Plants alter their morphology and cellular homeostasis to promote
resilience under a variety of heat regimes. Molecular processes that
underlie these responses have been intensively studied and found to
encompass diverse mechanisms operating across a broad range of cellular
components, timescales and temperatures. This review explores recent
progress throughout this landscape with a particular focus on
thermosensing in plants. Direct temperature sensors include the
photosensors phytochrome B and phototropin, the clock component ELF3 and
an RNA switch. In addition, there are heat-regulated processes mediated
by ion channels, lipids and lipid-modifying enzymes taking place at the
plasma membrane and the chloroplast. In some cases the mechanism of
temperature perception is well understood but in others this remains an
open question. Potential novel thermosensing mechanisms are based on
lipid and liquid phase separation. Finally, future research directions
of high temperature perception and signalling pathways are discussed.