Cortical actin filaments in guard cells respond differently to abscisic acid in wild-type and abi1-1 mutant Arabidopsis.
Cortical actin filaments in guard cells of Commelina communis L. show signal-specific organization during stomatal movements [S.-O. Eun and Y. Lee (1997) Plant Physiol 115: 1491-1498; S.-O. Eun and Y. Lee (2000) Planta 210: 1014-1017]. To study the roles of actin in signal transduction, it is advantageous to use Arabidopsis thaliana (L.) Heynh., an excellent model plant with numerous well-characterized mutants. Using an immunolocalization technique, we found that actin deployments in guard cells of A. thaliana were basically identical to those in C. communis: actin proteins were assembled into radial filaments under illumination, and were disassembled by ABA. In addition, we examined actin organization in an ABA-insensitive mutant (abi1-1) to test the involvement of protein phosphatase 2C (PP2C) in the control of actin structure. A clear difference was observed after ABA treatment, namely, neither stomatal closing nor depolymerization of actin filaments was observed in guard cells of the mutant. Our results indicate that PP2C participates in ABA-induced actin changes in guard cells.
Eun
S O
SO
Department of Life Science, Pohang University of Science and Technology, Korea.
Bae
S H
SH
Lee
Y
Y
D000040:Abscisic Acid / Q000494:pharmacology*; D008841:Actin Cytoskeleton / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins; D005455:Fluorescent Antibody Technique; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000502:physiology*; D019441:Plant Epidermis / Q000166:cytology / Q000502:physiology; D010937:Plant Growth Regulators / Q000494:pharmacology*; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D029701:Saccharomyces cerevisiae Proteins; D000040:Abscisic Acid; C087434:ABI1 protein, Arabidopsis; C087358:PTC1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C