Transgenic tobacco plants with reduced capability to detoxify reactive oxygen intermediates are hyperresponsive to pathogen infection

Reactive oxygen intermediates (ROI) play a critical role in the defense of plants against invading pathogens. Produced during the "oxidative burst," they are thought to activate programmed cell death (PCD) and induce antimicrobial defenses such as pathogenesis-related proteins. It was show...

Full description

Saved in:

Bibliographic Details
Published in:	Proceedings of the National Academy of Sciences - PNAS Vol. 96; no. 24; pp. 14165 - 14170
Main Authors:	Mittler, R, Herr, E.H, Orvar, B.L, Camp, W. van, Willekens, H, Inze, D, Ellis, B.E
Format:	Journal Article
Language:	English
Published:	United States National Academy of Sciences of the United States of America 23-11-1999 National Acad Sciences National Academy of Sciences
Subjects:	antisense RNA Apoptosis ascorbate peroxidase Ascorbate Peroxidases Bacteria biological resistance Biological Sciences Botany catalase Catalase - genetics Catalase - metabolism Cell death defense mechanisms DNA Enzymes experimental infections gene expression hypersensitive response Infections inhibition Leaves messenger RNA metabolic detoxification Nicotiana - metabolism Nicotiana - microbiology Nicotiana tabacum Oxygen pathogenesis-related proteins Pathogens peroxidases Peroxidases - genetics Peroxidases - metabolism plant diseases and disorders Plants Plants, Genetically Modified Plants, Toxic Pseudomonas - physiology Pseudomonas syringae pv. phaseolicola Pseudomonas syringae pv. tabaci reactive oxygen intermediates Reactive Oxygen Species - metabolism RNA, Antisense Tobacco Transgenic plants
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Reactive oxygen intermediates (ROI) play a critical role in the defense of plants against invading pathogens. Produced during the "oxidative burst," they are thought to activate programmed cell death (PCD) and induce antimicrobial defenses such as pathogenesis-related proteins. It was shown recently that during the interaction of plants with pathogens, the expression of ROI-detoxifying enzymes such as ascorbate peroxidase (APX) and catalase (CAT) is suppressed. It was suggested that this suppression, occurring upon pathogen recognition and coinciding with an enhanced rate of ROI production, plays a key role in elevating cellular ROI levels, thereby potentiating the induction of PCD and other defenses. To examine the relationship between the suppression of antioxidative mechanisms and the induction of PCD and other defenses during pathogen attack, we studied the interaction between transgenic antisense tobacco plants with reduced APX or CAT and a bacterial pathogen that triggers the hypersensitive response. Transgenic plants with reduced capability to detoxify ROI (i.e., antisense APX or CAT) were found to be hyperresponsive to pathogen attack. They activated PCD in response to low amounts of pathogens that did not trigger the activation of PCD in control plants. Our findings support the hypothesis that suppression of ROI-scavenging enzymes during the hypersensitive response plays an important role in enhancing pathogen-induced PCD.
Bibliography:	ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 To whom reprint requests should be addressed. E-mail: ron@vms.huji.ac.il. Edited by Marc C. E. Van Montagu, University of Gent, Ghent, Belgium, and approved August 24, 1999
ISSN:	0027-8424 1091-6490
DOI:	10.1073/pnas.96.24.14165