Arabidopsis VIP6/ELF8, the homolog of CTR9 component of the transcriptional complex PAF1, is essential for plant development

The VERNALIZATION INDEPENDENCE 6 (VIP6)/EARLY FLOWERING 8 (ELF8) gene of Arabidopsis thaliana encodes a protein homologous to CYCLIN THREE REQUIRING 9 (CTR9) component of the yeast transcriptional complex, RNA polymerase II-associated factor 1 (PAF1). It has been demonstrated that mutation alleles in the VIP6/ELF8 show early flowering phenotype, as well as other pleiotropic developmental defects. Here, we provide evidence that seeds with vip6/elf8 homozygous mutations were rarely obtained in all three independent lines of T-DNA insertion. Although viable seeds with homozygous mutant alleles were rarely obtained, they showed pleiotropic phenotype like mutants of other PAF1-related genes, and were sterile. These results suggest that the VIP6/ELF8 gene is essential for plant development.