2001 Fiscal Year Final Research Report Summary
Dessection of developmental program in rice
| Project/Area Number |
11306001
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Breeding science
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| Research Institution | The University of Tokyo |
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Principal Investigator |
NAGATO Yasuo Graduate School of Agricultural and Life Sciences, The University of Tokyo, Professor, 大学院・農学生命科学研究科, 教授 (10143413)
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| Co-Investigator(Kenkyū-buntansha) |
KITANO Hidemi Graduate School of Bioagricultural Sciences, Nagoya Univ., Associate Prof., 大学院・生命農学研究科, 助教授 (50144184)
HIRANO Hiroyuki Graduate School of Agricultural and Life Sciences, The University of Tokyo, Associate Prof., 大学院・農学生命科学研究科, 助教授 (00192716)
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| Project Period (FY) |
1999 – 2001
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| Keywords | rice / mutation / embryogenesis / leaf / flower formation / heterochrony / shoot apical meristem |
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| Research Abstract |
We have already revealed that at least four loci (SHL1〜SHL4) are involved in the initiation of shoot apical meristem (SAM) in rice. To address how SHL genes are associated with the maintenance of SAM, we have newly identified three weak alleles, shl2-6〜shl2-8, of SHL2 and one weak allele, shl1-3, of SHL1. It is revealed that SHL1 and SHL2 genes are indispensable for the maintenance of SAM. In addition, they also regulate the developmental pattern of leaf primordia. Weak shl alleles developed abnormal seedlings producing small thread-like leaves in irregular phyllotaxy. The seedling phenotype of weak shl alleles is similar to that of sho mutants. Double mutant of shl2-6 sho2 suggests that SHO2 function upstream of SHO2.
For dissecting developmental mechanism of panicle and flower, we have analyzed apo1 mutants showing abnormal organization of panicle and flowers. The apo1 produced terminal flowers due to the precocious transformation of meristem identity in rachis and branches. In apo1 flowers, lodicules were increased but stamens were decreased. A large number of pistils were produced indeterminately. These phenotypes suggest that APO1 gene regulates temporal y the transformation of meristem identity in reproductive phase.
To elucidate the program for root formation, we identified mutants defective in crown root (adventitious root) formation. Some mutants have defect in the elongation of root primordia, and the other failed to form root primordia. Thus, there exists a complex cascade of many genes in root formation.
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