Angelos Kanellis
Aristotle University of Thessaloniki, School of Pharmacy, Faculty Member
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Research Interests: Botany, Plant Biology, Seed germination, Plant biotechnology, Salt Stress, and 27 moreDrought Stress, Plant Molecular Biology, Gene expression, Arabidopsis thaliana, Glutamate, Salt, Salinity, Experimental Botany, Water Stress, Line, Gene, Droughts, Tomato, Arabidopsis, SALT TOLERANCE, Transgenic plants, Drought tolerance, Germination, Gen, Genetically Modified, Amino Acid Profile, Amino Acid Sequence, PLANT PROTEINS, Sodium Chloride, Transgenic plant, Lycopersicon esculentum, and Molecular Sequence Data
Research Interests: Water, Plant Biology, Tobacco, Immunohistochemistry, Signal Transduction, and 17 moreCucumber, Experimental Botany, Water Stress, Stomata, Enzyme, Transgenic plants, Hydrogen Peroxide, Water Loss, Ascorbic Acid, Enzyme activity, Cell Wall, Water Content, Electric Conductivity, Transgenic plant, Apoplast, Plant Transpiration, and Stomatal Conductance
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Background: Salvia diterpenes have been found to have health promoting properties. Among them, carnosic acid and carnosol, tanshinones and sclareol are well known for their cardiovascular, antitumor, antiinflammatory and antioxidant... more
Background: Salvia diterpenes have been found to have health promoting properties. Among them, carnosic acid and carnosol, tanshinones and sclareol are well known for their cardiovascular, antitumor, antiinflammatory and antioxidant activities. However, many of these compounds are not available at a constant supply and developing biotechnological methods for their production could provide a sustainable alternative. The transcriptome of S.pomifera glandular trichomes was analysed aiming to identify genes that could be used in the engineering of synthetic microbial systems.
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The effect of 2.5% 02 atmosphere with and without ethylene on the activities of hydrolytic enzymes associated with cell walls, and total protein profile during ripening of avocado fruits (Persea americana Mill., cv Hass) were... more
The effect of 2.5% 02 atmosphere with and without ethylene on the activities of hydrolytic enzymes associated with cell walls, and total protein profile during ripening of avocado fruits (Persea americana Mill., cv Hass) were investigated. The low 2.5% 02 atmosphere prevented the rise in the activities of cellulase, polygalacturonase, and acid phosphatase in avocado fruits whose ripening was initiated with ethylene. Addition of 100 microliters per liter ethylene to low 02 atmosphere did not alter these suppressive effects of 2.5% 02. Furthermore, 2.5% 02 atmosphere delayed the development of a number of polypeptides that appear during ripening of avocado fruits while at the same time new polypeptides accumulated. The composition of the extraction buffer and its pH greatly affected the recovery of cellulase activity and its total immunoreactive protein.
Phenylalanine ammonia-lyase (PAL) is the first enzyme of phenylpropanoid biosynthesis involved in the synthesis of a multiplicity of plant natural products. We have isolated and characterized a nearly full- length cDNA clone (pmPAL-1)... more
Phenylalanine ammonia-lyase (PAL) is the first enzyme of phenylpropanoid biosynthesis involved in the synthesis of a multiplicity of plant natural products. We have isolated and characterized a nearly full- length cDNA clone (pmPAL-1) corresponding to a melon fruit (Cucumis melo L. var. reticulatus) gene coding for a protein which is highly similar to PAL from other plants. Melon fruit PAL is transcriptionally induced both in response to fruit ripening and wounding. PAL gene expression follows the kinetics of expression of the ethylene biosynthetic genes during fruit development. In contrast, ethylene biosynthetic genes show different induction kinetics compared to PAL expression in response to wounding. Simi- lar results have been found for two other genes coding for enzymes involved in flavonoid biosynthesis (chalcone synthase, CHS; chalcone isomerase, CHI). Our results imply that regulation of defense gene expression in melon is a co-ordinated process in response to both ethylene and an ethylene-independent wound signal.
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A small family of at least four genes encodingmelon ascorbateoxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologousto... more
A small family of at least four genes encodingmelon ascorbateoxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologousto ascorbate oxidasesfromotherplantsand similar to othermulticopperoxidases. We describedetailed molecular studies addressing melon AO expression during organ specific differentiation, fruit development and ripening, and in response to wounding. In particular, AO transcript accumulation was induced in ovaries and the outer mesocarp of mature preclimacteric melon fruits, before the expression of genes encoding the necessary enzymatic activities for ethylene biosynthesis. On the other hand, AO was not expressed in late stages of fruit ripening and was repressed in wounded fruits. The role of ethylene in transcriptional regulation of AO is discussed.
