Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
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 ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Pavlovkin, J.
Right arrow Articles by Ullrich, C. I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pavlovkin, J.
Right arrow Articles by Ullrich, C. I.
Agricola
Right arrow Articles by Pavlovkin, J.
Right arrow Articles by Ullrich, C. I.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Experimental Botany, Vol. 53, No. 371, pp. 1143-1154, May 2002
© 2002 Oxford University Press

Original Papers

Evidence for high activity of xylem parenchyma and ray cells in the interface of host stem and Agrobacterium tumefaciens-induced tumours of Ricinus communis

Jan Pavlovkin1, Hisashi Okamoto2, Rebecca Wächter3, André Läuchli4 and Cornelia I. Ullrich3 5

1Institute of Experimental Phytopathology, Slovak Academy of Sciences, SK-90028-Ivánka pri Dunaji, Slovakia
2Mori-machi Laboratory of Plant Physiology, 443-5, Enden, Shizuoka, 437-0221, Japan
3Institut für Botanik, Technische Universität, Schnittspahnstr. 3, D-64287 Darmstadt, Germany
4University of California, Department of Land, Air, Water Resources, 151 Hoagland Hall, Davis, CA 95616-8627, USA

Rapidly developing tumours at hypocotyls of Ricinus communis, induced by Agrobacterium tumefaciens strain C58, were characterized by strong differentiation of vascular bundles and their functional connection to the host bundles. The stem/tumour interface showed increased xylem, with numerous vessels accompanied by multiseriate unlignified rays. To know how nutrients efficiently accumulate in the tumour sink tissue, cell electropotentials (Em) in cross-sections were mapped. The measured cells were identified by injected Lucifer Yellow. Xylem and phloem parenchyma cells and stem/tumour-located rays hyperpolarized to Em values of about -170 mV, which suggest high plasma membrane proton pump activities. Rapidly dividing cells of cambia or small tumour parenchyma cells had low Em. The tumour aerenchyma and the stem cortex cells displayed values close to the energy-independent diffusion potential. The lowest values were recorded in stem pith cells. Cell K+ concentrations largely matched the respective Em. The pattern of individual cell electropotentials was supplemented by whole organ voltage measurements. The voltage differences between the tumour surface and the xylem perfusion solution in stems attached to the tumours, the trans-tumour electropotentials (TTP), confirm the findings of respiration-dependent and phytohormone-stimulated high plasma membrane proton pump activity in intact tumours, mainly in the xylem and phloem parenchyma and ray cells. TTPs were inhibited by addition of NaN3, CN- plus SHAM or N2 gas in the xylem perfusion solution and by external N2 flushing. The data provide functional evidence for the structural basis of priority over the host shoot in nutrient flow from the stem to the tumour.

Key words: Agrobacterium tumefaciens-induced tumours, rays, respiration-dependent tumour energization, trans-tumour electropotential difference, xylem parenchyma.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Plant Physiol.Home page
R. Wachter, M. Langhans, R. Aloni, S. Gotz, A. Weilmunster, A. Koops, L. Temguia, I. Mistrik, J. Pavlovkin, U. Rascher, et al.
Vascularization, High-Volume Solution Flow, and Localized Roles for Enzymes of Sucrose Metabolism during Tumorigenesis by Agrobacterium tumefaciens
Plant Physiology, November 1, 2003; 133(3): 1024 - 1037.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.