Mg²⁺ Is a Missing Link in Plant Cell Ca²⁺ Signalling and Homeostasis-A Study on Vicia faba Guard Cells.

ABSTRACT: Hyperpolarization-activated calcium channels (HACCs) are found in the plasma membrane and tonoplast of many plant cell types, where they have an important role in Ca²⁺-dependent signalling. The unusual gating properties of HACCs in plants, i.e., activation by membrane hyperpolarization rather than depolarization, dictates that HACCs are normally open in the physiological hyperpolarized resting membrane potential state (the so-called pump or P-state); thus, if not regulated, they would continuously leak Ca²⁺ into cells. HACCs are permeable to Ca²⁺, Ba²⁺, and Mg²⁺; activated by H₂O₂ and the plant hormone abscisic acid (ABA); and their activity in guard cells is greatly reduced by increasing amounts of free cytosolic

SUBMITTER: Lemtiri-Chlieh F 

PROVIDER: S-EPMC7312177 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature