effects of manipulating phospholipase C on guard cell ABA-signalling

• Published in: Journal of experimental botany Vol. 55; no. 395; pp. 199 - 204
• Main Authors: Mills, L.N, Hunt, L, Leckie, C.P, Aitken, F.L, Wentworth, M, McAinsh, M.R, Gray, J.E, Hetherington, A.M
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Oxford University Press 01.01.2004; Oxford Publishing Limited (England)
• Subjects: Abscisic acid; Abscisic Acid - pharmacology; Biological and medical sciences; Calcium; Calcium - physiology; calcium ions; Cell physiology; Commelina - cytology; Commelina - drug effects; Commelina - enzymology; Commelina - physiology; Commelina communis; Drought; Enzymes; Fundamental and applied biological sciences. Psychology; guard cell; Guard cells; Heparin; inositol phosphates; isozymes; Kinetics; Molecular and cellular biology; Nicotiana - drug effects; Nicotiana - physiology; Perfusion; phospholipase C; Plant Growth Regulators - pharmacology; Plant Leaves - cytology; Plant Leaves - drug effects; Plant Leaves - enzymology; Plant Leaves - physiology; Plant physiology and development; Plants; promoter regions; resistance mechanisms; Signal transduction; Signal Transduction - physiology; signalling; Signalling in Abiotic Stress; Stomata; Stomatal conductance; stomatal movement; transgenic plants; Type C Phospholipases - metabolism; Water and solutes. Absorption, translocation and permeability; Short term; Monocotyledones; Calcium; Stimulant plant; Esterases; Phosphoric diester hydrolases; Nicotiana tabacum; Guard cell; Signal transduction; Regulation(control); Dicotyledones; Sesquiterpenes; Angiospermae; Stomatal movement; Abscisic acid; Plant growth substance; Transgenic plant; Solanaceae; Adaptation; Commelina communis; Enzyme; Long term; Phospholipase C; Commelinaceae; Hydrolases; Flower crop; Spermatophyta
• ISSN: 0022-0957; 1460-2431; 1460-2431
• DOI: 10.1093/jxb/erh027

Studies using stably transformed tobacco plants containing very low levels of PI-PLC in their guard cells show that this enzyme plays a role in the events associated with the inhibition of stomatal opening by ABA, but not in the cellular reactions that are responsible for ABA-induced stomatal closure. However, Commelina communis guard cells microinjected with the InsP3 antagonist, heparin, fail to close on addition of ABA. There are three possible explanations for this apparent data mismatch. The differences may be indicative of species-specific signalling pathways, the presence of a PI-PLC isoform(s) that is not down-regulated in these transgenic lines and/or they may reflect differences between short-term (acute) administration of an inhibitor and long-term (chronic) effects of gene manipulation. It is possible that the guard cell is a robust signalling system that is able to adapt or compensate for the chronic loss of PI-PLC, but which is unable to adjust quickly to acute loss of this component. It would be interesting to investigate this possibility further using either transient manipulation of gene expression or through the use of an inducible promoter.