When Heat Is on: Posttranslational Regulation of Flowering Under Warming Climates—Its Significance and Potential Coping Strategies

Global warming poses serious threats to plant reproduction and agricultural productivity by affecting the timing of flowering, a critical developmental transition. Although transcriptional regulation of flowering pathways has been extensively studied, posttranslational and protein-level regulatory mechanisms are gaining increasing attention as important thermosensory switches enabling rapid and reversible responses to temperature fluctuations. These mechanisms include temperature-dependent protein degradation, ubiquitination, liquid–liquid phase separation of intrinsically disordered proteins, protein sequestration, and dynamic protein–protein interactions. This review summarizes current understanding of posttranslational flowering time regulation under high-temperature conditions, focusing on the major interconnected thermosensory modules, such as the temperature-dependent proteostasis of floral repressors and the emergence of temperature-responsive liquid–liquid phase separation (LLPS) of intrinsically disordered proteins (IDPs). Recent discoveries indicate that temperature-responsive flowering relies not only on transcriptional networks but also on dynamic protein-level regulatory mechanisms, including ubiquitination, proteasomal degradation, and liquid–liquid phase separation. However, the fact that these mechanisms have not been validated in crop species leaves their translational potential an open question.