A homolog of splicing factor SF1 is essential for development and is involved in the alternative splicing of pre-mRNA in Arabidopsis thaliana

Plant J. 2014 May;78(4):591-603. doi: 10.1111/tpj.12491. Epub 2014 Apr 23.


During initial spliceosome assembly, SF1 binds to intron branch points and interacts with U2 snRNP auxiliary factor 65 (U2AF65). Here, we present evidence indicating that AtSF1, the Arabidopsis SF1 homolog, interacts with AtU2AF65a and AtU2AF65b, the Arabidopsis U2AF65 homologs. A mutant allele of AtSF1 (At5g51300) that contains a T-DNA insertion conferred pleiotropic developmental defects, including early flowering and abnormal sensitivity to abscisic acid. An AtSF1 promoter-driven GUS reporter assay showed that AtSF1 promoter activity was temporally and spatially altered, and that full AtSF1 promoter activity required a significant proportion of the coding region. DNA chip analyses showed that only a small proportion of the transcriptome was altered by more than twofold in either direction in the AtSF1 mutant. Expression of the mRNAs of many heat shock proteins was more than fourfold higher in the mutant strain; these mRNAs were among those whose expression was increased most in the mutant strain. An RT-PCR assay revealed an altered alternative splicing pattern for heat shock transcription factor HsfA2 (At2g26150) in the mutant; this altered splicing is probably responsible for the increased expression of the target genes induced by HsfA2. Altered alternative splicing patterns were also detected for the transcripts of other genes in the mutant strain. These results suggest that AtSF1 has functional similarities to its yeast and metazoan counterparts.

Keywords: Arabidopsis thaliana Heynh; SF1; abnormal abscisic acid; alternative splicing; development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Alternative Splicing*
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • DNA, Bacterial / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Genes, Essential / genetics
  • Germination / drug effects
  • Germination / genetics
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Microscopy, Confocal
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Plant Growth Regulators / pharmacology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • RNA Precursors / genetics*
  • RNA Precursors / metabolism
  • RNA Splicing Factors
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism
  • Seeds / drug effects
  • Seeds / genetics
  • Seeds / growth & development
  • Splicing Factor U2AF
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcriptome


  • Arabidopsis Proteins
  • DNA, Bacterial
  • DNA-Binding Proteins
  • HSFA2 protein, Arabidopsis
  • Heat Shock Transcription Factors
  • Heat-Shock Proteins
  • Nuclear Proteins
  • Plant Growth Regulators
  • Plant Proteins
  • RNA Precursors
  • RNA Splicing Factors
  • RNA-Binding Proteins
  • Ribonucleoproteins
  • SF1 protein, Arabidopsis
  • Splicing Factor U2AF
  • T-DNA
  • Transcription Factors
  • Green Fluorescent Proteins
  • Abscisic Acid

Associated data

  • GEO/GSE48114