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Isabel M Minguezmosquera - One of the best experts on this subject based on the ideXlab platform.

  • degradation of non esterified and esterified xanthophylls by free radicals
    Biochimica et Biophysica Acta, 2002
    Co-Authors: Antonio Perezgalvez, Isabel M Minguezmosquera
    Abstract:

    Abstract β-Carotene and other xanthophylls present in pepper fruit as both free and esterified forms were oxidized using a free radical initiator (2,2′-azo-bis-isobutyronitrile). Capsorubin was degraded most slowly, followed by zeaxanthin, Capsanthin, and β-carotene. The presence of keto groups at the ends of the polyene chain could be a structural factor contributing to this difference in reactivity. It was also shown that whereas Capsanthin and its esters and capsorubin and its esters were degraded at the same rate, zeaxanthin esters responded differently to the oxidation process, and were degraded more quickly than free zeaxanthin. The presence of unsaturated fatty acids (mainly linoleic) that esterify zeaxanthin help to accelerate the degradation of this xanthophyll and decreasing its antioxidant action. The antioxidant capacity of capsorubin and Capsanthin (both in free and esterified form) exclusive to the genus capsicum should be taken into account.

  • carotenoid biosynthesis changes in five red pepper capsicum annuum l cultivars during ripening cultivar selection for breeding
    Journal of Agricultural and Food Chemistry, 2000
    Co-Authors: Damaso Horneromendez, Ricardo Gomezladron De Guevara, Isabel M Minguezmosquera
    Abstract:

    Changes in the biosynthesis of individual carotenoid pigments have been investigated during fruit ripening of five cultivars of red pepper (Capsicum annuum L.): Mana, Numex, Belrubi, Delfin, and Negral (a chlorophyll-retaining mutant when ripe). The study was carried out throughout the ripening process, and with special emphasis on the ripe stage, to discover possible differences between cultivars and to characterize these by their carotenoid pattern and content for selecting the best varieties for breeding programs. Ripening fruit of the five cultivars showed the typical and characteristic pattern of carotenoid biosynthesis for the Capsicum genus. In the five cultivars, lutein and neoxanthin, both characteristic chloroplast pigments, decreased in concentration with ripening and eventually disappeared. beta-Carotene, antheraxanthin, and violaxanthin increased in concentration, and other pigments were biosynthesized de novo: zeaxanthin, beta-cryptoxanthin, Capsanthin, capsorubin, Capsanthin-5,6-epoxide, and cucurbitaxanthin A. A pool of zeaxanthin stands out of the rest of pigment during ripening, which reveals the importance of this pigment as a branching point in the carotenoid biosynthesis in Capsicum. Quantitatively, Negral cultivar showed the highest increase in total carotenoid content (48. 39-fold), followed by Mana and Delfin with 38.03- and 36.8-fold, respectively, and by Belrubi and Numex with 28.03- and 23.48-fold, respectively. In all the red varieties, there was an inverse relationship between total carotenoid content and the red to yellow isochromic pigment fraction ratio (R/Y) and the Capsanthin-to-zeaxanthin ratio (Caps/Zeax). This seems to be related to the carotenogenic capacity of the cultivar, and thus selection and breeding should not only seek a higher total carotenoid content but also attempt to increase these ratios. In the present study, the cultivar Mana had the highest total carotenoid content (13 208 mg/kg dwt), but the lowest R/Y (1.25) and Caps/Zeax (3.38) ratios, which are therefore the parameters to improve. The cultivar Negral had a high carotenoid content (8797 mg/kg dwt) and high R/Y and Caps/Zeax ratios and could be used for transfer of these characters in direct crosses with the cultivar Mana. The cultivar Numex had the highest Caps/Zeax ratio (7.17) and is thus an ideal progenitor for this character.

  • carotenoid biosynthesis changes in five red pepper capsicum annuum l cultivars during ripening cultivar selection for breeding
    Journal of Agricultural and Food Chemistry, 2000
    Co-Authors: Damaso Horneromendez, Ricardo Gomezladron De Guevara, Isabel M Minguezmosquera
    Abstract:

    Changes in the biosynthesis of individual carotenoid pigments have been investigated during fruit ripening of five cultivars of red pepper (Capsicum annuum L.):  Mana, Numex, Belrubi, Delfin, and Negral (a chlorophyll-retaining mutant when ripe). The study was carried out throughout the ripening process, and with special emphasis on the ripe stage, to discover possible differences between cultivars and to characterize these by their carotenoid pattern and content for selecting the best varieties for breeding programs. Ripening fruit of the five cultivars showed the typical and characteristic pattern of carotenoid biosynthesis for the Capsicum genus. In the five cultivars, lutein and neoxanthin, both characteristic chloroplast pigments, decreased in concentration with ripening and eventually disappeared. β-Carotene, antheraxanthin, and violaxanthin increased in concentration, and other pigments were biosynthesized de novo:  zeaxanthin, β-cryptoxanthin, Capsanthin, capsorubin, Capsanthin-5,6-epoxide, and cu...

