Abstract
Elevations in cytosolic free calcium concentration ([Ca(2+)](cyt)) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca(2+) 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 Ca(2+) influx across the plasma membrane, modulate apical [Ca(2+)](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.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
-
Arabidopsis / genetics
-
Arabidopsis / metabolism
-
Calcium / metabolism*
-
Calcium Channels / genetics
-
Calcium Channels / metabolism*
-
Calcium Signaling
-
Cell Membrane / metabolism
-
Cytosol / metabolism
-
Excitatory Amino Acid Agonists / pharmacology
-
Excitatory Amino Acid Antagonists / pharmacology
-
Flowers / genetics
-
Flowers / metabolism*
-
Gene Expression Regulation, Plant
-
Genes, Plant / genetics*
-
Glycine / pharmacology
-
Morphogenesis / drug effects
-
Nicotiana / genetics
-
Nicotiana / metabolism
-
Patch-Clamp Techniques
-
Plants, Genetically Modified
-
Pollen Tube / drug effects
-
Pollen Tube / growth & development
-
Pollen Tube / metabolism*
-
Racemases and Epimerases / genetics
-
Racemases and Epimerases / metabolism
-
Receptors, Glutamate / genetics*
-
Receptors, Glutamate / metabolism
-
Serine / metabolism*
-
Serine / pharmacology
Substances
-
Calcium Channels
-
Excitatory Amino Acid Agonists
-
Excitatory Amino Acid Antagonists
-
Receptors, Glutamate
-
Serine
-
6-Cyano-7-nitroquinoxaline-2,3-dione
-
Racemases and Epimerases
-
serine racemase
-
Calcium
-
Glycine