Phospholipase C is required for the control of stomatal aperture by ABA
The calcium-releasing second messenger inositol 1,4,5-trisphosphate is involved in the regulation of stomatal aperture by ABA. In other signalling pathways, inositol 1,4,5-trisphosphate is generated by the action of phospholipase C. We have studied the importance of phospholipase C in guard cell ABA-signalling pathways. Immunolocalisation of a calcium-activated phospholipase C confirmed the presence of phospholipase C in tobacco guard cells. Transgenic tobacco plants with considerably reduced levels of phospholipase C in their guard cells were only partially able to regulate their stomatal apertures in response to ABA. These results suggest that phospholipase C is involved in the amplification of the calcium signal responsible for reductions in stomatal aperture in response to ABA. As full ABA-induced inhibition of stomatal opening was not observed, our results support a role for the action of other calcium-releasing second messengers in the guard cell ABA-signalling pathway. It is not known whether these different calcium-releasing second messengers act in the same or parallel ABA-signalling pathways.
Document Type: Research Article
Affiliations: 1: Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK, 2: Department of Biological Sciences, University of Lancaster, Lancaster LA1 4YQ, UK, 3: Department of Plant Biochemistry, Centre for Chemistry and Chemical Engineering, Lund University, PO Box 124, SE-221 00 Lund, Sweden, 4: Department of Physiological Science, School of Medicine, University of Newcastle Upon Tyne, Newcastle Upon Tyne NE2 4HH, Tyne & Wear, UK, 5: Max Planck-Institut für Molekulare Pflanzenphysiologie, 14424 Potsdam, Germany, and 6: Abteilung, Molekularbiologie, Institut für Biochemie und Biologie, Universität Potsdam, Karl-Liebknecht-Strasse 25, Haus 20, D-14476 Golm/Potsdam, Germany
Publication date: April 1, 2003