Damaso Horneromendez - One of the best experts on this subject based on the ideXlab platform.

  • carotenoid biosynthesis changes in five red pepper capsicum annuum l cultivars during ripening cultivar selection for breeding
    Journal of Agricultural and Food Chemistry, 2000
    Co-Authors: Damaso Horneromendez, Ricardo Gomezladron De Guevara, Isabel M Minguezmosquera
    Abstract:

    Changes in the biosynthesis of individual carotenoid pigments have been investigated during fruit ripening of five cultivars of red pepper (Capsicum annuum L.): Mana, Numex, Belrubi, Delfin, and Negral (a chlorophyll-retaining mutant when ripe). The study was carried out throughout the ripening process, and with special emphasis on the ripe stage, to discover possible differences between cultivars and to characterize these by their carotenoid pattern and content for selecting the best varieties for breeding programs. Ripening fruit of the five cultivars showed the typical and characteristic pattern of carotenoid biosynthesis for the Capsicum genus. In the five cultivars, lutein and neoxanthin, both characteristic chloroplast pigments, decreased in concentration with ripening and eventually disappeared. beta-Carotene, antheraxanthin, and violaxanthin increased in concentration, and other pigments were biosynthesized de novo: zeaxanthin, beta-cryptoxanthin, Capsanthin, capsorubin, Capsanthin-5,6-epoxide, and cucurbitaxanthin A. A pool of zeaxanthin stands out of the rest of pigment during ripening, which reveals the importance of this pigment as a branching point in the carotenoid biosynthesis in Capsicum. Quantitatively, Negral cultivar showed the highest increase in total carotenoid content (48. 39-fold), followed by Mana and Delfin with 38.03- and 36.8-fold, respectively, and by Belrubi and Numex with 28.03- and 23.48-fold, respectively. In all the red varieties, there was an inverse relationship between total carotenoid content and the red to yellow isochromic pigment fraction ratio (R/Y) and the Capsanthin-to-zeaxanthin ratio (Caps/Zeax). This seems to be related to the carotenogenic capacity of the cultivar, and thus selection and breeding should not only seek a higher total carotenoid content but also attempt to increase these ratios. In the present study, the cultivar Mana had the highest total carotenoid content (13 208 mg/kg dwt), but the lowest R/Y (1.25) and Caps/Zeax (3.38) ratios, which are therefore the parameters to improve. The cultivar Negral had a high carotenoid content (8797 mg/kg dwt) and high R/Y and Caps/Zeax ratios and could be used for transfer of these characters in direct crosses with the cultivar Mana. The cultivar Numex had the highest Caps/Zeax ratio (7.17) and is thus an ideal progenitor for this character.

  • carotenoid biosynthesis changes in five red pepper capsicum annuum l cultivars during ripening cultivar selection for breeding
    Journal of Agricultural and Food Chemistry, 2000
    Co-Authors: Damaso Horneromendez, Ricardo Gomezladron De Guevara, Isabel M Minguezmosquera
    Abstract:

    Changes in the biosynthesis of individual carotenoid pigments have been investigated during fruit ripening of five cultivars of red pepper (Capsicum annuum L.):  Mana, Numex, Belrubi, Delfin, and Negral (a chlorophyll-retaining mutant when ripe). The study was carried out throughout the ripening process, and with special emphasis on the ripe stage, to discover possible differences between cultivars and to characterize these by their carotenoid pattern and content for selecting the best varieties for breeding programs. Ripening fruit of the five cultivars showed the typical and characteristic pattern of carotenoid biosynthesis for the Capsicum genus. In the five cultivars, lutein and neoxanthin, both characteristic chloroplast pigments, decreased in concentration with ripening and eventually disappeared. β-Carotene, antheraxanthin, and violaxanthin increased in concentration, and other pigments were biosynthesized de novo:  zeaxanthin, β-cryptoxanthin, Capsanthin, capsorubin, Capsanthin-5,6-epoxide, and cu...

