Manipulation of salicylate content in Arabidopsis thaliana by the expression of an engineered bacterial salicylate synthase.

Détails

ID Serval
serval:BIB_E40B06F8ABC7
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Manipulation of salicylate content in Arabidopsis thaliana by the expression of an engineered bacterial salicylate synthase.
Périodique
Plant Journal
Auteur(s)
Mauch F., Mauch-Mani B., Gaille C., Kull B., Haas D., Reimmann C.
ISSN
0960-7412 (Print)
ISSN-L
0960-7412
Statut éditorial
Publié
Date de publication
2001
Volume
25
Numéro
1
Pages
67-77
Langue
anglais
Résumé
Salicylic acid (SA) plays a central role as a signalling molecule involved in plant defense against microbial attack. Genetic manipulation of SA biosynthesis may therefore help to generate plants that are more disease-resistant. By fusing the two bacterial genes pchA and pchB from Pseudomonas aeruginosa, which encode isochorismate synthase and isochorismate pyruvate-lyase, respectively, we have engineered a novel hybrid enzyme with salicylate synthase (SAS) activity. The pchB-A fusion was expressed in Arabidopsis thaliana under the control of the constitutive cauliflower mosaic virus (CaMV) 35S promoter, with targeting of the gene product either to the cytosol (c-SAS plants) or to the chloroplast (p-SAS plants). In p-SAS plants, the amount of free and conjugated SA was increased more than 20-fold above wild type (WT) level, indicating that SAS is functional in Arabidopsis. P-SAS plants showed a strongly dwarfed phenotype and produced very few seeds. Dwarfism could be caused by the high SA levels per se or, perhaps more likely, by a depletion of the chorismate or isochorismate pools of the chloroplast. Targeting of SAS to the cytosol caused a slight increase in free SA and a significant threefold increase in conjugated SA, probably reflecting limited chorismate availability in this compartment. Although this modest increase in total SA content did not strongly induce the resistance marker PR-1, it resulted nevertheless in enhanced disease resistance towards a virulent isolate of Peronospora parasitica. Increased resistance of c-SAS lines was paralleled with reduced seed production. Taken together, these results illustrate that SAS is a potent tool for the manipulation of SA levels in plants.
Mots-clé
Amino Acid Sequence, Arabidopsis/genetics, Arabidopsis/physiology, Base Sequence, Caulimovirus/enzymology, Caulimovirus/genetics, Codon, Intramolecular Transferases/genetics, Intramolecular Transferases/metabolism, Lyases/genetics, Lyases/metabolism, Molecular Sequence Data, Phenols/metabolism, Plant Leaves/enzymology, Plants, Genetically Modified, Pseudomonas aeruginosa/enzymology, Pseudomonas aeruginosa/genetics, Recombinant Fusion Proteins/metabolism, Restriction Mapping, Salicylates/metabolism, Thiazoles
Pubmed
Web of science
Création de la notice
24/01/2008 14:00
Dernière modification de la notice
20/08/2019 16:07
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