まとめ
小麦の植物は大気中の二酸化炭素から酸素をセルロースに吸収しますが,植物の水の酸素は,最終的な酸素同位体比を大きく左右します. 植物用水の酸素は,セルロースの酸素同位体比に主要な影響を与える.
科学分野:
- 植物生理学 植物生理学
- イソトープ地球化学 イソトープ地球化学
- バイオジオケミストリー バイオジオケミストリー
背景:
- セルロース合成は植物にとって基本的なプロセスです.
- 植物における酸素同位体比 ((18) O/(16) O) は環境条件を反映している.
- 植物組織内の酸素源を理解することは,生態学的および生理学的研究にとって極めて重要です.
研究 の 目的:
- 二酸化炭素と水の酸素同位体比が小麦のセルロースの酸素同位体比に及ぼす影響を調査する.
- セルロースバイオシンセシス中の二酸化炭素と植物水間の酸素交換の範囲を決定する.
主な方法:
- 小麦の植物は,供給された二酸化炭素の異なる (18) O/(16) O比率で育てられました.
- セルロースは,小麦植物から精製されました.
- セルロースと植物用水の酸素同位体比 ((18) O/(16) O) は,同位体比質量スペクトロメトリを用いて測定した.
主要な成果:
- セルロース (18) O/(16) O比率は,二酸化炭素 (18) O/(16) O比率の大きな変動にもかかわらず,わずかな違いしか示さなかった.
- セルロース (18) O/(16) O比における観察された差異は,植物用水の差異をよく反映した.
- 二酸化炭素から派生した酸素は,セルロース合成中に植物水と容易に交換されます.
結論:
- 植物の内部水中の酸素同位体比は,陸上の植物のセルロースの (18) O/(16) O比を制御する支配的要因である.
- 二酸化炭素の酸素はセルロースに直接組み込まれないが,水と完全に交換される.
- この発見は,植物セルロースを,古気候と古環境の再構築の代理として使用することへの影響を及ぼします.
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