ISOLATION AND CHARACTERIZATION OF GENES INVOLVED IN SIGNAL TRANSDUCTION IN GUARD CELLS

¹ Department of Biology and Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116

² ZMBP, Center for Plant Molecular Biology, University of Tuebingen, D-72076, Tuebingen, Germany

³ Department of Molecular Biology, DLO-Center for Plant Breeding and Reproduction Research, AA Wageningen, The Netherlands

Stomatal guard cells provide a well-suited model cell system to understand early signal transduction events in plants in response to endogenous and environmental stimuli. However, the molecular nature of many components in guard cell signal transduction pathways remains to be elucidated. To expand our understanding of the signal transduction network in guard cells and to identify the molecular components that play important roles in stomatal movements, molecular genetic and physiological approaches were used. We constructed Arabidopsis guard cell cDNA libraries and isolated many signal transduction-related genes and putative ion channel genes using degenerate oligomer-based PCR. We have used a reverse-genetic strategy to identify disruptions in some of these genes from T-DNA- and transposon-tagged mutant populations of Arabidopsis. In addition, in situ hybridization and GFP fusions are currently in progress to examine the expression of the genes in guard cells. Patch-clamp, cell biological and molecular genetic analyses of the genes and Arabidopsis suppressor mutants will be discussed.