Abstract
To investigate molecular mechanisms controlling plant morphogenesis, we examined the morphology of primary roots of Arabidopsis thaliana and the organization of cortical microtubules in response to inhibitors of serine/threonine protein phosphatases and kinases. We found that cantharidin, an inhibitor of types 1 and 2A protein phosphatases, as previously reported for okadaic acid and calyculin A (R.D. Smith, J.E. Wilson, J.C. Walker, T.I. Baskin [1994] Planta 194: 516-524), inhibited elongation and stimulated radial expansion. Of the protein kinase inhibitors tested, chelerythrine, 6-dimethylaminopurine, H-89, K252a, ML-9, and staurosporine all inhibited elongation, but only staurosporine appreciably stimulated radial expansion. To determine the basis for the root swelling, we examined cortical microtubules in semithin sections of material embedded in butyl-methyl-methacrylate. Chelerythrine and 100 nM okadaic acid, which inhibited elongation without causing swelling, did not change the appearance of cortical arrays, but calyculin A, cantharidin, and staurosporine, which caused swelling, disorganized cortical microtubules. The stability of the microtubules in the aberrant arrays was not detectably different from those in control arrays, as judged by similar sensitivity to depolymerization by cold or oryzalin. These results identify protein phosphorylation and dephosphorylation as requirements in one or more steps that organize the cortical array of microtubules.
Full Text
The Full Text of this article is available as a PDF (2.1 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Angerer L. M., Angerer R. C. Localization of mRNAs by in situ hybridization. Methods Cell Biol. 1991;35:37–71. doi: 10.1016/s0091-679x(08)60568-3. [DOI] [PubMed] [Google Scholar]
- Baskin T. I., Bivens N. J. Stimulation of radial expansion in arabidopsis roots by inhibitors of actomyosin and vesicle secretion but not by various inhibitors of metabolism. Planta. 1995;197(3):514–521. doi: 10.1007/BF00196673. [DOI] [PubMed] [Google Scholar]
- Baskin T. I., Miller D. D., Vos J. W., Wilson J. E., Hepler P. K. Cryofixing single cells and multicellular specimens enhances structure and immunocytochemistry for light microscopy. J Microsc. 1996 May;182(Pt 2):149–161. doi: 10.1046/j.1365-2818.1996.135417.x. [DOI] [PubMed] [Google Scholar]
- Baskin T. I., Wilson J. E., Cork A., Williamson R. E. Morphology and microtubule organization in Arabidopsis roots exposed to oryzalin or taxol. Plant Cell Physiol. 1994 Sep;35(6):935–942. [PubMed] [Google Scholar]
- Blancaflor E. B., Hasenstein K. H. Time course and auxin sensitivity of cortical microtubule reorientation in maize roots. Protoplasma. 1995;185:72–82. doi: 10.1007/BF01272755. [DOI] [PubMed] [Google Scholar]
- Brinkley B. R. Microtubule organizing centers. Annu Rev Cell Biol. 1985;1:145–172. doi: 10.1146/annurev.cb.01.110185.001045. [DOI] [PubMed] [Google Scholar]
- Cyr R. J. Microtubules in plant morphogenesis: role of the cortical array. Annu Rev Cell Biol. 1994;10:153–180. doi: 10.1146/annurev.cb.10.110194.001101. [DOI] [PubMed] [Google Scholar]
- Cyr R. J., Palevitz B. A. Organization of cortical microtubules in plant cells. Curr Opin Cell Biol. 1995 Feb;7(1):65–71. doi: 10.1016/0955-0674(95)80046-8. [DOI] [PubMed] [Google Scholar]
- Gurland G., Gundersen G. G. Protein phosphatase inhibitors induce the selective breakdown of stable microtubules in fibroblasts and epithelial cells. Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):8827–8831. doi: 10.1073/pnas.90.19.8827. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hangarter R. P., Stasinopoulos T. C. Effect of fe-catalyzed photooxidation of EDTA on root growth in plant culture media. Plant Physiol. 1991 Jul;96(3):843–847. doi: 10.1104/pp.96.3.843. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Herbert J. M., Augereau J. M., Gleye J., Maffrand J. P. Chelerythrine is a potent and specific inhibitor of protein kinase C. Biochem Biophys Res Commun. 1990 Nov 15;172(3):993–999. doi: 10.1016/0006-291x(90)91544-3. [DOI] [PubMed] [Google Scholar]
