Chapter 16 - Mechanosensitive ion channels in plants

Abstract

Mechanosensitive (MS) channels are very important mechanosensory molecules, which are membrane-bound in nature. In response to various mechanical forces (gravity, vibration, touch, hyperosmotic), MS channels facilitate the passage of ions from one side of the membrane to another side. Various families of MS channels are present in bacteria, archaea, and eukaryotes without showing any evolutionarily relatedness. However, in plants, more than 20 mechanosensitive activities have been reported and these are widespread from lower (algae) to higher plants (Angiosperms). Previous studies revealed that MS channels were implicated in a wide range of physiological processes of plants such as pollen tube growth, plant–pathogen interactions, in the regulation of plastid shape and size, growth of lateral roots, and so on. To date, five families, such as MS channel of small conductance-like (MscS-like or MSL), mid1-complementing activity (MCA) channel, two-pore potassium (TPK) channel, piezo channel, and reduced hyperosmolality-induced [Ca2+] increase (OSCA) channel, are recognized in plants. They are present in the plasma membrane, tonoplast, and endosymbiotic organelles and showed different ion specificities. Some approaches such as gene knockout, overexpression, and patch-clamp techniques play very important roles to find out the functions of various plant MS channels. In this chapter, we mainly focus on the various roles of MS ion channels in plant development.