Figure 5.

T-DNA insertions in the βCA2 and βCA4 genes disrupt RNA synthesis. A, Gene models of βCA2 and βCA4. Blue boxes represent exons, blue lines represent introns, and red boxes represent untranslated regions. Triangles represent locations of each T-DNA insert within its gene. F, Forward primer; I, insert primer; R, reverse primer. Arrows represent the locations and orientations of primers. B, Genomic PCR showing the disruption of the βCA2 and βCA4 genes caused by the T-DNA insertions. Actin (At2g37620) was used as a positive control. C, Reverse transcription-PCR showing the absence of the βCA2 and βCA4 mRNAs in the various T-DNA lines. Actin (At2g37620) was used as a positive control. D, Western blot showing that the βCA2 protein is missing in the βca2 and βca2βca4 plants. Each lane contains 5 μg μL⁻¹ of total protein from leaf tissue.