Map-Based Cloning of a Protein Kinase Gene Conferring Disease Resistance in Tomato

TLDR

The Pto gene in tomato confers resistance to Pseudomonas syringae pv. tomato strains that express the avirulence gene avrPto. A yeast artificial chromosome clone spanning the Pto region was used to probe a leaf cDNA library, yielding a cDNA clone from a gene family that cosegregates with Pto.

Abstract

The Pto gene in tomato confers resistance to races of Pseudomonas syringae pv. tomato that carry the avirulence gene avrPto . A yeast artificial chromosome clone that spans the Pto region was identified and used to probe a leaf complementary DNA (cDNA) library. A cDNA clone was isolated that represents a gene family, at least six members of which genetically cosegregate with Pto . When susceptible tomato plants were transformed with a cDNA from this family, they were resistant to the pathogen. Analysis of the amino acid sequence revealed similarity to serine-threonine protein kinases, suggesting a role for Pto in a signal transduction pathway.