Role of Splicing factor SF1 in Temperature-Responsive Alternative Splicing of pre-mRNA.

Small changes in temperature affect plant ecological and physiological factors that impact agricultural production. Hence, understanding how temperature affects flowering is crucial for decreasing the effects of climate change on crop yields. Recent reports have shown that β, the major spliced isoform of ()-a flowering time gene, contributes to temperature-responsive flowering in . However, the molecular mechanism linking pre-mRNA processing and temperature-responsive flowering is not well understood. Genetic and molecular analyses identified the role of an splicing factor homolog, , in regulating temperature-responsive flowering. The loss-of-function mutant shows temperature insensitivity at different temperatures and very low levels of β transcript, but a significantly increased transcript level of the alternative splicing (AS) isoform, . An RNA immunoprecipitation (RIP) assay revealed that AtSF1 is responsible for ambient temperature-dependent AS of pre-mRNA, resulting in the temperature-dependent production of functional β transcripts. Moreover, alterations in other splicing factors such as / (/) and () did not impact the β/ ratio at different temperatures. Taken together, our data suggest that a temperature-dependent interaction between AtSF1 and pre-mRNA controls flowering time in response to temperature fluctuations.