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Expression of a nondegradable cyclin B1 affects plant development and leads to endomitosis by inhibiting the formation of a phragmoplast (2004)
| Venue: | Plant Cell |
| Citations: | 8 - 0 self |
BibTeX
@ARTICLE{Weingartner04expressionof,
author = {Magdalena Weingartner and A Marie-claire Criqui and C Pavla Binarova and D Anne-catherine Schmit},
title = {Expression of a nondegradable cyclin B1 affects plant development and leads to endomitosis by inhibiting the formation of a phragmoplast},
journal = {Plant Cell},
year = {2004},
pages = {643--657}
}
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Abstract
In plants after the disassembly of mitotic spindle, a specific cytokinetic structure called the phragmoplast is built, and after cytokinesis, microtubules populate the cell cortex in an organized orientation that determines cell elongation and shape. Here, we show that impaired cyclin B1 degradation, resulting from a mutation within its destruction box, leads to an isodiametric shape of epidermal cells in leaves, stems, and roots and retarded growth of seedlings. Microtubules in these misshaped cells are grossly disorganized, focused around the nucleus, whereas they were entirely missing or abnormally organized along the cell cortex. A high percentage of cells expressing nondestructible cyclin B1 had doubled DNA content as a result of undergoing endomitosis. During anaphase the cytokinesis-specific syntaxin KNOLLE could still localize to the midplane of cell division, whereas NPK1-activating kinesin-like protein 1, a cytokinetic kinesin-related protein, was unable to do so, and instead of the formation of a phragmoplast, the midzone microtubules persisted between the separated nuclei, which eventually fused. In summary, our results show that the timely degradation of mitotic cyclins in plants is required for the reorganization of mitotic microtubules to the phragmoplast and for proper cytokinesis. Subsequently, the presence of nondegradable cyclin B1 leads to a failure in organizing properly the cortical microtubules that determine cell elongation and shape.
Keyphrases
nondegradable cyclin b1 plant development cell cortex cell elongation separated nucleus destruction box proper cytokinesis npk1-activating kinesin-like protein cell division timely degradation organized orientation impaired cyclin b1 degradation misshaped cell cytokinesis-specific syntaxin knolle high percentage cytokinetic kinesin-related protein nondestructible cyclin b1 dna content cortical microtubule specific cytokinetic structure mitotic microtubule undergoing endomitosis mitotic spindle isodiametric shape epidermal cell mitotic cyclins
