Martine Devic and Marie-Edith Chabouté are equal contributors to this work.
QQT proteins colocalize with microtubules and are essential for early embryo development in Arabidopsis
Article first published online: 5 APR 2007
The Plant Journal
Volume 50, Issue 4, pages 615–626, May 2007
How to Cite
Lahmy, S., Guilleminot, J., Schmit, A.-C., Pelletier, G., Chaboute, M.-E. and Devic, M. (2007), QQT proteins colocalize with microtubules and are essential for early embryo development in Arabidopsis. The Plant Journal, 50: 615–626. doi: 10.1111/j.1365-313X.2007.03072.x
- Issue published online: 25 APR 2007
- Article first published online: 5 APR 2007
- Received 8 November 2006; revised 9 January 2007; accepted 16 January 2007.
- cell division
During Arabidopsis embryogenesis, the control of division between daughter cells is critical for pattern formation. Two embryo-defective (emb) mutant lines named quatre-quart (qqt) were characterized by forward and reverse genetics. The terminal arrest of qqt1 and qqt2 embryos was at the octant stage, just prior to the round of periclinal divisions that establishes the dermatogen stage . Homozygous embryos of a weaker allele of qqt1 were able to divide further, resulting in aberrant periclinal divisions. These phenotypic analyses support an essential role of the QQT proteins in the correct formation of the tangential divisions. That an important proportion of qqt1 embryos were arrested prior to the octant stage indicated a more general role in cell division. The analysis of QQT1 and QQT2 genes revealed that they belong to a small subgroup of the large family encoding ATP/GTP binding proteins, and are widely conserved among plants, vertebrates and Archaea. We showed that QQT1 and QQT2 proteins interact with each other in a yeast two-hybrid system, and that QQT1 and QQT2 tagged by distinct fluorescent probes colocalize with microtubules during mitosis, in agreement with their potential role in cell division and their mutant phenotype. We propose that QQT1 and QQT2 proteins participate in the organization of microtubules during cell division, and that this function is essential for the correct development of the early embryo.