Role of transglutaminase in pollen tube growth and in incompatibility-induced cell death S. Del Duca, A. Di Sandro, A. Scarpellini and D. Serafini Fracassini Dipartimento di Biologia e.s., Università di Bologna, via Irnerio 42, 40126 Bologna Higher plant fertilization is a complex process controlled by a variety of interactions between the male and female gametophytes1. The growth of a pollen tube has been shown to require an apical tip based Ca2+-gradient, the function of which is not fully understood2. We demonstrate that a Ca2+-dependent extracellular pollen tube transglutaminase (TGase) is an essential modulator of pollen tube growth. The extracellular enzyme co-localises with annular structures surrounding the pollen tube. Inhibition of transglutaminase by specific inhibitors or an anti-TGase monoclonal antibody blocked pollen tube growth. The extracellular pollen transglutaminase was also able to crosslink amines and the histidine-tagged green fluorescent protein (His6-Xpr-GFP)3 into exogenous proteins, consistent with a possible role for the extracellular pollen transglutaminase in the stabilisation of proteins in the style, to which the pollen tube becomes anchored. As self incompatibility triggers programmed cell death in pollen4, the TGase activity has been analyzed during these phenomena. References 1. Lord E. M. & Russel S. D. The mechanisms of pollination and fertilization in plants. Annu. Rev. Cell Dev. Biol. 18, 81-105 (2002). 2. Holdaway-Clarke T. L. & Hepler P. K. Control of pollen tube growth: role of ion gradients and fluxes. New Phytologist 159, 539–563 (2003). 3. Furutani Y., Kato A., Notoya M., Ghonei, M. A. & Hirose S. A Simple assay and histochemical localization of transglutaminase activity using a derivative of green fluorescent protein as a substrate. J. Histochem. Cytochem. 9, 247-258 (2001). 4. Thomas S.G. & Franklin-Tong V. Self-incompatibility triggers programmed cell death in Papaver pollen. Nature 429, 305-309 (2004).
S. Del Duca, A. Di Sandro, A. Scarpellini, Serafini Fracassini D. (2005). Role of transglutaminase in pollen tube growth and in incompatibility-induced cell death.
Role of transglutaminase in pollen tube growth and in incompatibility-induced cell death
DEL DUCA, STEFANO;DI SANDRO, ALESSIA;SERAFINI FRACASSINI, DONATELLA
2005
Abstract
Role of transglutaminase in pollen tube growth and in incompatibility-induced cell death S. Del Duca, A. Di Sandro, A. Scarpellini and D. Serafini Fracassini Dipartimento di Biologia e.s., Università di Bologna, via Irnerio 42, 40126 Bologna Higher plant fertilization is a complex process controlled by a variety of interactions between the male and female gametophytes1. The growth of a pollen tube has been shown to require an apical tip based Ca2+-gradient, the function of which is not fully understood2. We demonstrate that a Ca2+-dependent extracellular pollen tube transglutaminase (TGase) is an essential modulator of pollen tube growth. The extracellular enzyme co-localises with annular structures surrounding the pollen tube. Inhibition of transglutaminase by specific inhibitors or an anti-TGase monoclonal antibody blocked pollen tube growth. The extracellular pollen transglutaminase was also able to crosslink amines and the histidine-tagged green fluorescent protein (His6-Xpr-GFP)3 into exogenous proteins, consistent with a possible role for the extracellular pollen transglutaminase in the stabilisation of proteins in the style, to which the pollen tube becomes anchored. As self incompatibility triggers programmed cell death in pollen4, the TGase activity has been analyzed during these phenomena. References 1. Lord E. M. & Russel S. D. The mechanisms of pollination and fertilization in plants. Annu. Rev. Cell Dev. Biol. 18, 81-105 (2002). 2. Holdaway-Clarke T. L. & Hepler P. K. Control of pollen tube growth: role of ion gradients and fluxes. New Phytologist 159, 539–563 (2003). 3. Furutani Y., Kato A., Notoya M., Ghonei, M. A. & Hirose S. A Simple assay and histochemical localization of transglutaminase activity using a derivative of green fluorescent protein as a substrate. J. Histochem. Cytochem. 9, 247-258 (2001). 4. Thomas S.G. & Franklin-Tong V. Self-incompatibility triggers programmed cell death in Papaver pollen. Nature 429, 305-309 (2004).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
