scholarly journals Xylem Embolism in Response to Freeze-Thaw Cycles and Water Stress in Ring-Porous, Diffuse-Porous, and Conifer Species

1992 ◽  
Vol 100 (2) ◽  
pp. 605-613 ◽  
Author(s):  
John S. Sperry ◽  
June E. M. Sullivan
Keyword(s):  
Water Stress ◽  
Conifer Species ◽  
Xylem Embolism ◽  
Freeze Thaw ◽  
Diffuse Porous

scholarly journals Xylem Embolism in Ring-Porous, Diffuse-Porous, and Coniferous Trees of Northern Utah and Interior Alaska

Ecology ◽  
1994 ◽  
Vol 75 (6) ◽  
pp. 1736-1752 ◽  
Author(s):  
John S. Sperry ◽  
Kirk L. Nichols ◽  
June E. M. Sullivan ◽  
Sonda E. Eastlack
Keyword(s):  
Xylem Embolism ◽  
Coniferous Trees ◽  
Interior Alaska ◽  
Northern Utah ◽  
Diffuse Porous

scholarly journals Mechanism of Water Stress-Induced Xylem Embolism

1988 ◽  
Vol 88 (3) ◽  
pp. 581-587 ◽  
Author(s):  
John S. Sperry ◽  
Melvin T. Tyree
Keyword(s):  
Water Stress ◽  
Xylem Embolism

scholarly journals Root Severance at Harvest Increases Embolism and Decreases Sap Flow of Field-grown Acer rubrum L.

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 833-836 ◽  
Author(s):  
Patricia R. Knight ◽  
J. Roger Harris ◽  
Jody K. Fanelli
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Sap Flow ◽  
Water Status ◽  
Acer Rubrum ◽  
Red Maple ◽  
Flow Sensors ◽  
Xylem Embolism ◽  
Sap Flow Sensors ◽  
Old Trees

Root severance during field harvesting alters the water status of a tree, resulting in water stress and reduced post-transplant growth. Two experiments, using Acer rubrum L. (red maple), determined the influence of root severance at harvest on sap flow and xylem embolism. Trees 1.5–1.8 m tall (4 years old) were utilized in the first experiment, and trees 1.2–1.5 m tall (2 years old) were utilized in the second. Sap flow sensors were installed on the 4-year-old trees prior to root severance and remained on the trees until 1 week after harvest. Within 1 day after root severance sap flow was reduced and remained lower than nontransplanted (control) trees for the remainder of the experiment. Leaf stomatal conductance (Cs) of transplanted trees 1 week after root severance was lower than that of control trees, but leaf water potentials (ψ) were similar. In the second experiment, sap flow was reduced relative to control trees within 2 h after root severance. Although Cs was reduced 4 hours after root severance, ψ was not. Embolism increased within 24 hours of root severance. These results indicate that root severance quickly induces increased levels of embolism, which is associated with reduced sap flow.

Water-stress-induced xylem embolism in three species of conifers

1990 ◽  
Vol 13 (5) ◽  
pp. 427-436 ◽  
Author(s):  
J. S. SPERRY ◽  
M. T. TYREE
Keyword(s):  
Water Stress ◽  
Xylem Embolism

scholarly journals Xylem embolism spread is largely prevented by interconduit pit membranes until the majority of conduits are gas-filled

2021 ◽  
Author(s):  
Rodrigo Avila ◽  
Xinyi Guan ◽  
Cade Kane ◽  
Amanda Cardoso ◽  
Timothy Batz ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Potential ◽  
Small Degree ◽  
Conifer Species ◽  
Local Pressure ◽  
Xylem Embolism ◽  
Embolism Resistance ◽  
Potential Threshold ◽  
Xylem Conduits

Xylem embolism resistance varies across species influencing drought tolerance, yet little is known about the determinants of the embolism resistance of an individual conduit. Here we conducted an experiment using the optical vulnerability method to test whether individual conduits have a specific water potential threshold for embolism formation and whether pre-existing embolism in neighbouring conduits alters this threshold. Observations were made on a diverse sample of angiosperm and conifer species through a cycle of dehydration, rehydration and subsequent dehydration to death. Upon rehydration after the formation of embolism, no refilling was observed. When little pre-existing embolism was present, xylem conduits had a conserved, individual, embolism resistance threshold that varied across the population of conduits. The consequence of a variable conduit-specific embolism threshold is that a small degree of pre-existing embolism in the xylem results in an apparently more resistant xylem in a subsequent dehydration, particularly in angiosperms with vessels. While our results suggest that pit membranes separating xylem conduits are critical for maintaining a conserved individual embolism threshold for given conduit when little pre-exisiting embolism is present, as the percentage of embolized conduits increases, gas movement, local pressure differences, and connectivity between conduits increasingly contribute to embolism spread.

Hydraulic architecture of some diffuse-porous trees

1978 ◽  
Vol 56 (18) ◽  
pp. 2286-2295 ◽  
Author(s):  
Martin H. Zimmermann
Keyword(s):  
Water Stress ◽  
Specific Conductivity ◽  
Main Stem ◽  
Gravity Flow ◽  
Hydraulic Architecture ◽  
Fresh Weight ◽  
Leaf Specific Conductivity ◽  
Tree Stem ◽  
Diffuse Porous

The rate of flow of a dilute KCl solution through sections of stem, branches, and twigs was measured and expressed in microlitres per hour, under conditions of gravity flow, per gram fresh weight of leaves supplied by that section of xylem. This is called leaf-specific conductivity (LSC). It is not uniform throughout the tree, LSC of the stem being higher than that of branches. Furthermore, vascular junctions, such as the path from stem to branch, represent hydraulic constrictions. Distribution of LSC in the tree is primarily based on varying vessel diameters. Vessel diameters increase from top to bottom in the tree stem. They are smaller in branches than in the main stem, and there is a distinct constriction of diameters at the base of each branch. Functionally this means that when transpiration begins the pressure has to drop more rapidly in the xylem of lower lateral leaves than in those at the top of the tree. It also means that under conditions of water stress peripheral parts of the tree are more vulnerable than the trunk.

