Library Open Repository

Structure and Function of Tracheary Elements in Amborella Trichopoda

Downloads

Downloads per month over past year

Feild, TS and Zwieniecki, MA and Brodribb, TJ and Jaffre, T (2000) Structure and Function of Tracheary Elements in Amborella Trichopoda. International Journal of Plant Sciences, 161 (5). pp. 705-712. ISSN 1058-5893

[img] PDF
Amborella.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Recent phylogenetic analyses have placed the root of flowering plants near Amborella trichopoda, a woody plant restricted to cloud forest habitats in New Caledonia. A distinctive feature of A. trichopoda is its reported lack of xylem vessels. Here we present observations of pit membrane structure and end wall morphology for primary and secondary tracheary cells of A. trichopoda as well as field measurements of stem hydraulic properties of A. trichopoda compared with five cloud forest species from New Caledonia. Observations of stem radial sections revealed that the primary wall material in the protoxylem and metaxylem elements was intact. No large porosities (such as those that have been observed in the pit membranes of Nymphaeales) were observed. However, a few elliptical pits of tracheary cells in the secondary xylem appeared to lack pit membranes. These observations are consistent with our measurements of functional conduit length, which indicate that the longest open conduits are equal to the length of two secondary xylem elements joined end to end. Thus, the xylem of A. trichopoda appears to be functionally vesselless, with the caveat that connections between individual vascular elements may occasionally be open (i.e., lacking in at least one pit membrane). Sapwood area and leaf area–specific hydraulic conductivities of A. trichopoda are similar to those of conifers and angiosperms, with and without xylem vessels, growing in understory cloud forest environments. These findings bear on discussions of the morphology and ecology of the first flowering plants as well as on the possible causes of their diversification.

Item Type: Article
Keywords: Amborella, basal angiosperms, xylem hydraulic conductivity, vessel evolution.
Journal or Publication Title: International Journal of Plant Sciences
Page Range: pp. 705-712
ISSN: 1058-5893
Identification Number - DOI: 10.1086/314293
Date Deposited: 03 Dec 2007 04:11
Last Modified: 18 Nov 2014 03:25
URI: http://eprints.utas.edu.au/id/eprint/2616
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page