title: A naturally occurring splicing site mutation in the Brassica rapa FLC1 gene is associated with variation in flowering time.
abstract: FLOWERING LOCUS C (FLC), encoding a MADS-domain transcription factor in Arabidopsis, is a repressor of flowering involved in the vernalization pathway. This provides a good reference for Brassica species. Genomes of Brassica species contain several FLC homologues and several of these colocalize with flowering-time QTL. Here the analysis of sequence variation of BrFLC1 in Brassica rapa and its association with the flowering-time phenotype is reported. The analysis revealed that a G-->A polymorphism at the 5' splice site in intron 6 of BrFLC1 is associated with flowering phenotype. Three BrFLC1 alleles with alternative splicing patterns, including two with different parts of intron 6 retained and one with the entire exon 6 excluded from the transcript, were identified in addition to alleles with normal splicing. It was inferred that aberrant splicing of the pre-mRNA leads to loss-of-function of BrFLC1. A CAPS marker was developed for this locus to distinguish Pi6+1(G) and Pi6+1(A). The polymorphism detected with this marker was significantly associated with flowering time in a collection of 121 B. rapa accessions and in a segregating Chinese cabbage doubled-haploid population. These findings suggest that a naturally occurring splicing mutation in the BrFLC1 gene contributes greatly to flowering-time variation in B. rapa.
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Yuan
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.forename: Ri-Fei
authors.initials: RF
authors.lastname: Sun
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Zhang
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Xu
authors.forename: Guusje
authors.initials: G
authors.lastname: Bonnema
authors.forename: Xiao-Wu
authors.initials: XW
authors.lastname: Wang
mesh_terms: D029741:Brassica rapa / Q000235:genetics*; D003080:Cold Temperature; D035264:Flowers / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D008954:Models, Biological; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D022821:RNA Splice Sites / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D005819:Genetic Markers; D010940:Plant Proteins; D022821:RNA Splice Sites