Journal Article

AtFH1 formin mutation affects actin filament and microtubule dynamics in Arabidopsis thaliana

Amparo Rosero, Viktor Žárský and Fatima Cvrčková

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 64, issue 2, pages 585-597
Published in print January 2013 | ISSN: 0022-0957
Published online December 2012 | e-ISSN: 1460-2431 | DOI: https://dx.doi.org/10.1093/jxb/ers351

More Like This

Show all results sharing this subject:

  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Plant cell growth and morphogenesis depend on remodelling of both actin and microtubule cytoskeletons. AtFH1 (At5g25500), the main housekeeping Arabidopsis formin, is targeted to membranes and known to nucleate and bundle actin. The effect of mutations in AtFH1 on root development and cytoskeletal dynamics was examined. Consistent with primarily actin-related formin function, fh1 mutants showed increased sensitivity to the actin polymerization inhibitor latrunculin B (LatB). LatB-treated mutants had thicker, shorter roots than wild-type plants. Reduced cell elongation and morphological abnormalities were observed in both trichoblasts and atrichoblasts. Fluorescently tagged cytoskeletal markers were used to follow cytoskeletal dynamics in wild-type and mutant plants using confocal microscopy and VAEM (variable-angle epifluorescence microscopy). Mutants exhibited more abundant but less dynamic F-actin bundles and more dynamic microtubules than wild-type seedlings. Treatment of wild-type seedlings with a formin inhibitor, SMIFH2, mimicked the root growth and cell expansion phenotypes and cytoskeletal structure alterations observed in fh1 mutants. The results suggest that besides direct effects on actin organization, the in vivo role of AtFH1 also includes modulation of microtubule dynamics, possibly mediated by actin–microtubule cross-talk.

Keywords: Actin; Arabidopsis; At5g25500; LatB; microtubules; SMIFH2; VAEM

Journal Article.  6790 words.  Illustrated.

Subjects: Plant Sciences and Forestry