| Budget Amount *help |
¥15,500,000 (Direct Cost: ¥15,500,000)
Fiscal Year 2006: ¥4,300,000 (Direct Cost: ¥4,300,000)
Fiscal Year 2005: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2004: ¥6,800,000 (Direct Cost: ¥6,800,000)
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| Research Abstract |
1.Studies on the development of exine structure on the pollen surface.
We have found the insufficient exine structure of shepherd (shd) mutant. Our results in this study revealed that the SHD function is essential in the tapetal cells at the tetrad stage for the supplement of sporopollenin, a precursor of exine, onto the pollen surface. To identify more genes involved in the exine development, we screened the mutagenized Arabidopsis population by observing the pollen surface with scanning electron microscope, and isolated 12 mutants designated kaonashi. They included the mutants, having severely destroyed exine architecture and ones lacking normal bacula or tectum structures. Molecular cloning of mutated genes is in progress.
2.Studies on the formation of pollen coats.
The flaky pollen1-1(fkpl-1)mutant lacks the pollen coat completely, and results in the conditional male sterility, which is overcome by a high-humidity treatment. Electron microscopic observation revealed that the structures of lipid-containing tapetum-specific organelles, tapetosomes and elaioplasts, are severely affected by the mutation. These results indicate that the mevalonate pathway, in which the FKP1 is an essential component, is responsible for the development of tapetal organelles that are the major source of pollen coat components.
3.Involvements of jasmonic acid in the floral-organ development and pollen fertility
We propose a hypothesis that the biosynthesis of jasmonic acid in flower buds is triggered by auxin.
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