、32.58%和24.05%.因此,河套灌区番茄生产中保水剂应以沟施为主.

  15. Jasmonic acid accumulation and systemic photosynthetic and electrical changes in locally burned wild type tomato, ABA-deficient sitiens mutants and sitiens pre-treated by ABA.

    Science.gov (United States)

    Hlavinka, Jan; Nožková-Hlaváčková, Vladimíra; Floková, Kristýna; Novák, Ondřej; Nauš, Jan

    2012-05-01

    Burning the terminal leaflet of younger tomato (Lycopersicon esculentum Mill.) leaf caused local and systemic changes in the surface electrical potential (SEP) and gas exchange (GE) parameters. The local and systemic accumulation of endogenous abscisic acid (ABA) and jasmonic acid (JA) was measured 85 min after burning. The experiments were conducted with wild type (WT) plants, ABA-deficient mutant sitiens (SIT) and ABA pre-treated SIT plants (SITA). First changes in SEP were detected within 1.5 min after burning and were followed by a decrease in GE parameters within 3-6 min in WT, SIT and SITA plants. GE and SEP time courses of SIT were different and wave amplitudes of SEP of SIT were lower compared to WT and SITA. ABA content in WT and SITA control plants was similar and substantially higher compared to SIT, JA content was similar among WT, SIT and SITA. While changes in the ABA content in systemic leaves have not been recorded after burning, the systemic JA content was substantially increased in WT and more in SIT and SITA. The results suggest that ABA content governs the systemic reaction of GE and the SEP shape upon local burning. ABA, JA and SEP participate in triggering the GE reaction. The ABA shortage in the SIT in the reaction to burning is partly compensated by an enhanced JA accumulation. This JA compensation is maintained even in SIT endogenously supplied with ABA. A correlation between the systemic JA content and changes in GE parameters or SEP was not found.

  16. Comparison Study on Colonization of hilA Mutant and Parent Strains of Salmonella enteritidis in Vertically Infected Broiler Chickens

    Directory of Open Access Journals (Sweden)

    MohammadSadegh Madadi

    2015-10-01

    Full Text Available Background: Salmonella actively stimulates its own uptake into the epithelial cells by inducing cytoskeleton rearrangements and membrane ruffling triggered by some proteins secreted by Salmonella into the cytosol of the epithelial cells via a type III secretion system (TTSS encoded bygenes of the Salmonella pathogenicity island 1 (SPI-1. hilA is a transcriptional activator encoded on Salmonella Pathogenicity Island 1 (SPI-1 genes.Methods: To assess the importance of hilA in a simulation modeling of vertical infection and shedding of S. enteritidis in broiler chickens a long-term experiment was designed. Two groups of 200 fertile eggs were inoculated with 20 colony forming units (CFU of hilA mutant of S. enteritidis or its parent strain just prior to incubation. Thirty five birds of each group were housed in separate rooms. On days 2, 4, 7, 14, 21, 28 and 35 of age, cloacal swabs from live birds as well as samples from internal organs (intestinal tract, liver and spleen were evaluated by bacteriological or molecular methods.Results: In most of sampling days colonization and invasion of parent strain S. enteritidis in intestine (especially ceaca and internal organs of chickens were higher with compared to its hilA mutant but this mutant strain could still colonize in intestinal tract and even invade liver or spleen.Conclusion: Colonization of hilA mutant of S. enteritidis indicated that hilA gene is only one part of the modulators in Salmonella invasion mechanism. The ability of hilA mutant to multiply and persist in host internal organs including ceaca may promise further research for potential of hilA mutant to prevent the initial colonization of the intestinal tract by a virulent S. enteritidis strain

  17. Brucellosis vaccines: assessment of Brucella melitensis lipopolysaccharide rough mutants defective in core and O-polysaccharide synthesis and export.

    Directory of Open Access Journals (Sweden)

    David González

    Full Text Available BACKGROUND: The brucellae are facultative intracellular bacteria that cause brucellosis, one of the major neglected zoonoses. In endemic areas, vaccination is the only effective way to control this disease. Brucella melitensis Rev 1 is a vaccine effective against the brucellosis of sheep and goat caused by B. melitensis, the commonest source of human infection. However, Rev 1 carries a smooth lipopolysaccharide with an O-polysaccharide that elicits antibodies interfering in serodiagnosis, a major problem in eradication campaigns. Because of this, rough Brucella mutants lacking the O-polysaccharide have been proposed as vaccines. METHODOLOGY/PRINCIPAL FINDINGS: To examine the possibilities of rough vaccines, we screened B. melitensis for lipopolysaccharide genes and obtained mutants representing all main rough phenotypes with regard to core oligosaccharide and O-polysaccharide synthesis and export. Using the mouse model, mutants were classified into four attenuation patterns according to their multiplication and persistence in spleens at different doses. In macrophages, mutants belonging to three of these attenuation patterns reached the Brucella characteristic intracellular niche and multiplied intracellularly, suggesting that they could be suitable vaccine candidates. Virulence patterns, intracellular behavior and lipopolysaccharide defects roughly correlated with the degree of protection afforded by the mutants upon intraperitoneal vaccination of mice. However, when vaccination was applied by the subcutaneous route, only two mutants matched the protection obtained with Rev 1 albeit at doses one thousand fold higher than this reference vaccine. These mutants, which were blocked in O-polysaccharide export and accumulated internal O-polysaccharides, stimulated weak anti-smooth lipopolysaccharide antibodies. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that no rough mutant is equal to Rev 1 in laboratory models and question the notion that

  18. Plant genetics: increased outcrossing in hothead mutants.

    Science.gov (United States)

    Peng, Peng; Chan, Simon W-L; Shah, Govind A; Jacobsen, Steve E

    2006-09-28

    Arising from: S. J. Lolle, J. L. Victor, J. M. Young & R. E. Pruitt 434, 505-509 (2005); Lolle et al. reply. Lolle et al. report that loss-of-function alleles of the HOTHEAD (HTH) gene in Arabidopsis thaliana are genetically unstable, giving rise to wild-type revertants. On the basis of the reversion of many other genetic markers in hth plants, they suggested a model in which a cache of extragenomic information could cause genes to revert to the genotype of previous generations. In our attempts to reproduce this phenomenon, we discovered that hth mutants show a marked tendency to outcross (unlike wild-type A. thaliana, which is almost exclusively self-fertilizing). Moreover, when hth plants are grown in isolation, their genetic inheritance is completely stable. These results may provide an alternative explanation for the genome wide non-mendelian inheritance reported by Lolle et al.

  19. Google: a narrativa de uma marca mutante

    Directory of Open Access Journals (Sweden)

    Elizete de Azevedo Kreutz

    2010-01-01

    Full Text Available As marcas mutantes já fazem parte de nossa realidade, embora ainda não totalmente percebidas e/ou aceitas como tal. O presente artigo busca refletir sobre a relevância dessas novas estratégias de comunicação e branding, identificando suas principais características. Para isso, utilizamos o método de estudo de caso, o Google, ancorado nos métodos de pesquisa bibliográfica e de internet. A escolha foi intencional, posto que a organização é referência em sua categoria, mecanismo de busca, e reflete essa estratégia comunicacional contemporânea. Como resultado, as informações obtidas nos possibilitam compreender essa tendência de comportamento de marca que busca a interação com seus públicos.

  20. Capítulo VII: variabilidad genética y ambiental entre líneas de tomate "chonto", Lycopersicon esculentum Mill, sin utilizar pruebas de progenie

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    1994-12-01

    Full Text Available

    This paper reports the results of a study on genetic and environmental variability between 43 lines of "Chonto" tomato, Lycopersicon esculentum Mill, without using progeny offspring test. The experimental material were planted under field conditions using three randomized blocks. Data on individual plants were recorded for yield/plant, number of fruit/plant, average fruit weight, number of inflorescences/plant, number of fruits/inflorescence, number of locules/fruit, average locule weight, fruit shape index, pericarp thickness, days to flowering, harvest lenght, plant heigh, first inflorescence heigh, internode lenght, reaction to the presence of Scrobipalpula absoluta and Xanthomonas vesicatoria. The quantitative characters were subjeted to variance analysis in orden to evaluate the genetic and environmental variation. Heritability in the wide sense, genetic variability coeficient and the expected progress by selection were estimated. Fenotipic, environmental and genetic correlations among some evaluated characters were also carried out. Important  genotipic differences, at 1% of probability, for the evaluated characters were found. Generally, in the most of the evaluated characters the largest contribution of the total variation correspond to the genetic variation. The contribution of the environmental variation was very low.

    Con el fin de analizar la variabilidad genética y ambiental, de algunos caracteres agronómicos importantes en tomate "chonto" se evaluaron 43 líneas, en condiciones de campo utilizando un diseño experimental de bloques al azar con tres repeticiones. Los datos experimentales se obtuvieron a partir de tres plantas individuales por repetición y en plena competencia. Se evaluaron los siguientes caracteres cuantitativos: producción por planta, número de frutos por planta, peso promedio de frutos, número de inflorescencias por planta, número de frutos por inflorescencias, número de lóculos por fruto, peso

  1. Remote sensing and serological analysis of the resistance of tomato plants (Lycopersicon escylentum L.) to Tomato mosaic virus (ToMV)

    Science.gov (United States)

    Krezhova, Dora; Hristova, Dimitrina; Iliev, Ilko; Yanev, Tony

    Diseases caused by Tomato mosaic virus (ToMV) are among the most important factors lim-iting tomato production worldwide, as they can completely destroy the crop. ToMV occurs in most countries of the world, and causes disease epidemics in many crops. Systemic acquired resistance (SAR) is an inducible defence mechanism that plays a central role in disease re-sistance. SAR is induced by most pathogens that cause tissue necrosis. Spectral reflectance and chlorophyll fluorescence analysis were applied to establish injury of young tomato plants (Lycopersicon escylentum L.) infected with ToMV. Leaf spectral reflectance and chlorophyll fluorescence were registered by a portable Ocean Optics spectrometer USB 2000 in the visi-ble and near infrared spectral ranges (450-850 nm) at a spectral resolution of 1.5 nm. As a model system, tomato plants of cultivar Nuton resistant to ToMV were used. The plants were grown in a green house under controlled conditions. They were divided into six groups. The first group consisted of untreated (control) plants. At growth stage 4-6 expanded leaf, the second group was inoculated with ToMV. The other four groups were treated with following growth regulators: preparations Spermine, MEIA (beta-monomethyl ester of itaconic acid), (benzo(1,2,3)thiadiazole-7-carbothioic acid-S-methyl ester) and Phytoxin VS. On the next day, the tomato plants of these four groups were inoculated with ToMV. The viral concentrations in the plants were determined by the serological method Double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). All analysis were performed on detached leaves from 20 uninfected and up to 20 leaves from infected plants on the 7th and 14th day after the inocu-lation. The differences between the reflectance spectra of virus-infected and uninfected leaves were analysed in the four most informative for green plants wavelength intervals: green (520-580 nm), red (640-680 nm), red edge (690-710 nm) and near infrared (720-760 nm

  2. Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

    Energy Technology Data Exchange (ETDEWEB)

    Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E. (North Carolina State Univ., Raleigh (United States))

    1991-10-01

    The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  3. Mutants of Cercospora kikuchii Altered in Cercosporin Synthesis and Pathogenicity.

    Science.gov (United States)

    Upchurch, R G; Walker, D C; Rollins, J A; Ehrenshaft, M; Daub, M E

    1991-10-01

    We have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  4. Colony mutants of compatible nocardiae displaying variations in recombining capacity.

    Science.gov (United States)

    Brownell, G H; Walsh, R S

    1972-03-01

    Colonial morphology mutants of Nocardia erythropolis were isolated following ultraviolet (UV) irradiation. The alleles rou-1/smo-1 were located by recombinant analysis and found to be linked to previously mapped characters. On the basis of recombinant class type patterns obtained from various selective characters it was postulated that the rou-1 allele may span a region of unique nucleotides in the Mat-Ce genome. Recombination frequencies of rou-1 and smo-2 bearing mutants of the Mat-Ce mating type were found to differ by over 1000 fold. Attempts to demonstrate that low recombination frequencies produced by the Smo mutants were due to Rec(-) genes were unsuccessful. No increased sensitivity to either UV or X irradiation was observed by the Smo mutants. Acriflavine treatment of either Rou or Smo colony mutants failed to accelerate reversion or to alter the recombining potentials of the mutants.

  5. Screening and identification of mutants of Magnaporthe grisea by REMI

    Institute of Scientific and Technical Information of China (English)

    XIONG Ruyi; LIU Juan; ZHOU Yijun; FAN Yongjian; ZHENG Xiaobo

    2007-01-01

    The plasmid pUCATPH was used to establish a transformation system in wild-type isolate M131 of Magnaporthe grisea.Six hundred and thirty-nine transformants were obtained by restriction enzyme-mediated integration (REMI) with hygromycin B (hyg B) resistance as a tag.Morphological analysis of two of the REMI mutants confirmed that they produced little melanin under black light and continued for three generations.Pathogenicity identification of six mutants screened proved that they made pathogenicity changes on three sets of differential varieties with different resistance genes.Rep-PCR analyses showed that two morphological mutants and two pathogenicity mutants differed from wild-type isolate M131 at the molecular level.RFLP analyses were performed to study the four mutants at the molecular level and the integration sites of the plasmid DNA.The results showed that the plasmid was inserted into all four mutants and that the insertion sites were random.

  6. Mutant p53: multiple mechanisms define biologic activity in cancer

    Directory of Open Access Journals (Sweden)

    Michael Paul Kim

    2015-11-01

    Full Text Available The functional importance of p53 as a tumor suppressor gene is evident through its pervasiveness in cancer biology. The p53 gene is the most commonly altered gene in human cancer; however, not all genetic alterations are biologically equivalent. The majority of p53 alterations involve missense mutations that result in the production of mutant p53 proteins. Such mutant p53 proteins lack normal p53 function and may acquire novel functions, often with deleterious effects. Here, we review characterized mechanisms of mutant p53 gain of function in multiple model systems. In addition, we review mutant p53 addiction as emerging evidence suggests that tumors may depend on sustained mutant p53 activity for continued growth. We also discuss the role of p53 in stromal elements and their contribution to tumor initiation and progression. Lastly, current genetic mouse models of mutant p53 are reviewed and their limitations discussed.

  7. International skatteret

    DEFF Research Database (Denmark)

    Winther-Sørensen, Niels; Wittendorff, Jens

    1996-01-01

    De seneste 6 måneders udvikling indenfor international skatteret beskrives. NW-S har skrevet artiklens afsnit om udvalgte afgørelser og om EU-skatteret.......De seneste 6 måneders udvikling indenfor international skatteret beskrives. NW-S har skrevet artiklens afsnit om udvalgte afgørelser og om EU-skatteret....

  8. International indsats

    DEFF Research Database (Denmark)

    Sachs, Therese

    En analyse af Beredskabsstyrelsens internationale engagement og muligheder for international indsats fremover. Forslag til struktur logistisk og materielt samt til udvikling af personel-kompetencer......En analyse af Beredskabsstyrelsens internationale engagement og muligheder for international indsats fremover. Forslag til struktur logistisk og materielt samt til udvikling af personel-kompetencer...

  9. International Curriculums.

    Science.gov (United States)

    Neal, Larry L.

    This workshop presentation on international curriculums in the field of parks, recreation, leisure, cultural services, and travel/tourism comments that the literature is replete with articles addressing what the field is about, but not about curriculum issues, models, and structure. It reports an international survey of 12 college educators…

  10. Preliminary study on a gravity-insensitive rice mutant

    Institute of Scientific and Technical Information of China (English)

    金静; 朱诚; 张红心; 孙宗修

    2004-01-01

    A gravity-insensitive mutant was isolated from rice (Oryza sativa L. Cv. Zhonghua 11) transformed by Agrobacterium tumefaciens. The mutant's shoot growth (prostrate growth) was insensitive to gravity; whereas root growth displayed a normal positive gravitropism.Histological observation of root caps and leaf sheaths indicated that there was no significant difference in the number and size of amyloplasts in cells of the mutant and cells of the wild type

  11. Preliminary study on a gravity-insensitive rice mutant

    Institute of Scientific and Technical Information of China (English)

    金静; 朱诚; 张红心; 孙宗修

    2004-01-01

    A gravity-insensitive mutant was isolated from rice (Oryza sativa L. cv. Zhonghua 11) transformed by Agrobacterium tumefaciens. The mutant's shoot growth (prostrate growth) was insensitive to gravity; whereas root growth displayed a normal positive gravitropism. Histological observation of root caps and leaf sheaths indicated that there was no significant difference in the number and size of amyloplasts in cells of the mutant and cells of the wild type.

  12. [Eremothecium ashbyii mutants resistant to 2,6-diaminopurine].

    Science.gov (United States)

    Stepanov, A I; Beburov, M Iu; Zhdanov, V G

    1975-01-01

    3 groups of Eremothecium ashbyii mutants resistant to 5-10(-3) M 2,6-diaminopurine (DAP) ahve been obtained. The mutants of the 1st group (Dap-r) are selected from the initial susceptible strain by the ability to grow in the presence of 5-10(-3) M DAP. The mutants of the 2nd group (Azg-Dap-r) are selected in the selective background of two analogues of 5-10(-3) M DAP and 10(-4) M 8-azaguanine (AG). The mutants of the 3rd group (Azg-r - DAP-r) are isolated from the mutant Azg-r 34 resistant to 10(-4) M AG. The results of studying cross-resistance of mutants to DAP, AG and 8-azaadenine (AA) show that Dap-r and Azg-Dap-r mutants in contrast to Azg-r - Dap-r, have common phenotypic properties and can grow only on the analogues of adenine. DAP, but not AA, eliminates the inhibitory effect of AG on the growth of these mutants. This effect is probably due to deaminating DAP to guanine. Mutants Azg-r - Dap-r retain the initial resistance to 10(-4) M AG, but are susceptible to higher concentrations of AG and in this case DAP does not eliminate the inhibitory effect of AG. In all mutants obtained the effectiveness of the incorporation of 14C-adenine (but not 14C-guanine) is sharply reduced, thus indicating the absence of adenosine-monophosphate pyrophosphorylase activity. The mutants do not excrete purine-like compounds into the medium. In the course of the continuous growth of mutants in the presence of DAP but not of guanine the red intracellular pigment is formed which seems to be a complex of riboflavin with DAP. A disturbance in the synthesis of adenosine monophosphate pyrophosphorylase does not influence practically the level of the synthesis of riboflavin in E. ashbyii.

  13. Fatty acid biosynthesis in novel ufa mutants of Neurospora crassa.

    Science.gov (United States)

    Goodrich-Tanrikulu, M; Stafford, A E; Lin, J T; Makapugay, M I; Fuller, G; McKeon, T A

    1994-10-01

    New mutants of Neurospora crassa having the ufa phenotype have been isolated. Two of these mutants, like previously identified ufa mutants, require an unsaturated fatty acid for growth and are almost completely blocked in the de novo synthesis of unsaturated fatty acids. The new mutations map to a different chromosomal location than previously characterized ufa mutations. This implies that at least one additional genetic locus controls the synthesis of unsaturated fatty acids in Neurospora.

  14. International Specialization

    DEFF Research Database (Denmark)

    Kleindienst, Ingo; Geisler Asmussen, Christian; Hutzschenreuter, Thomas;

    2012-01-01

    Whether and how international diversification and cross-border arbitrage affects firm performance remains one of the major unresolved research questions in the strategy and international business literatures. We propose that knowing how much a firm has internationally diversified tells us very...... little about performance implications, if we do not know, and do not ask, how the firm has diversified. Therefore, building on the two broad arguments of operating flexibility and location-specific commitment, we develop a theoretical framework that focuses on the extent to which a firm's international...... arbitrage strategy is characterized by specialization versus replication and argue that these different strategies may have differential impact on profitability and risk reduction. Developing a sophisticated measure of international specialization and using a unique panel data set of 92 German MNEs to test...

  15. International Specialization

    DEFF Research Database (Denmark)

    Kleindienst, Ingo; Geisler Asmussen, Christian; Hutzschenreuter, Thomas

    2012-01-01

    Whether and how international diversification and cross-border arbitrage affects firm performance remains one of the major unresolved research questions in the strategy and international business literatures. We propose that knowing how much a firm has internationally diversified tells us very...... little about performance implications, if we do not know, and do not ask, how the firm has diversified. Therefore, building on the two broad arguments of operating flexibility and location-specific commitment, we develop a theoretical framework that focuses on the extent to which a firm's international...... arbitrage strategy is characterized by specialization versus replication and argue that these different strategies may have differential impact on profitability and risk reduction. Developing a sophisticated measure of international specialization and using a unique panel data set of 92 German MNEs to test...

  16. International Relations:

    DEFF Research Database (Denmark)

    This is the textbook for the Open University module International Relations: Continuity and Change in Global Politics. Instead of leading with a succession of theoretical 'isms', the module structures its presentation of the subject around six teaching ‘blocks’, each of which explores a dilemma......: Flat or uneven? Change and transformation in the international system • Block 3: Just or unjust? Intervention and inequality in the international system • Block 4: Top-down or bottom-up? Governance in the international system • Block 5: Secure or insecure? Pursuing security in the international system...... • Block 6: Continuity or change in global politics? Each block introduces new IR theories through discussions of the substantive dilemmas and adds in a layered way levels of analysis and conceptual complexity....

  17. Characterization of host-range mutants of cyanophage N-1.

    Science.gov (United States)

    Sarma, T A; Kaur, B

    1997-10-01

    Fifteen host-range (h) mutants of cyanophage N-1 were characterized with reference to their efficiency of plating, time of appearance, morphology and size of plaques on Nostoc muscorum and its three phage-resistant (Nm 1/N-1, Nm 2/N-1 and Nm 8/N-1) mutants. While phage N-1 did not adsorb to the three phage-resistant mutants, the h mutants differed one from the other in having lower or higher adsorption rate constants on N. muscorum or the phage-resistant mutants. The inability of majority of h mutants isolated on Nm 1/N-1 to grow in Nm 8/N-1 was shown to be due to a failure of adsorption. The h mutants also differed one from the other in their reversion (back mutation) frequencies. The lethal doses (LD37) required to kill 37% of free phage particles after UV-irradiation, heating and ethylenediamine tetraacetate (EDTA) treatment greatly varied. Most of the h mutants were found to be considerably more sensitive to UV and thermic inactivation than N-1 while they were resistant to EDTA. The h mutants except five of them were unable to multiply at 40 degrees C. The significance of these features is discussed.

  18. plenty, a novel hypernodulation mutant in Lotus japonicus.

    Science.gov (United States)

    Yoshida, Chie; Funayama-Noguchi, Sachiko; Kawaguchi, Masayoshi

    2010-09-01

    Nitrogen fixation in nodules that contain symbiotic rhizobial bacteria enables legumes to thrive in nitrogen-poor soils. However, this symbiosis is energy consuming. Therefore, legumes strictly control nodulation at both local and systemic levels. Mutants deficient in such controls exhibit a range of phenotypes from non-nodulation to hypernodulation. Here, we isolated a novel hypernodulation mutant from the M(2) progeny derived from Lotus japonicus MG-20 seeds mutagenized by irradiation with a carbon ion beam. We named the mutant 'plenty' because it formed more nodules than the wild-type MG-20. The nodulation zone in the plenty mutant was wider than that in the wild type, but not as enhanced as those in other previously reported hypernodulation mutants such as har1, klv or tml of L. japonicus. Unlike these hypernodulation mutants, the plenty mutant developed nodules of the same size as MG-20. Overall, the plenty mutant exhibited a unique phenotype of moderate hypernodulation. However, a biomass assay indicated that this unique pattern of hypernodulation was a hindrance to host plant growth. The plenty mutant displayed some tolerance to external nitrates and a normal triple response to ethylene. Grafting experiments demonstrated that the root of plenty was responsible for its hypernodulation phenotype. Genetic mapping indicated that the PLENTY gene was located on chromosome 2.

  19. Induction and selection of citrus mutant by gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Jung; Oh, Seung Kyu; Lee, Hyo Yeon [Jeju National University, Jeju (Korea, Republic of)

    2010-09-15

    We have subjected to gamma-irradiation to citrus buds and then grafted onto mature citrus tree. Mutant citrus branch lines have been induced. As a result of first selection, we found the several mutant lines showing interesting phenotypes such as higher sugar content. We have selected several branches showing good qualities such as higher sweetness and/or lower acidity. Some branch lines showed over 13 .deg. Brix sugar content and below 0.9% acidity. Other mutant branch lines showed the changes of shape, size, peel thickness, and fiber contents or distribution of fruits. The results suggest that gamma-irradiation is an effective tool for induction of citrus mutant lines.

  20. Generation of mouse mutants as tools in dissecting the molecular clock.

    Science.gov (United States)

    Anand, Sneha N; Edwards, Jessica K; Nolan, Patrick M

    2012-01-01

    Elucidation of the molecular basis of mammalian circadian rhythms has progressed dramatically in recent years through the characterization of mouse mutants. With the implementation of numerous mouse genetics programs, comprehensive sets of mutations in genes affecting circadian output measures have been generated. Although incomplete, existing arrays of mutants have been instrumental in our understanding of how the internal SCN clock interacts with the environment and how it conveys its rhythm to remote oscillators. The use of ENU mutagenesis has proven to be a significant contributor, generating mutations leading to subtle and distinct alterations in circadian protein function. In parallel, progress with mouse gene targeting allows one to study gene function in depth by ablating it entirely, in specific tissues at specific times, or by targeting specific functional domains. This has culminated in worldwide efforts to target every gene in the mouse genome allowing researchers to study multiple gene targeting effects systematically.

  1. Generation and screening of a comprehensive Mycobacterium avium subsp. paratuberculosis transposon mutant bank

    Directory of Open Access Journals (Sweden)

    Govardhan eRathnaiah

    2014-10-01

    Full Text Available Mycobacterium avium subsp. paratuberculosis (MAP is the etiologic agent of Johne’s Disease in ruminants. This enteritis has significant economic impact and worldwide distribution. Vaccination is one of the most cost effective infectious disease control measures. Unfortunately, current vaccines reduce clinical disease and shedding, but are of limited efficacy and do not provide long-term protective immunity. Several strategies have been followed to mine the MAP genome for virulence determinants that could be applied to vaccine and diagnostic assay development. In this study, a comprehensive mutant bank of 13,536 MAP K-10 Tn5367 mutants (P > 95% was constructed and screened in vitro for phenotypes related to virulence. This strategy was designated to maximize identification of genes important to MAP pathogenesis without relying on studies of other mycobacterial species that may not translate into similar effects in MAP. This bank was screened for mutants with colony morphology alterations, susceptibility to D-cycloserine, impairment in siderophore production or secretion, reduced cell association, and decreased biofilm and clump formation. Mutants with interesting phenotypes were analyzed by PCR, Southern blotting and DNA sequencing to determine transposon insertion sites. These insertion sites mapped upstream from the MAP1152-MAP1156 cluster, internal to either the Mod operon gene MAP1566 or within the coding sequence of lsr2, and several intergenic regions. Growth curves in broth cultures, invasion assays and kinetics of survival and replication in primary bovine macrophages were also determined. The ability of vectors carrying Tn5370 to generate stable MAP mutants was also investigated.

  2. Deletion of Osr2 Partially Rescues Tooth Development in Runx2 Mutant Mice.

    Science.gov (United States)

    Kwon, H J E; Park, E K; Jia, S; Liu, H; Lan, Y; Jiang, R

    2015-08-01

    Tooth organogenesis depends on genetically programmed sequential and reciprocal inductive interactions between the dental epithelium and neural crest-derived mesenchyme. Previous studies showed that the Msx1 and Runx2 transcription factors are required for activation of odontogenic signals, including Bmp4 and Fgf3, in the early tooth mesenchyme to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 acts downstream of Msx1 to activate Fgf3 expression. Recent studies identified Osr2 as a repressor of tooth development and showed that inactivation of Osr2 rescued molar tooth morphogenesis in the Msx1(-/-) mutant mice as well as in mice with neural crest-specific inactivation of Bmp4. Here we show that Runx2 expression is expanded in the tooth bud mesenchyme in Osr2(-/-) mutant mouse embryos and is partially restored in the tooth mesenchyme in Msx1(-/-)Osr2(-/-) mutants in comparison with Msx1(-/-) and wild-type embryos. Whereas mandibular molar development arrested at the bud stage and maxillary molar development arrested at the bud-to-cap transition in Runx2(-/-) mutant mice, both mandibular and maxillary molar tooth germs progressed to the early bell stage, with rescued expression of Msx1 and Bmp4 in the dental papilla as well as expression of Bmp4, p21, and Shh in the primary enamel knot in the Osr2(-/-)Runx2(-/-) compound mutants. In contrast to the Msx1(-/-)Osr2(-/-) compound mutants, which exhibit nearly normal first molar morphogenesis, the Osr2(-/-)Runx2(-/-) compound mutant embryos failed to activate the expression of Fgf3 and Fgf10 in the dental papilla and exhibited significant deficit in cell proliferation in both the dental epithelium and mesenchyme in comparison with the control embryos. These data indicate that Runx2 synergizes with Msx1 to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 controls continued tooth growth and morphogenesis beyond the cap stage through activation of Fgf3 and Fgf10 expression

  3. International Health

    Science.gov (United States)

    ... create refugee populations with immediate and long-term health problems. Some of the major diseases currently affecting ... also an international problem which can affect people's health. Many countries and health organizations are working together ...

