PORCUPINE (PCP) regulates development in response to temperature variations through alternative splicing in Arabidopsis

Plant development and growth are strongly influenced by environmental factors such as temperature fluctuations. Recent findings suggest that temperature-regulated alternative splicing (AS) plays a critical role in controlling the plant response to variations in temperature at the molecular level, allowing quick adaptation to the current conditions. However, AS factors in plants are largely uncharacterized. Here we describe the function of PORCUPINE (PCP), a bona fide AS regulator, which is essential for correct development of Arabidopsis thaliana at low ambient temperature and whose loss of function mutants show severe meristem defects. Our findings support a role for PCP in AS regulation and point to the misregulation of two genes involved in maintaining the shoot apical meristem stem cell fate, WUSCHEL (WUS) and CLAVATA3 (CLV3) as possible cause for the meristem defects affecting the mutants at low temperatures. In summary, we establish PCP as an important regulator of development in plants.