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Light-dependent regulation of ascorbate in tomato by a monodehydroascorbate reductase localized in peroxisomes and the cytosol.
Plant Biotechnol J. 2013 Apr; 11(3):344-54.PB

Abstract

Ascorbate is a powerful antioxidant in plants, and its levels are an important quality criteria in commercial species. Factors influencing these levels include environmental variations, particularly light, and the genetic control of its biosynthesis, recycling and degradation. One of the genes involved in the recycling pathway encodes a monodehydroascorbate reductase (MDHAR), an enzyme catalysing reduction of the oxidized radical of ascorbate, monodehydroascorbate, to ascorbate. In plants, MDHAR belongs to a multigene family. Here, we report the presence of an MDHAR isoform in both the cytosol and peroxisomes and show that this enzyme negatively regulates ascorbate levels in Solanum lycopersicum (tomato). Transgenic lines overexpressing MDHAR show a decrease in ascorbate levels in leaves, whereas lines where MDHAR is silenced show an increase in these levels in both fruits and leaves. Furthermore, the intensity of these differences is light dependent. The unexpected effect of this MDHAR on ascorbate levels cannot be explained by changes in the expression of Smirnoff-Wheeler pathway genes, or the activity of enzymes involved in degradation (ascorbate peroxidase) or recycling of ascorbate (dehydroascorbate reductase and glutathione reductase), suggesting a previously unidentified mechanism regulating ascorbate levels.

Authors+Show Affiliations

INRA, UR1052, Génétique et amélioration des fruits et légumes, Domaine St Maurice, Allée des Chênes, Montfavet, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23130940

Citation

Gest, Noé, et al. "Light-dependent Regulation of Ascorbate in Tomato By a Monodehydroascorbate Reductase Localized in Peroxisomes and the Cytosol." Plant Biotechnology Journal, vol. 11, no. 3, 2013, pp. 344-54.
Gest N, Garchery C, Gautier H, et al. Light-dependent regulation of ascorbate in tomato by a monodehydroascorbate reductase localized in peroxisomes and the cytosol. Plant Biotechnol J. 2013;11(3):344-54.
Gest, N., Garchery, C., Gautier, H., Jiménez, A., & Stevens, R. (2013). Light-dependent regulation of ascorbate in tomato by a monodehydroascorbate reductase localized in peroxisomes and the cytosol. Plant Biotechnology Journal, 11(3), 344-54. https://doi.org/10.1111/pbi.12020
Gest N, et al. Light-dependent Regulation of Ascorbate in Tomato By a Monodehydroascorbate Reductase Localized in Peroxisomes and the Cytosol. Plant Biotechnol J. 2013;11(3):344-54. PubMed PMID: 23130940.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Light-dependent regulation of ascorbate in tomato by a monodehydroascorbate reductase localized in peroxisomes and the cytosol. AU - Gest,Noé, AU - Garchery,Cécile, AU - Gautier,Hélène, AU - Jiménez,Ana, AU - Stevens,Rebecca, Y1 - 2012/11/06/ PY - 2012/07/27/received PY - 2012/09/28/revised PY - 2012/10/01/accepted PY - 2012/11/8/entrez PY - 2012/11/8/pubmed PY - 2013/12/19/medline SP - 344 EP - 54 JF - Plant biotechnology journal JO - Plant Biotechnol J VL - 11 IS - 3 N2 - Ascorbate is a powerful antioxidant in plants, and its levels are an important quality criteria in commercial species. Factors influencing these levels include environmental variations, particularly light, and the genetic control of its biosynthesis, recycling and degradation. One of the genes involved in the recycling pathway encodes a monodehydroascorbate reductase (MDHAR), an enzyme catalysing reduction of the oxidized radical of ascorbate, monodehydroascorbate, to ascorbate. In plants, MDHAR belongs to a multigene family. Here, we report the presence of an MDHAR isoform in both the cytosol and peroxisomes and show that this enzyme negatively regulates ascorbate levels in Solanum lycopersicum (tomato). Transgenic lines overexpressing MDHAR show a decrease in ascorbate levels in leaves, whereas lines where MDHAR is silenced show an increase in these levels in both fruits and leaves. Furthermore, the intensity of these differences is light dependent. The unexpected effect of this MDHAR on ascorbate levels cannot be explained by changes in the expression of Smirnoff-Wheeler pathway genes, or the activity of enzymes involved in degradation (ascorbate peroxidase) or recycling of ascorbate (dehydroascorbate reductase and glutathione reductase), suggesting a previously unidentified mechanism regulating ascorbate levels. SN - 1467-7652 UR - https://www.unboundmedicine.com/medline/citation/23130940/Light_dependent_regulation_of_ascorbate_in_tomato_by_a_monodehydroascorbate_reductase_localized_in_peroxisomes_and_the_cytosol_ L2 - https://doi.org/10.1111/pbi.12020 DB - PRIME DP - Unbound Medicine ER -