NADPH酸化酵素によって生成される活性酸素種は,植物細胞の成長を調節する
Julia Foreman1, Vadim Demidchik, John H F Bothwell
1Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.
Nature
|March 28, 2003
まとめ
植物の根と根毛の成長は,NADPH酸化酵素によって調節されるカルシウム (Ca2+) の吸収に依存しています. これらの酵素はCa2+チャネルを活性化する活性酸素種 (ROS) を生成し,細胞の膨張とミネラル吸収を促進します.
科学分野:
- 植物生物学 植物生物学
- 細胞生理学 細胞生理学
- 分子遺伝学 分子遺伝学
背景:
- 細胞の膨張,特に根と根毛の伸びは,植物水とミネラル吸収に不可欠です.
- カルシウムイオン (Ca2+) の流入は,植物根の細胞延長の速度を調節するために不可欠です.
- アラビドプシス・タリアナrhd2変異種は,Ca2+吸収が低下し,根毛が鈍化し,細胞の膨張が損なわれる.
研究 の 目的:
- 成長する植物根細胞におけるCa2+の吸収を制御する規制メカニズムを調査する.
- Ca2+の吸収と根の発達におけるRHD2遺伝子の機能を特定する.
主な方法:
- RHD2遺伝子産物のNADPH酸化酵素としての特徴.
- 野生型およびrhd2変異体の根毛における活性酸素種 (ROS) レベル測定.
- ディフェニレンヨドニウム (DPI) を使用したNADPH酸化酵素の活性抑制.
- 表現型的救済を観察するために,ROSでrhd2変異体の実験的治療.
主要な成果:
- RHD2は,根毛の成長においてROSの産生を司るNADPH酸化酵素として特定されました.
- ROSレベルは,野生型と比較して,rhd2変異体において有意に低下した.
- NADPH酸化酵素の活性抑制により,rhd2変異フェノタイプがフェノコピーされました.
- ROS治療はrhd2変異フェノタイプを部分的に救出し,Ca2+チャネル活動を強化しました.
結論:
- NADPH酸化酵素は,ROSを生成することによって,植物の根の発達に重要な役割を果たします.
- NADPHオキシダゼによって生成されるROSは,プラズマ膜Ca2+チャネルの活性化を通じて,植物細胞の膨張を調節する.
- この経路は,Ca2+の吸収と根の形態変異を制御する新しいメカニズムを強調しています.
関連する概念動画
01:24Redox Reactions
50.9K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
50.9K
02:19Morphogenesis
19.9K
Plant morphogenesis—the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation. Precursor cells differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.
19.9K
02:00Photoreceptors and Plant Responses to Light
22.5K
Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
22.5K
01:25Cell Signaling in Plants
4.5K
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...
4.5K
01:27Redox Reactions
1.2K
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
1.2K
01:29Oxygen Requirements and Growth Patterns
2.5K
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...
2.5K