Actin Cytoskeleton as Actor in Upstream and Downstream of Calcium Signaling in Plant Cells

In plant cells, calcium (Ca(2+)) serves as a versatile intracellular messenger, participating in several fundamental and important biological processes. Recent studies have shown that the actin cytoskeleton is not only an upstream regulator of Ca(2+) signaling, but also a downstream regulator. Ca(2+) has been shown to regulates actin dynamics and rearrangements via different mechanisms in plants, and on this basis, the upstream signaling encoded within the Ca(2+) transient can be decoded. Moreover, actin dynamics have also been proposed to act as an upstream of Ca(2+), adjust Ca(2+) oscillations, and establish cytosolic Ca(2+) ([Ca(2+)](cyt)) gradients in plant cells. In the current review, we focus on the advances in uncovering the relationship between the actin cytoskeleton and calcium in plant cells and summarize our current understanding of this relationship.