Simon Gilroy

Professor of Botany

Ph.D. Edinburgh 1987

B.A. Cambridge 1984


Phone: (608) 262 4009 - office

            (608) 262 4008 - lab

Fax: (608) 262 7509

email: sgilroy@wisc.edu


office: B117 Birge Hall


Botany Department

University of Wisconsin

Birge Hall

430 Lincoln Drive

Madison

WI 53706-1381

Recent Publications:

  1. •Monshausen GB, Bibikova TN, Messerli MA, Shi C, Gilroy S (2007) Oscillations in extracellular pH and reactive oxygen species modulate tip growth of Arabidopsis root hairs. Proceedings of the National Academy of Science USA, in press

  2. •Wu J, Kurten EL, Monshausen G, Hummel GM, Gilroy S, Baldwin IT. (2007) NaRALF, a peptide signal essential for the regulation of root hair tip apoplastic pH in Nicotiana attenuata, is required for root hair development and plant growth in native soils. Plant J. in press

  3. •Bibikova TN and Gilroy S. (2007) Calcium in Root Hair Growth. In Root Hairs (Emons AM, Ed.) Springer-Verlag, in press.

  4. •Pei ZM and Gilroy S. (2007) Calcium signaling. In Plant Signaling (Z. Yang, Ed.), Blackwell Publishing, in prerss.

  5. •Monshausen GB, Swanson SJ and Gilroy S. (2007) Plant mechanotransduction. In Plant Tropisms (P. Masson and S. Gilroy Eds), Blackwell Publishing, in press.

  6. •Jones DL, Blancaflor EB, Kochian LV and Gilroy S. (2007) Spatial coordination of aluminium uptake, production of reactive oxygen species, callose production and wall rigidification in maize roots. Plant Cell Environment 29:1309-1318.

  7. •Skirpan, A.L., Dowd, P.E., Sijacic, P., Jaworski, C.J., Gilroy, S. and Kao, T.-h. (2006) Identification and characterization of PiORP1, a Petunia oxysterol-binding related protein involved in receptor-kinase mediated signaling in pollen, and analysis of the ORP gene family in Arabidopsis. Plant Molecular Biology, 61:553-565.

  8. •Young LS, Harrison BR, Narayana Murthy UM, Moffatt BA, Gilroy S, Masson PH. (2006) Adenosine kinase modulates root gravitropism and cap morphogenesis in Arabidopsis. Plant Physiol. 142:564-573.

  9. •Dowd, P.E., Coursol, S., SkirpanA.L., Kao, T-h and Gilroy, S. (2006) A phospholipase C of Petunia, PetPLC1, regulates pollen tube growth. Plant Cell18:1438-1453.

  10. •Yoon, G.Y-Y., Dowd, P.E, Gilroy, S. and McCubbin, A.G. (2006) Calcium Dependent Protein Kinase isoforms have distinct functions in pollen tube growth, including the regulation of polarity. Plant Cell, 18(4):867-78.

  11. •Cyr, R.J., Dixit, R. and Gilroy, S. (2006) Live cell imaging using GFPs. The Plant Journal 45:599-615.

  12. •Bais, H.P., Weir, T.L., Perry, L.G., Gilroy,  S. and Vivanco,  J.M. (2006) Root exudates. Annu Rev Plant Biology, 57:233-266.

  13. •Li, J., Yang, H., Richter, G., Undurraga, S., Khodakovskaya, M., Gilroy, S. and Gaxiola, R. AVP1, a H+-PPase is required for organ development in Arabidopsis. Science 310: 121-125.

  14. •Vincent P, Chua M, Nogue F, Fairbrother A, Mekeel H, Xu Y, Allen N, Bibikova TN, Gilroy S, Bankaitis VA. (2005) A Sec14p-nodulin domain phosphatidylinositol transfer protein polarizes membrane growth of Arabidopsis thaliana root hairs. J Cell Biol. 28: 801-812.

  15. •Gu, Y., Fu, Y., Dowd, P., Li, S., Gilroy, S. and Yang, Z. (2005) ROP GTPase controls actin dynamics and tip growth in pollen tubes via two counteracting downstream pathways. J Cell Biol 169: 127-138

  16. •Coursol, S., Le Stunff, H., Lynch, D.V., Gilroy, S., Assmann, S.M., and Spiegel, S. (2005) Arabidopsis thaliana sphingosine kinase and the effects of phytosphingosine-1-phosphate on stomatal aperture. Plant Physiology 1367: 724-737

  17. •Bibikova, T.N., Assmann, S.M. and Gilroy, S. (2004) Ca2+ and pH as integrating signals in transport control. Annual Plant Reviews, 15: 232-258.