  4. International Reports.

    Science.gov (United States)

    Valauskas, Edward J.; Stowe, Jennifer L.; Haycock, Ken; Dodd, Frances

    1998-01-01

    Presents three reports: International Federation of Library Associations and Institutions; Special Libraries Association; and Canadian library trends, focusing on information technology and access to information and rights and examining provincial libraries and library education. (PEN)

  5. Juris International

    CERN Document Server

    A database on international trade law aimed at lawyers and legal counsel in developing and transition economies. Juris International is a multilingual collection (English, Spanish, and French) of legal information on international trade. Juris International aims to facilitate and reduce the work involved in research for business lawyers, advisers and in-house counsel, and state organizations in developing nd transition economies, by providing access to texts which have often been difficult to obtain. Its objective is to gather a large quantity of basic information at one site (favoring complete legal texts), without the need to send for the information, and consequently without excessive communication costs for users who d benefit from an efficient and cheap telecommunications network.

  6. Internal education

    OpenAIRE

    Anita Zagorc

    2016-01-01

    Research Question (RQ): The importance of internal trainings in an organization. Purpose: The purpose of research is to examine and present internal trainings in an organization and their contribution to greater success of an organization. The paper studies employee training in a company, how the organization itself looks after its employees during training, how trainings contribute to further development of organization and the advancement of knowledge for successful operation of organi...

  7. Chemotyping of yeast mutants using robotics.

    Science.gov (United States)

    Rieger, K J; El-Alama, M; Stein, G; Bradshaw, C; Slonimski, P P; Maundrell, K

    1999-07-01

    By now, the EUROFAN programme for the functional analysis of genes from the yeast genome has attained its cruising speed. Indeed, several hundreds of yeast mutants with no phenotype as tested by growth on standard media and no significant sequence similarity to proteins of known function are available through the efforts of various laboratories. Based on the methodology initiated during the pilot project on yeast chromosome III (Yeast 13, 1547-1562, 1997) we adapted it to High Throughput Screening (HTS), using robotics. The first 100 different gene deletions from EUROSCARF, constructed in an FY1679 strain background, were run against a collection of about 300 inhibitors. Many of these inhibitors have not been reported until now to interfere in vivo with growth of Saccharomyces cerevisiae. In the present paper we provide a list of novel growth conditions and a compilation of 49 yeast deletants (from chromosomes II, IV, VII, X, XIV, XV) corresponding to 58% of the analysed genes, with at least one clear and stringent phenotype. The majority of these deletants are sensitive to one or two compounds (monotropic phenotype) while a distinct subclass of deletants displays a hyper-pleiotropic phenotype with sensitivities to a dozen or more compounds. Therefore, chemotyping of unknown genes with a large spectrum of drugs opens new vistas for a more in-depth functional analysis and a more precise definition of molecular targets.

  8. Pharmacological correctors of mutant CFTR mistrafficking

    Directory of Open Access Journals (Sweden)

    Nicoletta ePedemonte

    2012-10-01

    Full Text Available The lack of phenylalanine 508 (∆F508 mutation in the CFTR Cl- channel represents the most frequent cause of cystic fibrosis (CF, a genetic disease affecting multiple organs such lung, pancreas, and liver. ∆F508 causes instability and misfolding of CFTR protein leading to early degradation in the endoplasmic reticulum and accelerated removal from the plasma membrane. Pharmacological correctors of mutant CFTR protein have been identified by high-throughput screening of large chemical libraries, by in silico docking of virtual compounds on CFTR structure models, or by using compounds that affect the whole proteome (e.g. histone deacetylase inhibitors or a single CFTR-interacting protein. The presence of multiple defects caused at the CFTR protein level by ∆F508 mutation and the redundancy of quality control mechanisms detecting ∆F508-CFTR as a defective protein impose a ceiling to the maximal effect that a single compound (corrector may obtain. Therefore, treatment of patients with the most frequent CF mutation may require the optimized combination of two drugs having additive or synergic effects.

  9. New types of Escherichia coli recombination-deficient mutants.

    Science.gov (United States)

    Freifelder, D

    1976-11-01

    A set of Escherichia coli mutants deficient in intramolecular recombination and different from those previously found is described. All have temperature-sensitive lethal mutations. The mutants have been characterized with respect to the following properties: the Pap phenotype, deoxyribonucleic acid synthesis, sensitivity to ultraviolet light, ability to support the growth of phage lambda, filament formation, and mutation frequency.

  10. Characterization of Gibberellin Receptor Mutants of Barley (Hordeum vulgare L.)

    Institute of Scientific and Technical Information of China (English)

    Peter M.Chandler; Carol A.Harding; Anthony R.Ashton; Mark D.Mulcair; Nicholas E.Dixon; Lewis N.Mander

    2008-01-01

    The sequence of Gidl (a gene for a gibberellin (GA) receptor from rice) was used to identify a putative orthoIogue from barley.This was expressed in E.coil,and produced a protein that was able to bind GA in vitro with both structural specificity and saturability.Its potential role in GA responses was investigated using barley mutants with reduced GA sensitivity (gsel mutants).Sixteen different gsel mutants each carried a unique nucleotide substitution in this sequence.In all but one case,these changes resulted in single amino acid substitutions,and,for the remaining mutant,a substitution in the 5' untranslated region of the mRNA is proposed to interfere with translation initiation.There was perfect linkage in segregating populations between new mutant alleles and the gsel phenotype,leading to the conclusion that the putative GID1 GA receptor sequence in barley corresponds to the Gsel locus.Determination of endogenous GA contents in one of the mutants revealed enhanced accumulation of bioactive GA1,and a deficit of C20 GA precursors.All of the gsel mutants had reduced sensitivity to exogenous GA3,and to AC94377 (a GA analogue) at concentrations that are normally 'saturating',but,at much higher concentrations,there was often a considerable response.The comparison between barley and rice mutants reveals interesting differences between these two cereal species in GA hormonal physiology.

  11. Mutants of Pseudomonas putida affected in poly-3-hydroxyalkanoate synthesis

    NARCIS (Netherlands)

    Ren, Q; Kessler, B; van der Leij, F; Witholt, B.

    1998-01-01

    The generation and characterization of Pseudomonas putida KT2442 mutants affected in poly-3-hydroxyalkanoate (PHA) synthesis are reported. The mutants from P. putida KT2442 carrying several copies of the PHA-polymerase-encoding gene (phaC) were isolated via N-methyl-N'-nitro-N-nitrosoguanidine chemi

  12. A Mutant Hunt Using the C-Fern (Ceratopteris Richardii)

    Science.gov (United States)

    Calie, Patrick J.

    2005-01-01

    A modification of the popular C-Fern system, the tropical fern Ceratopteris richardii is developed in which students plate out a genetically mixed set of fern spores and then select for specific mutants. This exercise can provide students with an experience in plant mutant selection and can be used as a platform to expose students to a diverse…

  13. Characterization of peroxisome-deficient mutants of Hansenula polymorpha

    NARCIS (Netherlands)

    Tan, Xuqiu; Titorenko, Vladimir I.; Klei, Ida J. van der; Sulter, Grietje J.; Haima, Peter; Waterham, Hans R.; Evers, Melchior; Harder, Willem; Veenhuis, Marten; Cregg, James M.

    1995-01-01

    In the methylotrophic yeast Hansenula polymorpha, approximately 25% of all methanol-utilization-defective (Mut(-)) mutants are affected in genes required for peroxisome biogenesis (PER genes). Previously, we reported that one group of pel mutants, termed Pim(-), are characterized by the presence of

  14. Absence of Pneumocystis dihydropteroate synthase mutants in Brittany, France.

    Science.gov (United States)

    Le Gal, Solène; Robert-Gangneux, Florence; Perrot, Maëla; Rouillé, Amélie; Virmaux, Michèle; Damiani, Céline; Totet, Anne; Gangneux, Jean-Pierre; Nevez, Gilles

    2013-05-01

    Archival Pneumocystis jirovecii specimens from 84 patients monitored at Rennes University Hospital (Rennes, France) were assayed at the dihydropteroate synthase (DHPS) locus. No patient was infected with mutants. The results provide additional data showing that P. jirovecii infections involving DHPS mutants do not represent a public health issue in Brittany, western France.

  15. Poliovirus Mutants Resistant to Neutralization with Soluble Cell Receptors

    Science.gov (United States)

    Kaplan, Gerardo; Peters, David; Racaniello, Vincent R.

    1990-12-01

    Poliovirus mutants resistant to neutralization with soluble cellular receptor were isolated. Replication of soluble receptor-resistant (srr) mutants was blocked by a monoclonal antibody directed against the HeLa cell receptor for poliovirus, indicating that the mutants use this receptor to enter cells. The srr mutants showed reduced binding to HeLa cells and cell membranes. However, the reduced binding phenotype did not have a major impact on viral replication, as judged by plaque size and one-step growth curves. These results suggest that the use of soluble receptors as antiviral agents could lead to the selection of neutralization-resistant mutants that are able to bind cell surface receptors, replicate, and cause disease.

  16. Phenotypic Characterization of a Female Sterile Mutant in Rice

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A female sterile mutant, derived from a spontaneous mutation, wasfirst discovered in rice (Oryza sativa L. ssp.indica) restorer line 202R. With normal flowering, the mutant exhibits an extremely Iow seed-setting rate. When the mutant is crossed as a pollen donor, the seeds set normally; whereas when it is used as a pollen receiver,no seeds are obtained even with mixed pollen grains of different varieties sprinkled over the stigmas. The floret of the mutant, consisting of six stamens and one pistil, looks the same as that of the wild type in the malefemale organs, except that less than 10% of the mutant florets have three stigmas on the ovary. Although the mutant has a low seed-setting rate, Its pollen fertility is approximately 87.1%, which is equal to that of the wild type. In addition, more than 90% of the mature embryo sacs of the mutant have complete inner structures. At every stage after pollination, the sperm, embryo, and endosperm are not found in the mutant embryo sac,whereas the disintegration of the egg cell that does not accomplish fertilization is visible. Through observations with a fluorescence microscope, we have found that the pollen grains germinate normally, whereas the pollen tube abnormally elongates in the style-transmitting tissue. The mutant pollen tubes display various defects in the style, such as slower elongation, conversed elongation, distorted elongation, swollen tips, or branched tips. As a result, the growth of the pollen tubes ceases in the style, and, therefore, the pollen tubes cannot reach the embryo sac and the process of double fertilization is blocked. Based on these observations,we conclude that this mutant, designated as fs-202R, is a novel type of female sterile mutation in rice, which causes the arrest of the elongation of the pollen tube.

  17. Isolation and Characterization of mAMSA-hypersensitive Mutants

    Science.gov (United States)

    Rogojina, Anna T.; Nitiss, John L.

    2008-01-01

    Topoisomerase II (Top2) is the primary target for active anti-cancer agents. We developed an efficient approach for identifying hypersensitive Top2 mutants and isolated a panel of mutants in yeast Top2 conferring hypersensitivity to the intercalator N-[4-(9-acridinylamino)-3-methoxyphenyl]methanesulphonanilide (mAMSA). Some mutants conferred hypersensitivity to etoposide as well as mAMSA, whereas other mutants exhibited hypersensitivity only to mAMSA. Two mutants in Top2, changing Pro473 to Leu and Gly737 to Val, conferred extraordinary hypersensitivity to mAMSA and were chosen for further characterization. The mutant proteins were purified, and their biochemical activities were assessed. Both mutants encode enzymes that are hypersensitive to inhibition by mAMSA and other intercalating agents and exhibited elevated levels of mAMSA-induced Top2:DNA covalent complexes. While Gly737 → Val Top2p generated elevated levels of Top2-mediated double strand breaks in vitro, the Pro473 → Leu mutant protein showed only a modest increase in Top2-mediated double strand breaks but much higher levels of Top2-mediated single strand breaks. In addition, the Pro473 → Leu mutant protein also generated high levels of mAMSA-stabilized covalent complexes in the absence of ATP. We tested the role of single strand cleavage in cell killing with alleles of Top2 that could generate single strand breaks, but not double strand breaks. Expression in yeast of a Pro473 → Leu mutant that could only generate single strand breaks conferred hypersensitivity to mAMSA. These results indicate that generation of single strand breaks by Top2-targeting agents can be an important component of cell killing by Top2-targeting drugs. PMID:18723844

  18. Amphitrite ornata Dehaloperoxidase (DHP): Investigations of Structural Factors That Influence the Mechanism of Halophenol Dehalogenation Using ;Peroxidase-like; Myoglobin Mutants and ;Myoglobin-like; DHP Mutants

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jing; Huang, Xiao; Sun, Shengfang; Wang, Chunxue; Lebioda, Lukasz; Dawson, John H. (SC)

    2012-05-14

    Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O{sub 2} transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity {approx}10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of 'peroxidase-like' Mb mutants and 'Mb-like' DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned {approx}0.3 and {approx}0.8 {angstrom}, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the 'DHP-like' position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the

  19. Study on Separation Force between Tomato(Lycopersicon esculentum)Fruit and Stalk%加工番茄果茎分离力研究

    Institute of Scientific and Technical Information of China (English)

    张进; 毕新胜; 肖彬彬; 黄国伟

    2012-01-01

    [Objective] The aim was to study separation force between tomato fruit and stalk, to provide a theoretical basis for realizing mechanized harvest of tomato in Xinjiang and designing its separation device. [ Method] The tomato of different sizes, types, maturity, which were now largely cultivated in Xinjiang, were selected to measured their separation force between fruit and stalk, and then the experimental data was analyzed using SPSS data processing system. [ Result ] The results showed that the separation force between the fruit and stalk was different among different tomato varieties, but the gap was not large, and the separation force between tomato fruit and stalk was 5 - 30 N. The separation force between fruit and stalk of tomato was became small with its increasing of maturity and fruit length, while which became big with fruit weight. The nonlinear relationship between separating force between fruit and stalk of tomato and its shape(X1 stands for tomato length,X2 stands for tomato diameter,X3 stands for tomato fruit weight) under red ripe, green ripe and yellow ripe were Y= -38. 724 173 1 - 0. 275 597 259 20X1 + 2.819 463 816 8Z, - 0.032 358 548 87X22 +0.001 019 364 693 3X32 ,F = 2. 046 9,P=0. 0193; Y=-6.682 740 10+0.455 089 173 7X1+ 0. 134 872 969 06X2 +0.151 548 034 07X3 - 0.005 066 287 946X1X2 - 0. 004 933 150 310X1X3 +0.004 653 746 236X2X3 ,F =3. 3805,P = 0. 0042;Y= 105.928 032 8-8. 830 147 147X1 +7. 367 868 154X2 - 0. 466 247 543 0X3 +0. 072 647 951 54X12 - 0. 071 425 628 00X22 + 0. 003 594 294 685X32,F = 2. 297 6 ,P = 0. 011 7, respectively. [ Conclusion] The study provides a theoretical basis on tomato harvesting machinery research.%[目的]研究加工番茄(Lycopersicon esculentum)果茎分离力,为实现新疆番茄机械化收获和设计番茄分离装置提供理论基础.[方法]以目前新疆大规模种植的加工番茄为研究对象,采集不同大小、种类、成熟度的加工番茄,测量果实与茎秆之间的分离力,运

  20. Fontes de resistência em acessos de Solanum (secção Lycopersicon a Verticillium dahliae raças 1 e 2 Sources of resistance to Verticillium dahliae races 1 and 2 in accessions of Solanum (section Lycopersicon

    Directory of Open Access Journals (Sweden)

    Bruno Eduardo C de Miranda

    2010-12-01

    Full Text Available A murcha-de-verticílio (Verticillium dahliae é uma das doenças mais severas do tomateiro (Solanum lycopersicum L.. Duas raças fisiológicas de V. dahliae foram caracterizadas infectando o tomateiro e ambas estão presentes no Brasil. A estratégia de controle mais efetiva para isolados da raça 1 tem sido a utilização de cultivares resistentes em associação com práticas culturais. Entretanto, não existem cultivares comerciais de tomate resistentes à raça 2 do patógeno. Neste contexto, torna-se importante a identificação de novas fontes de resistência que sejam efetivas contra as duas raças de V. dahliae. Buscou-se fontes de resistência a isolados de V. dahliae (raças 1 e 2. Cem acessos de uma coleção de germoplasma contendo espécies cultivadas e selvagens de Solanum (secção Lycopersicon foram inicialmente inoculados pelo método de imersão de raízes com um isolado de V. dahliae raça 1 (5 mL de uma suspensão de 10(6 conídios/mL em condições de casa de vegetação. A avaliação foi feita aos 30 dias após a inoculação, usando uma escala de notas variando de 1 (planta sadia a 5 (planta morta. Foram considerados resistentes os acessos que apresentaram nota média entre 1 e 2. Um grupo composto por 38 acessos classificados como resistentes neste primeiro ensaio foi reavaliado para resistência a outros quatro isolados de V. dahliae pertencentes às raças 1 e 2. As cultivares Ponderosa e Floradade foram utilizadas como controles. O ensaio foi conduzido em casa de vegetação em delineamento experimental de blocos ao acaso em arranjo fatorial 5 x 40, com três repetições (vasos com quatro plantas. A avaliação foi feita baseada nos parâmetros epidemiológicos: período de incubação e índice de doença. Foram identificados acessos com resistência raça-específica e também com resistência a ambas as raças. Estes acessos podem ser indicados para futuros programas de melhoramento genético visando incorporar

  1. Mapping pathological phenotypes in reelin mutant mice.

    Science.gov (United States)

    Michetti, Caterina; Romano, Emilia; Altabella, Luisa; Caruso, Angela; Castelluccio, Paolo; Bedse, Gaurav; Gaetani, Silvana; Canese, Rossella; Laviola, Giovanni; Scattoni, Maria Luisa

    2014-01-01

    Autism Spectrum Disorders (ASD) are neurodevelopmental disorders with multifactorial origin characterized by social communication deficits and the presence of repetitive behaviors/interests. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we assessed the behavioral, neurochemical, and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in the ultrasonic vocal repertoire and a general delay in motor development of reeler pups. We now report that adult male heterozygous (Het) reeler mice did not show social behavior and communication deficits during male-female social interactions. Wildtype and Het mice showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection) only Het mice showed an over response to stress. In addition to the behavioral studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in Het mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD neurobehavioral phenotype.

  2. Ethanol production using nuclear petite yeast mutants

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, A.; Oliver, S.G. [Department of Biomolecular Sciences, UMIST, Manchester (United Kingdom)

    1998-12-31

    Two respiratory-deficient nuclear petites, FY23{Delta}pet191 and FY23{Delta}cox5a, of the yeast Saccharomyces cerevisiae were generated using polymerase-chain-reaction-mediated gene disruption, and their respective ethanol tolerance and productivity assessed and compared to those of the parental grande, FY23WT, and a mitochondrial petite, FY23{rho}{sup 0}. Batch culture studies demonstrated that the parental strain was the most tolerant to exogenously added ethanol with an inhibition constant. K{sub i}, of 2.3% (w/v) and a specific rate of ethanol production, q{sub p}, of 0.90 g ethanol g dry cells{sup -1} h{sup -1}. FY23{rho}{sup 0} was the most sensitive to ethanol, exhibiting a K{sub i} of 1.71% (w/v) and q{sub p} of 0.87 g ethanol g dry cells{sup -1} h{sup -1}. Analyses of the ethanol tolerance of the nuclear petites demonstrate that functional mitochondria are essential for maintaining tolerance to the toxin with the 100% respiratory-deficient nuclear petite, FY23{Delta}pet191, having a K{sub i} of 2.14% (w/v) and the 85% respiratory-deficient FY23{Delta}cox5a, having a K{sub i} of 1.94% (w/v). The retention of ethanol tolerance in the nuclear petites as compared to that of FY23{rho}{sup 0} is mirrored by the ethanol productivities of these nuclear mutants, being respectively 43% and 30% higher than that of the respiratory-sufficient parent strain. This demonstrates that, because of their respiratory deficiency, the nuclear petites are not subject of the Pasteur effect and so exhibit higher rates of fermentation. (orig.)

  3. Mapping pathological phenotypes in Reelin mutant mice

    Directory of Open Access Journals (Sweden)

    Caterina eMichetti

    2014-09-01

    Full Text Available Autism Spectrum Disorders (ASD are neurodevelopmental disorders with multifactorial origin characterized by social communication and behavioural perseveration deficits. Several studies showed an association between the reelin gene mutation and increased risk of ASD and a reduced reelin expression in some brain regions of ASD subjects, suggesting a role for reelin deficiency in ASD etiology. Reelin is a large extracellular matrix glycoprotein playing important roles during development of the central nervous system. To deeply investigate the role of reelin dysfunction as vulnerability factor in ASD, we investigated the behavioural, neurochemical and brain morphological features of reeler male mice. We recently reported a genotype-dependent deviation in ultrasonic vocal repertoire and a general delay in motor development in reeler pups. We now report that adult male heterozygous reeler mice did not show social behaviour and communication deficits during male-female social interactions. Wildtype and heterozygous mice also showed a typical light/dark locomotor activity profile, with a peak during the central interval of the dark phase. However, when faced with a mild stressful stimulus (a saline injection only heterozygous mice showed an over response to stress. At the end of the behavioural studies, we conducted high performance liquid chromatography and magnetic resonance imaging and spectroscopy to investigate whether reelin mutation influences brain monoamine and metabolites levels in regions involved in ASD. Low levels of dopamine in cortex and high levels of glutamate and taurine in hippocampus were detected in heterozygous mice, in line with clinical data collected on ASD children. Altogether, our data detected subtle but relevant neurochemical abnormalities in reeler mice supporting this mutant line, particularly male subjects, as a valid experimental model to estimate the contribution played by reelin deficiency in the global ASD

  4. 10. international mouse genome conference

    Energy Technology Data Exchange (ETDEWEB)

    Meisler, M.H.

    1996-12-31

    Ten years after hosting the First International Mammalian Genome Conference in Paris in 1986, Dr. Jean-Louis Guenet presided over the Tenth Conference at the Pasteur Institute, October 7--10, 1996. The 1986 conference was a satellite to the Human Gene Mapping Workshop and had approximately 50 attendees. The 1996 meeting was attended by 300 scientists from around the world. In the interim, the number of mapped loci in the mouse increased from 1,000 to over 20,000. This report contains a listing of the program and its participants, and two articles that review the meeting and the role of the laboratory mouse in the Human Genome project. More than 200 papers were presented at the conference covering the following topics: International mouse chromosome committee meetings; Mutant generation and identification; Physical and genetic maps; New technology and resources; Chromatin structure and gene regulation; Rate and hamster genetic maps; Informatics and databases; and Quantitative trait analysis.

  5. Effect of different immunosuppressive drugs on calcineurin and its mutants

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Several mutants in Loop7 region and near Loop7 region of calcineurin A (CN A) subunit have been constructed and purified using site-directed mutagenesis.Their phosphatase activity and the corresponding solution conformation were examined.Their phosphatase activities between wild-type CN and mutants were compared to identify the interaction of different immunosuppressive drugs with CN.The results showed that the phosphatase activities of the mutants at Loop7 were much higher than the one of wild-type CN.Furthermore,circular dichroism spectra of the mutants revealed that their solution conformations gave rise in changes in native structure of the protein.Cyclophilin-CyclosporinA (CyP-CsA) significantly inhibited the phosphatase activity of wild-type CN,and had no effects on the phosphatase activity of mutants in Loop7 region,which indicates that the site-directed mutagenesis at Loop7 region made a significant change in the interaction between CyP-CsA and CN.Examination of the activities of these mutants resulted in the presence of immunosuppressive component from traditional Chinese drugs.The component of Chinese drug,ZIP1,could directly inhibit both CN and CN mutants without drug binding protein.These results suggest that the Loop7 region is an important structural area involved in the inhibition by CyP-CsA.It is valuable to further study the inhibition by ZIP1.

  6. Methods of producing protoporphyrin IX and bacterial mutants therefor

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  7. Epigenetic Suppression of T-DNA Insertion Mutants in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yangbin Gao; Yunde Zhao

    2013-01-01

    T-DNA insertion mutants have been widely used to define gene functions in Arabidopsis and in other plants.Here,we report an unexpected phenomenon of epigenetic suppression of T-DNA insertion mutants in Arabidopsis.When the two T-DNA insertion mutants,yucl-1 and ag-TD,were crossed together,the defects in all of the ag-TD plants in the F2 population were partially suppressed regardless of the presence of yucl-1.Conversion of ag-TD to the suppressed ag-TD (named as ag-TD*) did not follow the laws of Mendelian genetics.The ag-TD* could be stably transmitted for many generations without reverting to ag-TD,and ag-TD* had the capacity to convert ag-TD to ag-TD*.We show that epigenetic suppression of T-DNA mutants is not a rare event,but certain structural features in the T-DNA mutants are needed in order for the suppression to take place.The suppressed T-DNA mutants we observed were all intronic T-DNA mutants and the T-DNA fragments in both the trigger T-DNA as well as in the suppressed T-DNA shared stretches of identical sequences.We demonstrate that the suppression of intronic T-DNA mutants is mediated by trans-interactions between two ToDNA insertions.This work shows that caution is needed when intronic T-DNA mutants are used.

  8. Interne evalueringer

    DEFF Research Database (Denmark)

    Hansson, Finn

    Det er en gennemgående tese i denne undersøgelse af interne evalueringer, at en af de vigtigste kendetegn ved den New Public Management -dominerede udvikling af den offentlige sektors reguleringspolitik, som Danmark såvel som en række andre OECD lande har gennemlevet, er en omfattende brug af alle...

  9. Transparency International

    NARCIS (Netherlands)

    Hulten, van M. (Michel)

    2009-01-01

    Established in 1993, Transparency International (TI) defines itself as “the global civil society organization leading the fight against corruption, that brings people together in a powerful worldwide coalition to end the devastating impact of corruption on men, women and children around the wo

  10. International Business

    NARCIS (Netherlands)

    Anne van Delft

    2011-01-01

    Internationalisation is the expansion of a firms operations to foreign markets and includes not only import and export but also foreign direct investments and international cooperation. Today’s globalising economy has resulted in a growing number of small and medium enterprises (SMEs) undertaking

  11. International Entomology

    Science.gov (United States)

    Pests and diseases of plants in agriculture are a shared international problem. Yet some of the very places that pest invaders come from often lack the institutional structure and organization necessary to help in understanding the biology of the pest or disease. Strengthening entomology by stimulat...

  12. International Reports.

    Science.gov (United States)

    Tabb, Winston; Bender, David R.; Haycock, Ken; Horodyski, John

    2001-01-01

    Includes three annual reports: one from the International Federation of Library Associations and Institutions, the Special Libraries Association, and a report on innovations in Canadian libraries that discusses electronic initiatives, partnerships, books and publishing, school libraries, national issues, local challenges, and funding. (LRW)

  13. Ascott International

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    "Heart-to-Heart" Charity Event for Hearing-Impaired Children in Beijing On June 12, Ascott International North China held a "heart-to-heart" charity event for hearing-impaired children in the Heritage Room at the Ascott Beijing.

  14. 番茄Metacaspase基因(LeM)的克隆及其在大肠杆菌Rosetta中的高效表达%Cloning of Lycopersicon esculentum Metacaspase Gene (LeM) and Its Effective Expression in Escherichia coli Rosetta

    Institute of Scientific and Technical Information of China (English)

    马秋敏; 张雅丽; 刘金娜; 车英慧; 谢寒丁; 罗云波; 曲桂芹

    2011-01-01

    为获得可溶性的番茄Metacaspase蛋白,后续研究Metacaspase蛋白的酶学特性以及功能,利用RT-PCR方法克隆了番茄(Lycopersicon esculentum)中Metacaspase(LeM)全长cDNA,并成功地构建了LeM基因的原核表达载体重组质粒pET28a-LeM,转入大肠杆菌(Escherichia coli)BL21(DE3)PlysS和Rosetta中进行诱导表达,并对诱导表达条件进行了优化.SDS-PAGE结果显示,在37℃条件下,1 mmol/L IPTG诱导表达量最高,在BL21(DE3)PlysS菌株中重组蛋白主要以包涵体形式存在,而相同条件下在Rosetta菌株中多为可溶性表达.同时酶活测定显示,Rosetta上清中LeM的活性为33 RFU/min,显著高于BL21(DE3)PlysS 7RFU/min.本实验表明,不同菌株对Metacaspase的可溶性表达有很大影响.%To obtain the fusion protein of Lyco persicon esculentum Metacaspase (LeM) and study the characteristics and function of it, we cloned the open reading frame of LeM in Lycopersicon esculentum by RT-PCR, and successfully constructed the prokaryotic expression vector pET28a-LeM for LeM expression.The recombinant plasmid pET28a-LeM was transformed into Escherichia coli BL21 (DE3)PlysS and Rosette for expression, induced by IPTG, and the conditions of the expression was optimized.SDS-PAGE revealed that the best expression was induced by 1 mmol/L IPTG at 37℃ and the recombinant protein expressed mainly as inclusion body in E.coli BL21(DE3)PlysS while as fusion protein in E.coli Rosetta at the same condition.Enzyme activity assay showed that the activity of LeM in E.coli Rosetta was 33 RFU/min, which was much higher than 7 RFU/min of E.coli BL21 (DE3)PlysS.We demonstrate that the strain has a great influence on the expression of LeM fusion protein.

  15. Sensorimotor learning in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Lalonde, R; Strazielle, C

    2011-04-15

    Homozygous Dab1(scm) mouse mutants with cell ectopias in cerebellar cortex and neocortex were compared with non-ataxic controls on two tests of motor coordination: rotorod and grid climbing. Even at the minimal speed of 4 rpm and unlike controls, none of the Dab1(scm) mutants reached criterion on the constant speed rotorod. In contrast, Dab1(scm) mutants improved their performances on the vertical grid over the course of the same number of trials. Thus, despite massive cerebellar degeneration, sensorimotor learning for equilibrium is still possible, indicating the potential usefulness of the grid-climbing test in determining residual functions in mice with massive cerebellar damage.

