Calcium Signaling and the Response to Heat Shock in Crop Plants

Climate change and the increasing frequency of high temperature (HT) events are significant threats to global crop yields. To address this, a comprehensive understanding of how plants respond to heat shock (HS) is essential. Signaling pathways involving calcium (Ca²⁺), a versatile second messenger in plants, encode information through temporal and spatial variations in ion concentration. Ca²⁺ is detected by Ca²⁺-sensing effectors, including channels and binding proteins, which trigger specific cellular responses. At elevated temperatures, the cytosolic concentration of Ca²⁺ in plant cells increases rapidly, making Ca²⁺ signals the earliest response to HS. In this review, we discuss the crucial role of Ca²⁺ signaling in raising plant thermotolerance, and we explore its multifaceted contributions to various aspects of the plant HS response (HSR).