Xiaoxue Wang

Title : SKIP, a splicing factor, links alternative splicing to SWR1 chromatin remodeling complex and controls flowering time in Arabidopsis

Abstract:

S imilar 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 mutation of SKIP, skip-1, confers early flowering phenotype under long day (LD) and shot day (SD) conditions. SKIP is required for the splicing of serrated leaves and early flowering (SEF) pre-mRNA through directly binding, which encodes a component of the ATP-dependent SWR1 chromatin remodeling complex (SWR1-C). It has been reported that the SWR1-C exchanges histone H2A for H2A.Z, producing variant nucleosomes. The SWR1-C is required for H2A.Z deposition at flowering locus c (FLC), MADS affecting flowering (MAF) 4, and MAF5 chromatin (which encode central flowering-time suppressors), and promotes transcription at these loci. The skip-1 mutation caused the elevated accumulation of alternatively spliced SEF isoforms, including those showing intron retention. However, the level of mature SEF mRNA encoding functional SEF protein was reduced by skip-1. Defects in the splicing of SEF pre-mRNA reduced H2A.Z enrichment at the chromatin of FLC, MAF4, and MAF5, suppressed the expression of these genes; activated the expression of suppressor of constans 1 (SOC1), flowering locus T (FT), and twin sister of FT (TSF) (which encode flowering-time integrators); 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

Biography:

Xiaoxue Wang is a professor in Rice Research Institute at Shenyang Agricultural University. She obtained her Ph.D. in 1994. She used to be a visiting scientist and postdoctoral associate at Peking University, Yale University and University of California at Berkeley in the U.S.A.. In 2005, she worked at National Institute of Biological Sciences, Beijing. She is currently a professor in Agronomy College at Shenyang Agricultural University, China. She has published over 30 papers in the journal of The Plant Cell, BMC Biology, The Plant Journal, Plant Biotechnology Journal, Critical Reviews in Plant Sciences. Her researches focus on molecular mechanisms of plant development and responses to abiotic stresses by using Arabidopsis and rice as model organisms.