  16. Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

    2002-01-01

    Jasmonates induce plant-defence responses and act to regulate defence-related genes including positive feedback of the lipoxygenase 2 (LOX2) gene involved in jasmonate synthesis. To identify jasmonate-signalling mutants, we used a fusion genetic strategy in which the firefly luciferase (FLUC...... as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition...

  17. Mutant γPKC that causes spinocerebellar ataxia type 14 upregulates Hsp70, which protects cells from the mutant's cytotoxicity.

    Science.gov (United States)

    Ogawa, Kota; Seki, Takahiro; Onji, Tomoya; Adachi, Naoko; Tanaka, Shigeru; Hide, Izumi; Saito, Naoaki; Sakai, Norio

    2013-10-11

    Several missense mutations in the protein kinase Cγ (γPKC) gene have been found to cause spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that the mutant γPKC found in SCA14 is misfolded, susceptible to aggregation and cytotoxic. Molecular chaperones assist the refolding and degradation of misfolded proteins and prevention of the proteins' aggregation. In the present study, we found that the expression of mutant γPKC-GFP increased the levels of heat-shock protein 70 (Hsp70) in SH-SY5Y cells. To elucidate the role of this elevation, we investigated the effect of siRNA-mediated knockdown of Hsp70 on the aggregation and cytotoxicity of mutant γPKC. Knockdown of Hsp70 exacerbated the aggregation and cytotoxicity of mutant γPKC-GFP by inhibiting this mutant's degradation. These findings suggest that mutant γPKC increases the level of Hsp70, which protects cells from the mutant's cytotoxicity by enhancing its degradation.

  18. Construction and Verification of LuxS-negative Mutants of Streptococcus Mutans and the Effect of the Absence of LuxS Gene on the Acid Tolerance

    Institute of Scientific and Technical Information of China (English)

    YU Dan-ni; CHEN Jie; ZHANG Yao-chao; HAN Yu-zhi

    2009-01-01

    Objective: To knock out the entire Luxs gene of Streptococcus mutans(S.mutans) UA159 strain via homologous recombination and construct a Luxs-deleted mutant strain of S. Mutans. To study the difference between the acid resistance of S. Mutans Ingbritt C international standard strain and the acid resistance of LuxS mutant strain. Methods: Two DNA fragments locating in the upper and downstream of Luxs gene were amplified and a erythromycin resistance gene of PJT10 between them were engineered into PUC19 plasmid for constructing the recombination plasmid pUCluxKO. Electrotransformation of S.mutans cells with pUCluxKO-mutant resulted in isolation of erythromycin resistant S. Mutans transformants, which was identified by polymerase chain reaction, V.harveyi BB170 luminescence bioassay and sequencing analysis. Solutions of S. Mutans standard strain and LuxS mutant strain with same density were made and cultured at pH 3.5 to 7.0 BHI liquid for the same period.Terminal growth situation was compared.Firstly acidized in pH 5.5 BHI liquid,the two strains were cultured at pH 3.0 BHI liquid. The acid tolerance responses of the two strains were compared.Results:Restriction endonuclease analyses showed that pUCluxKO-mutant vector had been successfully recombined. The Luxs-deleted status of S.mutans mutants was confirmed by PCR with primers which were specific for the genes of Luxs and Erythromycin resistance. S.mutans mutant can not induce bioluminescence, indiating the mutant had been successfully recombined. After twenty generations of culture, the constructed Chinese S.mutans mutants were confirmed to be stable. Significant difference of aciduricity was observed between S.mutans standard strain and LuxS mutant strain.The acid resistance of standard strain was stronger than that of LuxS mutant strain.The two strains both displayed the capability of acid tolerance responses. Conclusion:The S.mutans gene allelic exchange plasmid is constructed correctively and a Luxs

  19. Selection of mutants of capsicum annuum induced by gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. I.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of); Lee, E. K. [Chungnam National Univ., Taejeon (Korea, Republic of)

    1998-06-01

    For induction and selection of mutations of Capsicum annuum L., dry seeds of pure lines No.1 and No.2 were irradiated with gamma ray of 150Gy, 200Gy and 250Gy. Various mutants were selected such as showing early maturity, short plant height, long fruit and chlorophyll mutations. Mutation frequency of No.1 line was 3.4% in the dose of 150Gy, while the frequency of No.2 line was 2.7% in the dose of 250Gy. For selection of resistant mutant to amino acid analog, the optimum concentration of 5-methyltryptophan (5-MT) and S-(2-aminoethyl)-L-cysteine were 25 ppm and 30 ppm, respectively. Four resistant mutant lines to 5-MT were selected among 400 mutant lines.

  20. Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase

    DEFF Research Database (Denmark)

    Jochimsen, Bjarne; Hove-Jensen, Bjarne; Garber, Bruce B.;

    1985-01-01

    This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity. This strain was isolated in a purE deoD gpt purine auxotroph by a procedure designed to select guanosine......-utilizing mutants. Strain GP122 had roughly 15% of the PRPP synthetase activity and 25% of the PRPP pool of its parent strain. The mutant exhibited many of the predicted consequences of a decreased PRPP pool and a defective PRPP synthetase enzyme, including: poor growth on purine bases; decreased accumulation of 5...... phosphoribosyltransferase, enzymes involved in the pyrimidine de novo biosynthetic pathway; growth stimulation by PRPP-sparing compounds (e.g. guanosine, histidine); poor growth in low phosphate medium; and increased heat lability of the defective enzyme. This mutant strain also had increased levels of guanosine 5...

  1. Generation of Peroxisome-Deficient Somatic Animal Cell Mutants.

    Science.gov (United States)

    Okumoto, Kanji; Fujiki, Yukio

    2017-01-01

    Cell mutants with a genetic defect affecting various cellular phenotypes are widely utilized as a powerful tool in genetic, biochemical, and cell biological research. More than a dozen complementation groups of animal somatic mutant cells defective in peroxisome biogenesis have been successfully isolated in Chinese hamster ovary (CHO) cells and used as a model system reflecting fatal human severe genetic disorders named peroxisome biogenesis disorders (PBD). Isolation and characterization of peroxisome-deficient CHO cell mutants has allowed the identification of PEX genes and the gene products peroxins, which directly leads to the accomplishment of isolation of pathogenic genes responsible for human PBDs, as well as elucidation of their functional roles in peroxisome biogenesis. Here, we describe the procedure to isolate peroxisome-deficient mammalian cell mutants from CHO cells, by making use of an effective, photo-sensitized selection method.

  2. Status and Perspectives on the Researches of Rice Glutelin Mutants

    Institute of Scientific and Technical Information of China (English)

    ZHENG Tian-qing; SHEN Wen-biao; ZHU Su-song; ZHAI Hu-qu; WAN Jian-min

    2003-01-01

    Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising offunctional rice breeding for special usage, glutelin mutants play a more and more important role in the func-tional rice breeding as well as eukaryotic gene expression and regulation research materials. For example, therice cultivar special for the patients suffering from kidney disease and diabetes could be developed from the riceglutelin mutants. In this paper, current researches on characterization, mutation mechanism and breeding us-age of various rice glutelin mutants, especially the low glutelin content cultivars, were all discussed with per-spectives on the trends of the glutelin mutant researches in the era of post-genomics.

  3. Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Nygaard, Per

    1982-01-01

    , stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib....... Kinetic analysis of the mutant PRib-PP synthetase revealed an apparent Km for ATP and ribose 5-phosphate of 1.0 mM and 240 μM respectively, compared to 60 μM and 45 μM respectively for the wild-type enzyme. ADP, which inhibits the wild-type enzyme at a concentration of 0.5 mM ribose 5-phosphate...

  4. Assessment of Genetic diversity in mutant cowpea lines using ...

    African Journals Online (AJOL)

    FKOLADE

    2016-11-09

    Nov 9, 2016 ... option of NTSYS, a rooted tree was also generated from the .... Dellarporta SF, Wood J, Hicks JB (1983). ... genetic diversity in Pigeon Pea (Cajanus sp). ... diversity in somatic mutants of grape (Vitis vinifera) cultivar Italia.

  5. Analysis of the aspartic acid metabolic pathway using mutant genes.

    Science.gov (United States)

    Azevedo, R A

    2002-01-01

    Amino acid metabolism is a fundamental process for plant growth and development. Although a considerable amount of information is available, little is known about the genetic control of enzymatic steps or regulation of several pathways. Much of the information about biochemical pathways has arisen from the use of mutants lacking key enzymes. Although mutants were largely used already in the 60's, by bacterial and fungal geneticists, it took plant research a long time to catch up. The advance in this area was rapid in the 80's, which was followed in the 90's by the development of techniques of plant transformation. In this review we present an overview of the aspartic acid metabolic pathway, the key regulatory enzymes and the mutants and transgenic plants produced for lysine and threonine metabolism. We also discuss and propose a new study of high-lysine mutants.

  6. Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Nygaard, Per

    1982-01-01

    . Kinetic analysis of the mutant PRib-PP synthetase revealed an apparent Km for ATP and ribose 5-phosphate of 1.0 mM and 240 μM respectively, compared to 60 μM and 45 μM respectively for the wild-type enzyme. ADP, which inhibits the wild-type enzyme at a concentration of 0.5 mM ribose 5-phosphate......, stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib...

  7. Characterization of Glutamine-Requiring Mutants of Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, Dick B.; Joosten, Han M.L.J.; Herst, Patricia M.; Drift, Chris van der

    1982-01-01

    Revertants were isolated from a glutamine-requiring mutant of Pseudomonas aeruginosa PAO. One strain showed thermosensitive glutamine requirement and formed thermolabile glutamine synthetase, suggesting the presence of a mutation in the structural gene for glutamine synthetase. The mutation conferri

  8. A reliable begomovirus inoculation method for screening Lycopersicon esculentum lines Um método de inoculação de begomovírus confiável para a seleção de linhagens de Lycopersicon esculentim

    Directory of Open Access Journals (Sweden)

    Alice K Inoue-Nagata

    2007-09-01

    Full Text Available Due to failures of infection after mechanical inoculation of begomovirus on tomato (Lycopersicon esculentum Mill. plants, an efficient and reliable begomovirus inoculation method was developed using the whitefly vector (Bemisia tabaci. Virus acquisition was carried out using a 'Tube-cage', made of a polypropylene tube, containing one to two day-old whiteflies and a tomato plant apex infected with a begomovirus isolate. After 48 h of acquisition access period, inoculation was done using a 'Ring-cage', containing viruliferous whiteflies, attached to the abaxial side of the leaf of young tomato plants. 48 hours after acquisition, the whiteflies were eliminated and the inoculated plants were incubated for 28 days under greenhouse conditions. Three viruliferous whiteflies per plant were enough to cause infection in susceptible tomato cv. Viradoro. This procedure was applied to test the resistance of tomato line 486-1 (resistant line in comparison with 'Viradoro' (susceptible cultivar. Dot blot hybridization confirmed the susceptibility of 'Viradoro' and the resistance of the line 486-1, showing the efficiency of this method for screening plants for disease resistance. This method is also a useful tool in detecting the presence of virus in inoculated (lower leaves and in non-inoculated (upper leaves in a given plant. Using this procedure, it was observed that the resistance of the line 486-1 probably is expressed in the inoculated leaf without virus translocation to the upper leaves.Devido às falhas encontradas no método de inoculação de begomovírus em plantas de tomateiro, um método eficiente e confiável de inoculação de begomovírus foi desenvolvido utilizando como vetor a mosca-branca (Bemisia tabaci. A aquisição viral foi realizada em uma armadilha ('Tube-cage' feita a partir de um tubo de polipropileno contendo moscas-brancas de um ou dois dias de idade e o ápice de uma planta de tomate infectada com um begomovírus. Após 48 horas de

  9. Resistant mechanism study of benzalkonium chloride selected Salmonella Typhimurium mutants.

    Science.gov (United States)

    Guo, Wei; Cui, Shenghui; Xu, Xiao; Wang, Haoyan

    2014-02-01

    Benzalkonium chloride is one of the invaluable biocides that is extensively used in healthcare settings as well as in the food processing industry. After exposing wild-type Salmonella Typhimurium 14028s or its AcrAB inactivation mutant to gradually increasing levels of benzalkonium chloride, resistance mutants S-41, S-150, S-AB-23, S-AB-38, and S-AB-73 were selected and these mutants also showed a 2-64-fold stable minimum inhibitory concentration (MIC) increase to chloramphenicol, ciprofloxacin, nalidixic acid, and tetracycline. In S-41 and S-150, the expression of acrB was increased 2.7- and 7.6-fold, and ΔtolC or ΔacrAB mutants of S-41 and S-150 showed the same MICs to all tested antimicrobials as the equivalent Salmonella Typhimurium 14028s mutants. However, in S-AB-23, S-AB-38, and S-AB-73, the expression of acrF was increased 96-, 230-, and 267-fold, respectively, and ΔtolC or ΔacrEF mutants of S-AB-23, S-AB-38, and S-AB-73 showed the similar MICs to all tested antimicrobials as the ΔtolC mutant of Salmonella Typhimurium 14028s. Our data showed that constitutively over-expressed AcrAB working through TolC was the main resistance mechanism in ST14028s benzalkonium chloride resistance mutants. However, after AcrAB had been inactivated, benzalkonium chloride-resistant mutants could still be selected and constitutively over-expressed, AcrEF became the dominant efflux pump working through TolC and being responsible for the increasing antimicrobial resistance. These data indicated that different mechanisms existed for acrB and acrF constitutive over-expression. Since exposure to benzalkonium chloride may lead to Salmonella mutants with a decreased susceptibility to quinolones, which is currently one of the drugs of choice for the treatment of life-threatening salmonelosis, research into the pathogenesis and epidemiology of the benzalkonium chloride resistance mutants will be of increasing importance.

  10. Liver International

    OpenAIRE

    Quarantini, Lucas de Castro [UNIFESP; Rodrigo A Bressan; Galvão, Amanda; Neves, Susana Batista; Raymundo PARANÁ

    2007-01-01

    p. 1098-1102 Objective: Evaluate the incidence of mental disorders using pegylated interferon plus ribavirin retreatment in nonresponder hepatitis C virus-infected patients. Method: The Mini-International Neuropsychiatric Interview (MINI) was used to evaluate 30 hepatitis C virus-infected interferon-nonresponder patients at baseline and following 4, 12 and 24 weeks of pegylated interferon retreatment. Results: During the pegylated interferon/ribavirin retreatment, 5(16.6%) patient...

  11. Teaching International Law: Concepts in International Relations

    Science.gov (United States)

    Starbird, Caroline; Pettit, Jenny; Singleton, Laurel

    2004-01-01

    This book is designed to introduce students to public international law. Topics covered include international public organizations, such as the United Nations and World Trade Organization, international courts, international human rights law, international trade law, and international environmental law. The goal of each study is to examine how…

  12. Targeting Palmitoyl Acyltransferases in Mutant NRAS-Driven Melanoma

    Science.gov (United States)

    2014-08-01

    regulation of synaptic and neuronal functions.17 A point mutation in DHHC21 was identified in the depilated (dep) mouse mutant, resulting in hair follicle ...and hair follicle differentiation. PLoS Genet. 5, e1000748. (19) Mansilla, F., Birkenkamp-Demtroder, K., Kruhoffer, M., Sorensen, F. B., Andersen, C...AWARD NUMBER: W81XWH-13-1-0203 TITLE: Targeting Palmitoyl Acyltransferases in Mutant NRAS-Driven Melanoma PRINCIPAL INVESTIGATOR: Xu Wu

  13. A relaxed mutant with an altered ribosomal protein L11.

    Science.gov (United States)

    Parker, J; Watson, R J; Friesen, J D

    1976-02-27

    Relaxed mutants of Escherichia coli have been isolated which have an altered electrophoretic mobility of ribosomal protein L11. It can be shown that reversion to stringency in one of these mutants occurs simultaneously with a reversion of L11 protein to tis normal mobility. The L11 structural gene, rplK, maping near rif, is carried by the bacteriophage lambdacI857S7drifd18, and is most likely identical with relC.

  14. Multiple defects in Escherichia coli mutants lacking HU protein.

    OpenAIRE

    Huisman, O; Faelen, M; Girard, D; Jaffé, A; Toussaint, A; Rouvière-Yaniv, J

    1989-01-01

    The HU protein isolated from Escherichia coli, composed of two partially homologous subunits, alpha and beta, shares some of the properties of eucaryotic histones and is a major constituent of the bacterial nucleoid. We report here the construction of double mutants totally lacking both subunits of HU protein. These mutants exhibited poor growth and a perturbation of cell division, resulting in the formation of anucleate cells. In the absence of HU, phage Mu was unable to grow, to lysogenize,...

  15. Isolation of new gravitropic mutants under hypergravity conditions

    Directory of Open Access Journals (Sweden)

    Akiko Mori

    2016-09-01

    Full Text Available Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upwards. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes. In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using Next-Generation Sequencing (NGS and Single Nucleotide Polymorphism (SNP-based markers. Using the endodermal-amyloplast less 1 (eal1 mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene (enhancer of eal1 mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis.

  16. Isolation of New Gravitropic Mutants under Hypergravity Conditions

    Science.gov (United States)

    Mori, Akiko; Toyota, Masatsugu; Shimada, Masayoshi; Mekata, Mika; Kurata, Tetsuya; Tasaka, Masao; Morita, Miyo T.

    2016-01-01

    Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using next-generation sequencing (NGS) and single nucleotide polymorphism (SNP)-based markers. Using the endodermal-amyloplast less 1 (eal1) mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g) restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene (enhancer of eal1) mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis.

  17. Molecular analysis of mutants of the Neurospora adenylosuccinate synthetase locus

    Indian Academy of Sciences (India)

    A. Wiest; A. J. McCarthy; R. Schnittker; K. McCluskey

    2012-08-01

    The ad-8 gene of Neurospora crassa, in addition to being used for the study of purine biology, has been extensively studied as a model for gene structure, mutagenesis and intralocus recombination. Because of this there is an extensive collection of well-characterized N. crassa ad-8 mutants in the Fungal Genetics Stock Center collection. Among these are spontaneous mutants and mutants induced with X-ray, UV or chemical mutagens. The specific lesions in these mutants have been genetically mapped at high resolution. We have sequenced the ad-8 locus from 13 of these mutants and identified the molecular nature of the mutation in each strain. We compare the historical fine-structure map to the DNA and amino acid sequence of each allele. The placement of the individual lesions in the fine-structure map was more accurate at the 5′ end of the gene and no mutants were identified in the 3′ untranslated region of this gene. We additionally analysed ad-8+ alleles in 18 N. crassa strains subjected to whole-genome sequence analysis and describe the variability among Neurospora strains and among fungi and other organisms.

  18. [Internal migration].

    Science.gov (United States)

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  19. Osmotic adjustment and the growth response of seven vegetable crops following water-deficit stress. [Phaseolus vulgaris L. ; Beta vulgaris L. ; Abelmoschus esculentus; Pisum sativum L. ; Capsicum annuum L. ; Spinacia oleracea L. ; Lycopersicon esculentum Mill

    Energy Technology Data Exchange (ETDEWEB)

    Wullschleger, S.D. (Oak Ridge National Lab., TN (United States)); Oosterhuis, D.M. (Univ. of Arkansas, Fayetteville (United States))

    1991-09-01

    Growth-chamber studies were conducted to examine the ability of seven vegetable crops- Blue Lake beam (Phaseolus vulgaris L.) Detroit Dark Red beet (Beta vulgaris L.) Burgundy okra (Abelmoschus esculentus) (Moench), Little Marvel pea (Pisum sativum L), California Wonder bell pepper (Capsicum annuum L), New Zealand spinach (Spinacia oleracea L), and Beefsteak tomato (Lycopersicon esculentum Mill.) - to adjust osmotically in response to water-deficit stress. Water stress was imposed by withholding water for 3 days, and the adjustment of leaf and root osmotic potentials upon relief of the stress and rehydration were monitored with thermocouple psychrometers. Despite similar reductions in leaf water potential and stomatal conductance among the species studied reductions in lead water potential an stomatal conductance among the species, crop-specific differences were observed in leak and root osmotic adjustment. Leaf osmotic adjustment was observed for bean, pepper, and tomato following water-deficit stress. Root osmotic adjustment was significant in bean, okra, pea and tomato. Furthermore, differences in leaf and root osmotic adjustment were also observed among five tomato cultivars. Leaf osmotic adjustment was not associated with the maintenance of leaf growth following water-deficit stress, since leaf expansion of water-stressed bean and pepper, two species capable of osmotic adjustment, was similar to that of spinach, which exhibited no leaf osmotic adjustment.

  20. 番茄果实中成熟衰老相关small RNAs的最新研究进展%Latest Research Progress of Small RNAs Related to Tomato (Lycopersicon esculentum) Fruit Ripening and Senescence

    Institute of Scientific and Technical Information of China (English)

    左进华; 王清; 鞠正; 曹东艳; 朱本忠; 罗云波; 高丽朴

    2016-01-01

    番茄(Lycopersicon esculentum)是研究果实成熟衰老的模式材料,其成熟是一个多基因调控的高度协调的遗传调控过程,伴随着色泽、质地、风味、香气和其他代谢等许多显著的生理生化变化.近年来,small RNAs作为一种新型的转录后调控因子受到越来越多的关注,几乎参与了动植物中所有的生理和生化过程.在植物中参与生长发育、果实成熟、生物和非生物胁迫反应等过程.本文系统地综述了番茄果实中small RNAs的分离鉴定现状,对番茄果实中与乙烯信号途径、颜色、风味、软化等代谢途径相关的small RNAs进行了系统总结,并展望了未来small RNAs在果实成熟过程中的相关研究方向.

  1. Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

    Science.gov (United States)

    de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

    2010-09-01

    Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens.

  2. LeMAPK1, LeMAPK2, and LeMAPK3 are associated with nitric oxide-induced defense response against Botrytis cinerea in the Lycopersicon esculentum fruit.

    Science.gov (United States)

    Zheng, Yanyan; Hong, Hui; Chen, Lin; Li, Jingyuan; Sheng, Jiping; Shen, Lin

    2014-02-12

    Nitric oxide (NO) and mitogen-activated protein kinases (MAPKs) are signal molecules involved in the disease resistance of plants. To investigate the role of tomato MAPKs in the NO-mediated defense response, mature green tomatoes (Lycopersicon esculentum Mill. cv. Qian-xi) were treated with a MAPKs inhibitor (1,4-diamino-2,3-dicyano-1,4-bis(o-amino-phenylmercapto) butadiene (U0126)), NO donor sodium nitroprusside (SNP), and SNP plus U0126. Treatment with U0126 increased the incidence of disease and size of lesion areas in the tomato fruits after being inoculated with Botrytis cinerea. NO enhanced the resistance of the tomato fruits against Botrytis cinerea invasion and the activities of nitric oxide synthase, Chitinase, β-1,3-glucanase, polyphenol oxidase, and phenylalanine ammonia-lyase. However, the effects of NO on disease resistance were weakened by the MAPKs inhibitor. Meanwhile, the relative expression of LeMAPK1, LeMAPK2, and LeMAPK3 in the (SNP + U0126)-treated fruits was lower than that in the SNP-treated fruits. The results suggest that LeMAPK1/2/3 are involved in NO-induced disease resistance of tomato fruits against Botrytis cinerea.

  3. Inactivation of ccmO in Synechococcus sp. Strain PCC 7942 Results in a Mutant Requiring High Levels of CO(2).

    Science.gov (United States)

    Marco, E; Martinez, I; Ronen-Tarazi, M; Orus, M I; Kaplan, A

    1994-03-01

    Inactivation of ccmO in Synechococcus sp. strain PCC 7942 resulted in a mutant which possesses aberrant carboxysomes and a normal inorganic carbon uptake capability but a reduced ability to photosynthetically utilize the internal inorganic carbon pool. Consequently, it exhibits low apparent photosynthetic affinity for extracellular inorganic carbon and demands high levels of CO(2) for growth.

  4. Spontaneous chlorophyll mutants of Pennisetum americanum: Genetics and chlorophyll quantities.

    Science.gov (United States)

    Koduru, P R; Rao, M K

    1980-05-01

    Thirteen spontaneously occurring chlorophyll deficient phenotypes have been described and their genetic basis was established. Ten of these - 'white', 'white tipped green', 'patchy white', 'white virescent', 'white striping 1', 'white striping 2', 'white striping 4', 'fine striping', 'chlorina' and 'yellow virescent' showed monogenic recessive inheritance and the remaining three - 'yellow striping', 'yellow green' and 'light green' seedling phenotypes showed digenic recessive inheritance. The genes for (i) 'white tipped green' (wr) and 'yellow virescent' (yv) and (ii) 'patchy white' (pw) and 'white striping 1' (wst 1) showed independent assortment. Further, the genes for 'white' (w), 'white tipped green' (wr) and 'yellow virescent' (yv) were inherited independently of the gene for hairy leaf margin (Hm).In the mutants - 'white tipped green', 'patchy white', 'white striping 1', 'white striping 2', 'fine striping', 'chlorina', 'yellow virescent', 'yellow striping', 'yellow green' and 'light green' phenotypes total quantity of chlorophyll was significantly less than that in the corresponding controls, while in 'white virescent' there was no reduction in the mature stage. For nine of the mutants the quantity of chlorophyll was also estimated in F1's (mutant x control green). In F1's of six of the mutants - 'white tip', 'patchy white', 'chlorina', 'yellow virescent', 'fine striping' and 'yellow striping' the quantity of chlorophyll was almost equal to the wild type. In the F1's of three of the mutants - 'white striping 1', 'white striping 2' and 'light green' an intermediate value between the mutant and wild types was observed. In 'yellow virescent' retarded synthesis of chlorophyll, particularly chlorophyll a was observed in the juvenile stage. Reduced quantity of chlorophyll was associated with defective chloroplasts. In the mutants - 'white tipped green, 'white virescent', 'fine striping', 'chlorina', 'yellow striping', 'yellow green' and 'light green' defective

  5. Isolation and characterization of selenate resistant mutants of Acremonium chrysogenum

    Directory of Open Access Journals (Sweden)

    Airton Vialta

    1999-01-01

    Full Text Available Mutants unable to convert exogenous sulfate to sulfite were isolated using the toxic analogue selenate. Three of twenty-eight isolated mutants were chromate sensitive. They showed a possible lesion in the gene that codes the ATP sulfurylase. The others were chromate resistant, and probably had a lesion in one or both of the genes that code the sulfate permease. Methionine increased the resistance levels to selenate. In addition, the frequency of spontaneous mutants obtained in a medium containing methionine was higher (between 2.4 x 10-6 and 18.0 x 10-6 than that obtained using a medium without any intentional source of sulfur (between 0.7 x 10-6 and 5.0 x 10-6. The original strain, as well as the mutants, were able to grow in a sulfur-free liquid medium even after 4 consecutive inoculation procedures. These results indicated the existence of sulfur traces in the medium and/or an efficient intracellular storage system. There was no significant difference between cephalosporin C production in mutants and the original strain.Mutantes incapazes de converter o sulfato extracelular em sulfito foram isolados utilizando o análogo tóxico selenato. De 28 mutantes isolados, apenas 3 foram sensíveis ao cromato, provavelmente apresentando lesão no gene que codifica a ATP sulfurilase. Os demais foram resistentes ao cromato e devem conter lesão no gene sB ou também no gene sC. A metionina elevou os níveis de resistência ao selenato e a freqüência de mutantes espontâneos obtida em meio contendo este aminoácido foi maior (entre 2,42 x 10-6 e 18,04 x 10-6 do que a obtida no meio sem a adição de qualquer fonte intencional de enxofre (entre 0,71 x 10-6 e 5,0 x 10-6. A linhagem original e os mutantes foram capazes de crescer, mesmo depois de quatro etapas de inóculo, fato que pode ser explicado pela existência de traços do referido elemento no meio e/ou a presença de um sistema eficiente de estocagem intracelular. A produção de cefalosporina C

  6. International Exchanges

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    On October 12,2015,Mr.Zhu Rui,CPAPD Secretary General,chaired informal discussions with U.S.young experts and scholars on arms control and non-proliferation.The two sides exchanged views on international arms control,disarmament,non-proliferation and nuclear security,etc.During October 12 to 16,2015,at the invitation of the CPAPD,a four-member delegation from the Vietnam Peace Committee headed by its Vice-President Ms.Nguyen Thi Hoang Van

  7. Isolation of Escherichia coli mutants defective in uptake of molybdate.

    Science.gov (United States)

    Hemschemeier, S; Grund, M; Keuntje, B; Eichenlaub, R

    1991-10-01

    For the study of molybdenum uptake by Escherichia coli, we generated Tn5lac transposition mutants, which were screened for the pleiotropic loss of molybdoenzyme activities. Three mutants A1, A4, and M22 were finally selected for further analysis. Even in the presence of 100 microM molybdate in the growth medium, no active nitrate reductase, formate dehydrogenase, and trimethylamine-N-oxide reductase were detected in these mutants, indicating that the intracellular supply of molybdenum was not sufficient. This was also supported by the observation that introduction of plasmid pWK225 carrying the complete nif regulon of Klebsiella pneumoniae did not lead to a functional expression of nitrogenase. Finally, molybdenum determination by induced coupled plasma mass spectroscopy confirmed a significant reduction of cell-bound molybdenum in the mutants compared with that in wild-type E. coli, even at high molybdate concentrations in the medium. A genomic library established with the plasmid mini-F-derived cop(ts) vector pJE258 allowed the isolation of cosmid pBK229 complementing the molybdate uptake deficiency of the chlD mutant and the Tn5lac-induced mutants. Certain subfragments of pBK229 which do not contain the chlD gene are still able to complement the Tn5lac mutants. Mapping experiments showed that the Tn5lac insertions did not occur within the chromosomal region present in pBK229 but did occur very close to that region. We assume that the Tn5lac insertions have a polar effect, thus preventing the expression of transport genes, or that a positively acting regulatory element was inactivated.

