Figure 10.

Complementation and phenotyping of cgep-2 expressing different CCEP variants. A, Images of homozygous cgep-2 and transgenic cgep-2 plants complemented with CGEP-STREPII and its modified forms S781R, C1, and C2. Plant were grown for 18 d on soil under a 16-h light/8-h dark cycle at 100-μmol photons m⁻² s⁻¹. For genotyping information, see Supplemental Figure S7. B, Detection of transgenic protein by STREPII and CGEP antisera in complemented plants by immunoblotting using stroma. Immunoblot with anti-CGEP and anti-STREPII serum to detect accumulation of transgenic CGEP protein and C-terminal cleavage in stroma of cgep-2, cgep-2/CGEP-S781R-STREP, cgep-2/CGEP-C1-STREPII, and cgep-2/CGEP-C2-STREPII. Whereas there are high levels of CGEP protein detected, the STREPII-tagged portion is not detected in cgep-2/CGEP-C1-STREPII—demonstrating that the C terminus is autocatalytically cleaved in this CGEP variant. By contrast, detection of STREPII in cgep-2/CGEP-C1-STREPII demonstrates that C-terminal cleavage is inhibited. The Ponceau stains shows the blot before immunodetection. Additional immunoblots using anti-STREPII and anti-CGEP are shown in Supplemental Figure S7. C, Rosette diameter of cgep-2 plants complemented with 35S-CGEP-STREPII and its modified forms S781R, C1, and C2. Plants were grown for 18 d on soil under a 16-h light/8-h dark cycle. Averages and sds are indicated for 10 plants per genotype (n = 10). Asterisks indicate a significant difference (**P < 0.01) between the indicated genotype and cgep-2.