PLANT MOLECULAR BIOLOGY IN JAPAN-PAST, PRESENT, AND FUTURE-
KIYOTAKA OKADA
Modern development of molecular genetic approach of plant biology was stated when a small weed, Arabidopsis thaliana, was chosen to be a model plant in mid 1980's, although some preceding studies were done by using several plant species such as tobacco, maize, and rice. Two Japanese groups finished sequencing of whole chloroplast genome in tobacco and liverwort. Studies of gene expression mechanism were done in systems of wheat histone and sweet potato storage proteins. In addition, molecular mechanisms of photosensing and photosynthesis were investigated by using pea and spinach. Studies of the pre-Arabidopsis time were rather individual and isolated.
It is noteworthy, when Arabidopsis studies were started at about the same time in several countries including Japan, U.S., and European countries, the research style was changed. Many researchers, who had trained in molecular genetics and molecular biology in prokaryote or in animal systems, joined the research in addition to people who learned plant sciences. Consequently, plant researches became more friendly and common to the investigators of other biological fields. In addition, the Arabidopsis researchers recognized the necessity of their unity in order to accelerate research. The researcher's community organized the Multinational Arabidopsis Research Steering Committee with the help of NSF, and discussed research goals of the long- and the short time span. One of the major goals was finishing sequencing of the whole genome by 2000. It was quite fortunate that the project will be completed by international cooperation among Japan, U.S. and European groups. It would be the first time for the plant researchers in different countries, also for researchers in Japan, to conduct their studies with close communication, competition, and collaboration.
I have started molecular genetic research on plant organogenesis and signaling systems working in plant morphogenesis using Arabidopsis in a newly-organized research group at the National Institute for Basic Biology led by Prof. Yoshiro Shimura in 1986. At that time, only a few research groups started to work on Arabidopsis in Japan, but the study became one of the major streams of plant science quickly. Numbers of interesting mutants were isolated systematically, and the molecular studies of the mutants unveiled the underlying genetic mechanism of several basic biological phenomena, for example, formation and maintenance of apical meristems, cell-fate determination of leaves, flowers, and roots, and signaling systems triggered by gravity, light, or by phytohormones.
The year 2000 is a critical time for plant science. A new 10-year goal of Arabidopsis research has been proposed based on the scheduled completion of the whole genome sequencing of Arabidopsis and rice. With the help of national support and international collaboration, plant science in Japan will aim to investigate the molecular mechanism of plant development and metabolic regulation, diversity and evolution of plants, and to apply the results for modern agriculture, and is expected to contribute to the promotion of international science.