  8. Defective glycinergic synaptic transmission in zebrafish motility mutants

    Directory of Open Access Journals (Sweden)

    Hiromi Hirata

    2010-01-01

    Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

  9. Auditory development in progressive motor neuronopathy mouse mutants.

    Science.gov (United States)

    Volkenstein, Stefan; Brors, Dominik; Hansen, Stefan; Berend, Achim; Mlynski, Robert; Aletsee, Christoph; Dazert, Stefan

    2009-11-06

    The present study was performed to elucidate the hearing development in the progressive motor neuronopathy (pmn) mouse mutant. This mouse has been used as a model for human motoneuron disease. A missense mutation in the tubulin-specific chaperon E (Tbce) gene on mouse chromosome 13 was localized as the underlying genetic defect. The protein encoded by the Tbce gene is essential for the formation of primary tubulin complexes. Studies on motoneurons show disorganization in microtubules and disturbed axonal transport, followed by retrograde degeneration of the motoneurons. A similar pathomechanism is also possible for hearing disorders where disrupted microtubules could cause functional deficits in spiral ganglion neurons or in cochlear hair cells. Click auditory brainstem response (ABR) audiometry in homozygous pmn mutants showed a normal onset of hearing, but an increasing hearing threshold from postnatal day 26 (P26) on to death, compared to heterozygous mutants and wild-type mice. Histological sections of the cochlea at different ages showed a regular morphology. Additionally, spiral ganglion explants from mutant and wild-type mice were cultured. The neurite length from pmn mutants was shorter than in wild-type mice, and the neurite number/explant was significantly decreased in pmn mutants. We show that the pmn mouse mutant is a model for a progressive rapid hearing loss from P26 on, after initially normal hearing development. Heterozygous mice are not affected by this defect. With the knowledge of the well-known pathomechanism of this defect in motoneurons, a dysfunction of cellular mechanisms regulating tubulin assembling suggests that tubulin assembling plays an essential role in hearing function and maintenance.

  10. Internal education

    Directory of Open Access Journals (Sweden)

    Anita Zagorc

    2016-09-01

    Full Text Available Research Question (RQ: The importance of internal trainings in an organization. Purpose: The purpose of research is to examine and present internal trainings in an organization and their contribution to greater success of an organization. The paper studies employee training in a company, how the organization itself looks after its employees during training, how trainings contribute to further development of organization and the advancement of knowledge for successful operation of organization. Method: How to achieve the purpose of research, used methods and theoretical approach. Results: Specific examples and opinions of employees. Results show the importance of trainings for an organization. We can see that all employees are fairly motivated and ready to participate in trainings and can adapt to changing business environment very well. The results demonstrate that all trainings in the organization are very important and welcome. Only with continuous learning, the organization can be successful and survive in the market despite strong competition. Organization: Trainings are designed for all employees inside an organization. Different employees participate in trainings in a different way as all trainings are divided into certain work and fields that are important for each individual or department in an organization. Society: Trainings have an impact on the whole organization by contributing to its development. Originality: The originality of study is what was new in the research, what is the value and originality of research. Limitations/Future Research: Research was limited to a small number of sources.

  11. A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice.

    Science.gov (United States)

    Bozue, Joel; Cote, Christopher K; Webster, Wendy; Bassett, Anthony; Tobery, Steven; Little, Stephen; Swietnicki, Wieslaw

    2012-07-01

    Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague. Published 2012. This article is a US Government work and is in the public domain in the USA.

  12. Distribution of dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutant alleles in Plasmodium vivax isolates from Thailand.

    Science.gov (United States)

    Thongdee, Pimwan; Kuesap, Jiraporn; Rungsihirunrat, Kanchana; Tippawangkosol, Pongsri; Mungthin, Mathirut; Na-Bangchang, Kesara

    2013-10-01

    The analysis of prevalence and distribution of pvdhfr and pvdhps mutations were performed in 169 samples collected from patients with Plasmodium vivax infection who attended the malaria clinics in the provinces along the three international borders of Thailand (Thai-Myanmar, Thai-Cambodian, and Thai-Malaysian borders). SNP-haplotypes of the pvdhfr at amino acid positions 13, 33, 57, 58, 61, 117, and 173 and of the pvdhps at positions 383 and 553 were examined by nested PCR-RFLP. Significant differences in the prevalence and distribution of pvdhfr and pvdhps combination alleles were observed in P. vivax isolates collected from all the three border areas. The most prevalent combination alleles were triple mutant pvdhfr 57L/58R/117T alleles/double wild-type pvdhps alleles (n=18), double mutant pvdhfr 58R/117N alleles/double wild-type pvdhps alleles (n=10), and triple mutant pvdhfr 58R/61M/117N alleles/double wild-type pvdhps alleles (n=52) or with single mutant pvdhps 383G allele (n=28), respectively. These information on prevalence and patterns of pvdhfr and pvdhps polymorphisms obtained from the present study suggest the presence of SP pressure on P. vivax isolates in Thailand which could be linked to the introduction of malaria from neighboring countries. Results did not support the application of SP for P. vivax control program in Thailand as well as the neighboring countries. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Screening of Mycobacterium avium subsp. paratuberculosis Mutants for Attenuation in a Bovine Monocyte-Derived Macrophage Model

    Directory of Open Access Journals (Sweden)

    Elise A Lamont

    2014-06-01

    Full Text Available Vaccination remains a major tool for prevention and progression of Johne’s disease, a chronic enteritis of ruminants worldwide. Currently there is only one licensed vaccine within the United States and two vaccines licensed internationally against Johne’s disease. All licensed vaccines reduce fecal shedding of Mycobacterium avium subsp. paratuberculosis (MAP and delay disease progression. However, there are no available vaccines that prevent disease onset. A joint effort by the Johne’s Disease Integrated Program (JDIP, a USDA-funded consortium, and USDA- APHIS/VS sought to identify transposon insertion mutant strains as vaccine candidates in part of a three phase study. The focus of the Phase I study was to evaluate MAP mutant attenuation in a well-defined in vitro bovine monocyte-derived macrophage (MDM model. Attenuation was determined by colony forming unit (CFUs counts and slope estimates. Based on CFU counts alone, the MDM model did not identify any mutant that significantly differed from the wild-type control, MAP K-10. Slope estimates using mixed models approach identified six mutants as being attenuated. These were enrolled in protection studies involving murine and baby goat vaccination-challenge models. MDM based approach identified trends in attenuation but this did not correlate with protection in a natural host model. These results suggest the need for alternative strategies for Johne’s disease vaccine candidate screening and evaluation.

  14. Effect of different immunosuppressive drugs on calcineurin and its mutants

    Institute of Scientific and Technical Information of China (English)

    阎力君; 于翠娟; 张丽芳; 魏群

    2000-01-01

    Several mutants in Loop7 region and near Loop7 region of calcineurin A (CN A) subunit have been constructed and purified using site-directed mutagenesis. Their phosphatase activity and the corresponding solution conformation were examined. Their phosphatase activities between wild-type CN and mutants were compared to identify the interaction of different immuno-suppressive drugs with CN. The results showed that the phosphatase activities of the mutants at Loop7 were much higher than the one of wild-type CN. Furthermore, circular dichroism spectra of the mutants revealed that their solution conformations gave rise in changes in native structure of the protein. Cyclophilin-CyclosporinA (CyP-CsA) significantly inhibited the phosphatase activity of wild-type CN, and had no effects on the phosphatase activity of mutants in Loop7 region, which indicates that the site-directed mutagenesis at Loop7 region made a significant change in the interaction between CyP-CsA and CN. Examination of the activities of these

  15. Normal aging modulates the neurotoxicity of mutant huntingtin.

    Directory of Open Access Journals (Sweden)

    Elsa Diguet

    Full Text Available Aging likely plays a role in neurodegenerative disorders. In Huntington's disease (HD, a disorder caused by an abnormal expansion of a polyglutamine tract in the protein huntingtin (Htt, the role of aging is unclear. For a given tract length, the probability of disease onset increases with age. There are mainly two hypotheses that could explain adult onset in HD: Either mutant Htt progressively produces cumulative defects over time or "normal" aging renders neurons more vulnerable to mutant Htt toxicity. In the present study, we directly explored whether aging affected the toxicity of mutant Htt in vivo. We studied the impact of aging on the effects produced by overexpression of an N-terminal fragment of mutant Htt, of wild-type Htt or of a beta-Galactosidase (beta-Gal reporter gene in the rat striatum. Stereotaxic injections of lentiviral vectors were performed simultaneously in young (3 week and old (15 month rats. Histological evaluation at different time points after infection demonstrated that the expression of mutant Htt led to pathological changes that were more severe in old rats, including an increase in the number of small Htt-containing aggregates in the neuropil, a greater loss of DARPP-32 immunoreactivity and striatal neurons as assessed by unbiased stereological counts.The present results support the hypothesis that "normal" aging is involved in HD pathogenesis, and suggest that age-related cellular defects might constitute potential therapeutic targets for HD.

  16. Mutant alpha-synuclein and autophagy in PC12 cells

    Institute of Scientific and Technical Information of China (English)

    Kangyong Liu; Chunfeng Liu; Chuancheng Ren; Yaping Yang; Liwei Shen; Xuezhong Li; Fen Wang; Zhenghong Qin

    2011-01-01

    Several studies have demonstrated that overexpression of mutant α-synuclein in PC12 cells is related to occurrence of autophagy.The present study established mutant a-synuclein (A30P)-transfected PC12 cells and treated them with the autophagy inducer rapamycin and autophagy inhibitor wortmannin, respectively.Results demonstrated that mutant o-synuclein resulted in cell death via autophagy and involved α-synuclein accumulation, membrane lipid oxidation, and loss of plasma membrane integrity.Mutant α-synuclein (A30P) also mediated toxicity of1-methyl-4-phenylpyridinium ion.Moreover, rapamycin inhibited a-synuclein aggregation, while wortmannin promoted o-synuclein aggregation and cell death.To further determine the role of autophagy due to mutant a-synuclein, the present study measured expression of microtubule-associated protein light chain 3.Results revealed that wortmannin and 1-methyl-4-phenylpyridinium ion inhibited expression of microtubule-associated protein light chain 3,while rapamycin promoted its expression.These findings suggested that abnormal aggregation of a-synuclein induced autophagic programmed cell death in PC12 cells.

  17. Cytokinin production by plant growth promoting rhizobacteria and selected mutants.

    Science.gov (United States)

    García de Salamone, I E; Hynes, R K; Nelson, L M

    2001-05-01

    One of the proposed mechanisms by which rhizobacteria enhance plant growth is through the production of plant growth regulators. Five plant growth promoting rhizobacterial (PGPR) strains produced the cytokinin dihydrozeatin riboside (DHZR) in pure culture. Cytokinin production by Pseudomonas fluorescens G20-18, a rifampicin-resistant mutant (RIF), and two TnphoA-derived mutants (CNT1, CNT2), with reduced capacity to synthesize cytokinins, was further characterized in pure culture using immunoassay and thin layer chromatography. G20-18 produced higher amounts of three cytokinins, isopentenyl adenosine (IPA), trans-zeatin ribose (ZR), and DHZR than the three mutants during stationary phase. IPA was the major metabolite produced, but the proportion of ZR and DHZR accumulated by CNT1 and CNT2 increased with time. No differences were observed between strain G20-18 and the mutants in the amounts of indole acetic acid synthesized, nor were gibberellins detected in supernatants of any of the strains. Addition of 10(-5) M adenine increased cytokinin production in 96- and 168-h cultures of strain G20-18 by approximately 67%. G20-18 and the mutants CNT1 and CNT2 may be useful for determination of the role of cytokinin production in plant growth promotion by PGPR.

  18. Characterization of a mutant glucose isomerase from Thermoanaerobacterium saccharolyticum.

    Science.gov (United States)

    Xu, Heng; Shen, Dong; Wu, Xue-Qiang; Liu, Zhi-Wei; Yang, Qi-He

    2014-10-01

    A series of site-directed mutant glucose isomerase at tryptophan 139 from Thermoanaerobacterium saccharolyticum strain B6A were purified to gel electrophoretic homogeneity, and the biochemical properties were determined. W139F mutation is the most efficient mutant derivative with a tenfold increase in its catalytic efficiency toward glucose compared with the native GI. With a maximal activity at 80 °C of 59.58 U/mg on glucose, this mutant derivative is the most active type ever reported. The enzyme activity was maximal at 90 °C and like other glucose isomerase, this mutant enzyme required Co(2+) or Mg(2+) for enzyme activity and thermal stability (stable for 20 h at 80 °C in the absence of substrate). Its optimum pH was around 7.0, and it had 86 % of its maximum activity at pH 6.0 incubated for 12 h at 60 °C. This enzyme was determined as thermostable and weak-acid stable. These findings indicated that the mutant GI W139F from T. saccharolyticum strain B6A is appropriate for use as a potential candidate for high-fructose corn syrup producing enzyme.

  19. Mutant number distribution in an exponentially growing population

    Science.gov (United States)

    Keller, Peter; Antal, Tibor

    2015-01-01

    We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück (1943 Genetics 28 491-511) 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mutants that grow stochastically according to a supercritical birth and death process. We give an exact expression for the generating function of the total number of mutants at a given wild-type population size. We present a simple expression for the probability of finding no mutants, and a recursion formula for the probability of finding a given number of mutants. In the ‘large population-small mutation’ limit we recover recent results of Kessler and Levine (2014 J. Stat. Phys. doi:10.1007/s10955-014-1143-3) for a fully stochastic version of the process.

  20. Hepatitis B escape mutants in Scottish blood donors.

    Science.gov (United States)

    Larralde, Osmany; Dow, Brian; Jarvis, Lisa; Davidson, Fiona; Petrik, Juraj

    2013-06-01

    Hepatitis B virus (HBV) remains as the viral infection with the highest risk of transmission by transfusion. This risk is associated with window period donations, occult HBV infection (OBI) and the emergence of escape mutants, which render blood donations false negative for hepatitis B surface antigen (HBsAg) serological testing. A retrospective study was conducted to gain insights into the molecular epidemiology of HBV escape mutants in Scottish blood donors. The criterion for selection was HBV positivity either by serology or nucleic acid testing (NAT). HBsAg detection was compared across several commercial immunoassays. The full length S gene from plasma samples was PCR amplified, cloned and expressed in HepG2 cells. Eight samples showed HBsAg discordant results, while 5 OBI samples were found. Four escape mutants, containing missense mutations in the S gene, are described here. These mutations impaired HBsAg detection both from HBV infected plasma samples and from recombinant proteins derived from its infected donors. Phylogenetic analysis showed that most of the mutants were clustered in the genotype D and were closely related to strains from Asia and the Middle East. We report here a proline substitution, outside the major hydrophilic region, that impaired HBsAg detection in vivo and in vitro, warning about the risk for the emergence of vaccine escape mutants with mutations outside the major neutralisation site.

  1. Rescue of cystathionine beta-synthase (CBS) mutants with chemical chaperones: purification and characterization of eight CBS mutant enzymes.

    Science.gov (United States)

    Majtan, Tomas; Liu, Lu; Carpenter, John F; Kraus, Jan P

    2010-05-21

    Missense mutations represent the most common cause of many genetic diseases including cystathionine beta-synthase (CBS) deficiency. Many of these mutations result in misfolded proteins, which lack biological function. The presence of chemical chaperones can sometimes alleviate or even restore protein folding and activity of mutant proteins. We present the purification and characterization of eight CBS mutants expressed in the presence of chemical chaperones such as ethanol, dimethyl sulfoxide, or trimethylamine-N-oxide. Preliminary screening in Escherichia coli crude extracts showed that their presence during protein expression had a significant impact on the amount of recovered CBS protein, formation of tetramers, and catalytic activity. Subsequently, we purified eight CBS mutants to homogeneity (P49L, P78R, A114V, R125Q, E176K, P422L, I435T, and S466L). The tetrameric mutant enzymes fully saturated with heme had the same or higher specific activities than wild type CBS. Thermal stability measurements demonstrated that the purified mutants are equally or more thermostable than wild type CBS. The response to S-adenosyl-L-methionine stimulation or thermal activation varied. The lack of response of R125Q and E176K to both stimuli indicated that their specific conformations were unable to reach the activated state. Increased levels of molecular chaperones in crude extracts, particularly DnaJ, indicated a rather indirect effect of the chemical chaperones on folding of CBS mutants. In conclusion, the chemical chaperones present in the expression medium were able to fully restore the activity of eight CBS mutants by improving their protein folding. This finding could have direct implications for the development of a therapeutical approach to pyridoxine unresponsive homocystinuria.

  2. Effects of 2,4-D and 4-CPA on yield and quality of the tomato, Lycopersicon esculentum Miller (Solanaceae)

    DEFF Research Database (Denmark)

    Gemici, Meliha; Türkyilmaz, B.; Tan, Kit

    2007-01-01

    economy. Our tests confirm that application of concentrations in excess of the recommended dosage produces deformed and inferior fruit, increases fruit number and incidence of parthenocarpy. The use of growth regulators led to an increase in the levels of the internal plant hormone indol-3 acetic acid......Synthetic plant growth substances augment plant growth when applied at specific concentrations; they are also reported as without causing significant increases in the amount of internal plant hormones. Exceeding recommended dosages, however, affects yield and quality adversely. An experiment......, to test the effects of high concentrations of two growth regulators 2,4- dichlorophenoxy acetic acid (2,4-D) and 4-chlorophenoxy acetic acid (4-CPA) on fruit development in the tomato plant, was carried out. This plant is grown on a large scale in Turkey, contributing to and supporting the national...

  3. Study on the Parameters of Specific Immune of BALB/c-Mutant Hairless Mice%BALB/c突变无毛小鼠免疫学特性指标的研究

    Institute of Scientific and Technical Information of China (English)

    王冬平; 李善如; 栾蓉晖; 李桂军

    2003-01-01

    The mutant gene of BALB/c-mutant hairless mice was assigned to chromosome 11, Genetic markers which have been tested suggested that the mutation is a new genetic locus that affected the skin and hair structure of the mouse The mutation was named uncoved, with the symbol Uncv . Uncv has been accepted by International Naming Committee of Mice, and the gene information of Uncv has been receipted by the mice's genebank . The skin is the biggest organ of the body , and is also the main physiological barrier between vivo and vitro . The skin is albe to produce and keep the part immunoresponses , inflammation . Many immunoresponses are related to the skin . The dissecting and breeding of the mutant mice show that their immune organs are normal and they can adopt to the general conditions. Objective To further study the mutant gene' s immune function of the BALB/c-mutant hairless mice . Method We tested the parameters of the immune system about two-day-old、two-month-old hairless mice and mutant sparse coat mice . After testing the parameters of CD4 + 、 CD3 + 、 CD8 + 、 CD19 + through flow cytometry and testing the IgG by ELISA. Results we found that CD19+ 、CD4+/CD8+ of male are higher than female about two-week-old mutant mice with sparse coat , but CD8+ of female is higher than the male, CD4+/CD8+ of male F2 sparse coat mice is higher than the female, CD19+ 、IgG of male mutant hairless mice is higher than the female . There were no significant differences among the male and the female about the two-month-old mutant hairless mice and the mutant sparse coat mice, CD4 + of male F2 two-month-old mutant hairless mice is higher than the female . Otherwise , we also found that the celluar immunity and humoral immunity of both two-week-old and two-month-old hairless mice are lower than the mutant sparse coat mice; only the celluar immunity of F2 mutant hairless mice is lower than the mutant sparse coat mice , but the humoral immunity is higher . The experiment suggest

  4. p21-ras effector domain mutants constructed by "cassette" mutagenesis

    DEFF Research Database (Denmark)

    Stone, J C; Vass, W C; Willumsen, B M;

    1988-01-01

    A series of mutations encoding single-amino-acid substitutions within the v-rasH effector domain were constructed, and the ability of the mutants to induce focal transformation of NIH 3T3 cells was studied. The mutations, which spanned codons 32 to 40, were made by a "cassette" mutagenesis...... technique that involved replacing this portion of the v-rasH effector domain with a linker carrying two BspMI sites in opposite orientations. Since BspMI cleaves outside its recognition sequence, BspMI digestion of the plasmid completely removed the linker, creating a double-stranded gap whose missing ras...... sequences were reconstructed as an oligonucleotide cassette. Based upon the ability of the mutants to induce focal transformation of NIH 3T3 cells, a range of phenotypes from virtually full activity to none (null mutants) was seen. Three classes of codons were present in this segment: one which could...

  5. How Life History Can Sway the Fixation Probability of Mutants.

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-07-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected.

  6. Antisense downregulation of mutant huntingtin in a cell model

    DEFF Research Database (Denmark)

    Hasholt, L.; Abell, K.; Norremolle, A.

    2003-01-01

    or by addition to the culture medium. Results Expression of the fusion protein containing the mutant huntingtin fragment resulted in diffuse green fluorescence in the cytoplasm and formation of aggregates in some of the NT2 cells and NT2-N neurons. We obtained antisense sequence-specific inhibition of expression...... of specific neurons in the brains of HD patients correlate with the expression of mutant huntingtin. Therefore, we have studied whether mutant huntingtin expression can be downregulated by antisense technique. Methods NT2 precursor cells and differentiated postmitotic NT2-N neurons, respectively, were...... transfected with plasmid constructs containing exon 1 of the HD gene with expanded CAG repeats in frame with the reporter protein EGFP. The transfected cell cultures were treated with a phosphorothioated antisense oligonucleotide (PS-ASHD/20+) or a control oligonucleotide either by cotransfection...

  7. Human mutant huntingtin disrupts vocal learning in transgenic songbirds.

    Science.gov (United States)

    Liu, Wan-Chun; Kohn, Jessica; Szwed, Sarah K; Pariser, Eben; Sepe, Sharon; Haripal, Bhagwattie; Oshimori, Naoki; Marsala, Martin; Miyanohara, Atsushi; Lee, Ramee

    2015-11-01

    Speech and vocal impairments characterize many neurological disorders. However, the neurogenetic mechanisms of these disorders are not well understood, and current animal models do not have the necessary circuitry to recapitulate vocal learning deficits. We developed germline transgenic songbirds, zebra finches (Taneiopygia guttata) expressing human mutant huntingtin (mHTT), a protein responsible for the progressive deterioration of motor and cognitive function in Huntington's disease (HD). Although generally healthy, the mutant songbirds had severe vocal disorders, including poor vocal imitation, stuttering, and progressive syntax and syllable degradation. Their song abnormalities were associated with HD-related neuropathology and dysfunction of the cortical-basal ganglia (CBG) song circuit. These transgenics are, to the best of our knowledge, the first experimentally created, functional mutant songbirds. Their progressive and quantifiable vocal disorder, combined with circuit dysfunction in the CBG song system, offers a model for genetic manipulation and the development of therapeutic strategies for CBG-related vocal and motor disorders.

  8. The use of mutants to probe models of gravitropism.

    Science.gov (United States)

    Firn, R D; Wagstaff, C; Digby, J

    2000-08-01

    It has been widely believed for more than 70 years that auxin plays a central role in the induction of differential growth which causes gravitropic curvature. However, this long-standing consensus about a role for auxin in gravitropism has only been achieved by allowing several mutually exclusive models to coexist. Furthermore, because there is no detailed model which is unchallenged by evidence, consensus is now centred on ill-defined models which have a low predictive value, hence are harder to challenge experimentally. An increasing number of mutants with abnormal gravitropic behaviour are becoming available. Such mutants should be very helpful in challenging existing models of gravitropism and in providing new evidence on which to build improved, more precise models. However, to date, most studies of mutants with abnormal gravitropism have been guided, experimentally and conceptually, by the old inadequate and vague models. Consequently, the full potential of modern molecular analysis in aiding our understanding of gravitropism has yet to be realized.

  9. Candida albicans mutant construction and characterization of selected virulence determinants.

    Science.gov (United States)

    Motaung, T E; Albertyn, J; Pohl, C H; Köhler, Gerwald

    2015-08-01

    Candida albicans is a diploid, polymorphic yeast, associated with humans, where it mostly causes no harm. However, under certain conditions it can cause infections ranging from superficial to life threatening. This ability to become pathogenic is often linked to the immune status of the host as well as the expression of certain virulence factors by the yeast. Due to the importance of C. albicans as a pathogen, determination of the molecular mechanisms that allow this yeast to cause disease is important. These studies rely on the ability of researchers to create deletion mutants of specific genes in order to study their function. This article provides a critical review of the important techniques used to create deletion mutants in C. albicans and highlights how these deletion mutants can be used to determine the role of genes in the expression of virulence factors in vitro.

  10. How does the NPM1 mutant induce leukemia?

    Directory of Open Access Journals (Sweden)

    Paolo Sportoletti

    2011-06-01

    Full Text Available NPM1 is the most frequently mutated gene in AML and the role of the NPM1 mutant in acute myeloid leukemia along with its leukemogenic potential are still under investigation. NPM1 genetic alterations can contribute to leukemogenesis through the direct oncogenic effect of the mutant protein and the concomitant loss of one functional allele. Npm1 loss determines tumor development in the mouse while in human NPM1 maps in a chromosomal region frequently loss in myelodysplastic syndrome (MDS. The NPM1 mutant cytoplasmic delocalization in leukemic blasts alters multiple cellular pathways through either loss or gain of function effects on different protein partners. Here we discuss the most relevant studies on the role of the NPM1 molecule in hematological malignancies and both in vitro and in vivo studies that are trying to elucidate the way by which the NPM1 mutation induces leukemia.

  11. Antisense downregulation of mutant huntingtin in a cell model

    DEFF Research Database (Denmark)

    Hasholt, L.; Abell, K.; Norremolle, A.;

    2003-01-01

    of specific neurons in the brains of HD patients correlate with the expression of mutant huntingtin. Therefore, we have studied whether mutant huntingtin expression can be downregulated by antisense technique. Methods NT2 precursor cells and differentiated postmitotic NT2-N neurons, respectively, were...... transfected with plasmid constructs containing exon 1 of the HD gene with expanded CAG repeats in frame with the reporter protein EGFP. The transfected cell cultures were treated with a phosphorothioated antisense oligonucleotide (PS-ASHD/20+) or a control oligonucleotide either by cotransfection...... or by addition to the culture medium. Results Expression of the fusion protein containing the mutant huntingtin fragment resulted in diffuse green fluorescence in the cytoplasm and formation of aggregates in some of the NT2 cells and NT2-N neurons. We obtained antisense sequence-specific inhibition of expression...

  12. Different blue-light requirement for the accumulation of transcripts from nuclear genes for thylakoid proteins in Nicotiana tabacum and Lycopersicon esculentum.

    Science.gov (United States)

    Palomares, R; Herrmann, R G; Oelmüller, R

    1991-11-01

    We have isolated recombinant lambda gt11 phages which carry cDNA clones for the major light-harvesting chlorophyll a/b-binding proteins of photosystem I (LHCPI) and II (LHCPII), subunit II of photosystem I, a chlorophyll a/b-binding protein of photosystem II (CP24), the Rieske iron-sulphur protein of the cytochrome b6/f complex, and the 33, 23 and 16 kDa proteins of the water-oxidizing complex of photosystem II from Nicotiana tabacum. The nucleotide sequences of cDNA clones encoding the precursors for LHCPI and the FeS protein are presented. If tobacco or tomato seedlings, or seedlings of a phytochrome-deficient aurea mutant of tomato which lacks more than 95% of the phytochrome of the isogenic wild type, are kept in blue light, the transcript level of each of these genes is higher than in seedlings grown in red light suggesting the involvement of a blue-UVA-light photoreceptor. In the case of LHCPI, a 1 min blue-light pulse applied to red-light-grown seedlings is sufficient to increase the transcript levels to those present in blue-light-grown seedlings, whereas almost no increase is observed for transcripts encoding the FeS and 33 kDa proteins. If dark-grown tomato seedlings receive a single far-red-light pulse, significant stimulation is detected for LHCPI transcripts, whereas transcripts encoding the FeS and 33 kDa proteins are not stimulated. It is concluded that the lower light requirement for the increase in the LHCPI transcript level is not specific for one of the light-dependent signal transduction chains.

