| Project/Area Number |
16580069
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied biochemistry
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
ITO Hiroyuki Hokkaido Univ., Grad.School of Agr., Asso.Prof., 大学院・農学研究科, 助教授 (10241366)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | ADP-glucose pyrophosphorylase / transitory starch / transgenic plants / mutated enzymes / allosteric regulation / 同化デンプン合成 / アロステリック調節 / starch-branching enzyme |
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| Research Abstract |
Plants have the ability to convert light energy to chemical energy and to fix atmospheric carbon dioxide by using the chemical energy. It is very important in the survival of plants to utilize the photoassimilate efficiently. It is generally known that the photosynthetic capacity is positively correlated with the accumulation of transitory starch. Therefore, to reinforce the metabolic capacity of transitory starch is expected to lead elevation of the photosynthetic capacity, the growth and the productivity. We have employed the modification of allosteric properties of ADP-glucose pyrophosphorylase (AGPase), which is the key enzyme of plant starch biosynthesis. Arabidopsis plants with modified allosteric AGPase showed the increase of metabolic capacity of transitory starch and thereby the plant growth. The aim in this study was to obtain the basic data for the improvement of rice plant productivity.
1.Expression of AGPase that is insensitive to known allosteric molecules
AGPase from Bacillus stearothermophillus is insensitive to known allosteric molecules. In this study, the gene for B.stearothermophillus AGPase (BsAGP) was introduced into Arabidopsis plants that is deficient in the leaf AGPase isoform. The AGPase activity and transitory starch levels in transgenic plants recovered only to the same levels as wild-type plants, indicating that BsAGP is regulated by unknown molecules in plants.
2.Organ-specific expression profiles of the genes for rice AGPase subunits
Analysis of RT-PCR products showed that 6 rice AGPase genes expressed differently in several organs. One of the 6 genes generated two transcripts by alteenative splicing, whose proteins located in different subcellular compartments, cytosol and amyloplasts.
3.Expression pattern of the candidate gene for rice ADP-glucose transporter
Analysis of RT-PCR products indicated that the transcripts for the candidate of rice ADP-glucose transporter accumulates predominantly in endosperms.
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