Figure 1.

Analysis of maize C₄ NADP-ME expression in Arabidopsis. A, NADP-ME activity from leaf crude extracts of wild type (wt; 12 ± 3.4 mU/mg protein) and the transgenic lines MEm2, MEm4, and MEm5 (67 ± 3.4, 297 ± 4.5, and 391 ± 1.6 mU/mg protein, respectively) measured at pH 8.0. Inset, Immunoblot analysis of C₄ NADP-ME showing a reactive band in the transgenic lines. Errors bars indicate sd (n = 6). B, Chloroplast import assay of C₄ NADP-ME encoded by the full-length cDNA. Lane 1, 66-kD translational product synthesized in vitro. Lane 2, Intact washed chloroplast after import. Lane 3, Intact washed chloroplasts treated with thermolysin after import showing the 62-kD protected mature protein. C, Immunodetection of maize C₄ NADP-ME in a leaf section of the transgenic line MEm5 using specific antibodies. A section of the wild type incubated with the same antibodies showed no reaction. The bar represents 5 μm.