Plant Molecular Biology

, Volume 44, Issue 1, pp 1–9 | Cite as

The Rop GTPase: an emerging signaling switch in plants

  • Zhi-Liang Zheng
  • Zhenbiao Yang


G proteins are ubiquitous molecular switches in eukaryotic signal transduction, but their roles in plant signal transduction had not been clearly established until recent studies of the plant-specific Rop subfamily of RHO GTPases. Rop participates in signaling to an array of physiological processes including cell polarity establishment, cell growth, morphogenesis, actin dynamics, H2O2 generation, hormone responses, and probably many other cellular processes in plants. Evidence suggests that plants have developed unique molecular mechanisms to control this universal molecular switch through novel GTPase-activating proteins and potentially through a predominant class of plant receptor-like serine/threonine kinases. Furthermore, the mechanism by which Rop regulates specific processes may also be distinct from that for other GTPases. These advances have raised the exciting possibility that the elucidation of Rop GTPase signaling may lead to the establishment of a new paradigm for G protein-dependent signal transduction in plants.

G proteins signal transduction Arabidopsis polar growth GTPase-activating proteins receptor-like kinases 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ashikari, M., Wu, J., Yano, M., Sasaki, T. and Yoshimura, A. 1999. Rice gibberellin-insensitive dwarf mutant gene Dwarf 1 encodes the alpha-subunit of GTP-binding protein. Proc. Natl. Acad. Sci. USA 96: 10284–10289.Google Scholar
  2. Aspenstrom, P. 1999. Effectors of the Rho GTPases. Curr. Opin. Cell Biol. 11: 95–102.Google Scholar
  3. Battey, N.H., James, N.C., Greenland, A.J. and Brownlee, C. 1999. Exocytosis and endocytosis. Plant Cell 11: 643–660.Google Scholar
  4. Bolwell, G.P. 1999. Role of active oxygen species and NO in plant defence responses. Curr. Opin. Plant Biol. 2: 287–294.Google Scholar
  5. Borg, S., Podenphant, L., Jensen, T.J. and Poulsen, C. 1999. Plant cell growth and differentiation may involve GAP regulation of Rac activity [published erratum appears in FEBS Lett. 458 (1999) 82]. FEBS Lett. 453: 341–345.Google Scholar
  6. Delmer, D.P., Pear, J.R., Andrawis, A. and Stalker, D.M. 1995. Genes for small GTP-binding proteins analogous to mammalian Rac are preferentially expressed in developing cotton fibers. Mol. Gen. Genet. 248: 43–51.Google Scholar
  7. Gibbon, B.C., Kovar, D.R. and Staiger, C.J. 1999. Latrunculin B has different effects on pollen germination and tube growth. Plant Cell 11: 2349–2364.Google Scholar
  8. Kawasaki, T., Henmi, K., Ono, E., Hatakeyama, S., Iwano, M., Satoh, H. and Shimamoto, K. 1999. The small GTP-binding protein rac is a regulator of cell death in plants [In process citation]. Proc. Natl. Acad. Sci. USA 96: 10922–10926.Google Scholar
  9. Kost, B., Lemichez, E., Spielhofer, P., Hong, Y., Tolias, K., Carpenter, C. and Chua, N.-H. 1999a. Rac homologues and compartmentalized phosphatidylinositol 4,5-bisphosphate act in a common pathway to regulate polar pollen tube growth. J. Cell Biol. 145: 317–330.Google Scholar
  10. Kost, B., Mathur, J. and Chua, N.H. 1999b. Cytoskeleton in plant development. Curr. Opin. Plant Biol. 2: 462–470.Google Scholar
  11. Lee, Y.-R.J. and Assmann, S.M. 1999. Arabidopsis thaliana ‘extralarge GTP-binding proteins’ (AtXLG1): a new class of Gproteins. Plant Mol. Biol. 40: 55–64.Google Scholar
  12. Li, H. and Yang, Z. 2000. Rho GTPase and the actin cytoskeleton. In: C.J. Staiger, F. Baluska, D. Volkmann and P. Barlow (Eds.) Rho GTPase and the Actin Cytoskeleton, Kluwer Academic Publishers, Dordrecht, Netherlands.Google Scholar
  13. Li, H., Wu, G., Ware, D., Davis, K.R. and Yang, Z. 1998. Arabidopsis Rho-related GTPases: differential gene expression in pollen and polar localization in fission yeast. Plant Physiol. 118: 407–417.Google Scholar
