Journal Article

An <i>Arabidopsis ACT2</i> Dominant-Negative Mutation, which Disturbs F-actin Polymerization, Reveals its Distinctive Function in Root Development

Taisuke Nishimura, Etsuo Yokota, Takuji Wada, Teruo Shimmen and Kiyotaka Okada

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 44, issue 11, pages 1131-1140
Published in print November 2003 | ISSN: 0032-0781
Published online November 2003 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcg158
An Arabidopsis ACT2 Dominant-Negative Mutation, which Disturbs F-actin Polymerization, Reveals its Distinctive Function in Root Development

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Eight functional actin genes are present in Arabidopsis. The functional characterization of these genes in loss-of-function mutants is difficult, because highly conserved isovariants are generally expressed in the same tissue. We isolated a novel semi-dominant mutant allele (act2-2D) of an actin gene, ACT2, with a missense mutation which causes an amino acid substitution at the surface of the ACT2 protein. ACT2 promoter::ACT2-2D transgenic plants showed the same phenotype as act2-2D, indicating that act2-2D is a dominant-negative mutant. act2-2D exhibited defects in the initiation and elongation of root hairs, the elongation of root epidermal cells, and growth in aerial portions. Specifically, radial cell expansion was reduced and occasional cell death occurred in trichoblasts but not in atrichoblasts of the root epidermis. In contrast, cell division patterns in the root meristem were not affected. act2-3, a loss-of-function ACT2 mutant, did not develop most of these morphological abnormalities. Actin filament (F-actin) bundles in root epidermal cells of act2-2D were shorter than in the wild type and in the loss-of-function mutant. We conclude that defective F-actin polymerization caused the aberrant cell morphology in a dominant-negative manner, and that ACT2 functions in cell elongation and root hair formation.

Keywords: Keywords: ACT2 — Arabidopsis thaliana — Cell expansion — Dominant-negative mutant — F-actin polymerization — Root hair development.; Abbreviations: F-actin, actin filament; CAPS, cleaved amplified polymorphic sequence; RT-PCR, reverse transcriptase-mediated polymerase chain reaction; UTR, untranslated region; SEM, scanning electron microscopy; PI, propidium iodide; SSLP, simple sequence length polymorphism.

Journal Article.  6241 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.