title: Optimal level of purple acid phosphatase5 is required for maintaining complete resistance to Pseudomonas syringae.
abstract: Plants possess an exceedingly complex innate immune system to defend against most pathogens. However, a relative proportion of the pathogens overcome host's innate immunity and impair plant growth and productivity. We previously showed that mutation in purple acid phosphatase (PAP5) lead to enhanced susceptibility of Arabidopsis to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Here, we report that an optimal level of PAP5 is crucial for mounting complete basal resistance. Overexpression of PAP5 impaired ICS1, PR1 expression and salicylic acid (SA) accumulation similar to pap5 knockout mutant plants. Moreover, plant overexpressing PAP5 was impaired in H2O2 accumulation in response to Pst DC3000. PAP5 is localized in to peroxisomes, a known site of generation of reactive oxygen species for activation of defense responses. Taken together, our results demonstrate that optimal levels of PAP5 is required for mounting resistance against Pst DC3000 as both knockout and overexpression of PAP5 lead to compromised basal resistance.
authors: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University Truro, NS, Canada.
authors: Sridhar
authors: S
authors: Ravichandran
authors: Department of Biology, Dalhousie University Halifax, NS, Canada.
authors: Sophia L
authors: SL
authors: Stone
authors: Department of Plant and Animal Sciences, Faculty of Agriculture, Dalhousie University Truro, NS, Canada.
authors: Bernhard
authors: B
authors: Benkel
authors: Aquatic and Crop Resource Development, National Research Council Canada Halifax, NS, Canada.
authors: Junzeng
authors: J
authors: Zhang
authors: Department of Chemistry, University of Prince Edward Island Charlottetown, PE, Canada.
authors: Fabrice
authors: F
authors: Berrue
authors: Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University Truro, NS, Canada.
authors: Balakrishnan
authors: B
authors: Prithiviraj
keywords: Arabidopsis; Pseudomonas syringae pv. tomato DC3000; disease resistance; purple acid phosphatase5 (PAP5); reactive oxygen species (ROS)