BIOSYNTHESES AND REGULATION OF PLANT HORMONES

摘要

Plant hormones are signal molecules, present in trace quantities. Changes in hormone concentration and tissue sensitivity mediate a whole range of developmental process in plants, many of which involve interactions with environmental factors. So far seven hormones are considered as major plant hormones, namely auxin, gibberellins, cytokinins, abscisic acid, ethylene, brassinosteroids and jasmonic acid. Each of these hormones has its own particular properties, so the pathways regulating their production and degradation are quite diverse and have been elucidated by use of chemistry, biochemistry, plant physiology, genetics and molecular genetics. Recently the genomic sequence of Arabidopsis is available for hormone study and that of the rice is also in hand. Now it is possible to study hormone biosyntheses and their regulation by reverse genetic approach. In this symposium I focused on biosyntheses of gibberellins, cytokinins and absisic acid, which we are now studying in my laboratories. Part of this paper involves some new results and data, which are now provisionally accepted in some journals. Therefore this paper is neither a review nor an original paper. However, this paper describes what I talked during the symposium. In order to give creditsto the researchers in the three different topics, major researchers are listed in parentheses.