Summary
Mitochondria are semi autonomous organelles, with their own genome and transcription/translation systems. Although the regulation of mitochondrial gene expression is fairly well characterized in the animal system, little is known about these processes in plants. We have been studying the expression of ORF25, a mitochondrial open reading frame, in normal male-fertile maize. In all the N lines that we have examined, the ORF25 transcript pattern is similar, except for that in B37N. We have compared ORF25 transcription patterns between B73N and B37N: B73N has one major transcript of 2,300 nucleotides and two minor transcripts of 3,400 and 1,600 nucleotides, while B37N has a single transcript, 3,400 bases long. The ORF25 reading frame and 5′ flanking regions have been analyzed by restriction mapping and found to be identical in these lines. Interestingly, the F1 progeny from reciprocal crosses between B73N and B37N have ORF25 transcript patterns identical to B73N. This suggests that the process of mitochondrial transcription is influenced by nuclear factors in normal cytoplasm. This factor(s) appears to be dominant in B73N and the F1 progeny. S1 nuclease analyses have revealed that identical fragments are protected in B73N and the F1 hybrids, indicating that the ORF25 transcripts in the F1 progeny are identical on the 5′ ends to those of the parent B73N. This nuclear regulation may be at the level of initiation of transcription or processing of the mtRNA.
Similar content being viewed by others
References
Abbott AG, Fauron CMR (1986) Structural alterations in a transcribe region of the T-type cytoplasmic male-sterile maize mitochondrial genome. Curr Genet 10:777–783
Dewey RE, Levings CS III, Timothy DH (1986) Novel recombinations in the maize mitochondrial genome produce a unique transcriptional unit in the Texas male-sterile cytoplasm. Cell 44:439–449
Fox TD, Costanzo MC, Strick CA, Marykwas DL, Seaver EC, Rosenthal JK (1988) Translational regulation of mitochondrial gene expression by nuclear genes of Saccharomyces cerevisiae. Philos. Trans R Soc London Ser B 319:83–208
Hanson MR, Conde MF (1985) Functioning and variation of cytoplasmic genomes: lessons from cytoplasmic-nuclear interactions affecting male fertility in plants. Int Rev Cytol 94:213–267
Kemble RJ, Gunn RE, Flavell RB (1980) Classification of normale and male-sterile cytoplasma in maize. II. Electrophoretic analysis of DNA species in mitochondria. Genetics 95:451–458
Kennell JC, Wise RP, Pring DR (1987) Influence of nuclear background on transcription of a maize mitochondrial region associated with Texas male-sterile cytoplasm. Mol Gen Genet 210:399–406
Laughnan JR, Gabay-Laughnan S (1983) Cytoplasmic male sterility in maize. Annu Rev Genet 17:27–48
Maniatis T, Fritsch EF, Sambrook J (1982) Molecular cloning: a laboratory manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor/NY
Newton JK, Kudsons C, Laughnan SG, Laughnan JR (1990) An abnormal growth mutant in maize has a defective mitochondrial cytochrome oxidase gene. The Plant Cell 2:107–113
Rigby PWJ, Diekmann M, Rodes C, Berg P (1977) Labelling DNA to high specific activity by nick translation with DNA polymerase I. J Mol Biol 113:237–251
Shumway LK, Bauman LF (1967) Nonchromosomal stripe of maize. Genetics 55:33–38
Southern EM (1975) Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol 98:503–517
Walker NH, Qin J, Abbott AG (1987) Northern hybridization analysis of mitochondrial gene expression in maize cytoplasm with varied nuclear backgrounds. Theor Appl Genet 74:531–537
Wang J, Barth J, Abbott AG (1991) Higher plant mitochondrial DNA expression. 1. Variant expression of the plant mitochondrial open reading frame, ORF25, in B37N and B73N maize lines. Theor Appl Genet
Author information
Authors and Affiliations
Additional information
Communicated by R. Hagemann
Rights and permissions
About this article
Cite this article
Gupta, D., Abbott, A.G. Higher plant mitochondrial DNA expression. Theoret. Appl. Genetics 82, 723–728 (1991). https://doi.org/10.1007/BF00227317
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00227317