The availability of the GA-metabolic genes is allowing the molecular mechanisms underlying the regulation of GA metabolism to be deciphered. Such studies have reinforced the importance of GAs as mediators of environmental signals, and are also revealing previously unsuspected crosstalk between the GA signaling pathways and those of other hormones. Furthermore, GA signal transduction has been shown to impinge directly on GA metabolism in the establishment of homeostasis for this hormone. Progress in understanding this process is likely to accelerate with the continuing impressive advances in our knowledge of GA signal transduction (Chapter D2).
Another benefit accruing from the availability of the GA-metabolic genes is the ability to manipulate GA biosynthesis and catabolism by altering expression of these genes (Chapter E7). Genetic manipulation of GA metabolism could provide an alternative to chemical treatments for control of plant growth and development and, furthermore, can be targeted to specific tissues or stages of development. It will also provide an important experimental tool to further understanding of GA biosynthesis and the function of GAs in plant development.