Hcp2, a Secreted Protein of the Phytopathogen Pseudomonas syringae pv. Tomato DC3000, Is Required for Fitness for Competition against Bacteria and Yeasts

• DOI: 10.1128/jb.00611-12
• Publication Date: 2012-06-30T04:44:51Z
• Authors: Minna Haapalainen; Hanna Mosorin; Federico Dorati; Ru-Fen Wu; Elina Roine; Suvi Taira; Riitta Nissinen; Laura Mattinen; Robert Jackson; Minna Pirhonen; Nai-Chun Lin
• Keywords: Pseudomonas syringae

ABSTRACT When analyzing the secretome of plant pathogen Pseudomonas syringae pv. tomato DC3000, we identified hemolysin-coregulated protein (Hcp) as one secreted proteins. Hcp is assumed to be an extracellular component type VI secretion system (T6SS). Two copies hcp genes are present in P. DC3000 genome, hcp1 (PSPTO_2539) and hcp2 (PSPTO_5435). We studied expression patterns tested fitness knockout mutants host colonization intermicrobial competition. found that gene expressed most actively at stationary growth phase Hcp2 via T6SS appears culture medium covalently linked dimers. Expression not induced planta does contribute virulence or Arabidopsis plants. Instead, required for survival competition with enterobacteria yeasts, its function associated suppression these competitors. This first report on bacterial T6SS-associated functioning yeast. Our results suggest may play important role fitness, allowing this survive under conditions where it has compete other microorganisms resources.