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Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants

Glucosinolates (GLSs) are a well-known class of specialized plant metabolites, distributed mostly in the order Brassicales. A vast research field in basic and applied sciences has grown up around GLSs owing to their presence in important agricultural crops and the model plant Arabidopsis thaliana, a...

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Autores principales: Sugiyama, Ryosuke, Hirai, Masami Y.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6691170/
https://www.ncbi.nlm.nih.gov/pubmed/31447873
http://dx.doi.org/10.3389/fpls.2019.01008
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author Sugiyama, Ryosuke
Hirai, Masami Y.
author_facet Sugiyama, Ryosuke
Hirai, Masami Y.
author_sort Sugiyama, Ryosuke
collection PubMed
description Glucosinolates (GLSs) are a well-known class of specialized plant metabolites, distributed mostly in the order Brassicales. A vast research field in basic and applied sciences has grown up around GLSs owing to their presence in important agricultural crops and the model plant Arabidopsis thaliana, and their broad range of bioactivities beneficial to human health. The major purpose of GLSs in plants has been considered their function as a chemical defense against predators. GLSs are physically separated from a specialized class of beta-thioglucosidases called myrosinases, at the tissue level or at the single-cell level. They are brought together as a consequence of tissue damage, primarily triggered by herbivores, and their interaction results in the release of toxic volatile chemicals including isothiocyanates. In addition, recent studies have suggested that plants may adopt other strategies independent of tissue disruption for initiating GLS breakdown to cope with certain biotic/abiotic stresses. This hypothesis has been further supported by the discovery of an atypical class of GLS-hydrolyzing enzymes possessing features that are distinct from those of the classical myrosinases. Nevertheless, there is only little information on the physiological importance of atypical myrosinases. In this review, we focus on the broad diversity of the beta-glucosidase subclasses containing known atypical myrosinases in A. thaliana to discuss the hypothesis that numerous members of these subclasses can hydrolyze GLSs to regulate their diverse functions in plants. Also, the increasingly broadening functional repertoires of known atypical/classical myrosinases are described with reference to recent findings. Assessment of independent insights gained from A. thaliana with respect to (1) the phenotype of mutants lacking genes in the GLS metabolic/breakdown pathways, (2) fluctuation in GLS contents/metabolism under specific conditions, and (3) the response of plants to exogenous GLSs or their hydrolytic products, will enable us to reconsider the physiological importance of GLS breakdown in particular situations, which is likely to be regulated by specific beta-glucosidases.
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spelling pubmed-66911702019-08-23 Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants Sugiyama, Ryosuke Hirai, Masami Y. Front Plant Sci Plant Science Glucosinolates (GLSs) are a well-known class of specialized plant metabolites, distributed mostly in the order Brassicales. A vast research field in basic and applied sciences has grown up around GLSs owing to their presence in important agricultural crops and the model plant Arabidopsis thaliana, and their broad range of bioactivities beneficial to human health. The major purpose of GLSs in plants has been considered their function as a chemical defense against predators. GLSs are physically separated from a specialized class of beta-thioglucosidases called myrosinases, at the tissue level or at the single-cell level. They are brought together as a consequence of tissue damage, primarily triggered by herbivores, and their interaction results in the release of toxic volatile chemicals including isothiocyanates. In addition, recent studies have suggested that plants may adopt other strategies independent of tissue disruption for initiating GLS breakdown to cope with certain biotic/abiotic stresses. This hypothesis has been further supported by the discovery of an atypical class of GLS-hydrolyzing enzymes possessing features that are distinct from those of the classical myrosinases. Nevertheless, there is only little information on the physiological importance of atypical myrosinases. In this review, we focus on the broad diversity of the beta-glucosidase subclasses containing known atypical myrosinases in A. thaliana to discuss the hypothesis that numerous members of these subclasses can hydrolyze GLSs to regulate their diverse functions in plants. Also, the increasingly broadening functional repertoires of known atypical/classical myrosinases are described with reference to recent findings. Assessment of independent insights gained from A. thaliana with respect to (1) the phenotype of mutants lacking genes in the GLS metabolic/breakdown pathways, (2) fluctuation in GLS contents/metabolism under specific conditions, and (3) the response of plants to exogenous GLSs or their hydrolytic products, will enable us to reconsider the physiological importance of GLS breakdown in particular situations, which is likely to be regulated by specific beta-glucosidases. Frontiers Media S.A. 2019-08-06 /pmc/articles/PMC6691170/ /pubmed/31447873 http://dx.doi.org/10.3389/fpls.2019.01008 Text en Copyright © 2019 Sugiyama and Hirai. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Sugiyama, Ryosuke
Hirai, Masami Y.
Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title_full Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title_fullStr Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title_full_unstemmed Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title_short Atypical Myrosinase as a Mediator of Glucosinolate Functions in Plants
title_sort atypical myrosinase as a mediator of glucosinolate functions in plants
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6691170/
https://www.ncbi.nlm.nih.gov/pubmed/31447873
http://dx.doi.org/10.3389/fpls.2019.01008
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