scholarly journals Xylem embolism in leaves does not occur with open stomata: evidence from direct observations using the optical visualization technique

2019 ◽  
Vol 71 (3) ◽  
pp. 1151-1159 ◽  
Author(s):  
Danielle Creek ◽  
Laurent J Lamarque ◽  
José M Torres-Ruiz ◽  
Camille Parise ◽  
Regis Burlett ◽  
...  
Keyword(s):  
Water Stress ◽  
Stomatal Closure ◽  
Safety Margin ◽  
Carbon Assimilation ◽  
Xylem Embolism ◽  
Growth And Survival ◽  
Direct Observations ◽  
Optical Visualization ◽  
Embolism Resistance ◽  
The One

Abstract Drought represents a major abiotic constraint to plant growth and survival. On the one hand, plants keep stomata open for efficient carbon assimilation while, on the other hand, they close them to prevent permanent hydraulic impairment from xylem embolism. The order of occurrence of these two processes (stomatal closure and the onset of leaf embolism) during plant dehydration has remained controversial, largely due to methodological limitations. However, the newly developed optical visualization method now allows concurrent monitoring of stomatal behaviour and leaf embolism formation in intact plants. We used this new approach directly by dehydrating intact saplings of three contrasting tree species and indirectly by conducting a literature survey across a greater range of plant taxa. Our results indicate that increasing water stress generates the onset of leaf embolism consistently after stomatal closure, and that the lag time between these processes (i.e. the safety margin) rises with increasing embolism resistance. This suggests that during water stress, embolism-mediated declines in leaf hydraulic conductivity are unlikely to act as a signal for stomatal down-regulation. Instead, these species converge towards a strategy of closing stomata early to prevent water loss and delay catastrophic xylem dysfunction.

scholarly journals Annual patterns of xylem embolism in high-yield apple cultivars

2017 ◽  
Vol 44 (6) ◽  
pp. 587 ◽  
Author(s):  
Barbara Beikircher ◽  
Stefan Mayr
Keyword(s):  
Soil Water ◽  
Hydraulic System ◽  
Starch Content ◽  
High Yield ◽  
Late Winter ◽  
Xylem Embolism ◽  
Freeze Thaw ◽  
Angiosperm Species ◽  
Soil Water Conditions ◽  
Annual Patterns

Temperate angiosperm species show pronounced annual patterns in xylem embolism. In this study, we investigated whether high-yield cultivars of Malus domestica Borkh. growing under optimised soil water conditions follow similar patterns to wild-type plants, and evaluated crucial factors for the formation of winter embolism and the subsequent restoration of the hydraulic system in spring. In five different cultivars growing at three different sites, various hydraulic and microclimatic parameters were monitored over three successive years. In all cultivars on all sites and in all years, the percentage loss of hydraulic conductivity (PLC) increased in autumn with freeze–thaw events and accumulated over winter. Maximum values were reached in late winter and differed significantly among cultivars. In spring, the hydraulic system was restored and PLC remained negligible during summer. Embolism formation in autumn was significantly correlated with the occurrence of freeze–thaw events, whereas further conductivity losses over winter were related to winter desiccation and influenced by climatic and cultivar-specific parameters. Restoration of the hydraulic system in spring was strongly linked to a decrease in the starch content of wood and buds, and soil temperature. Despite high soil water availability, hydraulic recovery took several weeks and was not completed before bud break. Spring is thus a critical phase for temperate angiosperms, especially for high-yield cultivars with risky hydraulic strategies.

scholarly journals Soil water-holding capacity mediates hydraulic and hormonal signals of near-isohydric and near-anisohydric Vitis cultivars in potted grapevines

2014 ◽  
Vol 41 (11) ◽  
pp. 1119 ◽  
Author(s):  
Sara Tramontini ◽  
Johanna Döring ◽  
Marco Vitali ◽  
Alessandra Ferrandino ◽  
Manfred Stoll ◽  
...  
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Stomatal Closure ◽  
Vitis Vinifera L ◽  
Cabernet Sauvignon ◽  
Xylem Embolism ◽  
Early Stress ◽  
Growing Conditions ◽  
Response To Water ◽  
Water Holding

Grapevine (Vitis vinifera L.) expresses different responses to water stress, depending not only on genotype, but also on the influence of vineyard growing conditions or seasonality. Our aim was to analyse the effects on drought response of two grapevine cultivars growing on two soils, one water draining (WD) containing sand 80% volume and the other water retaining (WR), with no sand. Under these two different water-holding capacities Syrah, displaying a near-anisohydric response to water stress, and Cabernet Sauvignon (on the contrary, near-isohydric) were submitted to water stress in a pot trial. Xylem embolism contributed to plant adaptation to soil water deprivation: in both cultivars during late phases of water stress, however, in Syrah, already at moderate early stress levels. By contrast, Syrah showed a less effective stomatal control of drought than Cabernet Sauvignon. The abscisic acid (ABA) influenced tightly the stomatal conductance of Cabernet Sauvignon on both pot soils. In the near-anisohydric variety Syrah an ABA-related stomatal closure was induced in WR soil to maintain high levels of water potential, showing that a soil-related hormonal root-to-shoot signal causing stomatal closure superimposes on the putatively variety-induced anisohydric response to water stress.

Sign in / Sign up

Export Citation Format

Share Document