Freeze/thaw-induced embolism depends on nadir temperature: the heterogeneous hydration hypothesis Ball, Marilyn en_US Canny, Martin en_US Huang, C en_US Egerton, J en_US Wolfe, Joseph en_US 2021-11-25T13:08:30Z 2021-11-25T13:08:30Z 2006 en_US
dc.description.abstract Freeze/thaw-induced embolism was studied in leaves of field-grown snow gum (Eucalyptus pauciflora) subject to frequent morning frosts. Juvenile trees were grown in buried pots, brought to the laboratory at different stages of acclimation and subjected to simulated frost-freezes (at 2 degrees C h(-1)) to nadir temperatures of -3 or -6 degrees C, which snow gums commonly experience. Frost-frozen and subsequently thawed leaves were cryo-fixed to preserve the distribution of water and were then examined by cryo-scanning electron microscopy. No embolisms were found in leaves frozen to -3 degrees C and thawed. In contrast, 34% of vessels were embolized in thawed leaves that had been frozen to -6 degrees C. This difference was seen also in the extent of extracellular ice blocks in the mid-vein expansion zones in leaves frozen to -3 and -6 degrees C, which occupied 3 and 14% of the mid-vein area, respectively. While the proportion of embolism depended on nadir temperature, it was independent of season (and hence of acclimation state). From the observation that increased embolism at lower nadir temperature was related to the freeze-induced redistribution of water, we hypothesize that the dehydration of cell walls and cells caused by the redistribution exerts sufficient tension on xylem water to induce cavitation on thawing. en_US
dc.identifier.issn 0140-7791 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.subject.other cell wall dehydration and rehydration en_US
dc.subject.other cryo-SEM en_US
dc.subject.other Eucalyptus pauciflora en_US
dc.subject.other expansion zones en_US
dc.subject.other extracellular ice en_US
dc.subject.other frost acclimation en_US
dc.title Freeze/thaw-induced embolism depends on nadir temperature: the heterogeneous hydration hypothesis en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.description.notePublic Author webpage: en_US
unsw.identifier.doiPublisher en_US
unsw.relation.faculty Science
unsw.relation.ispartofissue 5 en_US
unsw.relation.ispartofjournal Plant Cell and Environment en_US
unsw.relation.ispartofpagefrompageto 729-745 en_US
unsw.relation.ispartofvolume 29 en_US
unsw.relation.originalPublicationAffiliation Ball, Marilyn en_US
unsw.relation.originalPublicationAffiliation Canny, Martin en_US
unsw.relation.originalPublicationAffiliation Huang, C en_US
unsw.relation.originalPublicationAffiliation Egerton, J en_US
unsw.relation.originalPublicationAffiliation Wolfe, Joseph, Physics, Faculty of Science, UNSW en_US School of Physics *
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