Spectroelectrochemistry: A Survey of In-Situ Spectroscopic Techniques

In this technical paper a summary of the available in situ spectroelectrochemical methods, their basic principles, their typical applications, and their limitations is given. With respect to the names of the methods and usual abbreviations, the paper follows the literature as far as possible, but tries to point out inconsistencies. An introductory section gives a summary of the basic equations and introduces the IUPAC recommendations for quantities and symbols

Aequorin-based measurements of intracellular Ca(2+)-signatures in plant cells

Due to the involvement of calcium as a main second messenger in the plant signaling pathway, increasing interest has been focused on the calcium signatures supposed to be involved in the patterning of the specific response associated to a given stimulus. In order to follow these signatures we described here the practical approach to use the non-invasive method based on the aequorin technology. Besides reviewing the advantages and disadvantages of this method we report on results showing the usefulness of aequorin to study the calcium response to biotic (elicitors) and abiotic stimuli (osmotic shocks) in various compartments of plant cells such as cytosol and nucleus

Effect of Ca2+ Channel Block on Glycerol Metabolism in Dunaliella salina under Hypoosmotic and Hyperosmotic Stresses

The effect of Ca2+ channel blockers on cytosolic Ca2+ levels and the role of Ca2+ in glycerol metabolism of Dunaliella salina under hypoosmotic or hyperosmotic stress were investigated using the confocal laser scanning microscope (CLSM). Results showed that intracellular Ca2+ concentration increased rapidly when extracellular salinity suddenly decreased or increased, but the increase could be inhibited by pretreatment of Ca2+ channel blockers LaCl3, verapamil or ruthenium red. The changes of glycerol content and G3pdh activity in D. salina to respect to hypoosmotic or hyperosmotic stress were also inhibited in different degrees by pretreatment of Ca2+ channel blockers, indicating that the influx of Ca2+ via Ca2+ channels are required for the transduction of osmotic signal to regulate osmotic responses of D. salina to the changes of salinity. Differences of the three blockers in block effect suggested that they may act on different channels or had different action sites, including influx of Ca2+ from the extracellular space via Ca2+ channels localized in the plasma membrane or from intracellular calcium store via the mitochondrial. Other Ca2+-mediated or non-Ca2+-mediated osmotic signal pathway may exist in Dunaliella in response to hypoosmotic and hyperosmotic stresses