Temperature-dependent regulation ofArabidopsis thalianagrowth and development byLSM7

AbstractSM-like (LSM) proteins are highly conserved among eukaryotes. By promoting alternative splicing and modulating RNA levels, LSM proteins are key regulators of plant development and response to environmental signals. Here, we report thatArabidopsisLSM7 is essential for embryogenesis, and that downregulation ofLSM7results in temperature-dependent developmental defects. Performing a comprehensive transcriptome analysis, we observed thatLSM7modulates flowering, stress-responsive and auxin-related gene expression. Auxin metabolic profiling correlates with our transcriptome analyses and indicates a role of LSM7 in auxin homeostasis and signalling. We propose that LSM7 splicing activity is essential for plant acclimation and survival at different ambient temperatures and that alterations in auxin content are causally linked to the phenotypic defects in the mutant. This study highlights the essential role of LSM proteins in plant development and provides new insights into the molecular and metabolomic aspects underlying plant temperature acclimation.