Document Detail


Effects of the experimental blockage of the major veins on hydraulics and gas exchange of Prunus laurocerasus L. leaves.
MedLine Citation:
PMID:  12654872     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The impact of leaf vein blockage on leaf hydraulic conductance (K(L)), gas exchange (g(L)) and water potential (Psi(L)) was studied in Prunus laurocerasus L., a broad-leaved evergreen. For this purpose, leaves were measured for the three variables above, either with an intact leaf blade (controls) or with the midrib cut a third of the way up (cut a), or with the midrib cut at three different points and the first-order veins cut through near their insertion to the midrib (cut b), or with the midrib cut at 2 mm from the leaf base (cut c). All the cut surfaces were sealed with cyanoacrylate. A serial decrease of K(L) was recorded from cut a to cut c with respect to that measured for the controls, i.e. a K(L) loss of about 37% (cut a), 57% (cut b) and 87% (cut c). A positive linear relationship appeared to exist between g(L) and K(L) with a high correlation coefficient (r(2)=0.99) and a high statistical significance (P <0.01). Even under a severe drop in K(L) (as that induced by cut c), leaf water potential remained approximately constant and not statistically different from Psi(L) measured for the controls. In fact, Psi(L) ranged between -0.83 and -0.98 MPa, i.e. within the cavitation threshold of leaves in terms of the critical Psi(L) inducing a significant production of ultrasound acoustic emissions which was -0.94+/-0.09 MPa. The conclusion was that stomata were very sensitive to changes in K(L) and that stomatal closure led to the homeostatic maintenance of Psi(L) and cavitation avoidance.
Authors:
Andrea Nardini; Sebastiano Salleo
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of experimental botany     Volume:  54     ISSN:  0022-0957     ISO Abbreviation:  J. Exp. Bot.     Publication Date:  2003 Apr 
Date Detail:
Created Date:  2003-03-25     Completed Date:  2003-07-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9882906     Medline TA:  J Exp Bot     Country:  England    
Other Details:
Languages:  eng     Pagination:  1213-9     Citation Subset:  IM    
Affiliation:
Dipartimento di Biologia, Università di Trieste, Via L Giorgieri 10, 34127 Trieste, Italia. nardini@univ.triste.it
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MeSH Terms
Descriptor/Qualifier:
Biological Transport / physiology
Carbon Dioxide / metabolism*
Models, Biological
Oxygen / metabolism*
Plant Leaves / physiology*
Prunus / physiology*
Water / physiology*
Chemical
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7732-18-5/Water; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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