Deletions in the repertoire of Pseudomonas syringae pv. tomato DC3000 type III secretion effector genes reveal functional overlap among effectors.

Autor: Brian H Kvitko, Duck Hwan Park, André C Velásquez, Chia-Fong Wei, Alistair B Russell, Gregory B Martin, David J Schneider, Alan Collmer
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: PLoS Pathogens, Vol 5, Iss 4, p e1000388 (2009)
Druh dokumentu: article
ISSN: 1553-7366
1553-7374
DOI: 10.1371/journal.ppat.1000388
Popis: The gamma-proteobacterial plant pathogen Pseudomonas syringae pv. tomato DC3000 uses the type III secretion system to inject ca. 28 Avr/Hop effector proteins into plants, which enables the bacterium to grow from low inoculum levels to produce bacterial speck symptoms in tomato, Arabidopsis thaliana, and (when lacking hopQ1-1) Nicotiana benthamiana. The effectors are collectively essential but individually dispensable for the ability of the bacteria to defeat defenses, grow, and produce symptoms in plants. Eighteen of the effector genes are clustered in six genomic islands/islets. Combinatorial deletions involving these clusters and two of the remaining effector genes revealed a redundancy-based structure in the effector repertoire, such that some deletions diminished growth in N. benthamiana only in combination with other deletions. Much of the ability of DC3000 to grow in N. benthamiana was found to be due to five effectors in two redundant-effector groups (REGs), which appear to separately target two high-level processes in plant defense: perception of external pathogen signals (AvrPto and AvrPtoB) and deployment of antimicrobial factors (AvrE, HopM1, HopR1). Further support for the membership of HopR1 in the same REG as AvrE was gained through bioinformatic analysis, revealing the existence of an AvrE/DspA/E/HopR effector superfamily, which has representatives in virtually all groups of proteobacterial plant pathogens that deploy type III effectors.
Databáze: Directory of Open Access Journals
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