| Project/Area Number |
16K07467
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Evolutionary biology
|
|---|
| Research Institution | Akita Prefectural University |
|---|
Principal Investigator |
Suzuki Eiji 秋田県立大学, 生物資源科学部, 教授 (60211984)
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
|
|---|
| Keywords | 光合成 / シアノバクテリア / 貯蔵多糖 / 澱粉 / アミロペクチン / グリコーゲン / 進化 / ゲノム編集 |
|---|
| Outline of Final Research Achievements |
Growth rates, polysaccharides (glycogen or starch), and gene expression in cyanobacteria were determined under various environmental conditions. Accumulation of polysaccharide was found to be essential to the growth at non-optimal temperatures, as indicated through analyses using mutants defective in the glycogen synthesis. Under salt stress, different compatible solutes (glucosylglycerol or trehalose) were produced, depending on the degree of salt tolerance of the cyanobacterial species. Under nitrogen deficiency, a non-nitrogen fixing cyanobacterium exhibited growth inhibition, and the reserve polysaccharide was increased to much higher levels than in nitrogen replete conditions. In contrast, the polysaccharide in a nitrogen-fixing cyanobacterium showed diurnal accumulation and nocturnal degradation periodically. In the non-nitrogen fixing species exposed to nutrient deficiencies, transcripts for the genes responsible for inorganic nutrient uptake and assimilation were increased.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究で解析したシアノバクテリアの一部の種は植物型澱粉を生産する希少な原核生物である。本研究ではより一般的なグリコーゲン（原始的な貯蔵多糖）生産種と澱粉生産性シアノバクテリア種の代謝特性を比較することにより、澱粉蓄積の生理的意義、ならびに澱粉合成機構の進化に関する重要な知見を得ることができた。また原核生物の特徴として細胞小器官を持たないなど代謝機構は簡素であり、温度、塩濃度、栄養欠乏など外環境の変化に対してより強靱な耐性を備え、柔軟な応答を示すことが明らかとなった。これら植物型澱粉生産性シアノバクテリアの特性を活用し、これまでにない構造物性を有する新規澱粉素材の開発が期待できる。
|
