Fusion, rupture, and degeneration

Author(s)
Verena Ibl, Eszter Kapusi, Elsa Arcalis, Yasushi Kawagoe, Eva Stoger
Abstract

Cereal endosperm is a highly differentiated tissue containing specialized organelles for the accumulation of storage proteins. The endosperm of barley contains hordeins, which are ultimately deposited within protein storage vacuoles (PSVs). These organelles have been characterized predominantly by the histochemical analysis of fixed immature tissue samples. However, little is known about the fate of PSVs during barley endosperm development, and in vivo imaging has not been attempted in order to gain further insight. In this report, young seeds were followed through development to characterize the dynamic morphology of PSVs from aleurone, subaleurone, and central starchy endosperm cells. TIP3-GFP was used as a PSV membrane marker and several fluorescent tracers were used to identify membranes and monitor endomembrane organelles in real time. Whereas the spherical appearance of strongly labelled TIP3-GFP PSVs in the aleurone remained constant, those in the subaleurone and central starchy endosperm underwent substantial morphological changes. Fusion and rupture events were observed in the subaleurone, and internal membranes derived from both the tonoplast and endoplasmic reticulum were identified within these PSVs. TIP3-GFP-labelled PSVs in the starchy endosperm cells underwent a dramatic reduction in size, so that finally the protein bodies were tightly enclosed. Potential desiccation-related membrane-altering processes that may be causally linked to these dynamic endomembrane events in the barley endosperm are discussed.

Organisation(s)
External organisation(s)
Universität für Bodenkultur Wien, National Institute of Agrobiological Sciences
Journal
Journal of Experimental Botany
Volume
65
Pages
3249-3261
No. of pages
13
ISSN
0022-0957
DOI
https://doi.org/10.1093/jxb/eru175
Publication date
07-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
106052 Cell biology
Keywords
ASJC Scopus subject areas
Physiology, Plant Science
Portal url
https://ucris.univie.ac.at/portal/en/publications/fusion-rupture-and-degeneration(30e1e73c-81d5-4447-92dd-a5b1be944e59).html