Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Detection and localization of pectin methylesterase isoforms in pollen tubes of Nicotiana tabacum L.


Pectin methylesterases (PMEs) were detected in tobacco (Nicotiana tabacum) pollen tubes grown in vitro. Seven PME isoforms exhibiting a wide isoelectric-point (pI) range (5.3–9.1) were found in crude extracts of pollen tubes. These isoforms were mainly retrieved in supernatants after low- and high-speed separation of the crude extract. Two isoforms, with pIs 5.5 and 7.3 and molecular weight about 158 kDa, were detected by immunoblotting with anti-flax PME antiserum. Localization of pectins and PME isoforms in pollen tubes was investigated by immunogold labelling with JIM5 monoclonal antibodies and anti-flax PME antiserum, respectively. In germinated pollen grains, two PME isoforms were mainly detected in the exine, Golgi apparatus and secretory vesicles. In pollen tubes the same two PME isoforms were distributed along the outer face of the plasma membrane in the vicinity of the inner layer of the cell wall, in the Golgi and around secretory vesicles. In pollen grains, PME isoforms were, in some cases, mixed with acidic pectins in proximity to the outer surface of the plasma membrane. In pollen tubes the presence of PMEs inside secretory vesicles carrying esterified pectins supports the hypothesis that, during pollen tube growth, PMEs could be transferred by secretory vesicles in a precursor form and be activated at the tip where exocytosis takes place.

This is a preview of subscription content, log in to check access.

Author information

Additional information

Electronic Publication

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Li, Y., Mareck, A., Faleri, C. et al. Detection and localization of pectin methylesterase isoforms in pollen tubes of Nicotiana tabacum L.. Planta 214, 734–740 (2002). https://doi.org/10.1007/s004250100664

Download citation

  • Pectin methylesterase Cell wall Growth regulation Plasma membrane Pollen tube Nicotiana (pollen tube)