Fig. 2.

Analysis of spectinomycin-treated plants of WT genome composition. (A) Effect of spectinomycin on WT plants. Seeds were placed on a medium without or with 500 mg/L spectinomycin; 7-d-old seedlings are shown. Treated seedlings are albino, because inhibition of plastid translation prevents biogenesis of chlorophyll-containing photosynthetic complexes. (B) Ninety-day-old plantlets developed in the presence of spectinomycin. Although by this time, green plants had completed their life cycle, albino seedlings were comparable with bsm seedlings of similar age (Fig. 1B). (C) Thirty-day-old shoot in vitro culture. Transfer of spectinomycin-induced albinos to a medium supplemented with phytohormones promoted the growth and established albino shoot cultures composed from undifferentiated calli and de novo developed shoots. (D) RT-PCR analysis of splicing. Splicing analysis of atpF, rpl2, rps12, and clpP introns is detailed in Fig. 1 F and G. RNA was extracted from albino (w) or green (g) shoots. Control PCR is on genomic DNA (C).