  • xanthophyll esterification accompanying carotenoid overaccumulation in chromoplast of capsicum annuum ripening fruits is a constitutive process and useful for ripeness index
    Journal of Agricultural and Food Chemistry, 2000
    Co-Authors: Damaso Horneromendez, M I Minguezmosquera
    Abstract:

    Changes in xanthophyll esterification degree during pepper fruit ripening have been studied in five cultivars (Numex, Mana, Belrubi, Delfin, and Negral). Esterification of xanthophylls with fatty acids is seen to be a process that is contemporary with and directly linked to the transformation of chloroplast (present in the green fruit) into chromoplast (present in the red fruit). Changes in the fractions of free and partially and totally esterified carotenoids are similar between varieties, reflecting the constitutive nature of esterification as part of the ripening process and being controlled by it. From the first stages of ripening, the fraction of totally esterified pigments (zeaxanthin diester, β-cryptoxanthin diester, Capsanthin diester, and capsorubin diester) makes up almost 50% of the total carotenoid content. The proportion of the partially esterified pigment fraction (zeaxanthin monoester, Capsanthin monoester, and capsorubin monoester) in the total carotenoid content increases, with a gradual ...

Witoon Prinyawiwatkul - One of the best experts on this subject based on the ideXlab platform.

  • antioxidant activities of different colored sweet bell peppers capsicum annuum l
    Journal of Food Science, 2007
    Co-Authors: Zhimin Xu, C T Wu, Marlene E Janes, Witoon Prinyawiwatkul, Hong Kyoon No
    Abstract:

    ABSTRACT:  Antioxidant compounds and their antioxidant activity in 4 different colored (green, yellow, orange, and red) sweet bell peppers (Capsicum annuum L.) were investigated. The total phenolics content of green, yellow, orange, and red peppers determined by the Folin-Ciocalteau method were 2.4, 3.3, 3.4, and 4.2 μmol catechin equivalent/g fresh weight, respectively. The red pepper had significantly higher total phenolics content than the green pepper. Among the 4 different colored peppers, red pepper contained a higher level of β-carotene (5.4 μg/g), Capsanthin (8.0 μg/g), quercetin (34.0 μg/g), and luteolin (11.0 μg/g). The yellow pepper had the lowest β-carotene content (0.2 μg/g), while the green one had undetectable Capsanthin and the lowest content of luteolin (2.0 μg/g). The free radical scavenging abilities of peppers determined by the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) method were lowest for the green pepper (2.1 μmol Trolox equivalent/g) but not significantly different from the other 3 peppers. All 4 colored peppers exhibited significant abilities in preventing the oxidation of cholesterol or docosahexaenoic acid (DHA) (C22:6) during heating. However, these 4 peppers did not show significant differences in their abilities in preventing cholesterol oxidation. The green pepper showed slightly higher capability in preventing the oxidation of DHA compared to the other 3 peppers.

  • antioxidant activities of different colored sweet bell peppers capsicum annuum l
    Journal of Food Science, 2007
    Co-Authors: T Sun, Marlene E Janes, Witoon Prinyawiwatkul
    Abstract:

    Antioxidant compounds and their antioxidant activity in 4 different colored (green, yellow, orange, and red) sweet bell peppers (Capsicum annuum L.) were investigated. The total phenolics content of green, yellow, orange, and red peppers determined by the Folin-Ciocalteau method were 2.4, 3.3, 3.4, and 4.2 micromol catechin equivalent/g fresh weight, respectively. The red pepper had significantly higher total phenolics content than the green pepper. Among the 4 different colored peppers, red pepper contained a higher level of beta-carotene (5.4 microg/g), Capsanthin (8.0 microg/g), quercetin (34.0 microg/g), and luteolin (11.0 microg/g). The yellow pepper had the lowest beta-carotene content (0.2 microg/g), while the green one had undetectable Capsanthin and the lowest content of luteolin (2.0 microg/g). The free radical scavenging abilities of peppers determined by the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) method were lowest for the green pepper (2.1 micromol Trolox equivalent/g) but not significantly different from the other 3 peppers. All 4 colored peppers exhibited significant abilities in preventing the oxidation of cholesterol or docosahexaenoic acid (DHA) (C22:6) during heating. However, these 4 peppers did not show significant differences in their abilities in preventing cholesterol oxidation. The green pepper showed slightly higher capability in preventing the oxidation of DHA compared to the other 3 peppers.