  18. •Hou, G., Kramer, V.L., Wang, Y.S., Chen, R., Perbal, G., Gilroy, S. and Blancaflor, E.B. (2004)  The promotion of gravitropism in Arabidopsis roots upon actin disruption is coupled with the extended alkalinization of the columella cytoplasm and a persistent lateral auxin gradient. The Plant Journal, 39: 113-125.

  19. •McCubbin, A.G., Ritchie, S.M., Swanson, S.J. and Gilroy, S. (2004) The calcium-dependent protein kinase HvCDPK1 mediates the gibberellic acid response of the barley aleurone through regulation of vacuolar function. The Plant Journal, 36: 206-218.

  20. •Boonsirichai, K., Sedbrook, J.C., Chen, R., Gilroy, S. and Masson, P.H. (2003) ARG1 is a peripheral membrane protein that modulates gravityinduced cytoplasmic alkalinization and lateral auxin transport in plant statocytes. Plant Cell, 15, 2612-2625

  21. •Bais, H.P., Vepachedu, R., Gilroy, S., Callaway, R. and, Jorge M. Vivanco, J.M. (2003) Allelopathy and exotic plant invasion: from molecules and genes to communities. Science, 301:1377-1380

  22. •Bibikova T.N., Gilroy, S. (2003) Root hair development and function. Journal of Plant Growth Regulation. 21:383-415

  23. •Coursol, S., Fan, L.M., Stunff, H.L., Spiegel, S., Gilroy, S. and Assmann, S.M. (2003).. Sphingosine-1-phosphate signaling in Arabidopsis guard cells involves heterotrimeric G proteins. Nature 423: 651-654.

  24. •Massa, G.D., Fasano, J.M. and Gilroy, S. (2003) Ionic signaling in plant gravity and touch responses. Gravitational and Space Biology Bulletin16:71-82.

  25. •Massa, G.D. and S.  Gilroy, S. (2003) Touch and gravitropic set-point angle interact to modulate gravitropic growth in roots Advances in Space Research 31: 2195-2202

  26. •Massa, G.D. and Gilroy, S. (2003) Touch modulates gravity sensing to regulate the growth of primary roots of Arabidopsis thaliana. The Plant Journal 33, 435–445

  27. •Halperin, S.J., Gilroy, S. and Lynch, J.P. (2003) Sodium chloride reduces growth and cytosolic calcium, but does not affect cytosolic pH, in root hairs of Arabidopsis thaliana L. Journal of Experimental Botany, 54:1269-1280.

  28. •Fasano, J.M., Massa, G.D., Gilroy, S. (2002) Ionic signaling in plant responses to gravity and touch. Journal of Plant Growth Regulation 21: 71-88.

  29. •Ritchie, S., Swanson, S.J., Gilroy, S. (2002) From common signaling components to cell specific responses: insights from the cereal aleurone. Physiologia Plantarum, 115, 342-351.

  30. •Gardiner, J.C., Harper, J.D., Weerakoon, N.D., Collings, D.A., Ritchie, S., Gilroy, S., Cyr, R.J., Marc, J. (2001) A 90-kD phospholipase D from tobacco binds to microtubules and the plasma membrane. Plant Cell. 13 :2143-2158.

  31. •Fricker, M.D., Blancaflor, E.B., Meyer, A., Parsons, A., Plieth, C., Tlaka, M., Gilroy, S. (2001) Fluorescent probes for living cells. In Cell Biology, A Practical Approach,  (C. Hawes & B. Satiat-Jeunemaitre eds.), Oxford University Press, Oxford, pp 35-85.

  32. •Molendijk, A.J., Bischoff, F., Rajendrakumar, C.S.V., Friml, J., Braun, M., Gilroy, S. and Palme, K. (2001) Arabidopsis thaliana Rop GTPases are localized to root hairs and control polar growth. EMBO Journal, 20: 2779-2788.

