植物におけるキシレムの水力抵抗のヒドロゲル制御

M A Zwieniecki¹, P J Melcher, N M Michele Holbrook

¹Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA. mzwienie@oeb.harvard.edu

Science (New York, N.Y.)

|February 13, 2001

まとめ

植物ジレムの水力抵抗は,イオン濃度を増やすことで急速に低下します. 囲まれた穴におけるこのイオン媒介ヒドロゲル反応は,植物が水の流れを積極的に調節できることを示唆しています.

科学分野:

植物生理学植物生理学
Xylem Hydraulicsは,サイレムの水力学について説明しています.
バイオフィジックス生物物理学

背景:

ジレムは伝統的に植物における水の輸送のための受動的管として見られている.
植物の生存と生産性にとって,キセラム内の水流の調節を理解することは極めて重要です.

研究の目的:

植物ジレムの水力抵抗に対するイオン濃度の影響を調査する.
液体伝導性のイオン誘導による変化の根本的なメカニズムを探求する.

主な方法:

異なったイオン濃度,pH,および非極性溶媒下で植物キシレムの水力抵抗の測定.
観察された効果の局所化は,インターベッセルに囲まれたピット.

主要な成果:

イオン濃度の上昇は,キシレムの水力抵抗を急速に,実質的に,そして可逆的に低下させた.
観察された変化は,ヒドロゲル媒介のプロセス,特にペクチンの腫れと脱水と一致していました.
この効果は,インターベッセルに囲まれたピット膜の内部のマイクロチャネルに局限していた.

結論:

植物のキセレムは惰性管のシステムではなく,イオン媒介の調節機構を持っています.
囲まれたピット内のペクチンヒドロゲルは,水力抵抗を調節する上で重要な役割を果たします.
このメカニズムは,植物が内部水の流れを積極的に調節するための新しい経路を提供します.

さらに関連する動画

08:31

The Calibration and Use of Capacitance Sensors to Monitor Stem Water Content in Trees

Published on: December 27, 2017

08:52

Direct Infusion Device for Molecule Delivery in Plants

Published on: June 2, 2023

関連する概念動画

00:53

Tonicity in Plants

Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity delimits the magnitude and direction of osmosis and results in three possible scenarios that alter the volume of a cell: hypertonicity, hypotonicity, and isotonicity. Due to differences in structure and physiology, tonicity of plant cells is different from that of animal cells in some scenarios.Plants and Hypotonic EnvironmentsUnlike animal cells,...

02:04

Regulation of Transpiration by Stomata

During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.

01:57

Adaptations that Reduce Water Loss

Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.

02:41

Responses to Drought and Flooding

Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.

01:20

Tonicity in Plants

Plant cells maintain appropriate osmotic balance in extreme conditions. For instance, plants in dry environments store water in vacuoles, limit the opening of their stoma, and have thick, waxy cuticles to prevent unnecessary water loss. Some species of plants that live in salty environments store salt in their roots. As a result, water osmosis occurs in the root from the surrounding soil.
Tonicity
Tonicity describes the capacity of a cell to lose or gain water depending on the solute...

01:28

Bioreactor Controls-I

Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using...

関連する実験動画