OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data Supplemental Data OA All Versions of this Article: 21/3/701    most recent tpc.108.061960v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kandasamy, M. K. Articles by Meagher, R. B. Search for Related Content PubMed PubMed Citation Articles by Kandasamy, M. K. Articles by Meagher, R. B. Agricola Articles by Kandasamy, M. K. Articles by Meagher, R. B.

A Single Vegetative Actin Isovariant Overexpressed under the Control of Multiple Regulatory Sequences Is Sufficient for Normal Arabidopsis Development^[W],[OA]

Department of Genetics, Davison Life Sciences Complex, University of Georgia, Athens, Georgia 30602

¹ Address correspondence to meagher{at}uga.edu.

The relative significance of gene regulation and protein isovariant differences remains unexplored for most gene families, particularly those participating in multicellular development. Arabidopsis thaliana encodes three vegetative actins, ACT2, ACT7, and ACT8, in two ancient and highly divergent subclasses. Mutations in any of these differentially expressed actins revealed only mild phenotypes. However, double mutants were extremely dwarfed, with altered cell and organ morphology and an aberrant F-actin cytoskeleton (e.g., act2-1 act7-4 and act8-2 act7-4) or totally root-hairless (e.g., act2-1 act8-2). Our studies suggest that the three vegetative actin genes and protein isovariants play distinct subclass-specific roles during plant morphogenesis. For example, during root development, ACT7 was involved in root growth, epidermal cell specification, cell division, and root architecture, and ACT2 and ACT8 were essential for root hair tip growth. Also, genetic complementation revealed that the ACT2 and ACT8 isovariants, but not ACT7, fully rescued the root hair growth defects of single and double mutants. Moreover, we synthesized fully normal plants overexpressing the ACT8 isovariant from multiple actin regulatory sequences as the only vegetative actin in the act2-1 act7-4 background. In summary, it is evident that differences in vegetative actin gene regulation and the diversity in actin isovariant sequences are essential for normal plant development.

This article has been cited by other articles:

				S. O. Kotchoni, T. Zakharova, E. L. Mallery, J. Le, S. E.-D. El-Assal, and D. B. Szymanski The Association of the Arabidopsis Actin-Related Protein2/3 Complex with Cell Membranes Is Linked to Its Assembly Status But Not Its Activation Plant Physiology, December 1, 2009; 151(4): 2095 - 2109. [Abstract] [Full Text] [PDF]