An excellent system for studying the regulation of gene expression during higher plant development is the ethylene hormone induced fruit ripening process in tomatoes (Lycopersicon esculentum). In this proposal the program of gene expression induced by ethylene will be analyzed, genes whose expression significantly increases will be isolated, and the DNA sequences that control their expression will be identified. To this end, chimeric genes will be constructed containing putative 5' upstream regulatory sequences ligated to coding sequences of octopine synthase, a gene whose mRNA can readily be identified amongst the endogenous tomato mRNAs. The chimeric genes will be inserted into the tomato genome, plants regenerated from transformed cell lines, and the expression of the chimeric genes assayed in fruit from the regenerated plants. These experiments will provide new and basic information about how gene expression is regulated during development in higher organisms.