Dr. Okamoto studied biology at Nagoya University Japan, graduated in 1952. Joined the research groupled by Prof. Mori and Associate Professor Ohta in Biology Instiute of the same University. He received Ph D degree in 1960, worked there as a research and education staff, established the theory of electro-physiological structure of plant axial organ. He was invited as Professor from Yokohama City University. In 1990 and made the break-through to the discovery of “Yieldiin". He retired in 1995 , set up a private Mori Laboratory of Plant Physiology in Mori, Shizuoka, Japan.