Physiological and Molecular Studies of Phototropism in Arabidopsis thaliana

点击翻译按钮获取中文摘要

9601164 Briggs As sessile organisms, plants have evolved the capacity to respond to a wide range of environmental signals, one of the most important of which is light. Indeed, virtually every phase of a plant's development is regulated by its light environment. These collective responses are encompassed by the term photomorphogenesis. Since Koornneef et al. first described the hy (long hypocotyl) mutants of Arabidopsis, mutants have been central to photomorphogenesis research. The present award to study signal transduction in a blue light-activated system, phototropism, also relies heavily on the use of mutants. Dr. Brigg's laboratory has recently isolated a number of severe phototropism mutants in Arabidopsis thaliana designated nph for non-phototropic hypocotyl. They fall into four complementation groups, nph1-4. All five alleles of the first group, nph1, are deficient in or lack the phosphoprotein but show normal gravitropism, and it is the NPH1 gene that is focal point for this proposal. The working hypothesis is that NPH1 is the gene that encodes the phosphoprotein. As the weakest allele(nph1-2) shows altered spectral sensitivity for phototropism, NPH1 may itself be the photoreceptor. This research will contribute to extending our knowledge about the many ways in which light plays a role in plant growth and development.