Search results for "Solanum lycopersicum"
showing 10 items of 103 documents
Amino acids in the second transmembrane helix of the Lhca4 subunit are important for formation of stable heterodimeric light-harvesting complex LHCI-…
2007
Photosynthetic light-harvesting complexes (LHCs) are assembled from apoproteins (Lhc proteins) and non-covalently attached pigments. Despite a considerable amino acid sequence identity, these proteins differ in their oligomerization behavior. To identify the amino acid residues determining the heterodimerization of Lhca1 and Lhca4 to form LHCI-730, we mutated the poorly conserved second transmembrane helix of the two subunits. Mutated genes were expressed in Escherichia coli and the resultant proteins were refolded in vitro and subsequently analyzed by gel electrophoresis. Replacement of the entire second helix in Lhca4 by the one of Lhca3 abolished heterodimerization, whereas it had no eff…
Chlorophyll a fluorescence, antioxidant enzymes and lipid peroxidation in tomato in response to ozone and benomyl
2001
Ozone is a widely distributed phytotoxic air pollutant and is known to reduce the yield of several important agricultural crops in Spain. However, benomyl has been found to lessen the adverse impact of ozone on plants. We studied the effects of ozone and benomyl on chlorophyll a fluorescence, antioxidant enzymes, and lipid peroxidation in tomato (Lycopersicon esculentum Mill. cv. Tiny Tim) grown in open-top chambers in the field. Our results indicate that benomyl prevented the peroxidation of membrane lipids and increased protection of PSII from ozone. There was also a significant reduction in the activity of the antioxidant enzyme superoxide dismutase in ozone-exposed plants that had not b…
Colonization pattern of primary tomato roots by Pseudomonas fluorescens A6RI characterized by dilution plating, flow cytometry, fluorescence, confoca…
2004
Early colonization of primary tomato roots, grown in vitro, by Pseudomonas fluorescens A6RI, introduced by seed bacterization, was monitored for 7 days in three different root zones (zone A, apex+elongation+young hairy zone; zone B, hairy zone; zone C, old hairy zone+collar). Bacterial quantification was assessed by enumeration of (i) colony forming units (cfu) after dilution plating and of (ii) total bacterial cells by flow cytometry. Bacterial distribution and organization in the root zones were analyzed by fluorescence, confocal and scanning electron microscopy. For all sampling dates and zones, the densities of total bacterial cells were significantly higher than those of the cfu. The k…
Pseudomonas corrugata crpCDE is part of the cyclic lipopeptide corpeptin biosynthetic gene cluster and is involved in bacterial virulence in tomato a…
2014
Summary: Pseudomonas corrugataCFBP 5454 produces two kinds of cyclic lipopeptides (CLPs), cormycin A and corpeptins, both of which possess surfactant, antimicrobial and phytotoxic activities. In this study, we identified genes coding for a putative non-ribosomal peptide synthetase and an ABC-type transport system involved in corpeptin production. These genes belong to the same transcriptional unit, designated crpCDE. The genetic organization of this locus is highly similar to other PseudomonasCLP biosynthetic clusters. Matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis revealed that transporter and synthetase genomic knock-out mutants were u…
The Implication of Xyloglucan Endotransglucosylase/Hydrolase (XTHs) in Tomato Fruit Infection by Penicillium expansum Link. A
2007
In general, cell wall-degrading enzymes produced by plant pathogenic fungi are considered important pathogenicity factors. In this work, we evaluate the implication of xyloglucan endotransglucosylase/ hydrolase (XTHs), a potential hemicellulosic repairing enzyme, in the infection mechanism process by the fungus. This study investigated the SIXTHS expresion and xyloglucan endotransglucosylase (XET) activity during infection of two tomato fruit cultivars by Penicillium expansum Link. A. In infected fruits, XET specific activity decreased drastically after long infection periods, 24 and 48 h for Canario and Money Maker tomato fruits, respectively. Real Time RT-PCR of eleven SIXTHS also showed …
Determination of -Ascorbic Acid in Lycopersicon Fruits by Capillary Zone Electrophoresis
2001
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 …
Two-stage anaerobic digestion of tomato, cucumber, common reed and grass silage in leach-bed reactors and upflow anaerobic sludge blanket reactors
2010
Abstract Anaerobic digestion of tomato, cucumber, common reed and grass silage was studied in four separate two-stage reactor configuration consisting of leach bed reactor (LBR) and upflow anaerobic sludge blanket reactor (UASB). LBR studies showed that COD solubilization for cucumber and grass silage was higher (50%) than tomato (35%) and common reed (15%). Results also showed that 31–39% of initial TKN present in tomato and cucumber was solubilized in the leachates and 47–54% of the solubilized TKN was converted to NH4-N. The corresponding values for common reed and grass silage were 38–50% and 18–36%, respectively. Biomethanation of the leachates in UASB reactors resulted in methane yiel…
Colonization of tomato root by pathogenic and nonpathogenic Fusarium oxysporum strains inoculated together and separately into the soil.
2006
ABSTRACT In soil, fungal colonization of plant roots has been traditionally studied by indirect methods such as microbial isolation that do not enable direct observation of infection sites or of interactions between fungal pathogens and their antagonists. Confocal laser scanning microscopy was used to visualize the colonization of tomato roots in heat-treated soil and to observe the interactions between a nonpathogenic strain, Fo47, and a pathogenic strain, Fol8, inoculated onto tomato roots in soil. When inoculated separately, both fungi colonized the entire root surface, with the exception of the apical zone. When both strains were introduced together, they both colonized the root surface…
The nuclear protein Sge1 of Fusarium oxysporum is required for parasitic growth
2009
Dimorphism or morphogenic conversion is exploited by several pathogenic fungi and is required for tissue invasion and/or survival in the host. We have identified a homolog of a master regulator of this morphological switch in the plant pathogenic fungus Fusarium oxysporum f. sp. lycopersici. This non-dimorphic fungus causes vascular wilt disease in tomato by penetrating the plant roots and colonizing the vascular tissue. Gene knock-out and complementation studies established that the gene for this putative regulator, SGE1 (SIX Gene Expression 1), is essential for pathogenicity. In addition, microscopic analysis using fluorescent proteins revealed that Sge1 is localized in the nucleus, is no…
Proteomic analysis of the photosystem I light-harvesting antenna in tomato (Lycopersicon esculentum).
2004
Until now, more genes of the light-harvesting antenna of higher-plant photosystem I (PSI) than proteins have been described. To improve our understanding of the composition of light-harvesting complex I (LHCI) of tomato (Lycopersicon esculentum), we combined one- and two-dimensional (1-D and 2-D, respectively) gel electrophoresis with immunoblotting and tandem mass spectrometry (MS/ MS). Separation of PSI with high-resolution 1-D gels allowed separation of five bands attributed to proteins of LHCI. Immunoblotting with monospecific antibodies and MS/MS analysis enabled the correct assignment of the four prominent bands to light-harvesting proteins Lhcal -4. The fifth band was recognized by o…