Abiotic stress sensing in plants: Biochemical and biophysical basis

Plants cannot relocate when environmental conditions become unfavorable and therefore rely on sophisticated mechanisms to perceive, interpret, and respond to stresses. Stress sensing constitutes the first and often most decisive step in adaptation, because it determines how efficiently downstream signaling and protective responses are initiated. This review focuses on the biochemical and biophysical basis of abiotic-stress sensing, highlighting the fundamental molecular logic by which physical and chemical environmental changes are encoded, perceived, and converted into biological signals. We discuss representative sensing mechanisms associated with temperature stress, drought, salt and alkali stress, flooding, and soil compaction, and examine general messengers, including Ca²⁺ and reactive oxygen species, as central integrators across diverse abiotic stresses. Finally, we identify major outstanding questions, including the identity of the primary stress-associated cues, the spatial organization of sensing, and the perception of combined stresses, and highlight emerging approaches, including AI-driven biomolecular modeling, single-cell techniques, synthetic biology, and genome editing, as powerful tools to advance the mechanistic understanding of plant stress sensing.