The sequence information we can obtain from the isolated genes will provide valuable clues as to the mechanism of auxin transport and perception. In addition, we are using mutants of tomato which are defective in the gravitropic response to elucidate both the role of these proteins in auxin-regulated growth and other steps in the signal transduction process. Physiological and genetic analyses of the lazy-2 mutant of tomato, which has a reversed shoot gravitropic response to light, have shown that the phenotype is regulated by the plant photoreceptor phytochrome via a reversal of lateral auxin transport. The diageotropica mutant of tomato exhibits a greatly reduced gravitropic response and our current data indicate that the lesion involves a regulatory gene which modulates interactions between auxin and another plant growth hormone, cytokinin. Plant Molecular Biology.
Ethylene plays multiple roles in modulating the gravitropic response in tomato.
Genetic analysis of the roles of phytochromes A and B1 in the reversed gravitropic response of the lazy-2 tomato mutant. Plant Cell Environ. Rapid determination of gene expression patterns for large numbers of genes. The diageotropica gene differentially affects auxin and cytokinin responses throughout development in tomato.