  13. Nanoformulated cell-penetrating survivin mutant and its dual actions

    Directory of Open Access Journals (Sweden)

    Sriramoju B

    2014-07-01

    Full Text Available Bhasker Sriramoju, Rupinder K Kanwar, Jagat R Kanwar Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (NLIMBR, School of Medicine, Faculty of Health, Deakin University, Geelong, Australia Abstract: In this study, we investigated the differential actions of a dominant-negative survivin mutant (SurR9-C84A against cancerous SK-N-SH neuroblastoma cell lines and differentiated SK-N-SH neurons. In both the cases, the mutant protein displayed dual actions, where its effects were cytotoxic toward cancerous cells and proliferative toward the differentiated neurons. This can be explained by the fact that tumorous (undifferentiated SK-N-SH cells have a high endogenous survivin pool and upon treatment with mutant SuR9-C84A causes forceful survivin expression. These events significantly lowered the microtubule dynamics and stability, eventually leading to apoptosis. In the case of differentiated SK-N-SH neurons that express negligible levels of wild-type survivin, the mutant indistinguishably behaved in a wild-type fashion. It also favored cell-cycle progression, forming the chromosome-passenger complex, and stabilized the microtubule-organizing center. Therefore, mutant SurR9-C84A represents a novel therapeutic with its dual actions (cytotoxic toward tumor cells and protective and proliferative toward neuronal cells, and hence finds potential applications against a variety of neurological disorders. In this study, we also developed a novel poly(lactic-co-glycolic acid nanoparticulate formulation to surmount the hurdles associated with the delivery of SurR9-C84A, thus enhancing its effective therapeutic outcome. Keywords: survivin mutant, neurological disorders, protein therapeutics, inhibitor of apoptosis protein family, poly(lactic-co-glycolic acid

  14. Isolation of a Defective Prion Mutant from Natural Scrapie

    Science.gov (United States)

    Migliore, Sergio; Cosseddu, Gian Mario; Pirisinu, Laura; Riccardi, Geraldina; Nonno, Romolo

    2016-01-01

    It is widely known that prion strains can mutate in response to modification of the replication environment and we have recently reported that prion mutations can occur in vitro during amplification of vole-adapted prions by Protein Misfolding Cyclic Amplification on bank vole substrate (bvPMCA). Here we exploited the high efficiency of prion replication by bvPMCA to study the in vitro propagation of natural scrapie isolates. Although in vitro vole-adapted PrPSc conformers were usually similar to the sheep counterpart, we repeatedly isolated a PrPSc mutant exclusively when starting from extremely diluted seeds of a single sheep isolate. The mutant and faithful PrPSc conformers showed to be efficiently autocatalytic in vitro and were characterized by different PrP protease resistant cores, spanning aa ∼155–231 and ∼80–231 respectively, and by different conformational stabilities. The two conformers could thus be seen as different bona fide PrPSc types, putatively accounting for prion populations with different biological properties. Indeed, once inoculated in bank vole the faithful conformer was competent for in vivo replication while the mutant was unable to infect voles, de facto behaving like a defective prion mutant. Overall, our findings confirm that prions can adapt and evolve in the new replication environments and that the starting population size can affect their evolutionary landscape, at least in vitro. Furthermore, we report the first example of “authentic” defective prion mutant, composed of brain-derived PrPC and originating from a natural scrapie isolate. Our results clearly indicate that the defective mutant lacks of some structural characteristics, that presumably involve the central region ∼90–155, critical for infectivity but not for in vitro replication. Finally, we propose a molecular mechanism able to account for the discordant in vitro and in vivo behavior, suggesting possible new paths for investigating the molecular bases of

  15. Callus cultures of tomato mutants: I. Nutritional requirements.

    Science.gov (United States)

    Ulrich, J M; Mackinney, G

    1969-01-01

    Callus from hypocotyl, stem, and fruit tissue of tomato mutants was grown on a complex pea extract medium. The genotypes responded differently to the levels of nutrients and stimulators or inhibitors in the medium. Hypocotyl callus of yellow (r) tomato required K(2) SO(4) for quick establishment and continued steady growth for several months; callus of this mutant could also grow with 0.5 % dimethyl sulfoxide in the medium, although growth was less than the control. The red ghost (r(+) gh) mutant is sensitive to a toxic component in the pea extract, and makes its best growth with the standard minerals and vitamins, but in 1/2 concentration pea extract plus 5 % coconut water. Tangerine (t), red lutescent stem (r(+) l(2) ), and r(+) gh are mutants which respond differently to thiourea: t grows about the same at all concentrations, r(+) gh grows best at low thiourea, and r(+) l(2) grows best at the specific level of 20 mg/l thiourea. The recent active t or r(+) l(1) and r(+) l(2) isolates require supplementary auxin to which the older, slow-growing isolates do not respond. However, there is variation in growth response of different isolates of the same mutant. The several red (r(+) ) cultures are similar in their slow growth, but somewhat different in responses to specific nutrients. The recent (+) isolate is one of the most active cultures, in comparison to the slow growth of t callus isolated in 1964. It is therefore concluded that growth is affected both by the specific requirements of the mutant and by the age and vigor of isolates.

  16. Modeling of gap gene expression in Drosophila Kruppel mutants.

    Directory of Open Access Journals (Sweden)

    Konstantin Kozlov

    Full Text Available The segmentation gene network in Drosophila embryo solves the fundamental problem of embryonic patterning: how to establish a periodic pattern of gene expression, which determines both the positions and the identities of body segments. The gap gene network constitutes the first zygotic regulatory tier in this process. Here we have applied the systems-level approach to investigate the regulatory effect of gap gene Kruppel (Kr on segmentation gene expression. We acquired a large dataset on the expression of gap genes in Kr null mutants and demonstrated that the expression levels of these genes are significantly reduced in the second half of cycle 14A. To explain this novel biological result we applied the gene circuit method which extracts regulatory information from spatial gene expression data. Previous attempts to use this formalism to correctly and quantitatively reproduce gap gene expression in mutants for a trunk gap gene failed, therefore here we constructed a revised model and showed that it correctly reproduces the expression patterns of gap genes in Kr null mutants. We found that the remarkable alteration of gap gene expression patterns in Kr mutants can be explained by the dynamic decrease of activating effect of Cad on a target gene and exclusion of Kr gene from the complex network of gap gene interactions, that makes it possible for other interactions, in particular, between hb and gt, to come into effect. The successful modeling of the quantitative aspects of gap gene expression in mutant for the trunk gap gene Kr is a significant achievement of this work. This result also clearly indicates that the oversimplified representation of transcriptional regulation in the previous models is one of the reasons for unsuccessful attempts of mutant simulations.

  17. Regeneração de plantas híbridas entre Lycopersicon esculentum e L. peruvianum a partir de calos com dois anos de cultura in vitro Regeneration of Lycopersicon esculentum X L. peruvianum hybrid plants from two year old callus culture

    Directory of Open Access Journals (Sweden)

    Walter José Siqueira

    1988-01-01

    Full Text Available Calos obtidos da cultura in vitro de embrião imaturo do cruzamento interespecífico L. esculentum x L. peruvianum, praticamente perderam a capacidade morfogenética, após dois anos de subcultura. Na tentativa de recuperação do processo de organogênese desses calos, realizaram-se dois experimentos, utilizando-se os fitorreguladores ácido indolacético (IAA e 6-benziladenina (6-BA, cujas concentrações foram combinadas em dialélicos de 5 x 5 e 3 x 3. A composição de sais minerais e vitaminas baseou-se no meio de Murashige e Skoog, adicionando-se sacarose a 3% e ágar a 0,8%, e ajustando-se o pH final dos meios de cultura para 5,5. As condições para o dialélico 5 x 5 foram fotoperíodo de 16 horas de luz a 600 lux e temperatura de 25 ± 3°C. No dialélico 3 x 3, os tratamentos foram mantidos em câmara de crescimento a 2.000 lux, sob a mesma variação de temperatura e fotoperíodo. Em cada frasco, inoculou-se um calo com cerca de 1 cm³, totalizando quinze repetições. Avaliaram-se o desenvolvimento de calos, atribuindo-se uma escala de notas de 1 a 5, e a presença de plantas (organogênese após 30 dias de cultura. Observou-se o número total de plantas por tratamento, bem como o desenvolvimento das plantas em centímetro. No dialélico 5 x 5, a organogênese foi apenas incipiente em três tratamentos, porém as melhores combinações para o desenvolvimento dos calos foram de 0,5, 2,5 e 5,0µM de IAA com 2,5µM de 6-BA. No dialélico 3 x 3, houve a indução de plantas em sete tratamentos, sendo mais eficientes 25 e 50µM de 6-BA, sem auxina. O tratamento de 0,5 e 10,0µM de IAA e 6-BA, respectivamente, permitiu simultaneamente o crescimento de calos e a regeneração de plantas. Nota-se a influência das condições ambientais de manutenção das culturas, principalmente da intensidade de luz.Callus from Lycopersicon esculentum x L. peruvianum interespecific hybrids cultured in vitro lost their morphogenetic abilities after two

  18. HBV genotypes prevalence, precore and basal core mutants in Morocco.

    Science.gov (United States)

    Baha, Warda; Ennaji, My Mustapha; Lazar, Fatiha; Melloul, Marouane; El Fahime, Elmostafa; El Malki, Abdelouahad; Bennani, Abdelouaheb

    2012-08-01

    The study of hepatitis B virus (HBV) genomic heterogeneity has become a major issue in investigations aimed at understanding the relationship between HBV mutants and the wide spectrum of clinical and pathological conditions associated with HBV infection. The objective of the current study was to find out the pattern of HBV genotypes circulating in Morocco and to investigate the precore (PC) and basal core promoter (BCP) mutants' status in Moroccan chronic hepatitis B patients. Viral genotypes were determined in 221 chronic carriers using INNO-LiPA HBV assay and hemi-nested PCR. Phylogenetic analysis was performed in 70 samples, and multiplex PCR method was used to confirm some genotyping results. PC and CP mutants were determined using Inno-Lipa. All isolates were successfully genotyped. The genotype distribution was D in 90.45% of cases, A (5.9%), E (1 case), and mixed genotypes (5 A/D and 2 D/F) in 3.17% patients. HBV carried in the HBV/D samples could be assigned to D7 (63.3%), D1 (32.7%) and 2% of strains to each D4 and D5, all HBV/A belonged to A2 subgenotype and HBV/E strain could not be sub-genotyped. In 70 studied strains, HBV mutants were detected in 88.6% of cases; PC mutants were detected in (40%) of patients and 21.5% present a mixture of wild type and G1896A mutation. BCP mutants were observed in 65.7% of cases, 22.9% were found to have the T1762/1764A double mutation, 18.6% had A1762/1764T mutation and 22.9% of patients showed the A1762T/G1764A double mutation with either A1762T/G1764T mutation. Co-infection by PC and BCP mutants was detected in 52.9% of cases. Movement from place to place most likely shapes the observed genotype distribution and consequent prevalence of genotypes other than A2 or D7 in this population. High circulation of PC and BCP mutants is common in chronic hepatitis B infection in Morocco.

  19. Forward and reverse genetics: The LORE1 retrotransposon insertion mutants

    DEFF Research Database (Denmark)

    Fukai, Eigo; Malolepszy, Anna; Sandal, Niels Nørgaard

    2014-01-01

    The endogenous Lotus retrotransposon 1 (LORE1) transposes in the germ line of Lotus japonicus plants that carry an active element. This feature of LORE1 has been exploited for generation of a large non-transgenic insertion mutant population, where insertions have been annotated using next......-generation sequencing approaches. The LORE1 mutant lines are freely available and can be ordered online. Endogenous retrotransposons are also active in many other plant species. Based on the methods developed for LORE1 mutagenesis, it should be simple to establish similar systems in other species, once an appropriate...

  20. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    Science.gov (United States)

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  1. Repair effects of laser on mutants of filamentous fungi

    Science.gov (United States)

    Zhao, Yansheng; Xiao, Canpeng; Qian, Hailun; Su, Baoliang; Hu, Yujun; Deng, Jianhui

    1999-09-01

    The paper reports that penicillin-producing strains and lovastatin-producing strains were irradiated by UV and subsequently by laser (632.8 nm), and the reparation rate reached 297% and 264%. High-yield mutant was selected with improved potency of 24.5% and 30%, respectively; Gibberellin producing strains were treated with chemical agent LiCl, and then irradiated with 632.8 nm laser. One mutant with 189.6% increased potency was obtained. The experimental results indicated that using laser irradiation after UV or chemical agent mutation was a new useful method in breeding high-yield strains.

  2. Characterization of Sugar Insensitive (sis) Mutants of Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Susan I.

    2009-06-08

    Despite the fact that soluble sugar levels have been postulated to play an important role in the control of a wide variety of plant metabolic and developmental pathways, the mechanisms by which plants respond to soluble sugar levels remain poorly understood. Plant responses to soluble sugar levels are also important in bioenergy production, as plant sugar responses are believed to help regulate both carbon fixation and carbon partitioning. For example, accumulation of soluble sugars, such as sucrose and glucose, in source tissues leads to feedback inhibition of photosynthesis, thereby decreasing rates of carbon fixation. Soluble sugar levels can also affect sink strengths, affecting the rates of accumulation of carbon-based compounds into both particular molecular forms (e.g. carbohydrates versus lipids versus proteins) and particular plant organs and tissues. Mutants of Arabidopsis that are defective in the ability to respond to soluble sugar levels were isolated and used as tools to identify some of the factors involved in plant sugar response. These sugar insensitive (sis) mutants were isolated by screening mutagenized seeds for those that were able to germinate and develop relatively normal shoot systems on media containing 0.3 M glucose or 0.3 M sucrose. At these sugar concentrations, wild-type Arabidopsis germinate and produce substantial root systems, but show little to no shoot development. Twenty-eight sis mutants were isolated during the course of four independent mutant screens. Based on a preliminary characterization of all of these mutants, sis3 and sis6 were chosen for further study. Both of these mutations appear to lie in previously uncharacterized loci. Unlike many other sugar-response mutants, sis3 mutants exhibit a wild-type or near wild-type response in all phytohormone-response assays conducted to date. The sis6-1 mutation is unusual in that it appears to be due to overexpression of a gene, rather than representing a loss of function mutation

  3. Localization of transposon insertions in pathogenicity mutants of Erwinia amylovora and their biochemical characterization.

    Science.gov (United States)

    Bellemann, P; Geider, K

    1992-05-01

    Transposon Tn5, on a mobilizable ColE1 plasmid, on a Ti plasmid derepressed for bacterial transfer, and on the bacteriophage fd genome, was used to construct pathogenicity mutants of the fire blight pathogen Erwinia amylovora. Eleven nonpathogenic mutants were isolated from 1600 independent mutants screened. These mutants were divided into three types: auxotrophs, exopolysaccharide (EPS)-deficient mutants and a mutant of the dsp phenotype. According to their insertion sites the Tn5 mutants were mapped into several classes. Some of the mutants could be complemented with cosmid clones from a genomic library of the parent strain for EPS production on minimal agar. EPS-deficient mutants and the dsp mutant could complement each other to produce virulence symptoms on pear slices.

  4. Abscisic acid-deficient sit tomato mutant responses to cadmium-induced stress.

    Science.gov (United States)

    Pompeu, Georgia B; Vilhena, Milca B; Gratão, Priscila L; Carvalho, Rogério F; Rossi, Mônica L; Martinelli, Adriana P; Azevedo, Ricardo A

    2017-03-01

    There is a very effective cross-talk between signals triggered by reactive oxygen species and hormonal responses in plants, activating proteins/enzymes likely to be involved in stress tolerance. Abscisic acid (ABA) is known as a stress hormone that takes part in the integration of signals. This work aimed to characterize the biochemical response and ultrastructural changes induced by cadmium (Cd) in the Micro-Tom (MT) sitiens ABA-deficient mutant (sit) and its wild-type (MT) counterpart. MT and sit plants were grown over a 96-h period in the presence of Cd (0, 10, and 100 μM CdCl2). The overall results indicated increases in lipid peroxidation, hydrogen peroxide content and in the activities of the key antioxidant enzymes such as catalase, glutathione reductase, and ascorbate peroxidase in both genotypes. On the other hand, no alteration was observed in chlorophyll content, while the activity of another antioxidant enzyme, superoxide dismutase, remained constant or even decreased in the presence of Cd. Roots and shoots of the sit mutant and MT were analyzed by light and transmission electron microscopy in order to characterize the structural changes caused by the exposure to this metal. Cd caused a decrease in intercellular spaces in shoots and a decrease in cell size in roots of both genotypes. In leaves, Cd affected organelle shape and internal organization of the thylakoid membranes, whereas noticeable increase in the number of mitochondria and vacuoles in MT and sit roots were observed. These results add new information that should help unravel the relative importance of ABA in regulating the cell responses to stressful conditions induced by Cd apart from providing the first characterization of this mutant to oxidative stress.

  5. Dynamic features of carboxy cytoglobin distal mutants investigated by molecular dynamics simulations.

    Science.gov (United States)

    Zhao, Cong; Du, Weihong

    2016-04-01

    Cytoglobin (Cgb) is a member of hemoprotein family with roles in NO metabolism, fibrosis, and tumourigenesis. Similar to other hemoproteins, Cgb structure and functions are markedly influenced by distal key residues. The sixth ligand His(81) (E7) is crucial to exogenous ligand binding, heme pocket conformation, and physiological roles of this protein. However, the effects of other key residues on heme pocket and protein biological functions are not well known. In this work, a molecular dynamics (MD) simulation study of two single mutants in CO-ligated Cgb (L46FCgbCO and L46VCgbCO) and two double mutants (L46FH81QCgbCO and L46VH81QCgbCO) was conducted to explore the effects of the key distal residues Leu(46)(B10) and His(81)(E7) on Cgb structure and functions. Results indicated that the distal mutation of B10 and E7 affected CgbCO dynamic properties on loop region fluctuation, internal cavity rearrangement, and heme motion. The distal conformation change was reflected by the distal key residues Gln(62) (CD3) and Arg(84)(E10). The hydrogen bond between heme propionates with CD3 or E10 residues were evidently influenced by B10/E7 mutation. Furthermore, heme pocket rearrangement was also observed based on the distal pocket volume and occurrence rate of inner cavities. The mutual effects of B10 and E7 residues on protein conformational rearrangement and other dynamic features were expressed in current MD studies of CgbCO and its distal mutants, suggesting their crucial role in heme pocket stabilization, ligand binding, and Cgb biological functions. The mutation of distal B10 and E7 residues affects the dynamic features of carboxy cytoglobin.

  6. High-throughput identification of protein mutant stability computed from a double mutant fitness landscape.

    Science.gov (United States)

    Wu, Nicholas C; Olson, C Anders; Sun, Ren

    2016-02-01

    The effect of a mutation on protein stability is traditionally measured by genetic construction, expression, purification, and physical analysis using low-throughput methods. This process is tedious and limits the number of mutants able to be examined in a single study. In contrast, functional fitness effects can be measured in a high-throughput manner by various deep mutational scanning tools. Using protein GB 1, we have recently demonstrated the feasibility of estimating the mutational stability effect ( ΔΔG) of single-substitution based on the functional fitness profile of all double-substitutions. The principle is to identify genetic backgrounds that have an exhausted stability margin. The functional effect of an additional substitution on these genetic backgrounds can then be used to compute the mutational ΔΔG based on the biophysical relationship between functional fitness and thermodynamic stability. However, to identify such genetic backgrounds, the approach described in our previous study required a benchmark dataset, which is a set of known mutational ΔΔG. In this study, a benchmark-independent approach is developed. The genetic backgrounds of interest are identified using k-means clustering with the integration of structural information. We further demonstrated that a reasonable approximation of ΔΔG can also be obtained without taking structural information into account. In summary, this study describes a novel method for computing ΔΔG from double-substitution functional fitness profiles alone, without relying on any known mutational ΔΔG as a benchmark.

  7. Clostridium acetobutylicum Mutants That Produce Butyraldehyde and Altered Quantities of Solvents

    OpenAIRE

    Rogers, Palmer; Palosaari, Neil

    1987-01-01

    Spontaneous mutants of Clostridium acetobutylicum NRRL B643 that were resistant to allyl alcohol (AA) were selected and characterized. These mutants contained 10- to 100-fold reduced activities of butanol and ethanol alcohol dehydrogenase. The AA mutants formed two groups and produced no ethanol. Type 1 AA mutants produced significant amounts of a new solvent, butyraldehyde, and contained normal levels of the coenzyme A-dependent butyraldehyde dehydrogenase (BAD). Type 2 AA mutants produced n...

  8. Transfection of the cloned human excision repair gene ERCC-1 to UV-sensitive CHO mutants only corrects the repair defect in complementation group 2 mutants.

    NARCIS (Netherlands)

    M. van Duin (Mark); J.H. Janssen; J. de Wit (Jan); J.H.J. Hoeijmakers (Jan); L.H. Thompson; D. Bootsma (Dirk); A. Westerveld (Andries)

    1988-01-01

    textabstractThe human DNA-excision repair gene ERCC-1 is cloned by its ability to correct the excision-repair defect of the ultraviolet light- and mitomycin-C-sensitive CHO mutant cell line 43-3B. This mutant is assigned to complementation group 2 of the excision-repair-deficient CHO mutants. In ord

  9. Capítulo XI: análisis de la heterosis y de la habilidad combinatoria entre diferentes cultivares de tomate, Lycopersicon esculentum, Mill. a partir de un cruzamiento dialélico

    Directory of Open Access Journals (Sweden)

    Sanint P. Rodrigo

    1994-12-01

    Full Text Available

    An analysis of heterosis and combining ability of traits related with per plant production was carried out using a diallel crossing between different tomato cultivars, Lycopersicon esculentum Mill (six parents and 15 F, hybrids from all possible crossing in one direction, according to the methodology proposed by Griffing (1956, selecting experimental method 2, and model 1. In the genetic variation of all traits related to per plant production, the general combining ability (addite gene action and specific combining abilyty (non-aditive gene action effects participate jointly and in high1y significant manner. Hybrids Motelle x Angela I 5200, Motelle x Zarnbao y Licapal 21 x Zarnbao, exhibited high s.c.a. effects for the trait per plant production. Former effects related to high heterosis make these hybrids promising for later marketing.

    Se analizó la heterosis y la habilidad combinatoria para el carácter producción por planta y sus componentes, a partir de un cruzamiento dialélico (6 progenitores, 15 híbridos F1 sin incluir los recíprocos utilizando el método experimental 2, modelo 1 propuesto por Griffing (1956. Se encontraron diferencias altamente significativas para los efectos de h.c.g. y de h.c.e. para todos los caracteres estudiados. Los híbridos Motelle x Angela I 5100, Motelle x Zambao y Licapal-21 x Zambao presentaron altos efectos de h.c.e. para el carácter producción por planta. Los anteriores efectos asociados con altas heteroheltiosis hacen que estos híbridos sean promisorios para posterior comercialización.

  10. Análisis de la heterosis y de la habilidad combinatoria entre diferentes cultivares de tomate, Lycopersicon esculentum Mill. a partir de un cruzamiento dialélico

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    1989-06-01

    Full Text Available Se realizó el análisis de la heterosis y de la habilidad combinatoria entre 21 cultivares de tomate, para el carácter producción por planta y sus componentes a partir de un cruzamiento dialélico (6 progenitores, 15 híbridos F1, sin incluir los recíprocos: utilizando el método experimental 2, modelo I propuesto por Griffing (1956. Se encontraron diferencias altamente significativas para los efectos de hcg y de hce para todos los caracteres a excepción del carácter producción de frutos de primera (frutos de más de 180 g. Los híbridos Motelle x Ángela I 5100, Motelle x Zambao y Licapal 21 x Zambao presentaron altos efectos de h c e para el carácter producción por planta. Los anteriores efectos asociados con altas heterobeltiosis hacen que estos híbridos sean promisorios para una posterior comercialización.An analysis of heterosis and combining ability of traits related with per plant production was carried out using a diallele crossing between different tomate cultivars, Lycopersicon esculentum Mill (six parent and 15 F1 hybrids from as possible crossing in one direction, according to the methodology proposed by Griffing (1956, selecting experimental method 2, and model 1. In the genetic variation of all traits related to per plant production, except in first class fruit trait, the general combining ability (gen non addite action effects participate jointly and in highly significant manner. Hybrids Motelle x Angela I 5100, Motelle x Zambao y Licapal21 x Zambao, exhibited high s c a effects for the trait per plant production. Former effects related to high heterobeltyosis make these hybrids promising for later marketing.

  11. A bench-scale, cost effective and simple method to elicit Lycopersicon esculentum cv. PKM1 (tomato) plants against Cucumber mosaic virus attack using ozone-mediated inactivated Cucumber mosaic virus inoculum.

    Science.gov (United States)

    Sudhakar, N; Nagendra-Prasad, D; Mohan, N; Murugesan, K

    2007-12-01

    Studies were undertaken to evaluate ozone for inactivation of Cucumber mosaic virus present in the inoculum and to stimulate Lycopersicon esculentum cv. PKM1 (tomato) plants against Cucumber mosaic virus infection by using the inactivated Cucumber mosaic virus inoculum. Application of a T(4) (0.4mg/l) concentration of ozone to the inoculum containing Cucumber mosaic virus resulted in complete inactivation of the virus. The inactivated viral inoculum was mixed with a penetrator (delivery agent), referred to as T(4) preparation, and it was evaluated for the development of systemic acquired resistance in the tomato plants. Application of a T(4) preparation 5 days before inoculation with the Cucumber mosaic virus protected tomato plants from the effects of Cucumber mosaic virus. Among the components of the inactivated virus tested, coat protein subunits and aggregates were responsible for the acquired resistance in tomato plants. In field trials, the results of enzyme-linked immunosorbent assay revealed that, Cucumber mosaic virus accumulation was significantly less for all the test plants (16%) sprayed with the T(4) preparation than untreated control plants (89.5%) at 28 days postinoculation (dpi). A remarkable increase in the activities of the total soluble phenolics (10-fold) and salicylic acid (16-fold) was detected 5 days after the treatment in foliar extracts of test plants relative to untreated control plants. The results showed that treatment of tomato plants with inactivated viral inoculum led to a significant enhancement of protection against Cucumber mosaic virus attack in a manner that mimics a real pathogen and induces systemic acquired resistance.

  12. Study of radiation in fresh tomatoes (lycopersicon esculentum Mill) and in the levels of sauce lycopene; Estudo da radiacao ionizante em tomates in natura (lycopersicum esculentum Mill) e no teor de licopeno do molho

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, Adriana Diaz Toni

    2009-07-01

    The purpose of the present study was to determine the effects of ionizing radiation in tomatoes (Lycopersicon esculentum Mill) and at the same time to evaluate the influence of irradiation on the content of lycopene in a sauce made with these fruits irradiated. For this reason tomatoes were subjected to five treatments: control, T1 (0.25 kGy), T2 (0.5 kGy), T3 (1.0 kGy) and T4 (2.0 kGy) and evaluated at 3, 6, 9, 12, 15 and 20 days after irradiation, for the following analysis: maturity, texture, color, soluble solids, pH, acidity and total mass. Measurements were made of lycopene in fresh tomatoes and sauce by open column chromatography according to the ripening of them. The results showed that only the mass was not significantly different (p> 0.05). Treatments 1 and 2 proved to be effective in delaying the maturation and in the maintenance of firm texture (p <0.05). While T4 caused chemical reactions in the structure of tomato, compelling it to mature earlier because of pectin degradation. The completion of a sauce made from tomatoes irradiated to 0.25 kGy, didn't show a significant difference (p> 0.05) when compared to control. However, it didn't indicate lycopene degradation, as the doses of 1.0 and 2.0 kGy. Thus we can conclude that low doses are effective for maintaining pH, firmness, delayed senescence, mass and, in addition to not degrading the major bioactive compound of tomato, lycopene, suggest a higher bioavailability of this one, depending on the radiation application. (author)

  13. Salmonella Enteritidis flagellar mutants have a colonization benefit in the chicken oviduct.

    Science.gov (United States)

    Kilroy, Sofie; Raspoet, Ruth; Martel, An; Bosseler, Leslie; Appia-Ayme, Corinne; Thompson, Arthur; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

    2017-02-01

    Egg borne Salmonella Enteritidis is still a major cause of human food poisoning. Eggs can become internally contaminated following colonization of the hen's oviduct. In this paper we aimed to analyze the role of flagella of Salmonella Enteritidis in colonization of the hen's oviduct. Using a transposon library screen we showed that mutants lacking functional flagella are significantly more efficient in colonizing the hen's oviduct in vivo. A micro-array analysis proved that transcription of a number of flagellar genes is down-regulated inside chicken oviduct cells. Flagella contain flagellin, a pathogen associated molecular pattern known to bind to Toll-like receptor 5, activating a pro-inflammatory cascade. In vitro tests using primary oviduct cells showed that flagellin is not involved in invasion. Using a ligated loop model, a diminished inflammatory reaction was seen in the oviduct resulting from injection of an aflagellated mutant compared to the wild-type. It is hypothesized that Salmonella Enteritidis downregulates flagellar gene expression in the oviduct and consequently prevents a flagellin-induced inflammatory response, thereby increasing its oviduct colonization efficiency.

  14. Growth stimulation in inflorescences of an Arabidopsis tubulin mutant under microgravity conditions in space.

    Science.gov (United States)

    Hoson, T; Soga, K; Wakabayashi, K; Hashimoto, T; Karahara, I; Yano, S; Tanigaki, F; Shimazu, T; Kasahara, H; Masuda, D; Kamisaka, S

    2014-01-01

    Cortical microtubules are involved in plant resistance to hypergravity, but their roles in resistance to 1 g gravity are still uncertain. To clarify this point, we cultivated an Arabidopsis α-tubulin 6 mutant (tua6) in the Cell Biology Experiment Facility on the Kibo Module of the International Space Station, and analyzed growth and cell wall mechanical properties of inflorescences. Growth of inflorescence stems was stimulated under microgravity conditions, as compared with ground and on-orbit 1 g conditions. The stems were 10-45% longer and their growth rate 15-55% higher under microgravity conditions than those under both 1 g conditions. The degree of growth stimulation tended to be higher in the tua6 mutant than the wild-type Columbia. Under microgravity conditions, the cell wall extensibility in elongating regions of inflorescences was significantly higher than the controls, suggesting that growth stimulation was caused by cell wall modifications. No clear differences were detected in any growth or cell wall property between ground and on-orbit 1 g controls. These results support the hypothesis that cortical microtubules generally play an important role in plant resistance to the gravitational force.

