Characterisation of root plasma membrane Ca2+-permeable cation channels: Techniques and basic concepts

Abstract

Calcium is an important macronutrient, which is required for structural and regulatory needs. Elevation of the cytosolic free Ca2+ is widely accepted as a major signalling mechanism in plants, which encodes the information about a multitude of exogenous and endogenous stimuli. Ca2+ uptake by roots from the soil is a passive process, which is catalysed by specialised plasma membrane proteinaceous pores that are called cation channels. These channels demonstrate different biophysical and physiological characteristics and may belong to a number of gene families. This chapter summarises data on physiological techniques and basic concepts for investigation of Ca2+-permeable cation channels in plant root cells. The main focus of the chapter is on patch-clamp technique, ion-selective vibration microelectrodes and Ca2+-aequorin luminometry. In the past two decades, a combination of these techniques allowed to investigate Ca2+-permeable channels in higher plants and establish their crucial roles in plant cell physiology.