状菌根の共生における窒素の移転
Manjula Govindarajulu1, Philip E Pfeffer, Hairu Jin
1Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003, USA.
Nature
|June 10, 2005
まとめ
樹冠状菌類 (Arbuscular mycorrhizal fungi,AMF) は,アルギニンを経由して植物に窒素を転送する. この研究は,AMF共生における窒素同化と転位のための新しい代謝経路を明らかにしています.
科学分野:
- 植物と微生物の相互作用
- 菌類学 菌類学とは
- 植物生理学 植物生理学
背景:
- 樹木状菌根菌 (AMF) は,ほとんどの陸上の植物と重要な共生を形成し,栄養交換を促進します.
- この共生は,植物の栄養,地球規模の栄養循環,そして植物の進化にとって極めて重要です.
- AMFによる窒素の吸収と宿主植物への移動のメカニズムは,まだ十分に理解されていません.
研究 の 目的:
- 状菌類 (AMF) から宿主植物への窒素の吸収と移動の経路を解明する.
- AMFの共生の中で窒素転移に関与する分子機構と代謝のステップを特定する.
主な方法:
- 安定イソトープの標識実験は,窒素の同化と転位を追跡するために使用されました.
- 遺伝子発現の分析は,エクストララディカルおよびイントラディカルキノコ組織で行われました.
- 異なる窒素条件下での遺伝子発現の比較分析.
主要な成果:
- AMFによる根の外の無機窒素の吸収は,アミノ酸に組み込まれています.
- 窒素は,主にアルギニンとして,エクストララジカルからイントラジカル菌糸体に移転します.
- 窒素は炭素なしで植物に移され,異なる真菌のコンパートメントで特定の遺伝子発現パターンを伴う.
結論:
- AMF共生における窒素の同化と移転のための新しい代謝経路が特定されました.
- エクストララジカルミセリウムにおける窒素同化遺伝子の好ましい発現と,イントラジカルミセリウムにおけるアルギニン分解遺伝子は,提案されたメカニズムを支持する.
- この経路は,窒素の利用可能性と形態によって調節され,植物と真菌の栄養交換におけるその重要性を強調しています.
さらに関連する動画
06:43Inoculating and Observing Arbuscular Mycorrhizal Cultures on Superabsorbent Polymer-Based Autotrophic Systems
Published on: June 14, 2024
07:43Production of Arbuscular Mycorrhizal (AM) Fungal Inoculum and Phenotypic Evaluation of Rice and AM Symbiosis Under Saline Conditions
Published on: March 14, 2025
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...
02:11The Roles of Bacteria and Fungi in Plant Nutrition
Plants have the impressive ability to create their own food through photosynthesis. However, plants often require assistance from organisms in the soil to acquire the nutrients they need to function correctly. Both bacteria and fungi have evolved symbiotic relationships with plants that help the species to thrive in a wide variety of environments.
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...
01:09Microbe-Plant Interactions
Microbe-plant interactions represent a dynamic spectrum of associations shaped by intricate chemical signaling. These interactions can be neutral, beneficial, or detrimental, and profoundly influence plant physiology, growth, and ecosystem function. The plant microbiome, comprising bacteria, fungi, archaea, protists, and viruses, plays a pivotal role in mediating these effects through surface colonization, internal colonization, or systemic symbiosis.Mutualistic associations, particularly with...
01:26Microbes and the Nitrogen Cycle
The nitrogen cycle is a complex biogeochemical process critical to maintaining the balance of nitrogenous compounds in ecosystems. This cycle involves multiple microbial-mediated transformations through which nitrogen changes oxidation states, supporting essential ecological functions and contributing to plant and microbial growth.Nitrogen Fixation and AmmonificationNitrogen fixation initiates the cycle by converting inert atmospheric nitrogen (N₂) into bioavailable ammonia (NH₃), a process...