  15. Structures of starches from rice mutants deficient in the starch synthase isozyme SSI or SSIIIa.

    Science.gov (United States)

    Hanashiro, Isao; Higuchi, Toshiyuki; Aihara, Satomi; Nakamura, Yasunori; Fujita, Naoko

    2011-05-09

    Amylose and amylopectin of rice mutants deficient in a starch synthase (SS) isozyme in the endosperm, either SSI (ΔSSI) or SSIIIa (ΔSSIIIa), were structurally altered from those of their parent (cv. Nipponbare, Np). The amylose content was higher in the mutants (Np, 15.5%; ΔSSI, 18.2%; ΔSSIIIa, 23.6%), and the molar ratio of branched amylose and its side chains was increased. The chain-length distribution of the β-amylase limit dextrins of amylopectin showed regularity, which appeared consistent with the generally accepted cluster structure, and the degrees of polymerization found at the intersections were taken as the boundaries of the B-chain fractions. The mole % of the B(1)-B(3) fractions was changed slightly in ΔSSI, which is consistent with the proposed role of SSI in elongating the external part of clusters. In ΔSSIIIa, a significant increase in the B(1) fraction and a decrease in the B(2) and B(3) fractions were observed. The internal chain length of the B(2) and B(3) fractions appeared to be slightly altered, suggesting that the deficiency in SS affected the actions of branching enzyme(s).

  16. Conversion of neurons and glia to external-cell fates in the external sensory organs of Drosophila hamlet mutants by a cousin-cousin cell-type respecification.

    Science.gov (United States)

    Moore, Adrian W; Roegiers, Fabrice; Jan, Lily Y; Jan, Yuh-Nung

    2004-03-15

    The Drosophila external sensory organ forms in a lineage elaborating from a single precursor cell via a stereotypical series of asymmetric divisions. HAMLET transcription factor expression demarcates the lineage branch that generates two internal cell types, the external sensory neuron and thecogen. In HAMLET mutant organs, these internal cells are converted to external cells via an unprecedented cousin-cousin cell-fate respecification event. Conversely, ectopic HAMLET expression in the external cell branch leads to internal cell production. The fate-determining signals NOTCH and PAX2 act at multiple stages of lineage elaboration and HAMLET acts to modulate their activity in a branch-specific manner.

  17. Modeling dynamics of mutants in heterogeneous stem cell niche

    Science.gov (United States)

    Shahriyari, L.; Mahdipour-Shirayeh, A.

    2017-02-01

    Studying the stem cell (SC) niche architecture is a crucial step for investigating the process of oncogenesis and obtaining an effective stem cell therapy for various cancers. Recently, it has been observed that there are two groups of SCs in the SC niche collaborating with each other to maintain tissue homeostasis: border stem cells (BSCs), which are responsible in controlling the number of non-stem cells as well as stem cells, and central stem cells (CeSCs), which regulate the SC niche. Here, we develop a bi-compartmental stochastic model for the SC niche to study the spread of mutants within the niche. The analytic calculations and numeric simulations, which are in perfect agreement, reveal that in order to delay the spread of mutants in the SC niche, a small but non-zero number of SC proliferations must occur in the CeSC compartment. Moreover, the migration of BSCs to CeSCs delays the spread of mutants. Furthermore, the fixation probability of mutants in the SC niche is independent of types of SC division as long as all SCs do not divide fully asymmetrically. Additionally, the progeny of CeSCs have a much higher chance than the progeny of BSCs to take over the entire niche.

  18. Differentially expressed genes in white egg 2 mutant of silkworm ...

    African Journals Online (AJOL)

    use

    2011-12-21

    Dec 21, 2011 ... Our results hopefully shed light on the further study of molecular mechanism of white ... 2002). The mutant white egg 3 (w-3) has white eyes and eggs with ... As of other insects, the color of the eggs of silkworm mainly depends ...

  19. Early ripening mutants induced by colchicine in rice

    Institute of Scientific and Technical Information of China (English)

    CAIGuohai; YANWanchao; CAOXin

    1993-01-01

    In 1981-1983, the frequency and range of the mutants induced by colchicine were investigated in M2 and M3 of two indica-rice cultivars.Seedlings of M2 and M3 were treated with 0.05% colchicine solution at 4-5 leaf stage.

  20. Abnormal grooming activity in Dab1(scm) (scrambler) mutant mice.

    Science.gov (United States)

    Strazielle, C; Lefevre, A; Jacquelin, C; Lalonde, R

    2012-07-15

    Dab1(scm) mutant mice, characterized by cell ectopias and degeneration in cerebellum, hippocampus, and neocortex, were compared to non-ataxic controls for different facets of grooming caused by brief water immersions, as well as some non-grooming behaviors. Dab1(scm) mutants were strongly affected in their quantitative functional parameters, exhibiting higher starting latencies before grooming relative to non-ataxic littermates of the A/A strain, fewer grooming bouts, and grooming components of shorter duration, with an unequal regional distribution targeting almost totally the rostral part (head washing and forelimb licking) of the animal. Only bouts of a single grooming element were preserved. The cephalocaudal order of grooming elements appeared less disorganized, mutant and control mice initiating the grooming with head washing and forelimb licking prior to licking posterior parts. However, mutants differed from controls in that all their bouts were incomplete but uninterrupted, although intergroup difference for percentage of the incorrect transitions was not significant. In contrast to grooming, Dab1(scm) mice ambulated for a longer time. During walking episodes, they exhibited more body scratching than controls, possibly to compensate for the lack of licking different body parts. In conjunction with studies with other ataxic mice, these results indicate that the cerebellar cortex affects grooming activity and is consequently involved in executing various components, but not in its sequential organization, which requires other brain regions such as cerebral cortices or basal ganglia.

  1. Identification of a Gravitropism-Deficient Mutant in Rice

    Directory of Open Access Journals (Sweden)

    He Yan

    2017-03-01

    Full Text Available A gravitropism-deficient mutant M96 was isolated from a mutant bank, generated by ethyl methane sulfonate (EMS mutagenesis of indica rice accession ZJ100. The mutant was characterized as prostrate growth at the beginning of germination, and the prostrate growth phenotype ran through the whole life duration. Tiller angle and tiller number of M96 increased significantly in comparison with the wild type. Tissue section observation analysis indicated that asymmetric stem growth around the second node occurred in M96. Genetic analysis and gene mapping showed that M96 was controlled by a single recessive nuclear gene, tentatively termed as gravitropism-deficient M96 (gdM96, which was mapped to a region of 506 kb flanked by markers RM5960 and InDel8 on the long arm of chromosome 11. Sequencing analysis of the open reading frames in this region revealed a nucleotide substitution from G to T in the third exon of LOC_Os11g29840. Additionally, real-time fluorescence quantitative PCR analysis showed that the expression level of LOC_Os11g29840 in the stems was much higher than in the roots and leaves in M96. Furthermore, the expression level was more than four times in M96 stem than in the wild type stem. Our results suggested that the mutant gene was likely a new allele to the reported gene LAZY1. Isolation of this new allele would facilitate the further characterization of LAZY1.

  2. Development of sparse-seeded mutant kinnow (Citrus reticulata ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... The mutant was put to the conventional propagation up to mV5, for confirmation of the continuity of ... techniques with fruits such as citrus, grape (Vitis vinifera ... irradiated bud scions were grafted onto Citrus jambhiri rootstock,.

  3. Isolation and characterization of Escherichia coli mutants lacking inducible cyanase.

    Science.gov (United States)

    Guilloton, M; Karst, F

    1987-03-01

    To determine the physiological role of cyanate aminohydrolase (cyanase, EC 3.5.5.3) in bacteria, mutants of Escherichia coli K12 devoid of this inducible activity were isolated and their properties investigated. Five independent mutations were localized next to lac; three of them lay between lacY and codA. Thus cyanase activity could depend on the integrity of one gene or set of clustered genes; we propose for this locus the symbol cnt. Growth of the mutant stains was more sensitive to cyanate than growth of wild-type strains. This difference was noticeable in synthetic medium in the presence of low concentrations of cyanate (less than or equal to 1 mM). Higher concentrations inhibited growth of both wild-type and mutant strains. Urea in aqueous solutions dissociates slowly into ammonium cyanate. Accordingly wild-type strains were able to grow on a synthetic medium containing 0.5 M-urea whereas mutants lacking cyanase were not. We conclude that cyanase could play a role in destroying exogenous cyanate originating from the dissociation of carbamoyl compounds such as urea; alternatively cyanate might constitute a convenient nitrogen source for bacteria able to synthesize cyanase in an inducible way.

  4. Targeting adhesion signaling in KRAS, LKB1 mutant lung adenocarcinoma

    Science.gov (United States)

    Konen, Jessica; Koo, Junghui; Robinson, Brian S.; Wiles, Walter Guy; Huang, Chunzi; Martin, W. David; Behera, Madhusmita; Smith, Geoffrey H.; Hill, Charles E.; Rossi, Michael R.; Sica, Gabriel L.; Rupji, Manali; Chen, Zhengjia; Kowalski, Jeanne; Kasinski, Andrea L.; Ramalingam, Suresh S.; Khuri, Fadlo R.; Marcus, Adam I.

    2017-01-01

    Loss of LKB1 activity is prevalent in KRAS mutant lung adenocarcinoma and promotes aggressive and treatment-resistant tumors. Previous studies have shown that LKB1 is a negative regulator of the focal adhesion kinase (FAK), but in vivo studies testing the efficacy of FAK inhibition in LKB1 mutant cancers are lacking. Here, we took a pharmacologic approach to show that FAK inhibition is an effective early-treatment strategy for this high-risk molecular subtype. We established a lenti-Cre–induced Kras and Lkb1 mutant genetically engineered mouse model (KLLenti) that develops 100% lung adenocarcinoma and showed that high spatiotemporal FAK activation occurs in collective invasive cells that are surrounded by high levels of collagen. Modeling invasion in 3D, loss of Lkb1, but not p53, was sufficient to drive collective invasion and collagen alignment that was highly sensitive to FAK inhibition. Treatment of early, stage-matched KLLenti tumors with FAK inhibitor monotherapy resulted in a striking effect on tumor progression, invasion, and tumor-associated collagen. Chronic treatment extended survival and impeded local lymph node spread. Lastly, we identified focally upregulated FAK and collagen-associated collective invasion in KRAS and LKB1 comutated human lung adenocarcinoma patients. Our results suggest that patients with LKB1 mutant tumors should be stratified for early treatment with FAK inhibitors.

  5. Siim Nestor soovitab : Mutant Disco. Azymuth. Klubis Hollywood / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2003-01-01

    Mutant Disco klubis Prive 4. juulil. Brasiilia jazz-trio Azmuth klubis BonBon 5. juulil. Pidustuste sarja Hip Hop Cafe sünnipäeva tähistamisest klubis Hollywood 4. juulil, üritusest Ibiza Night 5. juulil

  6. Susceptibility genes for schizophrenia: mutant models, endophenotypes and psychobiology.

    Science.gov (United States)

    O'Tuathaigh, Colm M P; Desbonnet, Lieve; Moran, Paula M; Waddington, John L

    2012-01-01

    Schizophrenia is characterised by a multifactorial aetiology that involves genetic liability interacting with epigenetic and environmental factors to increase risk for developing the disorder. A consensus view is that the genetic component involves several common risk alleles of small effect and/or rare but penetrant copy number variations. Furthermore, there is increasing evidence for broader, overlapping genetic-phenotypic relationships in psychosis; for example, the same susceptibility genes also confer risk for bipolar disorder. Phenotypic characterisation of genetic models of candidate risk genes and/or putative pathophysiological processes implicated in schizophrenia, as well as examination of epidemiologically relevant gene × environment interactions in these models, can illuminate molecular and pathobiological mechanisms involved in schizophrenia. The present chapter outlines both the evidence from phenotypic studies in mutant mouse models related to schizophrenia and recently described mutant models addressing such gene × environment interactions. Emphasis is placed on evaluating the extent to which mutant phenotypes recapitulate the totality of the disease phenotype or model selective endophenotypes. We also discuss new developments and trends in relation to the functional genomics of psychosis which might help to inform on the construct validity of mutant models of schizophrenia and highlight methodological challenges in phenotypic evaluation that relate to such models.

  7. Genetic characterization of glossy-leafed mutant broccoli lines

    Science.gov (United States)

    Glossy mutants of Brassica oleracea L. have reduced or altered epicuticular wax on the surface of their leaves as compared to wild-type plants, conveying a shiny green appearance. Mutations conferring glossiness are common and have been found in most B. oleracea crop varieties, including cauliflower...

  8. A wilty mutant of rice has impaired hydraulic conductance.

    Science.gov (United States)

    Koizumi, Koji; Ookawa, Taiichiro; Satoh, Hikaru; Hirasawa, Tadashi

    2007-08-01

    The rice CM2088 mutant is the wilty phenotype and wilts markedly under well-watered sunny conditions. The leaf water potential and epidermal (mainly stomatal) conductance of CM2088 plants decreased significantly under conditions that induced intense transpiration, as compared with those of wild-type plants, revealing that the wilty phenotype was not the result of abnormal stomatal behavior but was due to an increase in resistance to water transport. The resistance to water transport was dramatically elevated in the node and the sheath and blade of a leaf of the mutant, but not in the root or stem. The diameter of xylem vessels in the large vascular bundles of the leaf sheath and the internode tended to be small, and the numbers of vessel elements with narrowed or scalariform perforation plates in the leaf blade and sheath were greater in the mutant than in the wild type. Most xylem vessels were occluded, with air bubbles in the leaf sheath of the mutant during the midday hours under intense transpiration conditions, while no bubbles were observed in plants that were barely transpiring, revealing that the significant increase in resistance to water transport was a result of the cavitation. The additive effects of cavitation in xylem vessels and the decreased diameter and deformed plates of vessel elements might be responsible for the wilty phenotype of CM2088.

  9. Enhanced longevity in tau mutant Syrian hamsters, Mesocricetus auratus

    NARCIS (Netherlands)

    Oklejewicz, Malgorzata; Daan, Serge

    2002-01-01

    The single-gene mutation tau in the Syrian hamster shortens the circadian period by about 20% in the homozygous mutant and simultaneously increases the mass-specific metabolic rate by about 20%. Both effects might be expected to lead to a change in longevity. To test such expectations, the life span

  10. Siim Nestor soovitab : Mutant Disco. Azymuth. Klubis Hollywood / Siim Nestor

    Index Scriptorium Estoniae

    Nestor, Siim, 1974-

    2003-01-01

    Mutant Disco klubis Prive 4. juulil. Brasiilia jazz-trio Azmuth klubis BonBon 5. juulil. Pidustuste sarja Hip Hop Cafe sünnipäeva tähistamisest klubis Hollywood 4. juulil, üritusest Ibiza Night 5. juulil

  11. Some Experiments with Respiratory Deficient Mutants of Yeast (Saccharomyces cerevisiae)

    Science.gov (United States)

    Freeland, P. W.

    1978-01-01

    Methods are described for the induction and identification of respiratory deficient mutants in yeast. Practical schemes are given to enable students to obtain dose-response information for physical and chemical mutagens such as heat, ultraviolet light, or acriflavine. A simple test for environmental mutagens is described. (Author/MA)

  12. Morphology and inheritance of a new rice leaf death mutant

    Institute of Scientific and Technical Information of China (English)

    CHENGZhakuan; GUMingkang

    1998-01-01

    A new mutant showing successive leaf death was selected in a mutmion populalion from an indica rice variety Zhongxian 3037 trealed with 94Co-γ rays. The leaves of this rnutanl began lodie on the emergence of tlle third leaf tip, and all leaves died sooner alter flowering. Consequently,

  13. Rest mutant zebrafish swim erratically and display atypical spatial preferences.

    Science.gov (United States)

    Moravec, Cara E; Li, Edward; Maaswinkel, Hans; Kritzer, Mary F; Weng, Wei; Sirotkin, Howard I

    2015-05-01

    The Rest/Nrsf transcriptional repressor modulates expression of a large set of neural specific genes. Many of these target genes have well characterized roles in nervous system processes including development, plasticity and synaptogenesis. However, the impact of Rest-mediated transcriptional regulation on behavior has been understudied due in part to the embryonic lethality of the mouse knockout. To investigate the requirement for Rest in behavior, we employed the zebrafish rest mutant to explore a range of behaviors in adults and larva. Adult rest mutants of both sexes showed abnormal behaviors in a novel environment including increased vertical swimming, erratic swimming patterns and a proclivity for the tank walls. Adult males also had diminished reproductive success. At 6 days post fertilization (dpf), rest mutant larva were hypoactive, but displayed normal evoked responses to light and sound stimuli. Overall, these results provide evidence that rest dysfunction produces atypical swimming patterns and preferences in adults, and reduced locomotor activity in larvae. This study provides the first behavioral analysis of rest mutants and reveals specific behaviors that are modulated by Rest.

  14. Metabolic reprogramming in mutant IDH1 glioma cells.

    Directory of Open Access Journals (Sweden)

    Jose L Izquierdo-Garcia

    Full Text Available Mutations in isocitrate dehydrogenase (IDH 1 have been reported in over 70% of low-grade gliomas and secondary glioblastomas. IDH1 is the enzyme that catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate while mutant IDH1 catalyzes the conversion of α-ketoglutarate into 2-hydroxyglutarate. These mutations are associated with the accumulation of 2-hydroxyglutarate within the tumor and are believed to be one of the earliest events in the development of low-grade gliomas. The goal of this work was to determine whether the IDH1 mutation leads to additional magnetic resonance spectroscopy (MRS-detectable changes in the cellular metabolome.Two genetically engineered cell models were investigated, a U87-based model and an E6/E7/hTERT immortalized normal human astrocyte (NHA-based model. For both models, wild-type IDH1 cells were generated by transduction with a lentiviral vector coding for the wild-type IDH1 gene while mutant IDH1 cells were generated by transduction with a lentiviral vector coding for the R132H IDH1 mutant gene. Metabolites were extracted from the cells using the dual-phase extraction method and analyzed by 1H-MRS. Principal Component Analysis was used to analyze the MRS data.Principal Component Analysis clearly discriminated between wild-type and mutant IDH1 cells. Analysis of the loading plots revealed significant metabolic changes associated with the IDH1 mutation. Specifically, a significant drop in the concentration of glutamate, lactate and phosphocholine as well as the expected elevation in 2-hydroxyglutarate were observed in mutant IDH1 cells when compared to their wild-type counterparts.The IDH1 mutation leads to several, potentially translatable MRS-detectable metabolic changes beyond the production of 2-hydroxyglutarate.

  15. Arabidopsis mutant bik1 exhibits strong resistance to Plasmodiophora brassicae

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2016-09-01

    Full Text Available Botrytis-induced kinase1 (BIK1, a receptor-like cytoplasmic kinase, plays an important role in resistance against pathogens and insects in Arabidopsis thaliana. However, it remains unknown whether BIK1 functions against Plasmodiophora brassicae, an obligate biotrophic protist that attacks cruciferous plants and induces gall formation on roots. Here, we investigated the potential roles of receptors FLS2, BAK1 and BIK1 in the infection of P. brassicae cruciferous plants. Wild-type plants, fls2 and bak1 mutants showed typical symptom on roots, and the galls were filled with large quantities of resting spores, while bik1 mutant plants exhibited strong resistance to P. brassicae. Compared with that of the wild-type plants, the root hair and cortical infection rate of bik1 mutant were significantly reduced by about 40-50%. A considerable portion of bik1 roots failed to form typical galls. Even if some small galls were formed, they were filled with multinucleate secondary plasmodia. The bik1 plants accumulated less reactive oxygen species (ROS at infected roots than other mutants and wild-type plants. Exogenous salicylic acid (SA treatment alleviated the clubroot symptoms in wild-type plants, and the expression of the SA signaling marker gene PR1 was significantly increased in bik1. Both sid2 (salicylic acid induction-deficient 2 and npr1-1 (non-expresser of PR genes that regulate systemic acquired resistance (SAR mutants showed increased susceptibility to P. brassicae compared with wild-type plants. These results suggest that the resistance of bik1 to P. brassicae is possibly mediated by SA inducible mechanisms enhance the resistance to clubroot disease.

  16. Metabolic differences in ripening of Solanum lycopersicum 'Ailsa Craig' and three monogenic mutants.

    Science.gov (United States)

    Beisken, Stephan; Earll, Mark; Baxter, Charles; Portwood, David; Ament, Zsuzsanna; Kende, Aniko; Hodgman, Charlie; Seymour, Graham; Smith, Rebecca; Fraser, Paul; Seymour, Mark; Salek, Reza M; Steinbeck, Christoph

    2014-01-01

    Application of mass spectrometry enables the detection of metabolic differences between groups of related organisms. Differences in the metabolic fingerprints of wild-type Solanum lycopersicum and three monogenic mutants, ripening inhibitor (rin), non-ripening (nor) and Colourless non-ripening (Cnr), of tomato are captured with regard to ripening behaviour. A high-resolution tandem mass spectrometry system coupled to liquid chromatography produced a time series of the ripening behaviour at discrete intervals with a focus on changes post-anthesis. Internal standards and quality controls were used to ensure system stability. The raw data of the samples and reference compounds including study protocols have been deposited in the open metabolomics database MetaboLights via the metadata annotation tool Isatab to enable efficient re-use of the datasets, such as in metabolomics cross-study comparisons or data fusion exercises.

  17. Kinetics of the E46Q mutant of photoactive yellow protein investigated by transient grating spectroscopy

    Science.gov (United States)

    Yang, Cheolhee; Kim, Tae Wu; Kim, Youngmin; Choi, Jungkweon; Lee, Sang Jin; Ihee, Hyotcherl

    2017-09-01

    To elucidate the role of internal proton transfer in the photodynamics of photoactive yellow protein (PYP), the photocycle of the Glu46Gln mutant of PYP (E46Q-PYP) is investigated by transient grating (TG) spectroscopy. Compared with wild-type PYP (wt-PYP), the first spectrally blue-shifted intermediate of E46Q-PYP is formed more slowly, which is consistent with the absence of direct protonation from Glu46 residue, if the parallel kinetic model for wt-PYP is invoked. The smaller conformational change in E46Q-PYP, as manifested by the smaller change in the diffusion coefficient, mainly arises from the relatively larger volume of the ground state E46Q-PYP than wt-PYP rather than from the smaller volume of the pB state.

  18. Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

    Science.gov (United States)

    Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

    2016-01-01

    Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon), to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin) containing genetically inactivated (± an N-terminal polyleucine tail) A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF) mutant (5-10x), F508delCFTR Golgi maturation (protein misfolding diseases.

  19. Biogenesis and Ultrastructure of Carboxysomes from Wild Type and Mutants of Synechococcus sp. Strain PCC 7942.

    Science.gov (United States)

    Orus, M. I.; Rodriguez, M. L.; Martinez, F.; Marco, E.

    1995-04-01

    Immature inclusions representing three progressive steps of carboxysome biogenesis have been identified in Synechococcus during the period of adaptation to low-CO2 conditions: (a) ring-shaped structures, (b) electron-translucent inclusions with the shape of a carboxysome and the internal orderly arrangement of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) molecules, and (c) carboxysomes with an internal electron-translucent area, which seem to be the penultimate stage of carboxysome maturation. The ability to build up normal carboxysomes is impaired in three (M3, EK6, and D4) of four high-carbon-requiring mutants studied in this work. M3 and EK6 exhibit abundant immature electron-translucent carboxysomes but no mature ones. This finding supports the contention that an open reading frame located 7.5 kb upstream of the gene encoding the large subunit of Rubisco (altered in M3) is involved in the carboxysome composition and confirms the structural role of the small subunit of Rubisco (slightly modified in EK6) in the assembly of these structures. D4 shows few typical carboxysomes and frequent immature types, its genetic lesion affecting the apparently unrelated gene encoding a subunit of phosphoribosyl aminoamidazole carboxylase of the purine biosynthesis pathway. Revertants EK20 (EK6) and RK13 (D4) have normal carboxysomes, which means that the restoration of the ability to grow under low CO2 coincides with the proper assembling of these structures. N5, a transport mutant due to the alteration of the gene encoding subunit 2 of NADH dehydrogenase, shows an increase in the number and size of carboxysomes and frequent bar-shaped ones.

  20. Comparative stability of dihydrofolate reductase mutants in vitro and in vivo.

    Science.gov (United States)

    Leontiev, V V; Uversky, V N; Gudkov, A T

    1993-01-01

    Dihydrofolate reductase mutants with amino acid replacements in the active center (Thr35-->Asp mutant, Arg57-->His mutant and the mutant with triple replacement Thr35-->Asp, Asn37-->Ser, Arg57-->His) were obtained by site-directed mutagenesis. The stabilization effect of trimethoprim and NADP.H on the protein tertiary structure in vitro has been investigated. In the case of mutants with a 'weak' tertiary structure (Thr35-->Asp35 and the triple mutant) the separate addition of ligands does not affect their stability. The simultaneous addition of these ligands to Thr35-->Asp35 and the triple mutant leads to the large increase in their stability. A distinct correlation was found between the in vitro studied stability of the mutant proteins to the urea- or heat-induced denaturation and the level of proteolytic degradation of these mutants previously observed in vivo.

  1. Pharmacodynamic assessment based on mutant prevention concentrations of fluoroquinolones to prevent the emergence of resistant mutants of Streptococcus pneumoniae.

    Science.gov (United States)

    Homma, Tomoyuki; Hori, Toshihiko; Sugimori, Giichi; Yamano, Yoshinori

    2007-11-01

    The objective of this study was to investigate the relationship between pharmacokinetic and pharmacodynamic parameters, on the basis of the mutant prevention concentration (MPC) concept, and the emergence of resistant mutants of Streptococcus pneumoniae to fluoroquinolone antibacterials. Some clinical isolates with various MIC and MPC values of moxifloxacin and levofloxacin were exposed under conditions simulating the time-concentration curves observed when moxifloxacin (400 or 80 mg, once a day) or levofloxacin (200 mg, twice a day) was orally administered by using an in vitro pharmacodynamic model. The decrease in susceptibility was evaluated by altering the population analysis profiles after moxifloxacin or levofloxacin treatment for 72 h. When the area under the concentration-time curve from 0 to 24 h (AUC(0-24))/MPC and peak concentration (C(max))/MPC were above 13.41 and 1.20, respectively, complete eradication occurred and no decrease in susceptibility was observed. On the other hand, when AUC(0-24)/MPC and C(max)/MPC were below 0.84 and 0.08, respectively, the susceptibility decreased. However, the time inside the mutant selective window and the time above the MPC did not show any correlation with the decrease in susceptibility. These results suggest that AUC(0-24)/MPC and C(max)/MPC are important parameters for predicting the emergence of resistant mutants and that higher values indicate greater effectiveness.

  2. Human GLTP and mutant forms of ACD11 suppress cell death in the Arabidopsis acd11 mutant

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; McKinney, Lea V; Pike, Helen

    2008-01-01

    The Arabidopsis acd11 mutant exhibits runaway, programmed cell death due to the loss of a putative sphingosine transfer protein (ACD11) with homology to mammalian GLTP. We demonstrate that transgenic expression in Arabidopsis thaliana of human GLTP partially suppressed the phenotype of the acd11 ...

  3. Metabolomic Characterization of Knockout Mutants in Arabidopsis: Development of a Metabolite Profiling Database for Knockout Mutants in Arabidopsis.

    Science.gov (United States)

    Fukushima, Atsushi; Kusano, Miyako; Mejia, Ramon Francisco; Iwasa, Mami; Kobayashi, Makoto; Hayashi, Naomi; Watanabe-Takahashi, Akiko; Narisawa, Tomoko; Tohge, Takayuki; Hur, Manhoi; Wurtele, Eve Syrkin; Nikolau, Basil J; Saito, Kazuki

    2014-05-14

    Despite recent intensive research efforts in functional genomics, the functions of only a limited number of Arabidopsis (Arabidopsis thaliana) genes have been determined experimentally, and improving gene annotation remains a major challenge in plant science. As metabolite profiling can characterize the metabolomic phenotype of a genetic perturbation in the plant metabolism, it provides clues to the function(s) of genes of interest. We chose 50 Arabidopsis mutants, including a set of characterized and uncharacterized mutants, that resemble wild-type plants. We performed metabolite profiling of the plants using gas chromatography-mass spectrometry. To make the data set available as an efficient public functional genomics tool for hypothesis generation, we developed the Metabolite Profiling Database for Knock-Out Mutants in Arabidopsis (MeKO). It allows the evaluation of whether a mutation affects metabolism during normal plant growth and contains images of mutants, data on differences in metabolite accumulation, and interactive analysis tools. Nonprocessed data, including chromatograms, mass spectra, and experimental metadata, follow the guidelines set by the Metabolomics Standards Initiative and are freely downloadable. Proof-of-concept analysis suggests that MeKO is highly useful for the generation of hypotheses for genes of interest and for improving gene annotation. MeKO is publicly available at http://prime.psc.riken.jp/meko/.

