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Leaf senescence is accompanied by an early disruption of the microtubule network in Arabidopsis

Citation

Keech, O and Pesquet, E and Gutierrez, L and Ahad, A and Bellini, C and Smith, SM and Gardestrom, P, Leaf senescence is accompanied by an early disruption of the microtubule network in Arabidopsis, Plant Physiology, 154, (4) pp. 1710-1720. ISSN 0032-0889 (2010) [Refereed Article]

Copyright Statement

 2010 American Society of Plant Biologists

DOI: doi:10.1104/pp.110.163402

Abstract

The dynamic assembly and disassembly of microtubules (MTs) is essential for cell function. Although leaf senescence is a well-documented process, the role of the MT cytoskeleton during senescence in plants remains unknown. Here, we show that both natural leaf senescence and senescence of individually darkened Arabidopsis (Arabidopsis thaliana) leaves are accompanied by early degradation of the MT network in epidermis and mesophyll cells, whereas guard cells, which do not senesce, retain their MT network. Similarly, entirely darkened plants, which do not senesce, retain their MT network. While genes encoding the tubulin subunits and the bundling/stabilizing MT-associated proteins (MAPs) MAP65 and MAP70-1 were repressed in both natural senescence and dark-induced senescence, we found strong induction of the gene encoding the MT-destabilizing protein MAP18. However, induction of MAP18 gene expression was also observed in leaves from entirely darkened plants, showing that its expression is not sufficient to induce MT disassembly and is more likely to be part of a Ca2+-dependent signaling mechanism. Similarly, genes encoding the MT-severing protein katanin p60 and two of the four putative regulatory katanin p80s were repressed in the dark, but their expression did not correlate with degradation of the MT network during leaf senescence. Taken together, these results highlight the earliness of the degradation of the cortical MT array during leaf senescence and lead us to propose a model in which suppression of tubulin and MAP genes together with induction of MAP18 play key roles in MT disassembly during senescence.

Item Details

Item Type:Refereed Article
Keywords:leaf senescence, microtubule network, arabidopsis thaliana
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Biological Sciences
Author:Smith, SM (Professor Steven Smith)
ID Code:101467
Year Published:2010
Web of Science® Times Cited:28
Deposited By:Plant Science
Deposited On:2015-06-24
Last Modified:2015-09-22
Downloads:0

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