RESUMO
A high level of the nucleotide sequence conservation was found for mitochondrial nad3 gene of carrot. Three silent nucleotide substitutions differentiate nad3 open reading frames from cytoplasmic male sterile and male fertile carrots. All these differences are preserved on the RNA level. Partial and silent editing also distinguished both carrots. Three of the C to U conversions were specific to the fertile line. In the two examined carrot lines editing did not affect the mode of alteration of encoded amino acids.
Assuntos
Daucus carota/genética , Mitocôndrias/genética , Proteínas Mitocondriais , Proteínas de Plantas/genética , Edição de RNA/genética , RNA/genética , Sequência de Aminoácidos , Códon/genética , Daucus carota/citologia , Regulação da Expressão Gênica de Plantas , RNA/metabolismo , RNA Mitocondrial , RNA de Plantas/genética , RNA de Plantas/metabolismo , Reprodução/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Seven populations and five mutant lines of the Andean lupin and four species from the section Albus were screened for their mitochondrial and chloroplast polymorphisms. For this purpose the RFLP method with EcoRI as a restriction enzyme was used. Lupinus luteus, Lupinus albus and Phaseolus vulgaris organellar clones as well as amplified fragments were used as probes. We found that mitochondrial probes were more suitable than chloroplast probes for identification of inter- and intra-specific variations within the examined material. Most mitochondrial probes differentiate the two species investigated. A high level of mitochondrial polymorphism was observed among the populations of L. mutabilis in contrast to monomorphism among the species in the section Albus. A limited polymorphism was detected between the mutant lines of L. mutabilis. We conclude from this study that the mitochondrial RFLP analysis is a valuable tool for identification of variability among Andean lupin populations.
RESUMO
A high level of the nucleotide sequence conservation of mitochondrial nad3 and rps12 genes was found in four lupin species. The only differences concern three nucleotides in the Lupinus albus rps12 gene and three nucleotides insertion in the L. mutabilis spacer. Northern blot analysis as well as RT-PCR confirmed cotranscription of the L. luteus genes because the transcripts detected were long enough.
Assuntos
DNA Mitocondrial/genética , Proteínas Mitocondriais , Proteínas de Plantas/genética , Plantas/genética , Sequência de Bases , Northern Blotting , Primers do DNA , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Southern blots of mitochondrial (mt) DNAs of three Lupinus species cleaved with three restriction enzymes were probed with Lupinus luteus mtDNA fragments containing 18S, 5S rRNA genes or a tRNA-like repeat. Comparison of the number of hybridizing bands and their intensity suggested that the mt 18S and 5S rRNA genes occur mostly in one copy in the genomes of three lupin species. The exception concerned the Lupinus angustifolius 5S rRNA gene showing two hybridizing bands of unequal intensity. The results of hybridization of the lupin mitochondrial genomes with a probe specific for the Lupinus luteus tRNA-like repeat pointed to the presence of such a repeat in other parts of the genomes besides the vicinity of the 18S rRNA gene. Northern hybridization analysis showed the presence of 18S, 5S and tRNA-like repeat transcripts similar in size in all lupin species.
Assuntos
DNA Mitocondrial/análise , Plantas/genética , RNA Ribossômico 18S/genética , RNA Ribossômico 5S/genética , RNA de Transferência/genética , DNA Mitocondrial/genética , DNA de Plantas/análise , DNA de Plantas/genética , RNA Ribossômico/genética , Sequências Repetitivas de Ácido NucleicoRESUMO
A lupine mitochondrial clone containing 5S rRNA gene is characterized. The gene is located on the same strand as 18S rRNA and separated from it by 190 nucleotides. The intergenic region in different plants shows high degree of homology. In the case of lupine and soybean 43 nucleotides upstream of 5S rRNA gene exhibits 100% of homology. Comparisons of lupine 5S rRNA gene sequence with other plant mitochondrial 5S rRNA genes displays high degree of homology (from 89.8% to 95.8%).
Assuntos
Carnívoros/genética , RNA Ribossômico 5S/genética , Animais , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , Plantas/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da EspécieRESUMO
Two minicircular DNAs of 1.2 kb (K1) and 1.4 kb (K2) were found in mitochondria of fertile lupin (Lupinus albus). The plasmid-like DNA, K1, was cloned, labelled and hybridized with mitochondrial DNA from three different species of lupin. We have found no evidence for integrated copies of K1 in any of the mitochondrial genomes probed in this study. No sequence homology between plasmid K1 and K2, and no homology of either with chloroplast DNA, has been detected. The K1 DNA is two-fold more abundant than the K2 DNA and about seven-fold more abundant than a unique segment of the mtDNA. The entire nucleotide sequence of the K1 DNA has been determined. This sequence exhibits a 340 base pair region with highly organized repeats. The sequence of K1 shows no substantial homology with sequence of other mitochondrial plasmids of higher plants.
Assuntos
DNA Mitocondrial/genética , Plantas/genética , Plasmídeos , Sequência de Bases , Southern Blotting , Dados de Sequência Molecular , Homologia de Sequência do Ácido NucleicoRESUMO
Transfer RNAs isolated from lupin chloroplasts and mitochondria were compared by two-dimensional gel electrophoresis. Twenty chloroplast and 24 mitochondrial tRNA species were identified. The saturation hybridization between lupin chloroplast DNA and 125I-labelled lupin chloroplast tRNAs pointed to the presence of about 34 tRNA genes in lupin chloroplast DNA. The number of mitochondrial tRNA genes estimated by the same method was about 30 genes. EcoRI restriction digest of lupin mitochondrial DNA probed with 32P-labelled lupin mitochondrial tRNAs revealed only a small number of positive restriction fragments. Some of these mitochondrial restriction fragments hybridized with 32P-labelled chloroplast tRNA.