  4. Mutants of GABA transaminase (POP2 suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh mutants in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Frank Ludewig

    Full Text Available BACKGROUND: The gamma-aminubutyrate (GABA shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. In plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (GAD, the mitochondrial enzymes GABA transaminase (GABA-T; POP2 and succinic semialdehyde dehydrogenase (SSADH. We have previously shown that compromising the function of the GABA-shunt, by disrupting the SSADH gene of Arabidopsis, causes enhanced accumulation of reactive oxygen intermediates (ROIs and cell death in response to light and heat stress. However, to date, genetic investigations of the relationships between enzymes of the GABA shunt have not been reported. PRINCIPAL FINDINGS: To elucidate the role of succinic semialdehyde (SSA, gamma-hydroxybutyrate (GHB and GABA in the accumulation of ROIs, we combined two genetic approaches to suppress the severe phenotype of ssadh mutants. Analysis of double pop2 ssadh mutants revealed that pop2 is epistatic to ssadh. Moreover, we isolated EMS-generated mutants suppressing the phenotype of ssadh revealing two new pop2 alleles. By measuring thermoluminescence at high temperature, the peroxide contents of ssadh and pop2 mutants were evaluated, showing that only ssadh plants accumulate peroxides. In addition, pop2 ssadh seedlings are more sensitive to exogenous SSA or GHB relative to wild type, because GHB and/or SSA accumulate in these plants. SIGNIFICANCE: We conclude that the lack of supply of succinate and NADH to the TCA cycle is not responsible for the oxidative stress and growth retardations of ssadh mutants. Rather, we suggest that the accumulation of SSA, GHB, or both, produced downstream of the GABA-T transamination step, is toxic to the plants, resulting in high ROI levels and impaired development.

  5. Enhancement of yellow pigment production by intraspecific protoplast fusion of Monascus spp. yellow mutant (ade(-)) and white mutant (prototroph).

    Science.gov (United States)

    Klinsupa, Worawan; Phansiri, Salak; Thongpradis, Panida; Yongsmith, Busaba; Pothiratana, Chetsada

    2016-01-10

    To breed industrially useful strains of a slow-growing, yellow pigment producing strain of Monascus sp., protoplasts of Monascus purpureus yellow mutant (ade(-)) and rapid-growing M. purpureus white mutant (prototroph) were fused and fusants were selected on minimal medium (MM). Preliminary conventional protoplast fusion of the two strains was performed and the result showed that only white colonies were detected on MM. It was not able to differentiate the fusants from the white parental prototroph. To solve this problem, the white parental prototroph was thus pretreated with 20mM iodoacetamide (IOA) for cytoplasm inactivation and subsequently taken into protoplast fusion with slow-growing Monascus yellow mutant. Under this development technique, only the fusants, with viable cytoplasm from Monascus yellow mutant (ade(-)), could thus grow on MM, whereas neither IOA pretreated white parental prototroph nor yellow auxotroph (ade(-)) could survive. Fifty-three fusants isolated from yellow colonies obtained through this developed technique were subsequently inoculated on complete medium (MY agar). Fifteen distinguished yellow colonies from their parental yellow mutant were then selected for biochemical, morphological and fermentative properties in cassava starch and soybean flour (SS) broth. Finally, three most stable fusants (F7, F10 and F43) were then selected and compared in rice solid culture. Enhancement of yellow pigment production over the parental yellow auxotroph was found in F7 and F10, while enhanced glucoamylase activity was found in F43. The formation of fusants was further confirmed by monacolin K content, which was intermediate between the two parents (monacolin K-producing yellow auxotroph and non-monacolin K producing white prototroph).

  6. A sorghum (Sorghum bicolor) mutant with altered carbon isotope ratio.

    Science.gov (United States)

    Rizal, Govinda; Karki, Shanta; Thakur, Vivek; Wanchana, Samart; Alonso-Cantabrana, Hugo; Dionora, Jacque; Sheehy, John E; Furbank, Robert; von Caemmerer, Susanne; Quick, William Paul

    2017-01-01

    Recent efforts to engineer C4 photosynthetic traits into C3 plants such as rice demand an understanding of the genetic elements that enable C4 plants to outperform C3 plants. As a part of the C4 Rice Consortium's efforts to identify genes needed to support C4 photosynthesis, EMS mutagenized sorghum populations were generated and screened to identify genes that cause a loss of C4 function. Stable carbon isotope ratio (δ13C) of leaf dry matter has been used to distinguishspecies with C3 and C4 photosynthetic pathways. Here, we report the identification of a sorghum (Sorghum bicolor) mutant with a low δ13C characteristic. A mutant (named Mut33) with a pale phenotype and stunted growth was identified from an EMS treated sorghum M2 population. The stable carbon isotope analysis of the mutants showed a decrease of 13C uptake capacity. The noise of random mutation was reduced by crossing the mutant and its wildtype (WT). The back-cross (BC1F1) progenies were like the WT parent in terms of 13C values and plant phenotypes. All the BC1F2 plants with low δ13C died before they produced their 6th leaf. Gas exchange measurements of the low δ13C sorghum mutants showed a higher CO2 compensation point (25.24 μmol CO2.mol-1air) and the maximum rate of photosynthesis was less than 5μmol.m-2.s-1. To identify the genetic determinant of this trait, four DNA pools were isolated; two each from normal and low δ13C BC1F2 mutant plants. These were sequenced using an Illumina platform. Comparison of allele frequency of the single nucleotide polymorphisms (SNPs) between the pools with contrasting phenotype showed that a locus in Chromosome 10 between 57,941,104 and 59,985,708 bps had an allele frequency of 1. There were 211 mutations and 37 genes in the locus, out of which mutations in 9 genes showed non-synonymous changes. This finding is expected to contribute to future research on the identification of the causal factor differentiating C4 from C3 species that can be used in the

  7. Increased leaf photosynthesis caused by elevated stomatal conductance in a rice mutant deficient in SLAC1, a guard cell anion channel protein.

    Science.gov (United States)

    Kusumi, Kensuke; Hirotsuka, Shoko; Kumamaru, Toshiharu; Iba, Koh

    2012-09-01

    In rice (Oryza sativa L.), leaf photosynthesis is known to be highly correlated with stomatal conductance; however, it remains unclear whether stomatal conductance dominantly limits the photosynthetic rate. SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO(2)]. In order to examine stomatal limitations to photosynthesis, a SLAC1-deficient mutant of rice was isolated and characterized. A TILLING screen of N-methyl-N-nitrosourea-derived mutant lines was conducted for the rice SLAC1 orthologue gene Os04g0674700, and four mutant lines containing mutations within the open reading frame were obtained. A second screen using an infrared thermography camera revealed that one of the mutants, named slac1, had a constitutive low leaf temperature phenotype. Measurement of leaf gas exchange showed that slac1 plants grown in the greenhouse had significantly higher stomatal conductance (g (s)), rates of photosynthesis (A), and ratios of internal [CO(2)] to ambient [CO(2)] (C (i)/C (a)) compared with wild-type plants, whereas there was no significant difference in the response of photosynthesis to internal [CO(2)] (A/C (i) curves). These observations demonstrate that in well-watered conditions, stomatal conductance is a major determinant of photosynthetic rate in rice.

  8. High-resolution mapping and genetic characterization of the Lazy-2 gravitropic mutant of tomato

    Science.gov (United States)

    Behringer, F. J.; Lomax, T. L.

    1999-01-01

    Mutation of the Lazy-2 (Lz-2) gene in tomato (Lycopersicon esculentum mill.) produces a phytochrome-dependent reversal of shoot gravitropism, providing a unique genetic resource for investigating how signals from light modulate gravitropism. We mapped the Lz-2 gene using RFLPs and a PCR-based technique to assess the feasibility of positional cloning. Analysis of a 1338 plant backcross population between L. esculentum and L. pennellii placed Lz-2 within a 1.2 cM interval on chromosome 5, 0.4 cM from TG504-CT201A interval. The inabililty to resolve these markers indicates that Lz-2 resides in a centromeric region in which recombination is highly suppressed. Lazy-2 is tightly linked to but does not encode the gene for ACC4, an enzyme involved in ethylene biosynthesis. We also observed that Lz-2 is partially dominant under certain conditions and stages of development.

  9. Improved solubility of replication factor C (RFC) Walker A mutants.

    Science.gov (United States)

    Marzahn, Melissa R; Bloom, Linda B

    2012-06-01

    Protein insolubility often poses a significant problem during purification protocols and in enzyme assays, especially for eukaryotic proteins expressed in a recombinant bacterial system. The limited solubility of replication factor C (RFC), the clamp loader complex from Saccharomyces cerevisiae, has been previously documented. We found that mutant forms of RFC harboring a single point mutation in the Walker A motif were even less soluble than the wild-type complex. The addition of maltose at 0.75 M to the storage and assay buffers greatly increases protein solubility and prevents the complex from falling apart. Our analysis of the clamp loading reaction is dependent on fluorescence-based assays, which are environmentally sensitive. Using wt RFC as a control, we show that the addition of maltose to the reaction buffers does not affect fluorophore responses in the assays or the enzyme activity, indicating that maltose can be used as a buffer additive for further downstream analysis of these mutants.

  10. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila.

    Science.gov (United States)

    Seki, Yuuichi; Tanimura, Teiichi

    2014-09-01

    A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms with shorter periods. We used a video-tracking method to monitor the movement of single flies, and clear ultradian rhythms were detected in the locomotor behaviour of wild type and clock mutant flies kept under constant dark conditions. In particular, the Pigment-dispersing factor mutant (Pdf 01) demonstrated a precise and robust ultradian rhythmicity, which was not temperature compensated. Our results suggest that Drosophila has an endogenous ultradian oscillator that is masked by circadian rhythmic behaviours.

  11. Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila

    Indian Academy of Sciences (India)

    Yuuichi Seki; Teiichi Tanimura

    2014-09-01

    A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms with shorter periods. We used a video-tracking method to monitor the movement of single flies, and clear ultradian rhythms were detected in the locomotor behaviour of wild type and clock mutant flies kept under constant dark conditions. In particular, the Pigment-dispersing factor mutant (Pdf01) demonstrated a precise and robust ultradian rhythmicity, which was not temperature compensated. Our results suggest that Drosophila has an endogenous ultradian oscillator that is masked by circadian rhythmic behaviours.

  12. Induction and use of artificial mutants in sweet potato

    Energy Technology Data Exchange (ETDEWEB)

    Marumine, Shokichi

    1984-03-01

    X-ray, ethylene imine, TSP and WCo were used as mutagen for sweet potato mutation breeding and visible variations were observed for all mutagen. In the case of WCo irradiation, mutation rate of skin color is 0.5-1.3% based on cutting. Direction and variation of dry matter and tuber yield of mutants which were induced by TSP and/or WCo irradiation showed more deteriorative variation than progressive variation but some induced mutant lines show same or superior characters than original line. In the case of TSP irradiation to tuber, obstruction is not so much up to dese of 10,000 ci per tuber but treatment of 330 ci per cutting approximate to LD50. By tuber treatment with WCo gamma rays, suppression of sprouting occurred in dose of 30kR. Tendency to increase a variation was not observed at higher doses. 50-200 ci per cutting or 300-500 ci per tuber in TSP treatment and 15 kR in WCo gamma-irradiation for tuber seemed to be optimum dosages. Hybrid seed of mutant selected for dry matter content was compared with that of original line and it was concluded that the variation of selected line was genetic. Mutant induced by TSP and WCo treatment was used as a parental material and progeny of the cross was selected for practical characters. As a result, a line of higher starch yield with high resistance to pest and disease was selected and this line was used as parental material of further breeding. (author).

  13. Azotobacter vinelandii mutS: nucleotide sequence and mutant analysis.

    OpenAIRE

    Le, O; Shen, B.; Iismaa, S E; Burgess, B K

    1993-01-01

    An Azotobacter vinelandii homolog to the Salmonella typhimurium mutS gene was discovered upstream of the fdxA gene. The product of this gene is much more similar to S. typhimurium MutS than either is to the HexA protein of Streptococcus pneumoniae. An A. vinelandii delta mutS mutant strain was shown to have a spontaneous mutation frequency 65-fold greater than that of the wild type.

  14. Reverse genetics in Chlamydomonas: a platform for isolating insertional mutants

    OpenAIRE

    de Montaigu Amaury; Magneschi Leonardo; Catalanotti Claudia; Yang Wenqiang; Mus Florence; Pootakham Wirulda; Gonzalez-Ballester David; Higuera Jose J; Prior Matthew; Galván Aurora; Fernandez Emilio; Grossman Arthur R

    2011-01-01

    Abstract A method was developed to identify insertional mutants of Chlamydomonas reinhardtii disrupted for selected target genes. The approach relies on the generation of thousands of transformants followed by PCR-based screenings that allow for identification of strains harboring the introduced marker gene within specific genes of interest. Our results highlight the strengths and limitations of two independent screens that differed in the nature of the marker DNA used (PCR-amplified fragment...

  15. Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer

    Science.gov (United States)

    2015-09-01

    transition occurs is unknown. In this proposal, we are studying the molecular and cellular mechanisms that cause this transition to occur in...weekly cancer center and pathology grand rounds amongst others. d. How were the results disseminated to communities of interest? Nothing to report...process and obtain high quality data recently. Therefore, we will be performing RNA sequencing on samples of EGFR mutant SCLC in the next couple of

  16. Functional analysis of Burkitt's lymphoma mutant c-Myc proteins

    OpenAIRE

    1996-01-01

    The c-myc gene encodes a sequence-specific DNA binding protein that activates transcription of cellular genes. Transcription activation by Myc proteins is regulated by phosphorylation of serine and threonine residues within the transactivation domain and by complex formation with the retinoblastoma-related protein p107. In Burkitt’s lymphoma, missense mutations within the c-Myc transactivation domain have been found with high frequency. It has been reported that mutant c-Myc proteins derived ...

  17. Aconitase causes iron toxicity in Drosophila pink1 mutants.

    Directory of Open Access Journals (Sweden)

    Giovanni Esposito

    2013-04-01

    Full Text Available The PTEN-induced kinase 1 (PINK1 is a mitochondrial kinase, and pink1 mutations cause early onset Parkinson's disease (PD in humans. Loss of pink1 in Drosophila leads to defects in mitochondrial function, and genetic data suggest that another PD-related gene product, Parkin, acts with pink1 to regulate the clearance of dysfunctional mitochondria (mitophagy. Consequently, pink1 mutants show an accumulation of morphologically abnormal mitochondria, but it is unclear if other factors are involved in pink1 function in vivo and contribute to the mitochondrial morphological defects seen in specific cell types in pink1 mutants. To explore the molecular mechanisms of pink1 function, we performed a genetic modifier screen in Drosophila and identified aconitase (acon as a dominant suppressor of pink1. Acon localizes to mitochondria and harbors a labile iron-sulfur [4Fe-4S] cluster that can scavenge superoxide to release hydrogen peroxide and iron that combine to produce hydroxyl radicals. Using Acon enzymatic mutants, and expression of mitoferritin that scavenges free iron, we show that [4Fe-4S] cluster inactivation, as a result of increased superoxide in pink1 mutants, results in oxidative stress and mitochondrial swelling. We show that [4Fe-4S] inactivation acts downstream of pink1 in a pathway that affects mitochondrial morphology, but acts independently of parkin. Thus our data indicate that superoxide-dependent [4Fe-4S] inactivation defines a potential pathogenic cascade that acts independent of mitophagy and links iron toxicity to mitochondrial failure in a PD-relevant model.

  18. Dihydrodipicolinate synthase in opaque and floury maize mutants

    NARCIS (Netherlands)

    Varisi, V.A.; Medici, L.O.; Meer, van der I.M.; Lea, P.J.; Azevedo, J.L.

    2007-01-01

    Dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) was isolated and studied in four high-lysine maize mutants (Oh43o1, Oh43o2, Oh43fl1 and Oh43fl2). The activity of DHDPS was analyzed at 16, 20, and 24 DAP and characterized in the presence of the amino acids, lysine, S-(2-aminoethyl)-l-cysteine (AEC)

  19. Metabolite profiling of two low phytic acid (lpa) rice mutants.

    Science.gov (United States)

    Frank, Thomas; Meuleye, Bertrand Seumo; Miller, Andreas; Shu, Qing-Yao; Engel, Karl-Heinz

    2007-12-26

    Two low phytic acid (lpa) rice mutant lines, Os-lpa-XS110-1 and Os-lpa-XS110-2, were grown together with their parent wild-type variety Xiushui 110 in four field trials. HPLC analysis of inositol phosphates in the seeds produced demonstrated that compared to the wild-type, the reduction in phytic acid content in Os-lpa-XS110-1 (-46%) was more pronounced than that in Os-lpa-XS110-2 (-23%). Lower inositol phosphates (InsP 3, InsP 4, InsP 5) were not detected in the mutants. The lpa mutants and the wild-type rice were subjected to comparative metabolite profiling by capillary gas chromatography. On average, 34% (Os-lpa-XS110-1) and 42% (Os-lpa-XS110-2) of the detected peaks were statistically significantly different between wild-type and mutants. However, only a few of these differences could be consistently observed for all field trials. Identification and quantification of the consistently different metabolites revealed that contents of myo-inositol and raffinose were increased in Os-lpa-XS110-1 but decreased in Os-lpa-XS110-2 compared to the wild-type. In addition, Os-lpa-XS110-1 exhibited increased levels of galactose and galactinol. Consideration of these metabolic changes in light of the routes involved in the biosynthesis of phytic acid indicated a disturbance in the early biosynthetic pathway of phytic acid in Os-lpa-XS110-2 (similar to the lpa-1 type mutation in maize) and a mutation event affecting phosphorylation of myo-inositol in Os-lpa-XS110-1 (similar to the lpa-3-type mutation).

  20. GREEN FLUORESCENT PIGMENT ACCUMULATED BY A MUTANT OF CELLVIBRIO GILVUS.

    Science.gov (United States)

    LOVE, S H; HULCHER, F H

    1964-01-01

    Love, Samuel H. (Bowman Gray School of Medicine, Winston-Salem, N.C.), and Frank H. Hulcher. Green fluorescent pigment accumulated by a mutant of Cellvibrio gilvus. J. Bacteriol. 87:39-45. 1964.-A mutant of Cellvibrio gilvus, designated strain 139A, liberated a green, fluorescent pigment into the surrounding culture medium. A study of the factors which affected the accumulation of this pigment led to the development of a chemically defined medium which supported maximal pigment accumulation in aerated, liquid cultures. d-Glucose, glycine or l-serine, l-phenylalanine, l-proline, and l-lysine comprised the organic components of this medium. The visible absorption spectrum of the pigment showed a maximal band at 400 mmu (pH 7.0). A difference spectrum between reduced and oxidized pigment showed loss of the band at 400 mmu upon oxidation. However, a methanol-extractable, flavinelike compound occurred in the wild strain but not in the mutant. Ferric ions added to the defined medium stimulated growth, with a concomitant reduction of pigment accumulation. Pigment was formed at a maximal rate during the stationary growth phase, and the highest yield was obtained by 18 hr. Organic solvents did not extract the pigment from water solutions. One and sometimes two, compounds absorbing at 400 mmu could be eluted by ion-exchange chromatography on Cellex-P (H(+)), which was used to separate the pigment from other components in the culture supernatants so that the radioactivity of the pigment could be measured. The mutant synthesized C(14)-labeled pigment from d-glucose-U-C(14) and from each of four amino acids (glycine-1-C(14), l-phenylalanine-U-C(14), l-proline-U-C(14), and l-lysine-U-C(14). Delta-Amino-levulenic acid-4-C(14) did not contribute C(14) to the pigment.

  1. GPNMB ameliorates mutant TDP-43-induced motor neuron cell death.

    Science.gov (United States)

    Nagahara, Yuki; Shimazawa, Masamitsu; Ohuchi, Kazuki; Ito, Junko; Takahashi, Hitoshi; Tsuruma, Kazuhiro; Kakita, Akiyoshi; Hara, Hideaki

    2017-08-01

    Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Community College Internal Auditors: Internal Audit Guidebook.

    Science.gov (United States)

    Jones, Ronna; And Others

    This guidebook includes information compiled by the "Audit Manual" committee of Community College Internal Auditors (CCIA) from several California community college districts regarding their internal auditing practices. The first section of the guidebook discusses the purpose of internal audits, indicating that audits assist members of…

  3. Potent Sensitisation of Cancer Cells to Anticancer Drugs by a Quadruple Mutant of the Human Deoxycytidine Kinase.

    Science.gov (United States)

    Coulibaly, Safiatou T; Rossolillo, Paola; Winter, Flore; Kretzschmar, Franziska K; Brayé, Mélanie; Martin, Darren P; Lener, Daniela; Negroni, Matteo

    2015-01-01

    Identifying enzymes that, once introduced in cancer cells, lead to an increased efficiency of treatment constitutes an important goal for biomedical applications. Using an original procedure whereby mutant genes are generated based on the use of conditional lentivector genome mobilisation, we recently described, for the first time, the identification of a human deoxycytidine kinase (dCK) mutant (G12) that sensitises a panel of cancer cell lines to treatment with the dCK analogue gemcitabine. Here, starting from the G12 variant itself, we generated a new library and identified a mutant (M36) that triggers even greater sensitisation to gemcitabine than G12. With respect to G12, M36 presents an additional mutation located in the region that constitutes the interface of the dCK dimer. The simple presence of this mutation halves both the IC50 and the proportion of residual cells resistant to the treatment. Furthermore, the use of vectors with self-inactivating LTRs leads to an increased sensitivity to treatment, a result compatible with a relief of the transcriptional interference exerted by the U3 promoter on the internal promoter that drives the expression of M36. Importantly, a remarkable effect is also observed in treatments with the anticancer compound cytarabine (AraC), for which a 10,000 fold decrease in IC50 occurred. By triggering the sensitisation of various cancer cell types with poor prognosis to two commonly used anticancer compounds M36 is a promising candidate for suicide gene approaches.

  4. Potent Sensitisation of Cancer Cells to Anticancer Drugs by a Quadruple Mutant of the Human Deoxycytidine Kinase.

    Directory of Open Access Journals (Sweden)

    Safiatou T Coulibaly

    Full Text Available Identifying enzymes that, once introduced in cancer cells, lead to an increased efficiency of treatment constitutes an important goal for biomedical applications. Using an original procedure whereby mutant genes are generated based on the use of conditional lentivector genome mobilisation, we recently described, for the first time, the identification of a human deoxycytidine kinase (dCK mutant (G12 that sensitises a panel of cancer cell lines to treatment with the dCK analogue gemcitabine. Here, starting from the G12 variant itself, we generated a new library and identified a mutant (M36 that triggers even greater sensitisation to gemcitabine than G12. With respect to G12, M36 presents an additional mutation located in the region that constitutes the interface of the dCK dimer. The simple presence of this mutation halves both the IC50 and the proportion of residual cells resistant to the treatment. Furthermore, the use of vectors with self-inactivating LTRs leads to an increased sensitivity to treatment, a result compatible with a relief of the transcriptional interference exerted by the U3 promoter on the internal promoter that drives the expression of M36. Importantly, a remarkable effect is also observed in treatments with the anticancer compound cytarabine (AraC, for which a 10,000 fold decrease in IC50 occurred. By triggering the sensitisation of various cancer cell types with poor prognosis to two commonly used anticancer compounds M36 is a promising candidate for suicide gene approaches.

  5. Histological Characterization of the Dicer1 Mutant Zebrafish Retina

    Directory of Open Access Journals (Sweden)

    Saeed Akhtar

    2015-01-01

    Full Text Available DICER1, a multidomain RNase III endoribonuclease, plays a critical role in microRNA (miRNA and RNA-interference (RNAi functional pathways. Loss of Dicer1 affects different developmental processes. Dicer1 is essential for retinal development and maintenance. DICER1 was recently shown to have another function of silencing the toxicity of Alu RNAs in retinal pigment epithelium (RPE cells, which are involved in the pathogenesis of age related macular degeneration. In this study, we characterized a Dicer1 mutant fish line, which carries a nonsense mutation (W1457Ter induced by N-ethyl-N-nitrosourea mutagenesis. Zebrafish DICER1 protein is highly conserved in the evolution. Zebrafish Dicer1 is expressed at the earliest stages of zebrafish development and persists into late developmental stages; it is widely expressed in adult tissues. Homozygous Dicer1 mutant fish (DICER1W1457Ter/W1457Ter have an arrest in early growth with significantly smaller eyes and are dead at 14–18 dpf. Heterozygous Dicer1 mutant fish have similar retinal structure to that of control fish; the retinal pigment epithelium (RPE cells are normal with no sign of degeneration at the age of 20 months.

  6. Recombination Phenotypes of Escherichia coli greA Mutants

    Directory of Open Access Journals (Sweden)

    Poteete Anthony R

    2011-03-01

    Full Text Available Abstract Background The elongation factor GreA binds to RNA polymerase and modulates transcriptional pausing. Some recent research suggests that the primary role of GreA may not be to regulate gene expression, but rather, to promote the progression of replication forks which collide with RNA polymerase, and which might otherwise collapse. Replication fork collapse is known to generate dsDNA breaks, which can be recombinogenic. It follows that GreA malfunction could have consequences affecting homologous recombination. Results Escherichia coli mutants bearing substitutions of the active site acidic residues of the transcription elongation factor GreA, D41N and E44K, were isolated as suppressors of growth inhibition by a toxic variant of the bacteriophage lambda Red-beta recombination protein. These mutants, as well as a D41A greA mutant and a greA deletion, were tested for proficiency in recombination events. The mutations were found to increase the efficiency of RecA-RecBCD-mediated and RecA-Red-mediated recombination, which are replication-independent, and to decrease the efficiency of replication-dependent Red-mediated recombination. Conclusion These observations provide new evidence for a role of GreA in resolving conflicts between replication and transcription.

  7. Molecular Imaging Of Metabolic Reprogramming In Mutant IDH Cells

    Directory of Open Access Journals (Sweden)

    Pavithra eViswanath

    2016-03-01

    Full Text Available Mutations in the metabolic enzyme isocitrate dehydrogenase (IDH have recently been identified as drivers in the development of several tumor types. Most notably, cytosolic IDH1 is mutated in 70-90% of low-grade gliomas and upgraded glioblastomas, and mitochondrial IDH2 is mutated in ~20% of acute myeloid leukemia cases. Wild-type IDH catalyzes the interconversion of isocitrate to α-ketoglutarate (α-KG. Mutations in the enzyme lead to loss of wild-type enzymatic activity and a neomorphic activity that converts α-KG to 2-hydroxyglutarate (2-HG. In turn, 2-HG, which has been termed an oncometabolite, inhibits key α-KG- dependent enzymes, resulting in alterations of the cellular epigenetic profile and, subsequently, inhibition of differentiation and initiation of tumorigenesis. In addition, it is now clear that the IDH mutation also induces a broad metabolic reprogramming that extends beyond 2-HG production, and this reprogramming often differs from what has been previously reported in other cancer types. In this review we will discuss in detail what is known to date about the metabolic reprogramming of mutant IDH cells and how this reprogramming has been investigated using molecular metabolic imaging. We will describe how metabolic imaging has helped shed light on the basic biology of mutant IDH cells and how this information can be leveraged to identify new therapeutic targets and to develop new clinically translatable imaging methods to detect and monitor mutant IDH tumors in vivo.

  8. Mutant p53 protein localized in the cytoplasm inhibits autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Tasdemir, Ezgi; Maiuri, Maria Chiara; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Vicencio, José Miguel; Soussi, Thierry; Kroemer, Guido

    2008-10-01

    The knockout, knockdown or chemical inhibition of p53 stimulates autophagy. Moreover, autophagy-inducing stimuli such as nutrient depletion, rapamycin or lithium cause the depletion of cytoplasmic p53, which in turn is required for the induction of autophagy. Here, we show that retransfection of p53(-/-) HCT 116 colon carcinoma cells with wild type p53 decreases autophagy down to baseline levels. Surprisingly, one third among a panel of 22 cancer-associated p53 single amino acid mutants also inhibited autophagy when transfected into p53(-/-) cells. Those variants of p53 that preferentially localize to the cytoplasm effectively repressed autophagy, whereas p53 mutants that display a prominently nuclear distribution failed to inhibit autophagy. The investigation of a series of deletion mutants revealed that removal of the DNA-binding domain from p53 fails to interfere with its role in the regulation of autophagy. Altogether, these results identify the cytoplasmic localization of p53 as the most important feature for p53-mediated autophagy inhibition. Moreover, the structural requirements for the two biological activities of extranuclear p53, namely induction of apoptosis and inhibition of autophagy, are manifestly different.

  9. [Minor beta thalassemia masked by a hemoglobin A2 mutant].

    Science.gov (United States)

    Omar, Souheil; Hammami, Mohamed Bassem; Taeib, Sameh Haj; Feki, Moncef; Abbes, Salem; Kaabachi, Naziha

    2010-09-01

    The elevation of hemoglobin A2 (HbA2) is an essential criterion in the diagnosis of minor ss thalassemia. To report a case of minor ss thalassemia HbA2 with normal HbA2 rate. We report the case of ten years old boy, with hypochromic microcytic anemia, refractory to iron treatment. The study of hemoglobin (Hb) has revealed the presence of a minor abnormal fraction of Hb, amounted to 2.8%, associated with the presence of HbF and normal levels of HbA2. Family study revealed the presence of two Hb abnormalities (ss thalassemia trait and HbA2 mutant) transmitted to offspring in isolation or associated. The genotypic study confirmed the presence of minor, 0 thalassemia and a ⁰/₀₀ gene mutation, causing a new mutant HbA2 named HbA2 Pasteur-Tunis [⁰/₀₀ 59(E3)LysgAsn(AAGgAAC)]. The presence of ⁰/₀₀ mutant reduces HbA2 level and could hide ss thalassemia trait. Rigorous and methodical interpretation of phenotypic data is crucial to not overlook the presence of ss thalassemia trait, whose diagnosis is crucial for genetic counseling and prenatal diagnosis.

