SKIP controls flowering time via the alternative splicing of SEF pre-mRNA in Arabidopsis

Zhibo Cui, Aizi Tong, Yiqiong Huo, Zhiqiang Yan, Weiqi Yang, Xianli Yang, Xiao-Xue Wang

Similar to other eukaryotes, splicing is emerging as an important process affecting development and stress tolerance in plants. Ski-interacting protein (SKIP), a splicing factor, is essential for circadian clock function and abiotic stress tolerance; however, the mechanisms whereby it regulates flowering time are unknown. In this study, we found that SKIP is required for the splicing of serrated leaves and early flowering (SEF) pre-messenger RNA (mRNA), which encodes a component of the ATP-dependent SWR1 chromatin remodeling complex (SWR1-C). Defects in the splicing of SEF pre-mRNA reduced H2A.Z enrichment at FLC, MAF4, and MAF5, suppressed the expression of these genes, and produced an early flowering phenotype in skip-1 plants. Our findings indicate that SKIP regulates SWR1-C function via alternative splicing to control the floral transition in Arabidopsis thaliana.