NADPH oxidase activity in pollen tubes is affected by calcium ions, signaling phospholipids and Rac/Rop GTPases
Language English Country Germany Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
22762791
DOI
10.1016/j.jplph.2012.05.014
PII: S0176-1617(12)00228-3
Knihovny.cz E-resources
- MeSH
- Cell Membrane enzymology metabolism MeSH
- Gene Expression MeSH
- Phospholipids metabolism MeSH
- Monomeric GTP-Binding Proteins metabolism MeSH
- NADPH Oxidases metabolism MeSH
- Olea enzymology growth & development physiology MeSH
- Hydrogen Peroxide pharmacology MeSH
- Protein Isoforms MeSH
- Pollen Tube enzymology growth & development MeSH
- rac GTP-Binding Proteins metabolism MeSH
- Reactive Oxygen Species metabolism MeSH
- Plant Proteins metabolism MeSH
- Signal Transduction MeSH
- Nicotiana enzymology growth & development physiology MeSH
- Calcium metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Phospholipids MeSH
- Monomeric GTP-Binding Proteins MeSH
- NADPH Oxidases MeSH
- Hydrogen Peroxide MeSH
- Protein Isoforms MeSH
- rac GTP-Binding Proteins MeSH
- Reactive Oxygen Species MeSH
- Plant Proteins MeSH
- Calcium MeSH
Reactive oxygen species (ROS) generated by NADPH oxidase (NOX) are crucial for tip growth of pollen tubes. However, the regulation of NOX activity in pollen tubes remains unknown. Using purified plasma membrane fractions from tobacco and olive pollen and tobacco BY-2 cells, we demonstrate that pollen NOX is activated by calcium ions and low abundant signaling phospholipids, such as phosphatidic acid and phosphatidylinositol 4,5-bisphosphate in vitro and in vivo. Our data also suggest possible synergism between Ca(2+) and phospholipid-mediated NOX activation in pollen. Rac/Rop small GTPases are also necessary for normal pollen tube growth and have been proposed to regulate ROS production in root hairs. We show here elevated ROS formation in pollen tubes overexpressing wild-type NtRac5 and constitutively active NtRac5, while overexpression of dominant-negative NtRac5 led to a decrease of ROS in pollen tubes. We also show that PA formed by distinct phospholipases D (PLD) is involved in pathways both upstream and downstream of NOX-mediated ROS generation and identify NtPLDδ as a PLD isoform acting in the ROS response pathway.
References provided by Crossref.org
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