関連する実験動画
Updated: Jun 26, 2026
06:27
Fast and Accurate Exhaled Breath Ammonia Measurement
Published on: June 11, 2014
植物における呼吸道代謝,サイズ,窒素の普遍的なスケーリング
Peter B Reich1, Mark G Tjoelker, Jose-Luis Machado
1Department of Forest Resources, University of Minnesota, St Paul, Minnesota 55108, USA. preich@umn.edu
Nature
|January 27, 2006
まとめ
植物の呼吸速度は,動物とは異なり,質量に等比的にスケールします. この発見は,さまざまな条件に一貫しており,植物と動物の間の異なる代謝スケーリングメカニズムを示唆しています.
科学分野:
- 植物生理学 植物生理学
- メタボリックスケーリング
- エコロジー エコロジー エコロジー
背景:
- 動物の新陳代謝は,3/4の法則で体量に比例する.
- 植物代謝も,このアロメトリックスケーリングルに従うと考えられていた.
- 植物や動物における同様のスケーリングは,フラクタル輸送ネットワークに起因する.
研究 の 目的:
- 植物全体の呼吸速度のスケーリングと植物質量を調査するために.
- 植物代謝スケーリングが確立された動物代謝規則に従っているかどうかを判断する.
- 呼吸速度と植物窒素含有量との関係を調べる.
主な方法:
- 43種の約500種の実験室および野外栽培の植物の呼吸データ分析.
- 呼吸速度のスケーリング指数と植物全体の質量の比較.
- 異なる成長条件下における全窒素含有量による呼吸速度のスケーリングの評価.
主要な成果:
- 植物全体の呼吸速度は,実験において,植物全体の質量で等比的に (指数 ≈ 1) 計測されるが,普遍的ではない.
- すべてのデータにおいて,植物全体の呼吸率と総窒素含有量との間に一貫した対比スケール関係が存在する.
- このイソメトリックスケーリングは,成長条件 (光,窒素,温度,CO2) や植物種または機能群とは無関係です.
結論:
- 植物には,動物とは異なる代謝スケーリングパターンがある.
- 植物全体の呼吸スケーリングは主に窒素含有量によるもので,総質量によるものではありません.
- 植物や動物における代謝のスケーリングは,明確な基礎的なメカニズムによって制御される.
関連する概念動画
01:49The Nitrogen Cycle
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
01:46The Calvin Benson Cycle
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
01:40Overview of Metabolism
Living cells constantly carry out various chemical reactions which are necessary for their proper functioning. These reactions are interlinked to one another via multiple pathways. The collection of these chemical reactions is known as metabolism.
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
01:20Overview of Nitrogen Metabolism
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
01:22Inorganic Nitrogen Assimilation
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme nitrate reductase...
01:29Oxygen Requirements and Growth Patterns
Microorganisms exhibit diverse oxygen requirements and growth patterns driven by their metabolic strategies and environmental adaptations. Oxygen, while essential for many organisms, can also be toxic under certain conditions, shaping how microorganisms grow and survive.Oxygen Requirements of MicroorganismsMicroorganisms are classified based on their ability to use or tolerate oxygen:● Obligate aerobes like Mycobacterium tuberculosis need oxygen for energy production, as it serves as the...