  33. •Gooljarsingh, L.T.,  Ramcharan, J., Gilroy, S., and Benkovic, S.J. (2001) Localization of GAR transformylase in Escherichia coli and mammalian cells Proceedings of the National Academy of Sciences USA 98: 6565-6570

  34. •Gilroy, S. and Trewavas, A.J. (2001) Signal transduction and processing in plant cells. Nature Molecular Cell Biology 2: 307-314

  35. •Fasano, J .M.  Swanson, S.J.  Blancaflor, E.B., Dowd, P., Kao, T-h.  and Gilroy, S. (2001) Changes in Cytoplasmic and Cell Wall pH are associated with the gravity response of the Arabidopsis root. The Plant Cell 13: 907-921

  36. •Ritchie, S., Gilroy, S. (2000) ABA activation of phospholipase D is localized to the plasma membrane and requires G-protein action. Plant Physiology,  124: 693-702.

  37. •Blancaflor, E.B., Gilroy, S. (2000) Plant cell biology in the new millenium: new tools and new insights. American Journal of Botany, 87: 1547-1560.

  38. •Ritchie, S., Swanson, S.J., Gilroy, S. (2000) The cell and molecular biology of endosperm development and function. Seed Science Research, 10: 193-212.

  39. •Romano, L., Jacob, T., Gilroy, S., and Assmann, S.M. (2000) Increases in cytosolic Ca2+ are not required for abscisic acid-inhibition of inward K+ currents in guard cells of Vicia faba L. Planta 211:209-217

  40. •Bibikova, T.N., and Gilroy, S. (2000) Calcium in root hair growth and development. In The Cellular and Molecular Biology of Root Hairs (R. Ridge and A.M. Emons eds). Springer verlag, Berlin, 141-163.

  41. •Gilroy, S. and Jones, D.L. (2000) Through form to function: development and nutrient transport in root hairs. Trends in plant Science, 5: 55-60.

Plants have a remarkable ability to monitor their environment and then integrate this information to control their growth and development. We are interested in understanding the molecules involved in how these signals are perceived and translated to the control of growth. An outline of some of our projects is described below.


Regulation of root growth responses

We have investigated the cellular basis for gravity and mechano-signaling in the growing root (reviewed in Fasano et al., 2002; Massa et al., 2003; Monshausen et al., 2007). We have mapped the sensory cells in the root using laser ablation (Blancaflor et al., 1998, 1999) and investigated the signaling events in these cells in response to gravity and touch stimulation. These studies have revealed a novel Ca2+ and pH-signaling system, with touch being mediated via Ca2+-dependent processes whilst gravity sensing operates via an actin- and pH-dependent mechanism (Fasano et al., 2001; Boonsirichai et al., 2003; Massa and Gilroy., 2003a,b; Hou et al., 2004).

Our root developmental analysis has also revealed alterations in cell wall pH and a cytosolic Ca2+ gradient and highly dynamic alterations in wall pH and reactive oxygen species production that combine to drive the expansion and morphogenesis of root hairs (Bibikova et al., 1998; 1999; Monshausen et al., 2007; reviewed in Bibikova and Gilroy, 2000, 2003, 2004, 2007; Gilroy and Jones, 2000). These ionic signals are in turn related to the localization of a monomeric G-protein that appears critical for the correct positioning and outgrowth of the root hair (Molendijk et al., 2001).

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Hormone/lipid signaling

Another major project in the lab is trying to define the signaling pathways responsible for plant hormone action (reviewed in Ritchie and Gilroy 1998; Ritchie et al., 2000, 2002; Gilroy and Trewavas, 2001). We have revealed novel lipid-based (phospholipase D) signaling mechanisms in response to the plant hormone ABA (Ritchie et al., 1998, 2000; Jacob et al., 1999). We have also characterized the spatial responses of seed tissues to hormones (Ritchie et al., 1999) and defined a role for Ca2+-dependent protein phosphorylation in this system (Ritchie et al., 1998; McCubbin et al. 2004). In collaboration with the Assman lab at PennState we have also identified a novel role for shingosine-based lipids in this process (Coursol et al., 2003, 2005). We have also revealed a role for lipid/Ca2+-dependent signaling in the regulation of tip growth in both pollen tubes and root hairs (e.g. Vincent et al., 2005; Gu et al., 2005; Yoon et al., 2006; Dowd et al., 2006; Skirpan et al., 2006).

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