Bilal Camara - One of the best experts on this subject based on the ideXlab platform.

  • characterization of plant carotenoid cyclases as members of the flavoprotein family functioning with no net redox change
    Plant Physiology, 2010
    Co-Authors: Alexis Samba Mialoundama, Alain Rahier, Bilal Camara, József Deli, Dimitri Heintz, Nurul Jadid, Paul Nkeng, Florence Bouvier
    Abstract:

    The later steps of carotenoid biosynthesis involve the formation of cyclic carotenoids. The reaction is catalyzed by lycopene β-cyclase (LCY-B), which converts lycopene into β-carotene, and by Capsanthin-capsorubin synthase (CCS), which is mainly dedicated to the synthesis of κ-cyclic carotenoids (Capsanthin and capsorubin) but also has LCY-B activity. Although the peptide sequences of plant LCY-Bs and CCS contain a putative dinucleotide-binding motif, it is believed that these two carotenoid cyclases proceed via protic activation and stabilization of resulting carbocation intermediates. Using pepper (Capsicum annuum) CCS as a prototypic carotenoid cyclase, we show that the monomeric protein contains one noncovalently bound flavin adenine dinucleotide (FAD) that is essential for enzyme activity only in the presence of NADPH, which functions as the FAD reductant. The reaction proceeds without transfer of hydrogen from the dinucleotide cofactors to β-carotene or Capsanthin. Using site-directed mutagenesis, amino acids potentially involved in the protic activation were identified. Substitutions of alanine, lysine, and arginine for glutamate-295 in the conserved 293-FLEET-297 motif of pepper CCS or LCY-B abolish the formation of β-carotene and κ-cyclic carotenoids. We also found that mutations of the equivalent glutamate-196 located in the 194-LIEDT-198 domain of structurally divergent bacterial LCY-B abolish the formation of β-carotene. The data herein reveal plant carotenoid cyclases to be novel enzymes that combine characteristics of non-metal-assisted terpene cyclases with those attributes typically found in flavoenzymes that catalyze reactions, with no net redox, such as type 2 isopentenyl diphosphate isomerase. Thus, FAD in its reduced form could be implicated in the stabilization of the carbocation intermediate.

  • induction and control of chromoplast specific carotenoid genes by oxidative stress
    Journal of Biological Chemistry, 1998
    Co-Authors: Florence Bouvier, Ralph A. Backhaus, Bilal Camara
    Abstract:

    Abstract The differentiation of chloroplasts into chromoplasts involves a series of biochemical changes that culminate with the intense accumulation of long chain chromophore carotenoids such as lycopene, rhodoxanthin, astaxanthin, anhydroeschsoltzxanthin, Capsanthin, and capsorubin. The signal pathways mediating these transformations are unknown. Chromoplast carotenoids are known to accumulate in green tissues experiencing stress conditions, and studies indicate that they provide efficient protection against oxidative stress. We tested the role of reactive oxygen species (ROS) as regulators of chromoplast carotenoid biosynthesis in vivo. The addition of ROS progenitors, such as menadione,tert-butylhydroperoxide, or paraquat and prooxidants such as diamide or buthionine sulfoximine to green pericarp discs of pepper fruits rapidly and dramatically induce the simultaneous expression of multiple carotenogenic gene mRNAS that give rise to Capsanthin. Similarly, down-regulation of catalase by amitrole induces expression of carotenogenic gene mRNAs leading to the synthesis of Capsanthin in excised green pericarp discs. ROS signals from plastids and mitochondria also contribute significantly to this process. Analysis of the Capsanthin-capsorubin synthase promoter in combination with a β-glucuronidase reporter gene reveals strong activation in transformed pepper protoplasts challenged with the above ROS. Collectively these data demonstrate that ROS act as a novel class of second messengers that mediate intense carotenoid synthesis during chromoplast differentiation.

