OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 151/2/809    most recent pp.109.141879v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Pumplin, N. Articles by Harrison, M. J. PubMed PubMed Citation Articles by Pumplin, N. Articles by Harrison, M. J. Agricola Articles by Pumplin, N. Articles by Harrison, M. J.

PLANTS INTERACTING WITH OTHER ORGANISMS

Live-Cell Imaging Reveals Periarbuscular Membrane Domains and Organelle Location in Medicago truncatula Roots during Arbuscular Mycorrhizal Symbiosis^1,[W],[OA]

Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (N.P., M.J.H.); and Department of Plant Biology, Cornell University, Ithaca, New York 14853 (N.P.)

In the arbuscular mycorrhizal symbiosis, the fungal symbiont colonizes root cortical cells, where it establishes differentiated hyphae called arbuscules. As each arbuscule develops, the cortical cell undergoes a transient reorganization and envelops the arbuscule in a novel symbiosis-specific membrane, called the periarbuscular membrane. The periarbuscular membrane, which is continuous with the plant plasma membrane of the cortical cell, is a key interface in the symbiosis; however, relatively little is known of its composition or the mechanisms of its development. Here, we used fluorescent protein fusions to obtain both spatial and temporal information about the protein composition of the periarbuscular membrane. The data indicate that the periarbuscular membrane is composed of at least two distinct domains, an "arbuscule branch domain" that contains the symbiosis-specific phosphate transporter, MtPT4, and an "arbuscule trunk domain" that contains MtBcp1. This suggests a developmental transition from plasma membrane to periarbuscular membrane, with biogenesis of a novel membrane domain associated with the repeated dichotomous branching of the hyphae. Additionally, we took advantage of available organelle-specific fluorescent marker proteins to further evaluate cells during arbuscule development and degeneration. The three-dimensional data provide new insights into relocation of Golgi and peroxisomes and also illustrate that cells with arbuscules can retain a large continuous vacuolar system throughout development.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Maria J. Harrison (mjh78{at}cornell.edu).

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.109.141879

^* Corresponding author; e-mail mjh78{at}cornell.edu.

Received May 25, 2009; accepted August 11, 2009; published August 19, 2009.