- Hugdahl J. D., Morejohn L. C. Rapid and Reversible High-Affinity Binding of the Dinitroaniline Herbicide Oryzalin to Tubulin from Zea mays L. Plant Physiol. 1993 Jul;102(3):725–740. doi: 10.1104/pp.102.3.725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hush J., Wu L., John P. C., Hepler L. H., Hepler P. K. Plant mitosis promoting factor disassembles the microtubule preprophase band and accelerates prophase progression in Tradescantia. Cell Biol Int. 1996 Apr;20(4):275–287. doi: 10.1006/cbir.1996.0031. [DOI] [PubMed] [Google Scholar]
- MacKintosh C., Beattie K. A., Klumpp S., Cohen P., Codd G. A. Cyanobacterial microcystin-LR is a potent and specific inhibitor of protein phosphatases 1 and 2A from both mammals and higher plants. FEBS Lett. 1990 May 21;264(2):187–192. doi: 10.1016/0014-5793(90)80245-e. [DOI] [PubMed] [Google Scholar]
- MacKintosh C., Klumpp S. Tautomycin from the bacterium Streptomyces verticillatus. Another potent and specific inhibitor of protein phosphatases 1 and 2A. FEBS Lett. 1990 Dec 17;277(1-2):137–140. doi: 10.1016/0014-5793(90)80828-7. [DOI] [PubMed] [Google Scholar]
- Ohta K., Shiina N., Okumura E., Hisanaga S., Kishimoto T., Endo S., Gotoh Y., Nishida E., Sakai H. Microtubule nucleating activity of centrosomes in cell-free extracts from Xenopus eggs: involvement of phosphorylation and accumulation of pericentriolar material. J Cell Sci. 1993 Jan;104(Pt 1):125–137. doi: 10.1242/jcs.104.1.125. [DOI] [PubMed] [Google Scholar]
- Ookata K., Hisanaga S., Bulinski J. C., Murofushi H., Aizawa H., Itoh T. J., Hotani H., Okumura E., Tachibana K., Kishimoto T. Cyclin B interaction with microtubule-associated protein 4 (MAP4) targets p34cdc2 kinase to microtubules and is a potential regulator of M-phase microtubule dynamics. J Cell Biol. 1995 Mar;128(5):849–862. doi: 10.1083/jcb.128.5.849. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shelden E., Wadsworth P. Stimulation of microtubule dynamic turnover in living cells treated with okadaic acid. Cell Motil Cytoskeleton. 1996;35(1):24–34. doi: 10.1002/(SICI)1097-0169(1996)35:1<24::AID-CM2>3.0.CO;2-I. [DOI] [PubMed] [Google Scholar]
- Smith Robert D., Walker John C. PLANT PROTEIN PHOSPHATASES. Annu Rev Plant Physiol Plant Mol Biol. 1996 Jun;47(NaN):101–125. doi: 10.1146/annurev.arplant.47.1.101. [DOI] [PubMed] [Google Scholar]
- Stone J. M., Walker J. C. Plant protein kinase families and signal transduction. Plant Physiol. 1995 Jun;108(2):451–457. doi: 10.1104/pp.108.2.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Verde F., Labbé J. C., Dorée M., Karsenti E. Regulation of microtubule dynamics by cdc2 protein kinase in cell-free extracts of Xenopus eggs. Nature. 1990 Jan 18;343(6255):233–238. doi: 10.1038/343233a0. [DOI] [PubMed] [Google Scholar]
- Wolniak S. M., Larsen P. M. Changes in the metaphase transit times and the pattern of sister chromatid separation in stamen hair cells of Tradescantia after treatment with protein phosphatase inhibitors. J Cell Sci. 1992 Aug;102(Pt 4):691–715. doi: 10.1242/jcs.102.4.691. [DOI] [PubMed] [Google Scholar]
- Yuan M., Shaw P. J., Warn R. M., Lloyd C. W. Dynamic reorientation of cortical microtubules, from transverse to longitudinal, in living plant cells. Proc Natl Acad Sci U S A. 1994 Jun 21;91(13):6050–6053. doi: 10.1073/pnas.91.13.6050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van der Hoeven P. C., Siderius M., Korthout H. A., Drabkin A. V., de Boer A. H. A calcium and free fatty acid-modulated protein kinase as putative effector of the fusicoccin 14-3-3 receptor. Plant Physiol. 1996 Jul;111(3):857–865. doi: 10.1104/pp.111.3.857. [DOI] [PMC free article] [PubMed] [Google Scholar]