SISTER OF FCA physically associates with SKB1 to regulate flowering time in Arabidopsis thaliana

Proper flowering time is important for the growth and development of plants, and both too early and too late flowering impose strong negative influences on plant adaptation and seed yield. Thus, it is vitally important to study the mechanism underlying flowering time control in plants. In a previous study by the authors, genome-wide association analysis was used to screen the candidate gene SISTER OF FCA (SSF) that regulates FLOWERING LOCUS C (FLC), a central gene encoding a flowering suppressor in Arabidopsis thaliana. SSF physically interacts with Protein arginine methyltransferase 5 (PRMT5, SKB1). Subcellular co—localization analysis showed that SSF and SKB1 interact in the nucleus. Genetically, SSF and SKB1 exist in the same regulatory pathway that controls FLC expression. Furthermore, RNA-sequencing analysis showed that both SSF and SKB1 regulate certain common pathways. This study shows that PRMT5 interacts with SSF, thus controlling FLC expression and facilitating flowering time control.