FIGURE 1.

Complementation of the ppi2 mutant by GTPase deficient Toc159GM K868R. A, phenotypes of homozygous ppi2 plants transformed with TAP-Toc159GM and TAP-Toc159GM K868R and untransformed A. thaliana plants. In the upper panel, untransformed plants are seedlings descended from a heterozygous ppi2 plant; in the lower panel an untransformed homozygous wild-type plant ecotype Wassilewskija is shown. B, chlorophyll levels in leaves of untransformed wild-type plants and homozygous ppi2 plants complemented by TAP-Toc159GM or TAP-Toc159GM K868R at 19 days after germination. C, confirmation of genotypes and the presence of the K868R single point mutation. PCR analysis of genomic DNA from plants shown above with primer sets specific for the ppi2 allele, the non-disrupted TOC159 gene (WT) and the transgene. Digestion of the transgene-specific PCR product by AseI is indicative of the presence of the K868R mutation that was introduced along with an AseI cleavage site. D, expression of the TAP-tagged proteins in the absence of endogenous Toc159. 50 μg of total protein extracts each were used for Western blotting with rabbit IgG for the detection of TAP-tagged protein and anti-Toc159 A-domain for the detection of endogenous full-length atToc159. The numbers in brackets represent the numbers of the transgenic plant lines (see supplemental Table S1).