Gast ::
| Hauptseite > Publikationsdatenbank > Functional repair of embolized vessels in maize roots after temporal drought stress, as demonstrated by magnetic resonance imaging |
| Hauptseite > Publikationsdatenbank > Functional repair of embolized vessels in maize roots after temporal drought stress, as demonstrated by magnetic resonance imaging |
| Journal Article | PreJuSER-964 |
; ; ; ; ;
2009
Wiley-Blackwell
Oxford [u.a.]
This record in other databases: 
Please use a persistent id in citations: doi:10.1111/j.1469-8137.2009.02919.x
Abstract: Xylem sap under high tension is in a metastable state and tends to cavitate, frequently leading to an interruption of the continuous water columns. Mechanisms of cavitation repair are controversially discussed. Magnetic resonance (MR) imaging provides a noninvasive, high spatial and temporal resolution approach to monitor xylem cavitation, refilling, and functionality. Spin density maps of drought-stressed maize taproots were recorded to localize cavitation events and to visualize the refilling processes; c. 2 h after release of the nutrient solution from the homemade MR imaging cuvette that received the root, late metaxylem vessels started to cavitate randomly as identified by a loss of signal intensity. After c. 6 h plants were rewatered, leading to a repair of water columns in five out of eight roots. Sap ascent during refilling, monitored with multislice MR imaging sequences, varied between 0.5 mm min(-1) and 3.3 mm min(-1). Flow imaging of apparently refilled vessels was performed to test for functional repair. Occasionally, a collapse of xylem vessels under tension was observed; this collapse was reversible upon rewatering. Refilling was an all-or-none process only observed under low-light conditions. Absence of flow in some of the apparently refilled vessels indicates that functionality was not restored in these particular vessels, despite a recovery of the spin density signal.
Keyword(s): Droughts (MeSH) ; Magnetic Resonance Spectroscopy (MeSH) ; Models, Biological (MeSH) ; Plant Exudates: metabolism (MeSH) ; Plant Roots: cytology (MeSH) ; Plant Roots: physiology (MeSH) ; Plant Transpiration (MeSH) ; Seedling: physiology (MeSH) ; Spin Labels (MeSH) ; Stress, Physiological (MeSH) ; Time Factors (MeSH) ; Xylem: physiology (MeSH) ; Zea mays: physiology (MeSH) ; Plant Exudates ; Spin Labels ; J ; cavitation (auto) ; collapse of xylem vessels (auto) ; drought stress (auto) ; flow imaging (auto) ; magnetic resonance (MR) imaging (microscopy) (auto) ; xylem refilling (auto) ; Zea mays (maize) (auto)
|
The record appears in these collections: |
PDF