Abstract 9808701 Zhou Plants have evolved a number of biochemical mechanism to resist attack by pathogenic organisms. One mechanism which is the subject of this research. In tomato, plants which have the resistance gene Pto are resistant to Pseudomonas syringae strains which express the gene avrPto. The Pto protein is a cytoplasmic protein kinase, which interacts with AvrPto inside the plant cell. These investigators have been looking for signaling components of this reaction, and have identified a serine/threonine kinase Ptil, which is a substrate of Pto kinase and seems to act downstream of Pto. They found that Pto also interacts with a class of transcription factors in tomato - Pti4, Pti5 and Pti6 which bind to a promoter of disease resistance genes. The focus of this research is to study the in vivo functions of the Pti proteins by looking at Pti mutants which do not interact with Pto, the effect of antisense RNA on Pti function and looking at he expression of the Pti proteins. This research will provide new information on the Pto-mediated signaling mechanisms, and also provide more information on the defense responses in disease resistance. Higher plants have the ability to sense and ward off invading pathogens. The mechanism by which this occurs is not known at the molecular level. These studies will characterize 4 tomato genes that play a role in plant defense. These studies will broaden our knowledge of plant-microbe interactions.
