Differential regulation of Arabidopsis plastid gene expression and RNA editing in non-photosynthetic tissues

Abstract

RNA editing is one of the post-transcriptional processes that commonly occur in plant plastids and mitochondria. In Arabidopsis, 34 C-to-U RNA editing events, affecting transcripts of 18 plastid genes, have been identified. Here, we examined the editing and expression of these transcripts in different organs, and in green and non-green seedlings (etiolated, cia5-2, ispF and ispG albino mutants, lincomycin-, and norflurazon-treated). The editing efficiency of Arabidopsis plastid transcripts varies from site to site, and may be specifically regulated in different tissues. Steady state levels of plastid transcripts are low or undetectable in etiolated seedlings, but most editing sites are edited with efficiencies similar to those observed in green seedlings. By contrast, the editing of some sites is completely lost or significantly reduced in other non-green tissues; for instance, the editing of ndhB-149, ndhB-1255, and ndhD-2 is completely lost in roots and in lincomycin-treated seedlings. The editing of ndhD-2 is also completely lost in albino mutants and norflurazon-treated seedlings. However, matK-640 is completely edited, and accD-794, atpF-92, psbE-214, psbF-77, psbZ-50, and rps14-50 are completely or highly edited in both green and non-green tissues. In addition, the expression of nucleus-encoded RNA polymerase dependent transcripts is specifically induced by lincomycin, and the splicing of ndhB transcripts is significantly reduced in the albino mutants and inhibitor-treated seedlings. Our results indicate that plastid gene expression, and the splicing and editing of plastid transcripts are specifically and differentially regulated in various types of non-green tissues.

The SLOW GROWTH3 Pentatricopeptide Repeat Protein Is Required for the Splicing of Mitochondrial NADH Dehydrogenase Subunit7 Intron 2 in Arabidopsis

“…Total RNA was isolated from 2-week-old Arabidopsis seedlings as described previously (Tseng et al, 2013). The RNA was treated with DNaseI prior to use in the assays.…”

The amino-terminal conserved domain of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase is critical for its function in oxygen-evolving photosynthetic organisms

“…[14][15][16][17][18][19][20] The 4-hydroxy-3-methylbut-2-enyl diphosphate (HMBPP) reductase, commonly known as HDR, isoprenoid synthesis H (IspH), or lysis-tolerant B (LytB), catalyzes the last step of the MEP pathway that converts HMBPP into a 5:1 mixture of IPP and DMAPP in Escherichia coli. 12,13 In Arabidopsis thaliana, the hdr-1 knockout mutant is albino lethal and the HDR transgene-induced genesilencing lines are albino, pale green, or variegated.…”

Dysfunctional chloroplasts up-regulate the expression of mitochondrial genes in Arabidopsis seedlings

“…Total RNA was isolated from 2-week-old Arabidopsis seedlings as described previously (Tseng et al 2013). 5 lg total RNA from each sample was used for RNA gel-blot analysis.…”