Figure 1.

Experimental design and sample results testing CUL1 function in self-incompatibility. (A) Diagram of crosses between transgenic CUL1 RNAi lines as pollen donors onto self-compatible (LA2157) or self-incompatible (LA2163) accessions of S. arcanum with inferred S-genotypes of each. (B) RT-PCR analysis of CUL1 expression in pollen of five independent T₀ CUL1 RNAi plants (T₀-1 to T₀-5) and nontransgenic control accession LA2163. (C) The frequency of transgenic and nontransgenic T₁ progeny from five independent CUL1 RNAi transformants (T₀-1, two T-DNA insertions; T₀-2 to T₀-5, one insertion) crossed onto SC LA2157 or three independent SI LA2163 plants. The segregation of the T-DNA in the progeny of pollinations onto LA2157 fits Mendelian ratios, whereas progeny from the crosses onto LA2163 show an extreme deficiency of transgenic plants. These data (and full results in Table S2) indicate that CUL1-silenced pollen are rejected on pistils of independent nontransgenic LA2163 plants with different S-genotypes.