A plant type 2 metallothionein (MT) from cork tissue responds to oxidative stress
Expression of plant metallothionein genes has been reported in a variety of senescing tissues, such as leaves and stems, ripening fruits, and wounded tissues, and has been proposed to function in both metal chaperoning and scavenging of reactive oxygen species. In this work, it is shown that MT is a...
| Publié dans: | Journal of experimental botany. - 1985. - 55(2004), 408 vom: 10. Dez., Seite 2483-93 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2004
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| Accès à la collection: | Journal of experimental botany |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Plant Proteins Copper 789U1901C5 Metallothionein 9038-94-2 |
| Résumé: | Expression of plant metallothionein genes has been reported in a variety of senescing tissues, such as leaves and stems, ripening fruits, and wounded tissues, and has been proposed to function in both metal chaperoning and scavenging of reactive oxygen species. In this work, it is shown that MT is also associated with suberization, after identifying a gene actively transcribed in Quercus suber cork cells as a novel MT. This cDNA, isolated from a phellem cDNA library, encodes a MT that belongs to type 2 plant MTs (QsMT). Expression of the QsMT cDNA in E. coli grown in media supplemented with Zn, Cd, or Cu has yielded recombinant QsMT. Characterization of the respective metal aggregates agrees well with a copper-related biological role, consistent with the capacity of QsMT to restore copper tolerance to a MT-deficient, copper-sensitive yeast mutant. Furthermore, in situ hybridization results demonstrate that RNA expression of QsMT is mainly observed under conditions related to oxidative stress, either endogenous, as found in cork or in actively proliferating tissues, or exogenous, for example, in response to H(2)O(2) or paraquat treatments. The putative role of QsMT in oxidative stress, both as a free radical scavenger via its sulphydryl groups or as a copper chelator is discussed |
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| Description: | Date Completed 03.02.2005 Date Revised 09.04.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |