Staphylococcus aureus pathogenicity on Arabidopsis thaliana is mediated either by a direct effect of salicylic acid on the pathogen or by SA-dependent, NPR1-independent host responses
Article first published online: 31 MAR 2005
The Plant Journal
Volume 42, Issue 3, pages 417–432, May 2005
How to Cite
Prithiviraj, B., Bais, H. P., Jha, A. K. and Vivanco, J. M. (2005), Staphylococcus aureus pathogenicity on Arabidopsis thaliana is mediated either by a direct effect of salicylic acid on the pathogen or by SA-dependent, NPR1-independent host responses. The Plant Journal, 42: 417–432. doi: 10.1111/j.1365-313X.2005.02385.x
- Issue published online: 31 MAR 2005
- Article first published online: 31 MAR 2005
- Received 19 December 2004; revised 18 January 2005; accepted 28 January 2005.
- plant–pathogen interaction;
- Staphylococcus aureus;
- salicylic acid
Staphylococcus aureus is a ubiquitous gram-positive bacterium that can cause superficial to serious systemic infections in animals and humans. Here we report the development of a plant infection model to study the pathogenesis of this bacterium. Three global regulatory mutants, RN6911 (agr−), ALC 488 (sarA−) ALC 842 (sarA−/agr−) and an alpha-toxin mutant defective in biofilm formation (DU1090) which are attenuated in animal pathogenesis, were also attenuated in their ability to infect plants, suggesting that these regulators that mediate synthesis of virulence factors essential for animal pathogenesis are also required for plant pathogenesis. Further, using Arabidopsis plants altered in defense responses such as the transgenic lines NahG [defective in salicylic acid (SA) accumulation], and 35S-LOX2(−) (defective in jasmonic acid production and hyper-accumulator of SA), and mutants ics1 (depleted in SA accumulation), and npr1-1 (non-expressor of pathogenesis-related protein) we show that resistance of Arabidopsis to typical plant pathogens and the animal pathogen S. aureus is conserved and is mediated by SA. The data presented here suggest that Arabidopsis thaliana resistance to S. aureus is mediated either by a direct effect of SA on the pathogen, specifically one that affects the attachment/aggregate formation on the root surface and reduces the pathogen's virulence, or by SA-dependent, NPR1-independent host responses.