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ABSTRACT Thesis (Ph. D.)--University of Maryland, College Park, 1987. On t.p. "2" is subscript. Vita. Includes bibliographical references (leaves 100-112).
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ABSTRACT Ascorbate oxidase activity and ascorbic acid content were followed during the development of muskmelon (Cucumis melo L. var. reticulatus) fruits. The enzyme was highly expressed in ovaries and very young fruit tissues, followed... more
ABSTRACT Ascorbate oxidase activity and ascorbic acid content were followed during the development of muskmelon (Cucumis melo L. var. reticulatus) fruits. The enzyme was highly expressed in ovaries and very young fruit tissues, followed by a decrease in 10- and 20-d-old fruits and an increase in 30- and 35-d-old fruits which coincided with early events of fruit ripening. Ascorbic acid content was negatively correlated with ascorbate oxidase activity. The enzyme was purified to homogeneity following ion exchange, affinity and gel filtration chromatographic trials. The purified enzyme was a glycoprotein of molecular weight 137000 composed of two subunits of molecular weight 68000, and formed by six isoenzymes with isoelectric points in the range of pH 7.7 to 8.3. Its electron paramagnetic resonance and optical spectra were in agreement with other copper proteins and the enzyme contained eight copper atoms per dimeric molecule. The K-m of the enzyme for ascorbic acid was 50 mu M. Ascorbate oxidase activity was inhibited by azide and by EDTA, two inhibitors of copper proteins. Optimal conditions for enzyme activity was pH 5.5, and a temperature of 37 degrees C. Polyclonal antibodies were produced against the purified protein and immunoprecipitated ascorbate oxidase activity.
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The activity, protein, and isoenzymic profiles of glutamate de- hydrogenase (CDH) and glutamine synthetase (CS) were studied during development and ripening of avocado (Percea americana Mill. cv Hass) fruit. During fruit development, the... more
The activity, protein, and isoenzymic profiles of glutamate de- hydrogenase (CDH) and glutamine synthetase (CS) were studied during development and ripening of avocado (Percea americana Mill. cv Hass) fruit. During fruit development, the activity and protein content of both GDH and CS remained relatively constant. In contrast, considerable changes in these enzymes were observed during ripening of avocado fruit. The
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Citrus fruit is prone to develop peel pitting during development and storage, which greatly decreases its fresh market value because of the deterioration of the peel. In the present study, we have examined the effect of different... more
Citrus fruit is prone to develop peel pitting during development and storage, which greatly decreases its fresh market value because of the deterioration of the peel. In the present study, we have examined the effect of different temperatures (15 degrees C and 4 degrees C), waxing and mechanical damage on the changes in the activity of phenylalanine ammonia-lyase (PAL) and the incidence of peel pitting in 'Fengjie' navel orange (Citrus sinensis Osbeck) fruits. The expression levels of PAL2, PAL6 genes in the peel during the development of peel pitting have been investigated through semi-quantitative PCR method. The incidence of peel pitting was greatly enhanced by waxing and mechanical damage and was decreased in lower temperature storage (4 degrees C) (Fig.1). Waxing and mechanical damage might be the important factors inducing peel pitting and suitable low temperature could decrease the incidence of this disease. The PAL activity increased during the whole storage period i...
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Page 273. 10 Physiological, Biochemical, and Molecular Aspects of Ethylene Biosynthesis and Action JEAN-CLAUDE PECH, MONDHER BOUZAYEN, and ALAIN LATCHE Ecole Nationale Superieure Agronomique de Toulouse ...
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The activity, protein, and isoenzymic profiles of glutamate de-hydrogenase (GDH) and glutamine synthetase (GS) were studied during development and ripening of avocado (Percea americana Mill. cv Hass) fruit. During fruit development, the... more
The activity, protein, and isoenzymic profiles of glutamate de-hydrogenase (GDH) and glutamine synthetase (GS) were studied during development and ripening of avocado (Percea americana Mill. cv Hass) fruit. During fruit development, the activity and protein content of both GDH and GS remained relatively constant. In contrast, considerable changes in these enzymes were observed during ripening of avocado fruit. The specific activity of GDH increased about 4-fold, coincident with a similar increase in GDH protein content and mRNA levels. On the other hand, GS specific activity showed a decline at the end of the ripening process. On the isoenzymic profile of GDH, changes in the prevalence of the seven isoenzymes were found, with a predominance of the more cathodal isoenzymes in the unripe and of the most anodal isoenzymes in the ripe fruit. Two-dimensional electrophoresis revealed that avocado fruit GDH consists of two subunits whose association gives rise to seven isoenzymes. The resu...