  10. Characterization and Fine Mapping of the ibf Mutant in Rice

    Institute of Scientific and Technical Information of China (English)

    Jiajun Cui; Shengci Fan; Tian Shao; Zejun Huang; Dali Zheng; Ding Tang; Ming Li; Qian Qian; Zhukuan Cheng

    2007-01-01

    The pigment is an important character in plant development. In the present study, we characterized and fine mapped one inhibitor for brown furrows gene (ibf) in rice (Oryza sativa L.). in the Ibf mutant, brown pigments specifically accumulate in the furrows of hulls as seeds mature and reach a maximum level in dry seeds. Genetic analysis showed that the mutant phenotype is controlled by one recessive nuclear gene, which was finally mapped in a 90-kb reglon on the long arm of chromosome 9. Polymerase chain reaction and Southern blotting analysis revealed that there was a 26 kb deletion in the 90-kb region in the mutant. Since all the open reading frames outside the gap in the delimited reglon had no detectable difference in DNA sequence with the wild-type, we postulated that the Ibf locus should be located in the gap. Through gene annotation and reverse transcription-polymerase chain reaction (RT-PCR) analysis, we selected OsKF1 encoding a kelch repeat-containing F-box family protein as the candidate gene of ibf.

  11. Potent inhibition of HIV-1 replication by a Tat mutant.

    Science.gov (United States)

    Meredith, Luke W; Sivakumaran, Haran; Major, Lee; Suhrbier, Andreas; Harrich, David

    2009-11-10

    Herein we describe a mutant of the two-exon HIV-1 Tat protein, termed Nullbasic, that potently inhibits multiple steps of the HIV-1 replication cycle. Nullbasic was created by replacing the entire arginine-rich basic domain of wild type Tat with glycine/alanine residues. Like similarly mutated one-exon Tat mutants, Nullbasic exhibited transdominant negative effects on Tat-dependent transactivation. However, unlike previously reported mutants, we discovered that Nullbasic also strongly suppressed the expression of unspliced and singly-spliced viral mRNA, an activity likely caused by redistribution and thus functional inhibition of HIV-1 Rev. Furthermore, HIV-1 virion particles produced by cells expressing Nullbasic had severely reduced infectivity, a defect attributable to a reduced ability of the virions to undergo reverse transcription. Combination of these inhibitory effects on transactivation, Rev-dependent mRNA transport and reverse transcription meant that permissive cells constitutively expressing Nullbasic were highly resistant to a spreading infection by HIV-1. Nullbasic and its activities thus provide potential insights into the development of potent antiviral therapeutics that target multiple stages of HIV-1 infection.

  12. Potent inhibition of HIV-1 replication by a Tat mutant.

    Directory of Open Access Journals (Sweden)

    Luke W Meredith

    Full Text Available Herein we describe a mutant of the two-exon HIV-1 Tat protein, termed Nullbasic, that potently inhibits multiple steps of the HIV-1 replication cycle. Nullbasic was created by replacing the entire arginine-rich basic domain of wild type Tat with glycine/alanine residues. Like similarly mutated one-exon Tat mutants, Nullbasic exhibited transdominant negative effects on Tat-dependent transactivation. However, unlike previously reported mutants, we discovered that Nullbasic also strongly suppressed the expression of unspliced and singly-spliced viral mRNA, an activity likely caused by redistribution and thus functional inhibition of HIV-1 Rev. Furthermore, HIV-1 virion particles produced by cells expressing Nullbasic had severely reduced infectivity, a defect attributable to a reduced ability of the virions to undergo reverse transcription. Combination of these inhibitory effects on transactivation, Rev-dependent mRNA transport and reverse transcription meant that permissive cells constitutively expressing Nullbasic were highly resistant to a spreading infection by HIV-1. Nullbasic and its activities thus provide potential insights into the development of potent antiviral therapeutics that target multiple stages of HIV-1 infection.

  13. Cystinosis (ctns) zebrafish mutant shows pronephric glomerular and tubular dysfunction

    Science.gov (United States)

    Elmonem, Mohamed A.; Khalil, Ramzi; Khodaparast, Ladan; Khodaparast, Laleh; Arcolino, Fanny O.; Morgan, Joseph; Pastore, Anna; Tylzanowski, Przemko; Ny, Annelii; Lowe, Martin; de Witte, Peter A.; Baelde, Hans J.; van den Heuvel, Lambertus P.; Levtchenko, Elena

    2017-01-01

    The human ubiquitous protein cystinosin is responsible for transporting the disulphide amino acid cystine from the lysosomal compartment into the cytosol. In humans, Pathogenic mutations of CTNS lead to defective cystinosin function, intralysosomal cystine accumulation and the development of cystinosis. Kidneys are initially affected with generalized proximal tubular dysfunction (renal Fanconi syndrome), then the disease rapidly affects glomeruli and progresses towards end stage renal failure and multiple organ dysfunction. Animal models of cystinosis are limited, with only a Ctns knockout mouse reported, showing cystine accumulation and late signs of tubular dysfunction but lacking the glomerular phenotype. We established and characterized a mutant zebrafish model with a homozygous nonsense mutation (c.706 C > T; p.Q236X) in exon 8 of ctns. Cystinotic mutant larvae showed cystine accumulation, delayed development, and signs of pronephric glomerular and tubular dysfunction mimicking the early phenotype of human cystinotic patients. Furthermore, cystinotic larvae showed a significantly increased rate of apoptosis that could be ameliorated with cysteamine, the human cystine depleting therapy. Our data demonstrate that, ctns gene is essential for zebrafish pronephric podocyte and proximal tubular function and that the ctns-mutant can be used for studying the disease pathogenic mechanisms and for testing novel therapies for cystinosis. PMID:28198397

  14. Inositol depletion restores vesicle transport in yeast phospholipid flippase mutants.

    Science.gov (United States)

    Yamagami, Kanako; Yamamoto, Takaharu; Sakai, Shota; Mioka, Tetsuo; Sano, Takamitsu; Igarashi, Yasuyuki; Tanaka, Kazuma

    2015-01-01

    In eukaryotic cells, type 4 P-type ATPases function as phospholipid flippases, which translocate phospholipids from the exoplasmic leaflet to the cytoplasmic leaflet of the lipid bilayer. Flippases function in the formation of transport vesicles, but the mechanism remains unknown. Here, we isolate an arrestin-related trafficking adaptor, ART5, as a multicopy suppressor of the growth and endocytic recycling defects of flippase mutants in budding yeast. Consistent with a previous report that Art5p downregulates the inositol transporter Itr1p by endocytosis, we found that flippase mutations were also suppressed by the disruption of ITR1, as well as by depletion of inositol from the culture medium. Interestingly, inositol depletion suppressed the defects in all five flippase mutants. Inositol depletion also partially restored the formation of secretory vesicles in a flippase mutant. Inositol depletion caused changes in lipid composition, including a decrease in phosphatidylinositol and an increase in phosphatidylserine. A reduction in phosphatidylinositol levels caused by partially depleting the phosphatidylinositol synthase Pis1p also suppressed a flippase mutation. These results suggest that inositol depletion changes the lipid composition of the endosomal/TGN membranes, which results in vesicle formation from these membranes in the absence of flippases.

  15. Temperature Sensitivity of Neural Tube Defects in Zoep Mutants.

    Science.gov (United States)

    Ma, Phyo; Swartz, Morgan R; Kindt, Lexy M; Kangas, Ashley M; Liang, Jennifer Ostrom

    2015-12-01

    Neural tube defects (NTD) occur when the flat neural plate epithelium fails to fold into the neural tube, the precursor to the brain and spinal cord. Squint (Sqt/Ndr1), a Nodal ligand, and One-eyed pinhead (Oep), a component of the Nodal receptor, are required for anterior neural tube closure in zebrafish. The NTD in sqt and Zoep mutants are incompletely penetrant. The penetrance of several defects in sqt mutants increases upon heat or cold shock. In this project, undergraduate students tested whether temperature influences the Zoep open neural tube phenotype. Single pairs of adults were spawned at 28.5°C, the normal temperature for zebrafish, and one half of the resulting embryos were moved to 34°C at different developmental time points. Analysis of variance indicated temperature and clutch/genetic background significantly contributed to the penetrance of the open neural tube phenotype. Heat shock affected the embryos only at or before the midblastula stage. Many factors, including temperature changes in the mother, nutrition, and genetic background, contribute to NTD in humans. Thus, sqt and Zoep mutants may serve as valuable models for studying the interactions between genetics and the environment during neurulation.

  16. Identification of Pfdhfr mutant variants in Plasmodium berghei model

    Directory of Open Access Journals (Sweden)

    Chairat Uthaipibull

    2011-12-01

    Full Text Available Parasite resistance to antimalarials is a major burden in controlling malaria disease. Genetic mutations within the parasites are found to be the factor in conferring resistance to drugs. In this study, the power of random mutant library and transgenic parasite systems were employed to identify mutations on the antimalarial drug target, viz. Plasmodium falciparum dihydrofolate reductase (DHFR, which could contribute to resistance, and to elucidate the functionality of resistant mutant parasites in P. berghei. Using the moderate drug-resistant PfdhfrS108N gene as template, we generated a library of Pfdhfr mutants by error-prone PCR followed by transfection and selection in P. berghei. Two clones of transgenic P. berghei expressing PfDHFR of interest due to the position of mutations, i.e. PbPfDHFR3m1 (M55I+S108N+S189C and PbPfDHFR3m2 (C50Y+S108N+F116S, were selected for drug sensitivity test. Although these transgenic parasite clones showed similar reproducibility with the parental transgenic P. berghei, expressing PfDHFR with mutation at S108N (PbPfS108N in response to antifolate pyrimethamine, this study reconfirms that this P. berghei model is effective in predicting the evolution of Pfdhfr mutations in vivo. This approach can be applied during the development of new antifolates with better effective properties against drug resistant parasites.

  17. Genes and Alcohol Consumption: Studies with Mutant Mice

    Science.gov (United States)

    Mayfield, Jody; Arends, Michael A.; Harris, R. Adron; Blednov, Yuri A.

    2017-01-01

    In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test. PMID:27055617

  18. Genes and Alcohol Consumption: Studies with Mutant Mice.

    Science.gov (United States)

    Mayfield, J; Arends, M A; Harris, R A; Blednov, Y A

    2016-01-01

    In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test.

  19. Pattern formation mechanisms in motility mutants of Myxococcus xanthus

    CERN Document Server

    Starruss, Joern; Jakovljevic, Vladimir; Sogaard-Andersen, Lotte; Deutsch, Andreas; Baer, Markus

    2016-01-01

    Formation of spatial patterns of cells is a recurring theme in biology and often depends on regulated cell motility. Motility of M. xanthus depends on two motility machineries: the S-engine and A-engine. Moving M. xanthus cells can organize into spreading colonies or spore-filled fruiting bodies depending on their nutritional status. To understand these two pattern formation processes and the contributions by the two motility machineries, as well as cell reversal, we analyze spatial self-organization in 3 strains: i) a mutant that moves unidirectionally without reversing by the A-motility system only, ii) a unidirectional mutant that is also equipped with the S-motility system, and iii) the wild-type that, in addition to the two motility systems, reverses its direction of movement. The mutant moving by the A-engine illustrates that collective motion in the form of large moving clusters can arise in gliding bacteria due to steric interactions of the rod-shaped cells, without the need of invoking any biochemica...

  20. 番茄玉米间作对番茄叶片光合特性的影响%Influences of Tomato (Lycopersicon esculentum )/Maize (Zea mays L.) Intercropping on Photosynthetic Characteristics of Tomato Leaves

    Institute of Scientific and Technical Information of China (English)

    董华芳

    2012-01-01

    [Objective] The purpose was to discuss tomato leaves photosynthetic characteristics under tomato/maize intercropping. [Method] The 3 tomato varieties ( 6629, Jinaihong and Yuxing) and 2 maize varieties(Tiannuo8hao and Tianmi2hao) were used to study the influences of tomato/ maize intercropping on photosynthetic characteristics of tomato leaves by using the Ii-6400 portable photosynthesis system. [Result] The results showed that there were highly significant differences on the net photosynthetic rate, conductance to H2O and the intercellular CO2 concentration of tomato leaves between tomato/maize intercropping and monoculture. The net photosynthetic rate and conductance to H2O of tomato leaves under tomato/maize intercropping were decreased significantly compared with monoculture. The intercellular C02 concentration of tomato leaves under tomato/maize intercropping was increased significantly compared with monoculture. But the influences to 3 varieties were different, the influences to 6629 was lower relatively, and the Jinaihong and Yuxing were larger relatively. [ Conclusion] The study provides a theoretical basis for tomato cultivation and management.%[目的]探讨番茄(Lycopersicon esculentum)玉米(Zea mays L.)间作条件下的番茄叶片光合特性.[方法]以6629、金矮红、豫星3个番茄品种和甜糯八号、田蜜二号2个玉米品种为试验材料,将番茄与玉米进行间作,利用Li-6400便携式光合仪在自然光照条件下,测定番茄叶片的净光合速率、气孔导度等参数.[结果]番茄玉米间作降低了番茄叶片的净光合速率和气孔导度,增大了其叶片胞间CO2浓度,与单作相比,差异均达到了极显著水平.不同番茄品种变化幅度不同,其中6629受影响较小,金矮红和豫星受影响较大.[结论]该研究可为番茄栽培管理提供理论依据.

  1. Effects of Oscillating Pollination on Fruit Setting, Production and Quality of Tomato(Lycopersicon esculentum) in Spring%振荡授粉在春番茄坐果及产量品质上的效果

    Institute of Scientific and Technical Information of China (English)

    李军; 孔庆祥; 刘凤军; 王先龙; 高娟

    2012-01-01

    [Objective] The aim was to discuss the effects of oscillating pollination on fruit setting, production and quality of tomato in spring, and find out a new no hormone pollination method for tomato. [ Method ] The rate of fruii setting, speed of fruit setting, speed of fruit enlargement, production and quality of tomato treated by oscillating pollination, applying Fanqieling and natural pollination were comparatively analyzed in spring. [ Result] The results showed that oscillating pollination could improve setting rate and growth of fruit. The fruit setting rate was the highest in three treatments on first truss fruit after applying Fanqieling, while it was the highest on second and third truss after oscillating pollination. The bunch uniformity, fruit enlargement speed, early - stage yield were higher with applying Fanqieling than those with oscillating pollination. The content of solution sugar was significant lower with oscillating pollination than that with natural pollination, while the content of lycopene was significant higher. [ Conclusion ] Oscillating pollination can replace Fanqieling to promote tomato fruit setting, and realize no hormone tomato production.%[目的]探讨振荡授粉对春番茄(Lycopersicon esculentum)坐果、产量和品质的影响,以寻找一种番茄无激素授粉的新方法.[方法]以春番茄为材料,对比振荡授粉、施用番茄灵和自然授粉对其坐果率、坐果速度、番茄果实膨大速度、产量和品质的影响.[结果]与自然授粉相比,振荡授粉与施用番茄灵增加了番茄的坐果率,促进了果实发育.第1穗花坐果率施用番茄灵较好,在第2、3穗花上振荡授粉较好.振荡授粉在坐果整齐度、果实膨大连度及早期产量等方面不如施用番茄灵.振荡授粉的番茄可溶性糖含量稍差于自然授粉,但番茄红素含量显著升高.[结论]振荡授粉可以代替番茄灵促进番茄坐果,实现无激素番茄生产.

  2. Habilidad combinatoria para el carácter producción por planta y sus componentes primarios en un cruzamiento dialélico de siete líneas de tomate "Chonto" Lycopersicon esculentum, Mill

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    1990-06-01

    Full Text Available Se evaluaron siete líneas progenitoras de tomate "Chonto" (Ángela Gigante, Licapal21, Raminho, Olho Roxo, 1258,1475 Y 1507 y 21 híbridos, sin incluir los recíprocos, mediante el método experimental 2 y modelo tipo 1 propuesto por Griffing (1956. En la expresión de los caracteres producción por planta y peso promedio de fruto se encontraron diferencias significativas tanto para la habilidad combinatoria general (acción génica aditiva como para la habilidad combinatoria específica (acción génica no aditiva, pero con predominio de ésta última. En la expresión del carácter número de frutos por planta se encontró diferencias para los dos tipos de habilidad combinatoria pero, con predominio de la acción génica aditiva. Los híbridos Licapal 21 x Raminho, Ángela Gigante x 1258 y Ángela Gigante x Raminho exhibieron los mayores efectos de habilidad combinatoria específica y los mayores valores promedios, para el carácter producción por planta.An analysis of combining ability of traits related with production per plant was carried out using a diallel crossing between different "Chonto" tomato cultivar, Lycopersicon esculentum Mill. (Seven parents and 21 F1 hybrids from all possible crossing in one direction, according to the methodology propose d by Griffing (1956, selecting experimental method 2, and model. Significant differences were found for the two types of combining ability (g.c.a. and s.c.a. on the expression of the characters production per plant, fruits per plant and fruit mean weight. A non-additive gene action was prevailing for the characters production per plant and fruit mean weight. Hybrids Licapal- 21 x Raminho, Angela Gigante x 1258 and Angela Gigante x Rarninho, exhibited high s.c.a. effects and heigh mean production per plant.

  3. In silico screening of 393 mutants facilitates enzyme engineering of amidase activity in CalB

    Directory of Open Access Journals (Sweden)

    Martin R. Hediger

    2013-08-01

    Full Text Available Our previously presented method for high throughput computational screening of mutant activity (Hediger et al., 2012 is benchmarked against experimentally measured amidase activity for 22 mutants of Candida antarctica lipase B (CalB. Using an appropriate cutoff criterion for the computed barriers, the qualitative activity of 15 out of 22 mutants is correctly predicted. The method identifies four of the six most active mutants with ≥3-fold wild type activity and seven out of the eight least active mutants with ≤0.5-fold wild type activity. The method is further used to screen all sterically possible (386 double-, triple- and quadruple-mutants constructed from the most active single mutants. Based on the benchmark test at least 20 new promising mutants are identified.

  4. dnaA suppressor (dasF) mutants of Escherichia coli are stable DNA replication (sdrA/rnh) mutants.

    Science.gov (United States)

    Torrey, T A; Atlung, T; Kogoma, T

    1984-01-01

    The possible allelic relationship between dasF (dnaA suppressor) and sdrA/rnh (stable DNA replication/RNase H) mutations was examined. dasF mutations could not only suppress various dnaA(ts) mutations, but also the insertional inactivation of the dnaA gene or deletion of the oriC sequence, as could sdrA mutations. dasF mutants were found to exhibit the stable DNA replication phenotype, and the sensitivity to rich media, of sdrA mutants. The dasF and sdrA mutations were mapped very closely between metD and proA on the E. coli genetic map. The mutations were recessive to the wild-type allele for all the above phenotypes. It was concluded that dasF is allelic to sdrA/mh.

  5. Lü Shengrong Competes Internationally

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Little-known by her Chinese compatriots but wellknown in the international sports world, L(?) Shengrong,president of the International Badminton Federation (IBF) and member of the International Olympic Committee (IOC), has had a legendary career.

  6. Properties of Streptomyces fradiae Mutants Blocked in Biosynthesis of the Macrolide Antibiotic Tylosin

    OpenAIRE

    Baltz, Richard H.; Seno, Eugene T.

    1981-01-01

    We isolated numerous mutants of Streptomyces fradiae blocked in tylosin biosynthesis after N-methyl-N′-nitro-N-nitrosoguanidine mutagenesis. These mutants were classified into nine groups, based upon the tylosin-like compounds produced and upon cofermentation analyses. More than 80% of the mutants isolated produced no tylosin-like compounds, and the majority of these were blocked only in the formation of tylactone. Four classes of mutants blocked in the biosynthesis or addition of tylosin sug...

  7. Gibberellins and Carotenoids in the Wild Type and Mutants of Gibberella fujikuroi

    OpenAIRE

    1991-01-01

    A new screening procedure was used to isolate 14 gib mut ts of Gi!'berella_ fujikurof wit modi cations the production of gibberellins. The production of carotenmds and g bberellms was mvestlgated m the gib mutants and in representative car mutants with various modifications of carotenoid biosynthesis. The determinations of gibberellins were carried out with a simplified ftuorescence method. One of the mutants lacked both gibberellins and carotenoids. In many mutants the two path...

  8. Mutants as an aid to the study of higher plant photomorphogenesis.

    OpenAIRE

    Adamse, P.

    1988-01-01

    Study of photomorphogenesis is often complicated by the interaction of different photoreceptors regulating a given process or by the induction of multiple effects by a single photoreceptor. Mutants in which particular components of the morphogenetic pathways are eliminated provide the possibility of studying a more simplified form of photomorphogenesis. Three classes of photomorphogenetic mutants are proposed: photoreceptor, transduction chain and response mutants. In this study three mutants...

  9. Isolation and characterization of Streptococcus mutans mutants defective in adherence and aggregation.

    OpenAIRE

    Murchison, H; Larrimore, S; Curtiss, R

    1981-01-01

    A method was developed which enriched for mutants of Streptococcus mutans that exhibit defects in adherence to glass, aggregation, or both. Mutants were isolated from derivatives of strains PS14 (serotype c) and 6715 (serotype g) after mutagenesis with either ethyl methane sulfonate or nitrous acid. Cell survival after mutagenesis was kept above 1 to 2% to enhance the probability that mutants resulted from single mutational events. A total of 117 mutants were isolated; they also displayed non...

  10. Production of Extracellular Pigment by a Mutant of Monascus kaoliang sp. nov

    OpenAIRE

    Lin, Ching-Fwu; Iizuka, Hiroshi

    1982-01-01

    A hyperpigment-producing mutant, R-10847, was derived from Monascus kaoliang F-2 (ATCC 26264) through a series of mutagenesis steps. The mutant produced a large quantity of Monascus pigment when grown in mantou (steamed bread) by solid culture. The mutant produced pigments extracellularly by extruding the pigments outside the cell in a lump together with some viscous substances. The productivity of pigment was about 100-fold greater than that of the wild type. The mutant lost the capability o...

  11. Properties of Streptomyces fradiae Mutants Blocked in Biosynthesis of the Macrolide Antibiotic Tylosin

    OpenAIRE

    Baltz, Richard H; Seno, Eugene T.

    1981-01-01

    We isolated numerous mutants of Streptomyces fradiae blocked in tylosin biosynthesis after N-methyl-N′-nitro-N-nitrosoguanidine mutagenesis. These mutants were classified into nine groups, based upon the tylosin-like compounds produced and upon cofermentation analyses. More than 80% of the mutants isolated produced no tylosin-like compounds, and the majority of these were blocked only in the formation of tylactone. Four classes of mutants blocked in the biosynthesis or addition of tylosin sug...

  12. Grain product of 34 soya mutant lines;Rendimiento de grano de 34 lineas mutantes de soya

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron E, J.; Mastache L, A. A.; Valencia E, F.; Diaz V, G. E. [Colegio Superior Agropecuario del Estado de Guerrero, Vicente Guerrero No. 81, Col. Centro, 40000 Iguala, Guerrero (Mexico); Cervantes S, T. [Instituto de Recursos Geneticos y Productividad, Colegio de Posgraduados, Carretera Mexico-Texcoco Km. 36.5, Montecillo, 56230 Texcoco, Estado de Mexico (Mexico); De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.; Gatica T, M. A. [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R{sub 4}M{sub 18}) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co{sup 60} gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L{sub 25} and L{sub 32} produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

  13. New non detrimental DNA binding mutants of the Escherichia coli initiator protein DnaA

    DEFF Research Database (Denmark)

    Asklund, Marlene; Atlung, Tove

    2004-01-01

    an extensive mutational analysis of the DNA-binding domain of the Escherichia coli DnaA protein using mutagenic PCR. We analyzed mutants exhibiting more or less partial activity by selecting for complementation of a dnaA(Ts) mutant strain at different expression levels of the new mutant proteins. The selection...

  14. Photocontrol of seed germination of wild type and long-hypocotyl mutants of Arabidopsis thaliana

    NARCIS (Netherlands)

    Cone, J.W.

    1985-01-01

    This thesis reports research on the photocontrol of seed germination of wildtype and long-hypocotyl mutants of Arabidopsis thaliana. The mutants show reduced photoinhibition of hypocotyl growth in white light in comparison to that of wildtype. In monochromatic light some of the mutants also show no

  15. Blue ghosts: a new method for isolating amber mutants defective in essential genes of Escherichia coli

    DEFF Research Database (Denmark)

    Brown, S; Brickman, E R; Beckwith, J

    1981-01-01

    We describe a technique which permits an easy screening for amber mutants defective in essential genes of Escherichia coli. Using this approach, we have isolated three amber mutants defective in the rho gene. An extension of the technique allows the detection of ochre mutants and transposon inser...

  16. An improved method for rapid generation and screening of Bacillus thuringiensis phage-resistant mutants.

    Science.gov (United States)

    Gillis, Annika; Mahillon, Jacques

    2014-11-01

    A simple method to isolate, screen and select phage-resistant mutants of Bacillus thuringiensis was developed. The traditional double-layer agar method was improved by a combination of the spotting assay using a lytic phage, to generate the bacterial-resistant mutants, with an inverted spotting assay (ISA), to rapidly screen the candidate-resistant mutants.

  17. Inverse polymerase chain reaction for rapid gene isolation in Arabidopsis thaliana insertion mutants

    NARCIS (Netherlands)

    Vanderhaeghen, R.; Scheres, B.J.G.; Montagu, M. van; Lijsebetten, M. van

    1992-01-01

    Recently, many mutants have been isolated in the model plant Arabidopsis thaliana by the insertion of the Agrobacterium tumefaciens T-DNA into the plant genome. Instead of applying Southern analysis on these insertion mutants and to avoid the construction of mutant- derived genomic libraries, we pro

  18. Surveying your internal customers.

    Science.gov (United States)

    Weir, V L

    1998-06-01

    Internal customers often are overlooked when business techniques are applied. By applying common external customer satisfaction survey techniques to internal business functions, one hospital identified areas for improvement.

  19. TAE226, a Bis-Anilino Pyrimidine Compound, Inhibits the EGFR-Mutant Kinase Including T790M Mutant to Show Anti-Tumor Effect on EGFR-Mutant Non-Small Cell Lung Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Hiroki Otani

    Full Text Available TAE226, a bis-anilino pyrimidine compound, has been developed as an inhibitor of focal adhesion kinase (FAK and insulin-like growth factor-I receptor (IGF-IR. In this study, we investigated the effect of TAE226 on non-small-cell lung cancer (NSCLC, especially focusing on the EGFR mutational status. TAE226 was more effective against cells with mutant EGFR, including the T790M mutant, than against cells with wild-type one. TAE226 preferentially inhibited phospho-EGFR and its downstream signaling mediators in the cells with mutant EGFR than in those with wild-type one. Phosphorylation of FAK and IGF-IR was not inhibited at the concentration at which the proliferation of EGFR-mutant cells was inhibited. Results of the in vitro binding assay indicated significant differences in the affinity for TAE226 between the wild-type and L858R (or delE746_A750 mutant, and the reduced affinity of ATP to the L858R (or delE746_A750 mutant resulted in good responsiveness of the L858R (or delE746_A750 mutant cells to TAE226. Of interest, the L858R/T790M or delE746_A750/T790M mutant enhanced the binding affinity for TAE226 compared with the L858R or delE746_A750 mutant, resulting in the effectiveness of TAE226 against T790M mutant cells despite the T790M mutation restoring the ATP affinity for the mutant EGFR close to that for the wild-type. TAE226 also showed higher affinity of about 15-fold for the L858R/T790M mutant than for the wild-type one by kinetic interaction analysis. The anti-tumor effect against EGFR-mutant tumors including T790M mutation was confirmed in mouse models without any significant toxicity. In summary, we showed that TAE226 inhibited the activation of mutant EGFR and exhibited anti-proliferative activity against NSCLCs carrying EGFR mutations, including T790M mutation.

  20. Fate of a Pseudomonas savastanoi pv. savastanoi type III secretion system mutant in olive plants (Olea europaea L.).

    Science.gov (United States)

    Pérez-Martínez, Isabel; Rodríguez-Moreno, Luis; Lambertsen, Lotte; Matas, Isabel M; Murillo, Jesús; Tegli, Stefania; Jiménez, Antonio J; Ramos, Cayo

    2010-06-01

    Pseudomonas savastanoi pv. savastanoi strain NCPPB 3335 is a model bacterial pathogen for studying the molecular basis of disease production in woody hosts. We report the sequencing of the hrpS-to-hrpZ region of NCPPB 3335, which has allowed us to determine the phylogenetic position of this pathogen with respect to previously sequenced Pseudomonas syringae hrp clusters. In addition, we constructed a mutant of NCPPB 3335, termed T3, which carries a deletion from the 3' end of the hrpS gene to the 5' end of the hrpZ operon. Despite its inability to multiply in olive tissues and to induce tumor formation in woody olive plants, P. savastanoi pv. savastanoi T3 can induce knot formation on young micropropagated olive plants. However, the necrosis and formation of internal open cavities previously reported in knots induced by the wild-type strain were not observed in those induced by P. savastanoi pv. savastanoi T3. Tagging of P. savastanoi pv. savastanoi T3 with green fluorescent protein (GFP) allowed real-time monitoring of its behavior on olive plants. In olive plant tissues, the wild-type strain formed aggregates that colonized the intercellular spaces and internal cavities of the hypertrophic knots, while the mutant T3 strain showed a disorganized distribution within the parenchyma of the knot. Ultrastructural analysis of knot sections revealed the release of extensive outer membrane vesicles from the bacterial cell surface of the P. savastanoi pv. savastanoi T3 mutant, while the wild-type strain exhibited very few vesicles. This phenomenon has not been described before for any other bacterial phytopathogen during host infection.