| Project/Area Number |
11460029
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Plant nutrition/Soil science
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| Research Institution | Tohoku University |
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Principal Investigator |
MAKINO Amane Associate Professor, Graduate School of Agricultural Science, 大学院・農学研究科, 助教授 (70181617)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥12,300,000 (Direct Cost: ¥12,300,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2000: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Keywords | Photosynthesis / Biomass / Oryza sativa L. / Rubisco / Transgenic plant / Nitrogen use / Growth / Rice / 呼吸 / 遺伝子組替 / デンプン / コムギ / 窒素 / 高CO_2 / Triticum aestivm L. / Oryza Sativa L. / 形質転換体植物 / Orysasativa L |
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| Research Abstract |
In this study, I examined how the potential capacity of photosynthesis is related to the growth and biomass of the whole plant. Although most of the dry weight of plants consists of photosynthetic products, many studies have shown that the photosynthetic rate per unit of leaf area does not necessarily reflect the rate of the whole-plant growth and biomass. I considered that morphology and allocation of biomass and N at the level of the whole plant as well as leaf photosynthesis are important for plant growth. Of course, transgenic rice plants with decreased Rubisco showed lower rates of photosynthesis and had smaller growth and biomass. However, potential photosynthesis in a leaf was also regulated at the level of the whole-plant growth. For example, I found the decrease in leaf-N content induced by CO_2 enrichment. This phenomenon was of crucial importance for plant growth under CO_2 enrichment. This decrease in leaf-N content was not due to dilution of N caused by relative increases in the leaf area or plant biomass. This was the result of a change in N allocation of the whole plant. During long-term growth under CO_2 enrichment, rice re-allocated N away from leaf blades to leaf sheaths and roots. In contrast, the rbcS antisense rice plants preferentially allocated N and biomass into leaf blades. Thus,plants regulate photosynthesis in a leaf by changing the N and biomass allocation within the whole plant.
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