Paper of the month (May 2011)

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Glutamate Receptor–Like Genes Form Ca2+ Channels in Pollen Tubes and Are Regulated by Pistil d-Serine

Erwan Michard1,*, Pedro T. Lima1, Filipe Borges1, Ana Catarina Silva1, Maria Teresa Portes1, João E. Carvalho1, Matthew Gilliham2, Lai-Hua Liu3, Gerhard Obermeyer4, and José A. Feijó1,5,†

Author Affiliations:

1Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, P-2780-156 Oeiras, Portugal.
2Waite Research Institute and School of Agriculture, Food and Wine, University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia.
3Key Laboratory of Plant and Soil Interaction, College of Resources and Environmental Sciences, China Agriculture University, 100193 Beijing, China.
4Molecular Plant Biophysics and Biochemistry, Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria.
5Universidade de Lisboa, Faculdade de Ciências, Departamento de Biologia Vegetal, Campo Grande C2, 1749-016 Lisboa, Portugal.

Reference: Michard et al (2011) Science, Vol. 332 no. 6028 pp. 434-437 (doi: 10.1126/science.1201101)

Abstract

Elevations in cytosolic free calcium concentration ([Ca2+]cyt) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca2+ channels initiating this signal in plants is still under debate. Here, we show by pharmacology and loss-of-function mutants that in tobacco and Arabidopsis, glutamate receptor–like channels (GLRs) facilitate Ca2+ influx across the plasma membrane, modulate apical [Ca2+]cyt gradient, and consequently affect pollen tube growth and morphogenesis. Additionally, wild-type pollen tubes grown in pistils of knock-out mutants for serine-racemase (SR1) displayed growth defects consistent with a decrease in GLR activity. Our findings reveal a novel plant signaling mechanism between male gametophyte and pistil tissue similar to amino acid–mediated communication commonly observed in animal nervous systems.

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