| Project/Area Number |
17K07598
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Science in genetics and breeding
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| Research Institution | Hokkaido University |
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Principal Investigator |
Abe Jun 北海道大学, 農学研究院, 特任教授 (00192998)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | ダイズ / 生殖生長 / FLOWERING LOCUS T / 伸育性 / 落花現象 / 柱頭 / 開花 / 茎頂 / 相転換 / 種子発育 / 花粉発芽 / FLOWERING LOCUST / 育種学 / 生理学 / 発現制御 / 遺伝子 / 遺伝学 |
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| Outline of Final Research Achievements |
Roles of photoperiods and FLOWERING LOCUS T orthologs, FT2a and FT5a, in the control of post-flowering reproductive growths in soybean were studied. The transition of growth phases from vegetative to reproductive at shoot apical meristem was conditioned mainly by FT5a, but not FT2a. FT5a specifically formed a protein complex with FDL06, a soybean ortholog of a transcription factor FD. The complex upregulated floral meristem identity genes, such as APETALA1 orthologs, and in turn repressed the growth habit gene Dt1 to terminate the stem growth. Most of flowers produced in long days are aborted in photoperiod-sensitive cultivars. This flower abortion was attributed to the ungermination of pollen grains on the stigma developed in long days, which was covered by pellicle, an outer layer of stigma, fulfilled by lipids. It was suggested that the structural or physiological nature of pellicle is an important determinant to trigger the germination of pollen grains.
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| Academic Significance and Societal Importance of the Research Achievements |
ダイズの収量は、主に総節数と咲いた花が莢へと成熟する割合によって決定される。主茎の総節数は、開花後の茎頂分裂組織の栄養から生殖生長への相転換の様式で決定されるが、本研究の結果、開花を誘導するフロリゲンとして知られるFLOWERING LOCUS T遺伝子のダイズオルソログFT5aが主茎の生長を規定する重要な働きをなすことが明らかになった。さらに、長日条件下で頻繁に生じる落花現象は、柱頭上での花粉の未発芽に起因しており、柱頭を覆う脂質からなるペリクルが花粉の発芽を抑制していると考えられた。これらの知見は、多収性とその安定性を目指すダイズ育種に貢献する。
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