Decoding plant thermosensors: mechanism of temperature perception and stress adaption

Abstract

Global climate change, characterized by increased frequency and intensity of extreme temperature events, poses significant challenges to plant survival and crop productivity. While considerable research has elucidated plant responses to temperature stress, the molecular mechanisms, particularly those involved in temperature sensing, remain incompletely understood. Thermosensors in plants play a crucial role in translating temperature signals into cellular responses, initiating the downstream signaling cascades that govern adaptive processes. This review highlights recent advances in the identification and classification of plant thermosensors, exploring their physiological roles and the biochemical mechanisms by which they sense temperature changes. We also address the challenges in thermosensor discovery and discuss emerging strategies to uncover novel thermosensory mechanisms, with implications for improving plant resilience to temperature stress in the face of a rapidly changing climate.

Keywords: crops; plants; stress; temperature; thermosensor.

Figure 1

Potential thermosensing mechanisms in RNA thermosensors. (A) The heat-sensitive hairpin structure in the PIF7 mRNA 5′-UTR becomes a looser conformation at high temperatures, enhancing protein translation. (B) psaA mRNA senses temperature rising to unfold the hairpin structure within its 5′-UTR and facilitates psaA translation. (C) Temperature changes may affect alternative splicing by altering RNA secondary structure.

Figure 2

Potential thermosensing mechanisms in protein thermosensors. (A) phyB involved in Arabidopsis temperature perception and heat-tolerance formation. (B) A phototropin in liverwort functions as thermosensors by preventing the inactivation of its active forms at low temperature. (C) ELF3 responds to temperature by phase separation. (D) TWA1-mediated transcriptional repression by interacting with JAM2 and TPL. Arrows indicate positive regulation and T-bars indicate negative regulation.

Figure 3

Potential thermosensing mechanisms in plasma membrane-associated protein-based thermosensors. Ca²⁺ and 2′, 3′-cAMP are important molecules involved in regulation temperature-stress response. Cold and heat-induced Ca²⁺ signatures may be decoded by Ca²⁺ sensors or Ca²⁺ -related proteins and thus regulate COR and HSR gene expression. TT3.1 senses high temperature to translocate to the endosomes, where it degrades protein TT3.2. TT3.2 degradation boosts chloroplast function at high temperatures. COLD6 interacted with cold-induced OSM1 to trigger an increase in the level of 2’, 3’-cAMP to promote chilling tolerance. TT3.1 proteins translocate from the PM to endosomes, ubiquitinating the chloroplast precursor protein TT3.2 to prevent chloroplast thylakoid damage and improving heat tolerance. Hik33 kinase domain might be phosphorylated under cold conditions, and then transferred to Hik19, and finally to Rer1, regulating the expression of the desB to adapt to cold stress. CRPK1 was activated by cold stress, phosphorylating 14-3-3 proteins and triggering 14-3-3 proteins to translocate into the nucleus to attenuate the CBF signaling. The COG1-OsSERL2 complex causes the activation of OsMAPK3 to transmit cold signal from the membrane to the cytoplasm, enhancing cold tolerance. Arrows indicate positive regulation and T-bars indicate negative regulation.