Two distinct Pseudomonas effector proteins interact with the Pto kinase and activate plant immunity.
The Pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of Pseudomonas syringae that express the protein AvrPto. Pto and AvrPto physically interact, and this interaction is required for activation of host resistance. We identified a second Pseudomonas protein, AvrPtoB, that interacts specifically with Pto and is widely distributed among plant pathogens. AvrPtoB is delivered into the plant cell by the bacterial type III secretion system, and it elicits Pto-specific defenses. AvrPtoB has little overall sequence similarity with AvrPto. However, AvrPto amino acids, which are required for interaction with Pto, are present in AvrPtoB and required for its interaction with Pto. Thus, two distinct bacterial effectors activate plant immunity by interacting with the same host protein kinase through a similar structural mechanism.
Kim
Young Jin
YJ
Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA.
Lin
Nai Chun
NC
Martin
Gregory B
GB
D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005822:Genetic Vectors / Q000235:genetics; D007107:Immune System / Q000201:enzymology* / Q000382:microbiology; D007113:Immunity, Innate / Q000235:genetics; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins; D020033:Protein Isoforms / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D011549:Pseudomonas / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; C081695:avrPto protein, Pseudomonas syringae; C084354:Pto protein, Lycopersicon; D017346:Protein Serine-Threonine Kinases