Plant Physiol.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on February 16, 2007; 10.1104/pp.106.091827

This Article
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow All Versions of this Article:
143/4/1975    most recent
pp.106.091827v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nardini, A.
Right arrow Articles by Salleo, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nardini, A.
Right arrow Articles by Salleo, S.
Agricola
Right arrow Articles by Nardini, A.
Right arrow Articles by Salleo, S.

Received October 23, 2006
Accepted January 27, 2007

A Reduced Content of Homogalacturonan Does Not Alter the Ion-mediated Increase in Xylem Hydraulic Conductivity in Tobacco

Andrea Nardini *, Antonio Gascó , Felice Cervone , and Sebastiano Salleo

Dipartimento di Biologia, Università di Trieste, 34127 Trieste, Italia; Dipartimento di Biologia Vegetale, Università di Roma La Sapienza, 00185 Roma, Italia

* Corresponding author; email: nardini{at}units.it.

Xylem hydraulic conductivity (Ks) in stems of tobacco wild type SR1 was compared to that of PG7 and PG16, two transgenic lines with increased levels of expression of the gene encoding the Aspergillus niger endopolygalacturonase (AnPGII). Activity of AnPGII removes in planta blocks of homogalacturonan (HG) with deesterified carboxyls, thus increasing the degree of neutrality (DE) of pectins. The effect was tested of K+ in increasing stem Ks using model plants with more neutral polysaccharides in primary walls and, hence, in intervessel pit membranes. Ks measured with deionized water was compared to that with KCl solutions at increasing concentrations ({Delta}Ks, %). Plants transformed for HG-DE showed a dwarfed phenotype but {Delta}Ks did not differ among the three experimental groups. The ion-mediated hydraulic effect saturated at a KCl concentration of 25 mM in SR1 plants. All the three tobacco lines showed {Delta}Ks of around +12.5% and +17.0% when perfused with 10 and 25 mM KCl, respectively. Because the modification of HG content did not influence the ion-mediated hydraulic enhancement, we suggest that pectin components other than HG (like RGI and/or RGII) might play important roles in the hydrogel behaviour of pit membranes.




This article has been cited by other articles:


Home page
 Plant Physiol.Home page
S. Ferrari, R. Galletti, D. Pontiggia, C. Manfredini, V. Lionetti, D. Bellincampi, F. Cervone, and G. De Lorenzo
Transgenic Expression of a Fungal endo-Polygalacturonase Increases Plant Resistance to Pathogens and Reduces Auxin Sensitivity
Plant Physiology, February 1, 2008; 146(2): 669 - 681.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 2007 by the American Society of Plant Biologists