|1.Research Institution||Nara Institute of Science and Technology|
|160th Committee on Plant Biotechnology for the Environment, Food，and Resources|
|3.Term of Project||FY 1997 〜 FY 2001|
|5.Title of Project||Multiple Molecular Improvement of Photosynthesis and Plant Performances for Crop Productivity|
|Name||Institution,Department||Title of Position|
|Akiho Yokota||Nara Institute of Science and Technology, Graduate School of Biological Science||Professor|
|Names||Institution,Department||Title of Position|
|Kazuyuki Hiratsuka||Nara Institute of Science and Technology, Graduate School of Biological Science||Professor|
|Junko Kyozuka||Nara Institute of Science and Technology, Graduate School of Biological Science||Associate Professor|
|Kazuya Yoshida||Nara Institute of Science and Technology, Graduate School of Biological Science||Associate Professor|
8.Summary of Research Results
This project aimed at clarifying the molecular basis for improving the productivity of plants.
The following findings were obtained in the project for 5 years.
We analyzed the functions of the gene and the proteins functioning in acclimation of the plants to high light intensity and found several new genes and proteins involved in the regulation of energy production in photosynthesis. Two genes for CO2 pump and two genes for HCO3- pump were identified with Synechocystis PCC6803. With the green alga Chlamydomonas reihardii, the signal transduction pathway for signaling the low CO2 concentration to the downstream genes. We devised the method to synthesize up to 200 mg/ml of a foreign protein in chloroplasts by tobacco chloroplast transformation. This will open a window for the industrial production of medical or pharmaceutical proteins in plants. The expression of the gene for cyanobacterial FBP/SBPase in tobacco chloroplasts caused the productivity of the transformant to increase 50% compared with the wild plants. This finding gave us a chance to get an international patent, that have attracted foreign companies. We cloned five genes essential for differentiation of flower of rice plants. We devised a molecular method to increase the content of lipids in tobacco seeds with aid of chloroplast transformation. The genetic manipulation of the lipid metabolism also caused the increase in the lipid content in leaves and thereby retarded senescence of leaves. It was also found that the increment in the assimilation power for sulfur rendered plants to be resistant to heavy metals. We also examined the methods to increase the frequency and expression of the genes transferred into the nucleolus and chloroplast genomes. These findings will be important for designing high-productivity plants in the future.
(1)chloroplast transformation、(2)genes for inorganic concentration、(3)improvement of Calvin cycle
(4)regulation of photosynthetic electron transport、(5)inflorescence meristem-specific genes of rice、(6)structure-function relationship in RuBisCo
(7)gene manipulation of lipid production、(8)genes for nutrient utilization、(9)vectors for stable plant transformation