Abstract Detail

Xylem apoplast-symplast interactions

Hacke, Uwe [1].

Aquaporins in stems and roots - tissue level localization and function.

Long-distance water transport in the xylem is in essence a physical process. Yet, in addition to the rapid flow of water between vessels and tracheids, there is radial movement of water between growth rings as well as an exchange of water between xylem and phloem. Much work has focused on the efficiency of the conduit network in terms of maximizing axial flow or on its vulnerability to cavitation. Less is known about radial movement of water and exchange of water between ray cells and vessels. Since the latter process involves flow through membranes, it will likely be facilitated by aquaporin water channels. Using images from immunolabeling and in situ hybridization experiments on poplar and spruce, I will show in which cells and tissues aquaporins are present. Strong signals occurred in various regions of cross sections, including the cambial region, phloem, and rays. Water channels in stems were expressed in a manner that allows hydraulic coupling between xylem and other tissues that may serve as water reservoirs, i.e., bark parenchyma, phloem, and pith parenchyma cells. In the cambial region, water channels may help sustain rapid cell division and expansion of developing xylem and phloem cells.

Broader Impacts:

1 - University of Alberta, Renewable Resources, 442 Earth Sciences Building, Edmonton, AB, T6G 2E3, Canada

Keywords:
aquaporins
xylem
immunolabeling.

Presentation Type: Symposium or Colloquium Presentation
Session: C3
Location: Belle-Chasse/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 10:45 AM
Number: C3011
Abstract ID:134
Candidate for Awards:None