Physiological roles of Arabidopsis MCA1 and MCA2 based on their dynamic expression patterns.

Determining the mechanisms by which plants sense and respond to mechanical stimuli is crucial for unraveling the detailed processes by which plants grow and develop. Mechanosensitive (MS) channels, including MCA1 and its paralog MCA2 in Arabidopsis thaliana, may be essential for these processes. Although significant progress has been made in elucidating the physiological roles of MS channels, comprehensive insights into their expression dynamics remain elusive.

Ca-permeable mechanosensitive channels MCA1 and MCA2 mediate cold-induced cytosolic Ca increase and cold tolerance in Arabidopsis.

Cold shock triggers an immediate rise in the cytosolic free calcium concentration ([Ca]) in Arabidopsis thaliana and this cold-induced elevation of [Ca] is inhibited by lanthanum or EGTA. It is suggested that intracellular calcium mainly contributes to the cold-induced [Ca] response by entering into the cytosol. Two calcium-permeable mechanosensitive channels, MCA1 and MCA2 (mid1-complementing activity), have been identified in Arabidopsis.

MCA1 and MCA2 that mediate Ca2+ uptake have distinct and overlapping roles in Arabidopsis.

Ca(2+) is important for plant growth and development as a nutrient and a second messenger. However, the molecular nature and roles of Ca(2+)-permeable channels or transporters involved in Ca(2+) uptake in roots are largely unknown. We recently identified a candidate for the Ca(2+)-permeable mechanosensitive channel in Arabidopsis (Arabidopsis thaliana), named MCA1.