Assuntos
Cloroplastos/química , DNA/análise , Fabaceae/genética , Mitocôndrias/química , Plantas Medicinais , RNA de Transferência/análise , Eletroforese em Gel Bidimensional , RNA de Transferência/genéticaRESUMO
Mitochondrial DNA (mtDNA) was isolated from lupine. Restriction analysis was used to estimate its size, which is about 180 kb. A BamHI bank of this mtDNA was constructed using plasmids pBR322 and pBR327 as vectors. Eight clones containing plasmids hybridizing to mitochondrial tRNA (mttRNA) were isolated. Restriction maps of these plasmids were determined. Six of these plasmids hybridized to unique fragments and two to two fragments of very similar size, all obtained by BamHI cleavage of mtDNA.
Assuntos
DNA Mitocondrial/genética , Plantas/genética , RNA de Transferência/genética , Clonagem Molecular , Enzimas de Restrição do DNA , Desoxirribonuclease BamHI , Hibridização de Ácido Nucleico , PlasmídeosRESUMO
Transfer RNAs were isolated from plants representing mono- and dicotyledons: wheat embryos and lupin seeds. The two tRNA preparations were compared by polyacrylamide-gel-electrophoresis mapping. Transfer RNAs extracted from the separated spots were tested for acceptance of 11 amino acids. Comparison of electrophoretic mobility of respective tRNA species indicates the overall similarity of tRNA populations in the two plants studied. Especially, isoaccepting tRNAs for glycine, tyrosine and valine and some of isoacceptors of tRNAArg, tRNAAsp, tRNALeu, tRNALys and tRNAPhe occupy identical or closely similar positions on both polyacrylamide-gel maps. However, some tRNA isoacceptors from one population have no counterparts in the second one, which may indicate differences in their primary structures.
Assuntos
Plantas/análise , RNA de Transferência/análise , Triticum/análise , Eletroforese em Gel de PoliacrilamidaRESUMO
During germination of lupin seeds, the levels of in-vivo tRNA aminoacylation increase in different ways, depending on the species of tRNA. Column chromatography of tRNA on reverse-phase-chromatography (RPC-5) has shown the presence of 4 peaks of isoleucyl-tRNA, 5 of leucyl-tRNA, 5 of lysyl-tRNA, 2 of tyrosyl-tRNA, and 4 of valyl-tRNA. Cochromatography of periodate treated and control tRNA preparations, labeled with radioactive amino acids, indicates identical aminoacylation in vivo of isoaccepting tRNAs during plant development. One isoacceptor of isoleucine tRNA changes its elution profile after periodate treatment.
RESUMO
Polyribosome-bound and -unbound isoaccepting species of tRNALys and tRNAIle, isolated from lupin cotyledons, were compared by RPC-5 chromatography and it was found that polyribosomes preferentially bind some of the isoaccepting species. The preference in binding of given isoacceptors changes with the age of lupin seedling. The results suggest that the tRNALys species recognising the same codons can affect the rate of translation in lupin cotyledons.
Assuntos
Plantas/metabolismo , Polirribossomos/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Códon/metabolismo , Isoleucina , Lisina , Fatores de TempoRESUMO
RPC-5 chromatography of [14C]isoleucyl-tRNA shows the presence of 5 tRNAIle species in lupin seeds. The two major species have been isolated using RPC-5 and Sepharose 4B chromatography. The acceptor activity of the purified tRNAs ranges from 1350 pmoles (tRNA2Ile) to 1510 pmoles (tRNA1Ile) of isoleucine per one A260 unit of tRNA. The two tRNAs have similar thermal denaturation profiles but differ in the composition of the major and minor bases, 3'-terminal nucleotide sequences, and the titration curves with MgCl2. It is concluded that the two major tRNAIle species are coded for by different genes.
Assuntos
RNA de Transferência/isolamento & purificação , Cloretos/metabolismo , Fabaceae , Genes , Temperatura Alta , Isoleucina , Magnésio/metabolismo , Desnaturação de Ácido Nucleico , Terminação Traducional da Cadeia Peptídica , Plantas MedicinaisRESUMO
1. The lupin cotyledons contain two cytoplasm-specific lysine tRNAs, one chloroplast-specific, one mitochondria-specific species, and three species common to all the cell compartments investigated; the lysine tRNAs were separated by reversed-phase chromatography (RPC-5). 2. The two cytoplasmic lysine tRNAs are predominant in the tRNALys isolated from the whole tissue. Their level and relative ratios change during germination (Augustyniak & Pawelkiewicz, 1978, Phytochemistry, 17, 15-18). 3. The organellar tRNA constitutes about 20% of the total tRNA in the cotyledons of 7-day-old lupin seedlings.
Assuntos
Fabaceae/análise , Plantas Medicinais , RNA de Transferência/análise , Aminoacil-tRNA Sintetases/isolamento & purificação , Cloroplastos/análise , Citoplasma/análise , Mitocôndrias/análiseRESUMO
Analysis of the nucleoside composition of five lysine tRNAs from lupin seeds has shown their general similarity to other eukaryotic lysine tRNAs, except that lupin lysine tRNAs do not contain either t6A, Tm, or thioderivatives of uridine. It is assumed that each of the lupin tRNALys is coded for by a separate gene. The acceptor activity of the analysed tRNAs ranged from about 1200 (tRNA3Lys, tRNA4Lys, tRNA5Lys) to 1470 (tRNA2Lys) pmoles of lysine per one A260 unit of tRNA.