  • metabolism of cyclic carotenoids a model for the alteration of this biosynthetic pathway in capsicum annuum chromoplasts
    Plant Journal, 1995
    Co-Authors: Philippe Hugueney, Alfredo Badillo, Bilal Camara, Annelyse Klein, Hsuching Chen, Joseph Hirschberg, Marcel Kuntz
    Abstract:

    The biosynthetic pathway of cyclic carotenoid is known to be quantitatively and qualitatively different in the non-green plastids of Capsicum annuum fruits compared with chloroplasts. Here, the cloning is described of a novel cDNA from this organism, which encodes an enzyme catalyzing the cyclization of lycopene to β-carotene when expressed in Escherichia coli. The corresponding gene is constitutively expressed during fruit development. Significant amino acid sequence identity was observed between this enzyme and Capsanthin/capsorubin synthase which is involved in the synthesis of the species-specific red carotenoids of C. annuum fruits. The latter enzyme was found also to possess a lycopene β-cyclase activity when expressed in E. coli. A model is proposed for the origin of the Capsanthin/capsorubin synthase gene and the role of this enzyme, together with the newly cloned lycopene cyclase, in the specific re-channeling of linear carotenoids into β-cyclic carotenoids in C. annuum ripening fruits.

  • Identification of a plastid protein involved in vesicle fusion and/or membrane protein translocation
    Proceedings of the National Academy of Sciences of the United States of America, 1995
    Co-Authors: Philippe Hugueney, Florence Bouvier, Alfredo Badillo, Marcel Kuntz, Alain D'harlingue, Bilal Camara
    Abstract:

    Structural evidence has accumulated suggesting that fusion and/or translocation factors are involved in plastid membrane biogenesis. To test this hypothesis, we have developed an in vitro system in which the extent of fusion and/or translocation is monitored by the conversion of the xanthophyll epoxide (antheraxanthin) into the red ketocarotenoid (Capsanthin). Only chromoplast membrane vesicles from red pepper fruits (Capsicum annuum) contain the required enzyme. Vesicles prepared from the mutant yellow cultivar are devoid of this enzyme and accumulate antheraxanthin. The fusion and/or translocation activity is characterized by complementation due to the synthesis of Capsanthin and the parallel decrease of antheraxanthin when the two types of vesicles are incubated together in the presence of plastid stroma. We show that the extent of conversion is dependent upon an ATP-requiring protein that is sensitive to N-ethylmaleimide. Further purification and immunological analysis have revealed that the active factor, designated plastid fusion and/or translocation factor (Pftf), resides in a protein of 72 kDa. cDNA cloning revealed that mature Pftf has significant homology to yeast and animal (NSF) or bacterial (Ftsh) proteins involved in vesicle fusion or membrane protein translocation.

  • structure of a functional geranylgeranyl pyrophosphate synthase gene from capsicum annuum
    Plant Molecular Biology, 1995
    Co-Authors: Alfredo Badillo, Johannes Steppuhn, Jean Deruere, Bilal Camara, Marcel Kuntz
    Abstract:

    A geranylgeranyl pyrophosphate synthase (GGPPS) gene from Capsicum annuum (bell pepper) was cloned. The nucleotide sequence shows that this gene, like the Capsanthin/capsorubin gene but unlike the phytoene synthase gene from C. annuum, is not interrupted by an intron. Southern blot analysis of C. annuum genomic DNA suggests the presence of a single gene highly similar to the cDNA and also of additional related sequences. The present data suggest that this cloned gene is functional.

Marcel Kuntz - One of the best experts on this subject based on the ideXlab platform.

  • metabolism of cyclic carotenoids a model for the alteration of this biosynthetic pathway in capsicum annuum chromoplasts
    Plant Journal, 1995
    Co-Authors: Philippe Hugueney, Alfredo Badillo, Bilal Camara, Annelyse Klein, Hsuching Chen, Joseph Hirschberg, Marcel Kuntz
    Abstract:

    The biosynthetic pathway of cyclic carotenoid is known to be quantitatively and qualitatively different in the non-green plastids of Capsicum annuum fruits compared with chloroplasts. Here, the cloning is described of a novel cDNA from this organism, which encodes an enzyme catalyzing the cyclization of lycopene to β-carotene when expressed in Escherichia coli. The corresponding gene is constitutively expressed during fruit development. Significant amino acid sequence identity was observed between this enzyme and Capsanthin/capsorubin synthase which is involved in the synthesis of the species-specific red carotenoids of C. annuum fruits. The latter enzyme was found also to possess a lycopene β-cyclase activity when expressed in E. coli. A model is proposed for the origin of the Capsanthin/capsorubin synthase gene and the role of this enzyme, together with the newly cloned lycopene cyclase, in the specific re-channeling of linear carotenoids into β-cyclic carotenoids in C. annuum ripening fruits.

