Gamma-tubulin is essential for microtubule organization and development in Arabidopsis.
The process of microtubule nucleation in plant cells is still a major question in plant cell biology. gamma-Tubulin is known as one of the key molecular players for microtubule nucleation in animal and fungal cells. Here, we provide genetic evidence that in Arabidopsis thaliana, gamma-tubulin is required for the formation of spindle, phragmoplast, and cortical microtubule arrays. We used a reverse genetics approach to investigate the role of the two Arabidopsis gamma-tubulin genes in plant development and in the formation of microtubule arrays. Isolation of mutants in each gene and analysis of two combinations of gamma-tubulin double mutants showed that the two genes have redundant functions. The first combination is lethal at the gametophytic stage. Disruption of both gamma-tubulin genes causes aberrant spindle and phragmoplast structures and alters nuclear division in gametophytes. The second combination of gamma-tubulin alleles affects late seedling development, ultimately leading to lethality 3 weeks after germination. This partially viable mutant combination enabled us to follow dynamically the effects of gamma-tubulin depletion on microtubule arrays in dividing cells using a green fluorescent protein marker. These results establish the central role of gamma-tubulin in the formation and organization of microtubule arrays in Arabidopsis.
Pastuglia
Martine
M
Station de Génétique et d'Amélioration des Plantes, Institut National de la Recherche Agronomique, 78026 Versailles Cedex, France. pastugli@versailles.inra.fr
Azimzadeh
Juliette
J
Goussot
Magali
M
Camilleri
Christine
C
Belcram
Katia
K
Evrard
Jean-Luc
JL
Schmit
Anne-Catherine
AC
Guerche
Philippe
P
Bouchez
David
D
D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005854:Germ Cells / Q000166:cytology; D008870:Microtubules / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018517:Plant Roots / Q000166:cytology; D011058:Pollen / Q000166:cytology; D036226:Seedlings / Q000166:cytology; D014404:Tubulin / Q000172:deficiency / Q000302:isolation & purification / Q000378:metabolism*
D004269:DNA, Bacterial; C036483:T-DNA; D014404:Tubulin