1999 Volume 6 Pages 1-8
During the last decade, tremendous developments have been in plant genetic engineering techniques and many important transgenic cereal plants have been successfully produced. Almost all of the new techniques in genetic manipulation depend upon the successful regeneration of plants from in vitro cultures such as callus, suspension cells and protoplasts. In this paper, I briefly describe the contributions of Japanese researchers to the development of in vitro culture and gene transformation of cereals, especially rice, and discuss a number of recent advances in this area of research in Japan. In Japan, rice is the most important crop. On the background of intensive basic researches on rice plants, as early as 1964, after the pioneering work of Furuhashi and Yatazawa (1964), the in vitro culture of rice was established in 1967. After the protoplast culture system was established, the first transgenic rice plants were regenerated from rice protoplasts via the direct gene transformation system in 1988. Recently, the Agrobacterium-mediated transformation system was established in rice plants by a research group at JT (Japan Tobacco Inc.) in 1994. A number of transgenic rice plants with various useful genes introduced, including genes conferring tolerance to environmental stresses, resistance to disease and insects, and improving the quality and yield, have been produced at various laboratories. The environmental risk evaluation of transgenic rice plants has been completed, and virus resistant-rice and low allergenic protein-rice have been developed for commercial use. Among the cereals, wheat has proved to be one of the most difficult species to transform. We established the in vitro culture of wheat in 1978 and succeeded in the production of transgenic wheat plants by using particle bombardment in 1995. The transgenic barley plants have been obtained by both protoplast-mediated and microprojectile-mediated transformation systems. Recently, the Agrobacterium-mediated transformation system has been established in maize. In Japan, the Rice Genome Project has been proceeding intensively and genes beneficial for improving crop plants will be isolated and characterized in rice plants. Isolation of useful genes will allow rapid development of beneficial cultivars in not only rice but also other cereals including wheat, barley and maize.