Biomaterial Database

Direct evidence for selective modulation of psbA, rpoA, rbcL and 16S RNA stability during barley chloroplast development. 1993

M Kim, and D A Christopher, and J E Mullet

Department of Biochemistry and Biophysics, Texas A & M University, College Station 77843.

The turnover of RNAs encoded by seven different barley chloroplast genes was analyzed after treatment of barley shoots with tagetitoxin, a selective inhibitor of chloroplast transcription. Changes in RNA stability were examined during chloroplast development using basal and apical leaf sections of 4.5-day-old dark-grown seedlings and apical leaf sections of 4.0-day-old dark-grown seedlings which had been illuminated for 12 h. Of the RNAs examined, a 2.6 kb unspliced precursor of tRNA(lys) exhibited the shortest half-life, which was estimated to be 3 h. The 16S rRNA and psbA mRNA had the longest estimated half-lives, which were greater than 40 h. Among mRNAs, half-lives were estimated to range from 6 h for psaA mRNA, to over 40 h for psbA mRNA. Therefore, barley chloroplast mRNAs have long half-lives relative to bacterial mRNAs. The stability of atpB mRNA and the unspliced precursor of tRNA-lys was not altered during chloroplast development, while the stability of psaA mRNA decreased 2-fold. In contrast, the stability of the 16S rRNA and mRNAs for rpoA, psbA and rbcL increased during chloroplast development. The stability of 16S rRNA increased markedly during chloroplast development in the dark and this increase was maintained in illuminated seedlings. The stability of rbcL mRNA increased 2.5-fold during chloroplast development in the dark, and then decreased 2-fold in chloroplasts of light-grown plants. The initial increase in rpoA and psbA mRNA stability was also light-independent, with total increases in stability of at least 5-fold. In the case of rpoA, the stability of 2 of the 13 polycistronic rpoA transcripts that were detected in dark-grown plants was selectively increased during chloroplast development. In conclusion, the stability of some transcripts is selectively increased and further modulated during chloroplast development in barley. We propose that the selective stabilization of chloroplast mRNA, which occurred independent of light, is an indication that non-light regulated developmental signals are involved in barley chloroplast mRNA stability.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009943	Organophosphorus Compounds	Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.	Organophosphorus Compound,Organopyrophosphorus Compound,Organopyrophosphorus Compounds,Compound, Organophosphorus,Compound, Organopyrophosphorus,Compounds, Organophosphorus,Compounds, Organopyrophosphorus
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D003998	Dicarboxylic Acids	Acyclic acids that contain two carboxyl groups and have the formula HO2C-R-CO2H, where R may be an aromatic or aliphatic group.	Acids, Dicarboxylic
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D001467	Hordeum	A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.	Barley,Hordeum vulgare
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D012336	RNA, Ribosomal, 16S	Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.	16S Ribosomal RNA,16S rRNA,RNA, 16S Ribosomal,Ribosomal RNA, 16S,rRNA, 16S
D012357	RNA, Transfer, Lys	A transfer RNA which is specific for carrying lysine to sites on the ribosomes in preparation for protein synthesis.	Lysine-Specific tRNA,Transfer RNA, Lys,tRNALys,tRNA(Lys),Lys Transfer RNA,Lysine Specific tRNA,RNA, Lys Transfer,tRNA, Lysine-Specific