Protein networks: integrating pathways for plant heat stress adaptation.

Plants' immobility renders them highly vulnerable to heat stress, which disrupts water relations, photosynthesis, respiration, and cellular homeostasis, ultimately reducing growth and yield. To survive, plants deploy a multifaceted heat stress response (HSR) that integrates calcium signaling, molecular chaperones, antioxidant enzymes, and phytohormonal networks. This review synthesizes recent advances in understanding the molecular crosstalk between phytohormones and protein synthesis during plant heat stress responses, with a particular focus on two key HSR modules: protein synthesis pathways, especially heat shock proteins (HSPs), and phytohormone signaling networks involving abscisic acid, cytokinins, ethylene, salicylic acid, and jasmonic acid. It also highlights the convergence of these pathways through calcium-dependent protein kinases (CDPKs) and reactive oxygen species (ROS) signaling. We present mechanistic insights into: (1) CDPK-mediated activation of heat shock transcription factors (HSFs) and hormone-responsive factors; (2) APX-driven ROS scavenging and its impact on crop thermotolerance; and (3) hormone-engineered strategies that enhance yield stability under high temperatures. By consolidating findings from recent meta-analyses and molecular studies, we identify critical nodes for biotechnological intervention, such as CDPK and APX overexpression, and propose field-oriented research priorities, including hormone-engineered crop trials and integrative breeding approaches. This forward-looking framework can help guide biotechnological interventions to enhance crop resilience and support the development of climate-smart crops aimed at safeguarding global food security in a warming world.