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Based on our previous results that peroxidase is induced in dividing tobacco protoplasts but it is not expressed in the nondividing grapevine (Vitis vinifera L.) protoplasts during culture (C.I. Siminis, A.K. Kanellis, K.A.... more
Based on our previous results that peroxidase is induced in dividing tobacco protoplasts but it is not expressed in the nondividing grapevine (Vitis vinifera L.) protoplasts during culture (C.I. Siminis, A.K. Kanellis, K.A. Roubelakis-Angelakis [1993] Physiol Plant 87: 263-270), we further tested the hypothesis that oxidative stress may be implicated in the recalcitrance of plant protoplasts. The expression of catalase, a major defense enzyme against cell oxidation, was studied during isolation and culture of mesophyll protoplasts from the recalcitrant grapevine and regenerating tobacco (Nicotiana tabacum L.). Incubation of tobacco leaf strips with cell wall-degrading enzymes resulted in a burst of catalase activity and an increase in its immunoreactive protein; in contrast, no such increases were found in grapevine. The cathodic and anodic catalase isoforms consisted exclusively of subunits [alpha] and [beta], respectively, in tobacco, and of subunits [beta] and [alpha], respective...
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A small family of at least four genes encoding melon ascorbate oxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologous to... more
A small family of at least four genes encoding melon ascorbate oxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologous to ascorbate oxidases from other plants and similar to other multicopper oxidases. We describe detailed molecular studies addressing melon AO expression during organ specific differentiation, fruit development and ripening, and in response to wounding. In particular, AO transcript accumulation was induced in ovaries and the outer mesocarp of mature preclimacteric melon fruits, before the expression of genes encoding the necessary enzymatic activities for ethylene biosynthesis. On the other hand, AO was not expressed in late stages of fruit ripening and was repressed in wounded fruits. The role of ethylene in transcriptional regulation of AO is discussed.
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Research Interests: Genetics, Plant Biology, Scanning Electron Microscopy, Medicinal Plants, Plant Molecular Biology, and 14 moreGene expression, Expressed Sequence Tags, Plant Secondary Metabolism, Chemical Analysis, Cytotoxic Activity, Cistus, Amino Acid Sequence, Base Sequence, Heterologous Expression, Medicinal Plant, Fresh Weight, Full Length Movies, cDNA library, and Biochemistry and cell biology
Research Interests: Plant Biology, Transcription Factors, Melatonin, Antioxidants, Peroxidase, and 16 moreGlutathione, Proline, Plant Roots, Superoxide Dismutase, Soil sciences, Citrus, SALT TOLERANCE, Plant Physiology and Biochemistry, Phenols, Ascorbic Acid, Seedling, CARBOHYDRATES, Glutathione Reductase, PLANT PROTEINS, Sodium Chloride, and Plant Leaves
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Research Interests: Plant Biology, Gene expression, Copper, Stress response, Plant Growth Regulators, and 16 moreLight, Fruit, Steady state, Fruit set and development, Germination, Ascorbic Acid, Heat stress, Seedling, Fruit Ripening, Gene Family, Salicylic Acid, Cucumis Melo, Planta, Cell Expansion, Jasmonic Acid, and Cell Growth
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Research Interests: Plant Biology, Abiotic Stress, Cell line, Sequence alignment, Natural Product, and 16 moreOxidoreductases, Terpenes, Droughts, Secondary Metabolites, Enzyme, Antioxidant Activity, Molecular cloning, Cistus, Multienzyme complexes, Physiological Stress Markers, Amino Acid Sequence, Salicylic Acid, PLANT PROTEINS, *Hot Temperature, Gene expression profiling, and Plant Leaves
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1 Vakgroep Moleculaire Genetica en Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, KLLedeganckstraat 35, B-9000, Gent, Belgium 2 Department of Pharmacy, Aristotle University of... more
1 Vakgroep Moleculaire Genetica en Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, KLLedeganckstraat 35, B-9000, Gent, Belgium 2 Department of Pharmacy, Aristotle University of Thessaloniki, GR-540 06, Thessaloniki, ...