Abstract
Previously, we isolated a rice TPR-containing nuclear protein, IABP4, that is specifically bound to particular rice importin α protein whose expression is down-regulated by light. In an effort to elucidate the function of IABP4, first we tried to examine the phenotype of null mutation in its Arabidopsis homolog, At2g06210 (vip6/elf8). T-DNA insertional-mutagenized lines were obtained from the Salk Institute or Kazusa DNA Research Institute. Though we repeated PCR-based screening for the null mutant seedlings that have T-DNA insertion into both copies of the gene, only seedlings of wild or heterozygous genotypes were found, and not those with homozygous genotype. Therefore, we examined seed development in immature siliques. On average, 40% of seeds on heterozygous plants were aborted, whereas 10% of seeds on wild-type plants were aborted. These results suggest that homozygous knockout mutation of this gene might have caused embryonic lethality.
