Limited Responsiveness of Chloroplast Gene Expression during Acclimation to High Light in Tobacco.

摘要: Acclimation to changing light intensities poses major challenges plant metabolism and has been shown involve regulatory adjustments in chloroplast gene expression. However, this regulation not examined at a plastid genome-wide level for many genes, it is unknown whether their expression responds altered intensities. Here, we applied comparative ribosome profiling transcriptomic experiments analyze changes transcript accumulation translation leaves of tobacco (Nicotiana tabacum) seedlings after transfer from moderate physiological high light. Our time-course data revealed almost unaltered levels only mild occupancy during 2 d exposure. Ribosome on the psbA mRNA (encoding D1 reaction center protein PSII) increased that petG decreased slightly treatment. Transfer did induce substantial alterations pausing. low conditions resulted strong PSII photoinhibition distinct light-induced activation translation, which was further confirmed by reciprocal shift experiments. In low-light-to-high-light experiments, as well treatments, all other genes remained virtually unaltered. Altogether, our suggest light-acclimated plants upregulate single gene, psbA, acclimation results indicate occurs already Possible reasons otherwise effects intensity differentiated chloroplasts are discussed.