Search results for "Chloroplast"
showing 10 items of 145 documents
Balanced Gene Losses, Duplications and Intensive Rearrangements Led to an Unusual Regularly Sized Genome in Arbutus unedo Chloroplasts
2013
Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast geno…
Reticulation or divergence: the origin of a rare serpentine endemic assessed with chloroplast, nuclear and RAPD markers
2002
Species of Armeria from the southern part of the Iberian Peninsula have been postulated to undergo extensive reticulate evolution based on ITS sequences as well as morphometric, eco-geographical evidence and crossing experiments. The hypothesis that a rare serpentine endemic (A. villosa subsp. carratracensis) originated from a cross between another serpentine tolerant endemic (A. colorata) and a widespread limestone species (A. villosa subsp. longiaristata) is tested with molecular markers. Sequences from two chloroplast regions [trnL (UAA)-trnF (GAA) and trnD (GUC)-trnT (GGU)], from nuclear ribosomal DNA (ITS-1 + 5.8S + ITS-2) as well as RAPD data are used. Variation in chloroplast and nuc…
Genetic diversity of Dioscorea dumetorum (Kunth) Pax using Amplified Fragment Length Polymorphisms (AFLP) and cpDNA
2010
We have utilized Amplified Fragment Length Polymorphisms (AFLP) in conjunction with chloroplast DNA (cpDNA) sequence data to study the genetic diversity in 53 accessions of Dioscorea dumetorum from six countries in West and Central Africa. Our results provide a comparison of the two marker systems with regards to their applicability to differentiate intraspecific genotypes and the grouping of the accessions based on localities of collection. A total of 1052 AFLP fragments (of which 94.1% were polymorphic) produced from twelve primer combinations indicate a relatively high level of polymorphism among the accessions. Three major genetic groups that do not strictly follow a geographic distribu…
The Effect of Phosphinothricin (Glufosinate) on Photosynthesis II. The Causes of Inhibition of Photosynthesis
1987
It was shown in the previous study that phosphinothricin (glufosinate) causes an accumulation of ammonia and inhibition of photosynthesis. The extent to which there is a connection between these two processes is now investigated in the present study. First of all. the role of NH3 per se in the impairment of photosynthesis was to be clarified. For this purpose, the inhibition of photosynthesis was investigated in relation to exogenously applied ammonia in chloroplasts, protoplasts and entire leaves. The comparison with the experimental results in leaves in which the ammonia was formed endogenously (by action of phosphinothricin) shows that the ammonia toxicity at least cannot be solely resp…
Molecular Composition of Glutamine Synthetase of Sinapis alba L.
1988
Chloroplastic glutamine synthetase of Sinapis alba, purified to homogeneity by a simple three step procedure, revealed a molecular weight of about 395 kDa. The native enzyme is composed of eight subunits of identical molecular weight (about 50 kDa (each), although isoelectrofocusing yielded six distinct bands in the pH 5.6 region of the gel. Labelling of the enzyme with the glutamate analogue herbicide [14C]phosphinothricin and with [γ-32P]ATP indicated that glutamine synthetase has eight reactive centers per molecule. The native enzyme dissociated into two enzymatically active subaggregates of about 195 kDa after Mg2+ deprivation.
Purification of hydroperoxide lyase from green bell pepper (Capsicum annuum L.) fruits for the generation of C6-aldehydes in vitro.
2002
The aim of this work was to compare the efficiency of different extracts of hydroperoxide lyase from green bell peppers in producing aldehydes: a crude extract, a chloroplastic fraction, and a purified enzyme were investigated. From a crude extract, the HPO lyase was purified by ion-exchange chromatography with a 22.3-fold increase in purification factor. Analysis by SDS-PAGE electrophoresis under denaturating conditions showed only one protein with a molecular weight of 55 kDa, whereas size-exclusion chromatography indicated a molecular weight of 170 kDa. A maximum of 7500 mg of aldehydes per g of protein was obtained with the purified enzyme within 20 min of bioconversion compared to 392 …
Nuclear and chloroplast DNA variation in Cephalaria squamiflora (Dipsacaceae), a disjunct Mediterranean species
2009
Cephalaria squamiflora is a chamaephyte restricted to rupicolous habitats in islands of the Western (Balearic Islands, Sardinia) and Eastern Mediterranean (Crete and few Aegean islands). Four narrowly distributed races (subspp. squamiflora, mediterranea, ebusitana, balearica) have been described to encompass the morphological variation within the species. We have used nuclear ribosomal ITS and cpDNA sequences to assess how the patterns of molecular differentiation are related to taxonomic and geographic boundaries. Extensive intragenomic ITS variation was detected in samples from all territories, the average sequence divergence among cloned ribotypes was 1.339%. The parsimony network of clo…
Temporal and spatial diversification of the African disjunct genus Androcymbium (Colchicaceae)
2009
Abstract The genus Androcymbium (Colchicaceae) includes 57 species that are distributed in the extreme northern and southern portions of Africa, mainly in regions with a Mediterranean climate. We present the first phylogeographic analysis of the genus with species from all five of its distribution areas (North Africa, Horn of Africa, Namibia, western South Africa, and eastern South Africa). We used sequence data from six chloroplast regions and one nuclear region. Phylogeographic reconstructions were conducted using both parsimony and Bayesian inference methods. Molecular dating estimates using a Bayesian approach suggest a middle Miocene (13.4 ± 1.5 mya) origin of the genus; this approach …
Chloroplast DNA and isozyme analysis of the progenitor-derivative species relationship between Senecio nebrodensis and S. viscosus (Asteraceae )
1995
A comparison of chloroplast DNA (cpDNA) and isozyme diversity in Senecio nebrodensis L., a species restricted to certain mountain ranges in Spain, and S. viscosus L., a widespread ruderal species in Europe, revealed that S. viscosus possessed the more common of two cpDNA haplotypes resolved in S. nebrodensis and contained only a small subset of the alleles found in S. nebrodensis at enzyme coding loci. The two species shared one restriction length mutation and one site mutation in their cpDNA, which distinguished them from other European Senecio species examined previously. Taken overall, these results support the hypothesis that S. nebrodensis and S. viscosus are related as a progenitor-de…
Photoaffinity cross-linking of F1ATPase from spinach chloroplasts by 3'-arylazido-beta-alanyl-8-azido ATP.
1994
UV irradiation of the ATPase (CF1) from spinach chloroplasts in the presence of 3'-arylazido-beta-alanyl-8-azido ATP (8,3'-DiN3ATP) results in a nucleotide-dependent inactivation of the enzyme and in a nucleotide-dependent formation of alpha-beta cross-links. The results demonstrate an interfacial localization of the nucleotide binding sites on CF1.