Bedinger 9707384 The long term objective of the research in my laboratory is to understand molecular events in the reproduction of higher plants, including gametogenesis and pollination. The study of pollen-specific gene products, including the Pex (Pollen-extensin) proteins, has been the focus of a major effort. Although we have performed molecular and localization studies on these proteins that strongly suggest that they play an important role in pollination, we lack the genetic data that firmly establishes that the Pex proteins are essential for pollen function. One way to obtain this data is through the use of antisense-expressing transgenic plants. We have cloned both maize and tomato versions of the Pex genes. This proposal is to fund visits to two laboratories to learn how to transform tomato (and tomato pollen) and maize, and to analyze the transgenic plants that are produced. Our assays for pollen function encompass genetic transmission of mutant genotypes, pollen structure, pollen tube germination and structure, and pollen-pistil interactions.