  14. Li, H., Lin, Y., Heath, R.M., Zhu, M.X. and Yang, Z. 1999. Control of pollen tube tip growth by a Rop GTPase-dependent pathway that leads to the tip-localized calcium influx. Plant Cell 11: 1731–1742.Google Scholar
  15. Lin, Y. and Yang, Z. 1997. Inhibition of pollen tube elongation by microinjected anti-Rop1Ps antibodies suggests a crucial role for Rho-type GTPases in the contol of tip growth. Plant Cell 9: 1647–1659.Google Scholar
  16. Lin, Y., Wang, Y., Zhu, J. and Yang, Z. 1996. Localization of a rho GTPase implies a role in tip growth and movement of the generative cell in pollen tubes. Plant Cell 8: 293–303.Google Scholar
  17. Ma, H. 1994. GTP-binding proteins in plants: new members of an old family. Plant Mol. Biol. 26: 1611–1636.Google Scholar
  18. Ma, H., Yanofsky, M.F. and Meyerowitz, E.M. 1990. Molecular cloning and characterization of GPA1, a G protein α subunit gene from Arabidopsis thaliana. Proc. Natl. Acad. Sci. USA 87: 3821–3825.Google Scholar
  19. Mackay, J.G. and Hall, A. 1998. Rho GTPases. J. Biol. Chem. 273: 20685–20688.Google Scholar
  20. Malhó , R. and Trewavas, A.J. 1996. Localized apical increases of cytosolic free calcium control pollen tube orientation. Plant Cell 8: 1935–1949.Google Scholar
  21. Malhó , R., Read, N.D., Trewavas, A.J. and Salomé Pais, M. 1995. Calcium channel activity during pollen tube growth and reorientation. Plant Cell 7: 1173–1184.Google Scholar
  22. Mathur, J., Spielhofer, P., Kost, B. and Chua, N. 1999. The actin cytoskeleton is required to elaborate and maintain spatial patterning during trichome cell morphogenesis in Arabidopsis thaliana. Development 126: 5559–5568.Google Scholar
  23. Potikha, T.S., Collins, C.C., Johnson, D.I., Delmer, D.P. and Levine, A. 1999. The involvement of hydrogen peroxide in the differentiation of secondary walls in cotton fibers. Plant Physiol. 119: 849–858.Google Scholar
  24. Rodriguez-Concepcion, M., Yalovsky, S. and Gruissem, W. 1999. Protein prenylation in plants: old friends and new targets. Plant Mol. Biol. 39: 865–870.Google Scholar
  25. Sternweis, P.C. 1996. G proteins in signal transduction. In: C.-H. Heldin and M. Purton (Eds.) G proteins in signal transduction, Chapman & Hall, London, pp. 285–301.Google Scholar
  26. Szymanski, D.B., Marks, M.D. and Wick, S.M. 1999. Organized F-actin is essential for normal trichome morphogenesis in Arabidopsis. Plant Cell 11: 2331–2348.Google Scholar
  27. Trotochaud, A.E., Hao, T., Wu, G., Yang, Z. and Clark, S.E. 1999. The CLAVATA1 receptor-like kinase requires CLAVATA3 for its assembly into a signaling complex that includes KAPP and a Rho-related protein. Plant Cell 11: 393–405.Google Scholar
  28. Weiss, C.A., Garnaat, C.W., Mukai, K., Yu, Y. and Ma, H. 1994. Isolation of cDNAs encoding guanine nucleotide-binding protein β-subunit homologues from maize (ZGB1) and Arabidopsis (AGB1). Proc. Natl. Acad. Sci. USA 91: 9554–9558.Google Scholar
  29. Winge, P., Brembu, T. and Bones, A.M. 1997. Cloning and characterization of rac-like cDNAs from Arabidopsis thaliana. Plant Mol. Biol. 35: 483–495.Google Scholar
  30. Xing, T., Higgins, V.J. and Blumwald, E. 1997. Race-specific elicitors of Cladosporium fulvum promote translocation of cytosolic components of NADPH oxidase to the plasma membrane of tomato cells. Plant Cell 9: 249–259.Google Scholar
  31. Yang, Z. 1998. Signaling tip growth in plants. Curr. Opin. Plant Biol. 1: 525–530.Google Scholar
  32. Yang, Z. and Watson, J.C. 1993. Molecular cloning and characterization of rho, a ras-related small GTP-binding protein from the garden pea. Proc. Natl. Acad. Sci. USA 90: 8732–8736.Google Scholar
  33. Zheng, Z.-L. and Yang, Z. 2000. The Rop GTPase switch turns on polar growth in pollen. Trends Plant Sci. 5: 298–303.Google Scholar

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Zhi-Liang Zheng
    • 1
  • Zhenbiao Yang
    • 1
  1. 1.Department of Botany and Plant SciencesUniversity of CaliforniaRiversideUSA

Personalised recommendations