Abstract
Arabidopsis Cdf1 (cell growth defect factor-1) was isolated as a cell death inducer when expressed in yeast (Kawai-Yamada et al, JBC, 2005). In Arabidopsis genome, there are three Cdf-related genes (Cdf1-3). To investigate the cellular localization of Cdf family proteins in plants, GFP-fused Cdf1-3 were expressed in Arabidopsis. Microscopic analysis demonstrated that Cdf1-3-GFP proteins localized on plastid envelope. Furthermore, the analysis of T-DNA inserted plants demonstrated that the heterozygous Cdf1 mutant showed normal vegetative phenotypes under optimal growth conditions, but embryos homozygous for Cdf1 arrested at the globular stage. Such phenotype was complemented by the overexpression of Cdf1. These data indicate that plastid envelope protein Cdf1 is essential during embryogenesis. Furthermore, T-DNA inserted plants in Cdf1-3 demonstrated delayed phenotype in dark-induced leaf senescence. The possible function of Cdf family proteins in embryogenesis and senescence will be presented.
