2005 Fiscal Year Final Research Report Summary
Enhancement of rice photosynthesis functions by modifying the activating enzyme for carbon dioxide fixation
| Project/Area Number |
15580012
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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 |
Crop science/Weed science
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| Research Institution | Kobe University |
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Principal Investigator |
HATANAKA Tomoko Kobe University, Faculty of Agriculture, Lecturer, 農学部, 講師 (40254461)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIDA Naotsugu Kobe University, Faculty of Agriculture, Professor, 農学部, 教授 (70151884)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Rice / Rubisco activase / Wild species / Transformation / Carbon dioxide fixation / Photosnythesis |
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| Research Abstract |
First, we investigated photosynthesis abilities of several wild species of genus Oryza. According to the results, O.australiensis, which has EE genome, showed the higher efficiency than a cultivated species, O.sativa, which has AA genome. Nevertheless, the DNA sequence of Rubisco activase gene that activates Rubisco, which is considered as a limiting factor for photosynthesis rates, was insignificantly similar to the one of O.sativa (their homology was 98%).
Next, O.sativa L.cv.Nipponbare was transformed with rice Rubisco activase gene driven by Cab promoter via Agrobacterium. We obtained several dozen transgenic plants. However, their Rubisco activase contents were much lower than that of the wild type probably because of the severe co-suppressions. Therefore we have not created over-expressing transgenic plants of Rubisco activase.
Meanwhile, we also obtained antisense Rubisco activase introduced transgenic rice plants. Our research showed that 20 - 25% of regular Rubisco activase contents could keep the normal photosynthesis rate under a stable high light condition, but it would not enough if they were under variable light conditions.
Now we are continuing some plans to utilize other species, such as barley, corn, spinach, bean, or another promoter, CAMV35S, instead of Cab promoter and to introduce them into rice plants.
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