April 18, 2002 --- A joint research project between Honda subsidiary Honda R&D Co., Ltd. and Nagoya University has succeeded in identifying and clarifying the action mechanism of a gene that reduces the height of rice plants.

The semi-dwarfing gene, called "sd1", controls the hormonal regulation of a rice plant. Loss of this gene's function causes the reduction of the plant size, which results in helping the plant resist falling down and thereby an increase in crop yield.

Professor Makoto Matsuoka of Nagoya University's Bioscience Center, who conducted the joint research effort with Honda R&D, succeeded in clarifying the action mechanism of the plant hormone biosynthesized by this gene. It is expected that identifying this gene could lead to a substantial reduction in the time and labor required for cultivating rice varieties with high crop yields. There is also a possibility of applying this knowledge to other kinds of crops. The results of the study will appear in the scientific journal "Nature," to be published on April 18.

Honda R&D's research facility at Kazusa Akademia Park in Kisarazu City, Chiba Prefecture, has been conducting research on plant genes since December 2000. Honda R&D has also been supporting research on cultivated varieties of Japanese rice through natural crossbreeding at the test-breeding field in Kasetsart University in Thailand.

This project is part of Honda's policy of conducting research on various universal issues, such as energy conservation and global environmental protection. Rice represents a model plant in the research on cereal genes. Honda plans to continue with its research efforts on the genes related to increases in crop yield, aiming also at achieving improvements in resistance to dry weather and changes in the temperature or insects which cause crop damage. Through these research efforts, Honda aims to contribute to solving such universal issues as food shortages.