|SHABALA, LANA - UNI OF TASMANIA AUSTRALIA
|SHABALA, SERGEY - UNI OF TASMANIA AUSTRALIA
Submitted to: Plant and Cell Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2007
Publication Date: 1/1/2008
Citation: Nemchinov, L.G., Shabala, L., Shabala, S. 2008. Calcium Efflux as a Component of Hypersensitive Response of Nicotiana benthamiana to Pseudomonas syringae. Plant And Cell Physiology. 49(1):40-46.
Interpretive Summary: The overall goal of this work is to provide new insight into plant/pathogen interactions, to investigate mechanisms of plant defense reaction against microbial attack and to develop new ways to improve disease resistance in crops. We demonstrated that plants response to the initial pathogen invasion with a strong uptake of calcium which is needed to trigger protective response. Our data also suggest that outflow of calcium may be required to expand and complete defense reaction. Accordingly, we suggest that the existing model of resistance response should be amended to include calcium efflux as an important component of pathogen surveillance mechanism in plants. These findings will benefit plant pathologists, plant physiologists, and other ARS scientists by providing new knowledge about plant-pathogen interactions and helping further investigations leading to improved crop disease resistance.
Technical Abstract: Using a model plant Nicotiana benthamiana we have demonstrated that initial calcium uptake in response to HR (hypersensitive response)-causing pathogen, P. syringae pv syringae 61 is followed by the net calcium efflux initiated at about 12 hrs after the bacterial challenge and sustained for at least 48 hrs. Our data suggest that calcium acts not only as an important second messenger in the activation of resistance responses but also as a downstream mediator of later cell death acceleration and completion of defense reaction. Accordingly, we suggest that the existing model of HR should be amended to include such Ca2+ pump.