%0 Book %1 Raschietal_1993 %C Cambridge, England %D 1993 %E Raschi, A. %E Borghetti, M. %E Grace, J. %I Cambridge University Press %K bibtex-import, citeulikeExport diameter, droughtbolism, embolism, freezebolism, refilling, snowgumpapermaybe, unread %T Water transport in plants under climatic stress

@book{Raschietal_1993, added-at = {2019-03-31T01:14:40.000+0100}, address = {Cambridge, England}, biburl = {https://www.bibsonomy.org/bibtex/2d0ed3b7ec19ed91c10ad7d1d14f7389d/dianella}, citeulike-article-id = {1523854}, comment = {(private-note)herbs cavitate at similar pressure to trees! banana has a very low embolism tension: 0.2 MPa Ultrasound vs audible sound clicks Cavitation causes bubbles at around vacuum pressure. "A tiny amount of gas with a lot of water vapour" Add water, bubble shrinks and goes, don't add water, then with time gases diffuse from in tissues and embolism occurs. I don't believe: "when plants cavitate... they must lose water through their... walls" unlikely that plants would generate enough tension to break the H bonds, more likely bubble already present. Briggs (1950) says water becomes very vulnerable between 5-0oC Experiments show LESS vulnerable in this range, but MORE vulnerable below 0. Chapter 2: Oertli (phi)psub(xylem) = (phi)p(sub)wall = (phi)(sub) cell =(phi)p(sub)cell + (phi)pi(sub)cell since (phi)pi < 0 (phi)p(sub)cell) > that of the xylem or the cell wall. the (hydrostatic?) pressure in the cell wall is always less than the pressure in the cell How do they get refilled again: Hypothesis: ray parenchyma responsible for refilling by pumping cations? (SEE wodzicki \& Brown 1970) Hypothesis: Capillary action: meniscus of residual water causes a reduced (phi) in the adjacent cells Zimmermann (1964)'s hypothesis: cavitated tracheids are replaced by new growth Hammel(1967)'s hypothesis: Bordered pits close due to the pressure rise as ice expands. The pressure dissolves bubbles. Sucoff 1969: the embolism of one tracheid allows others to dissolve bubbles Hygen 1965, Havis 1970: Conduction continues by flow through cell wall capillaries. Robson and Petty (bari and hallet 1974) During ice/water interfaces above 2.5mms-1 bubbles nucleate. bubbles observed in the centre of lumens not necessarily due to last freeze. pit aspiration between adjacent tracheids is unlikely during freezing.... but it could conceivably occur where there are localised differences in density/structure a very complicated hypothesis about the movement of water during freezing, including movement in the apoplast cell wall water freezes at lower temperatures because it's partially bound Embolism depends on thawing rate and transpiration rate (low, high -> tensions -> pit aspiration maybe (oi! really?) and/or embolism) Sperry p86 it's because of the low solubility of gases in ice, that's why you get bubbles. Larger-volume conduits are more vulnerable than smaller ones (larger bubbles form in higher volume conduits?) (therein) Acer refilled by root and stem pressures (therein) vitis refilled by root pressures (therein) Circumstantial evidence of refilling nightly in some herbs by roots pressures (eg. maize, plantago) (therein) hydraulic conductivity = mass flow rate/pressure gradient mass flow rate measured by mass of outflow pressure gradient driven by gravity. Typical biological sap tensions : 2MPa}, editor = {Raschi, A. and Borghetti, M. and Grace, J.}, interhash = {bffa3fde95a2794472d43285745f737c}, intrahash = {d0ed3b7ec19ed91c10ad7d1d14f7389d}, keywords = {bibtex-import, citeulikeExport diameter, droughtbolism, embolism, freezebolism, refilling, snowgumpapermaybe, unread}, posted-at = {2007-07-31 06:39:44}, priority = {2}, publisher = {Cambridge University Press}, timestamp = {2019-03-31T01:16:26.000+0100}, title = {{Water transport in plants under climatic stress}}, year = 1993 }