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.