  • Identification of a plastid protein involved in vesicle fusion and/or membrane protein translocation
    Proceedings of the National Academy of Sciences of the United States of America, 1995
    Co-Authors: Philippe Hugueney, Florence Bouvier, Alfredo Badillo, Marcel Kuntz, Alain D'harlingue, Bilal Camara
    Abstract:

    Structural evidence has accumulated suggesting that fusion and/or translocation factors are involved in plastid membrane biogenesis. To test this hypothesis, we have developed an in vitro system in which the extent of fusion and/or translocation is monitored by the conversion of the xanthophyll epoxide (antheraxanthin) into the red ketocarotenoid (Capsanthin). Only chromoplast membrane vesicles from red pepper fruits (Capsicum annuum) contain the required enzyme. Vesicles prepared from the mutant yellow cultivar are devoid of this enzyme and accumulate antheraxanthin. The fusion and/or translocation activity is characterized by complementation due to the synthesis of Capsanthin and the parallel decrease of antheraxanthin when the two types of vesicles are incubated together in the presence of plastid stroma. We show that the extent of conversion is dependent upon an ATP-requiring protein that is sensitive to N-ethylmaleimide. Further purification and immunological analysis have revealed that the active factor, designated plastid fusion and/or translocation factor (Pftf), resides in a protein of 72 kDa. cDNA cloning revealed that mature Pftf has significant homology to yeast and animal (NSF) or bacterial (Ftsh) proteins involved in vesicle fusion or membrane protein translocation.

  • structure of a functional geranylgeranyl pyrophosphate synthase gene from capsicum annuum
    Plant Molecular Biology, 1995
    Co-Authors: Alfredo Badillo, Johannes Steppuhn, Jean Deruere, Bilal Camara, Marcel Kuntz
    Abstract:

    A geranylgeranyl pyrophosphate synthase (GGPPS) gene from Capsicum annuum (bell pepper) was cloned. The nucleotide sequence shows that this gene, like the Capsanthin/capsorubin gene but unlike the phytoene synthase gene from C. annuum, is not interrupted by an intron. Southern blot analysis of C. annuum genomic DNA suggests the presence of a single gene highly similar to the cDNA and also of additional related sequences. The present data suggest that this cloned gene is functional.

  • xanthophyll biosynthesis in chromoplasts isolation and molecular cloning of an enzyme catalyzing the conversion of 5 6 epoxycarotenoid into ketocarotenoid
    Plant Journal, 1994
    Co-Authors: Florence Bouvier, Marcel Kuntz, Philippe Hugueney, Alain Dharlingue, Bilal Camara
    Abstract:

    Summary The late steps of carotenoid biosynthesis in plants involve the formation of xanthophyUs. Little is known about the enzymology of these steps. This paper reports the purification to homogeneity of a xantho- phyll biosynthetic enzyme from Capsicum annuum chromoplasts, which catalyzes the conversion of the ubiquitous 5,6.epoxycarotenoids, antheraxanthin and violaxanthin, into Capsanthin and capsorubin, respectively. Owing to its bifunctionallty, the name Capsanthin-capsorubin synthase is proposed for this new enzyme. The purified enzyme is a monomer with a molecular mass of 50 kDa. Antibodies raised against this enzyme allowed the isolation of a full- length cDNA clone encoding a Capsanthin capserubin synthase high molecular weight precursor. The primary deduced structure reveals the presence of a consensus nucleotide binding site. The capeanthin- capsorubin synthase gene is specifically expressed during chromoplast development in fruits accumu- lating ketocarotenoids, but not in mutants impaired in this biosynthetic step. phytofluene desaturase (Hugueney

  • structure and expression of two plant genes encoding chromoplast specific proteins occurrence of partially spliced transcripts
    Biochemical and Biophysical Research Communications, 1994
    Co-Authors: Jean Deruere, Florence Bouvier, Johannes Steppuhn, Bilal Camara, Annelyse Klein, Marcel Kuntz
    Abstract:

    The genes encoding fibrillin and Capsanthin-capsorubin synthase are specifically expressed during fruit ripening in Capsicum annuum, leading to the accumulation of these two proteins in chromoplasts. Here, we report for the first time the cloning of genomic DNA fragments encoding these two enzymes, as well as DNA fragments containing upstream regions which are potentially involved in the regulation of the expression of these genes. While the Capsanthin-capsorubin synthase gene is uninterrupted, the fibrillin gene is interrupted by two introns, the first one being inefficiently spliced. Occurrence of unspliced transcripts is apparently not related to a post-transcriptional mechanism controlling the synthesis of fibrillin or an alternative polypeptide. This work provides tools for studies on gene activation and intron splicing in plants.