1995 Fiscal Year Final Research Report Summary
Genetic Control of Biosyn thesis and Timing of Differentiation in Chloroplast
| Project/Area Number |
06804050
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
IBA Koh Kyushu University, Fac.of Sci., Professor, 理学部, 教授 (10192501)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIMURA Mitsuo Kyushu University, Honorary professor, 名誉教授 (40037255)
MORIKAWA Hiromichi Hiroshima University, Fac, of Sci., Professor, 大学院理学研究科, 教授 (00089129)
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| Project Period (FY) |
1994 – 1995
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| Keywords | chloroplast / rpo gene / virescent mutant / cell differentiation / rice |
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| Research Abstract |
The conversion of proplastid into chloroplast is accompanied by activations of plastid and nuclear genes encoding chloroplast proteins. Northern analysis showed that in rice the transcripts of plastid RNA polymerase gene cluster (rpoB-rpoC1-rpoC2) and ribosomal protein genes (rps7, rps15) accumulated at a strictly limited stage of early leat development prior to the accumulation of transcripts of photosynthetic genes (rbcL, rbcS, psbA, cab1). In the seedlings of a temperaturesensitive chlorophyll-deficient mutant of rice, virescent (nu_1), such stage-specific accumulation of the rpo and rps gene transcripts was missing under a restrictive temperature (20ﾟC). Instead, the accumulation occurred at a later stage of leaf maturation. In such mutant seedlings, expressions of other plastid genes (psbA, rbcL, 16SrRNA) were strongly suppressed and the normal chlroplast development was disturbed. These results suggest that the formation of transcription and translation capacities has a high priority in early chloroplast development, and that the construction of functionally active chloroplast transcription/translation apparatus is highly stage-specific in the leaf development.
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