Search results for "CHLOROPLAST"

Rapid radiation of North American desert genera of the Papaveraceae: Evidence from restriction site mapping of PCR-amplified chloroplast DNA fragments

1995

Phylogenetic relationships of a group of North American desert genera of the Papaveraceae subfam. Papaveroideae and Platystemonoideae were investigated with an RFLP analysis of three PCR-amplified chloroplast genome regions. In agreement with earlier results it was found that subfam. Platystemonoideae is nested within subfam. Papaveroideae. The group under study is characterized by a large number of generic autapomorphies but only few informative synapomorphies. This is interpreted as strong evidence for a rapid radiation event caused by major climatic changes in the past. Poor phylogenetic resolution seems to reflect biological reality and not to be an experimental artifact. There is also …

Phylogeny of Veronica in the Southern and Northern Hemispheres based on plastid, nuclear ribosomal and nuclear low-copy DNA

2010

The cosmopolitan and ecologically diverse genus Veronica with approximately 450 species is the largest genus of the newly circumscribed Plantaginaceae. Previous analyses of Veronica DNA sequences were in stark contrast to traditional systematics. However, analyses did not allow many inferences regarding the relationship between major groups identified, hindering further analysis of diversification and evolutionary trends in the genus. To resolve the backbone relationships of Veronica, we added sequences from additional plastid DNA regions to existing data and analyzed matching data sets for 78 taxa and more than 5000 aligned characters from nuclear ribosomal DNA and plastid DNA regions. The…

Chloroplast signal length requirement reflects the outer membrane and TOC complex dimension

2015

Background and Purpose: The evolution of an efficient preprotein targeting and translocation system was a central prerequisite for the endosymbiotic integration of a -proteobacteria and cyanobacteria as cellular organelles. Today, it is widely accepted that during evolution most (pre-)proteins destined for these two organelles were equipped with an N-terminal targeting signal for localization. While multiple modes of evolution of these extensions are currently discussed, all evolved signals serve the same function – forming a signal for targeting to the correct organelle and translocation across both membranes. We aimed to generalize the current idea for the length requirement of the N-term…

Chloroplast morphology and pyrenoid ultrastructural analyses reappraise the diversity of the lichen phycobiont genus Trebouxia (Chlorophyta)

2022

Abstract Trebouxiophyceae is a wide class of green algae comprising coccoid and elliptic unicells, filaments, blades and colony-forming species that occur in diverse terrestrial and aquatic environments. Within this class, the genus Trebouxia Puymaly is among the most widespread lichen phycobionts worldwide. However, the 29 formally described species based on the combination of morphological traits and genetic diversity woefully underrepresented the overall species-level diversity recognized in the genus. In Trebouxia, reliable differentiation and characterization of the species-level lineages can be achieved by studying the diversity of key diagnostic features of pyrenoid ultrastructure an…

Suitability of chloroplast LSU rDNA and its diverse group I introns for species recognition and phylogenetic analyses of lichen-forming Trebouxia alg…

2009

To date, species identification of lichen photobionts has been performed principally on the basis of microscopic examinations and molecular data from nuclear-encoded genes. In plants, the chloroplast genome has been more readily exploited than the nuclear genome for systematic investigations. At the present time, very little information is available about the chloroplast genome of lichen-forming algae. For this reason, we have sequenced a portion of the gene encoding for the chloroplast large sub-unit rRNA (LSU rDNA) as a new molecular marker. Sequencing of the chloroplast LSU rDNAs revealed the existence of an unusual diversity of group I introns (a total of 31) within 15 analyzed Trebouxi…

Specific sequence elements in the 5′ untranslated regions of rbcL and atpB gene mRNAs stabilize transcripts in the chloroplast of Chlamydomonas reinh…

2001

Using a series of point mutations in chimeric reporter gene constructs consisting of the 5' regions of the Chlamydomonas chloroplast rbcL or atpB genes fused 5' to the coding sequence of the bacterial uidA (GUS) gene, RNA-stabilizing sequence elements were identified in vivo in the 5' untranslated regions (5' UTRs) of transcripts of the chloroplast genes rbcL and atpB in Chlamydomonas reinhardtii. In chimeric rbcL 5' UTR:GUS transcripts, replacement of single nucleotides in the 10-nt sequence 5'-AUUUCCGGAC-3', extending from positions +38 to +47 relative to the transcripts' 5' terminus, shortened transcript longevity and led to a reduction in transcript abundance of more than 95%. A similar…

Changes in the 5?-untranslated region of the rbcL gene accelerate transcript degradation more than 50-fold in the chloroplast of Chlamydomonas reinha…

2003

Using uidA (beta-glucuronidase; GUS) reporter gene constructs, the 5'-untranslated region (UTR) of the Chlamydomonas chloroplast rbcL gene was screened by deletion and mutational analysis for the presence of a promoter element that previous studies implied to reside within the first 63 base pairs of the UTR. Deleting a large segment of the rbcL 5'UTR in a 3'--5' direction to position +36, changing the remaining 36 base pairs at the 5' end of the UTR, and increasing by five base pairs the distance between the rbcL 5'UTR and the basic promoter element located at position -10 did not abolish transcription from the basic rbcL promoter. It is concluded that the apparent loss of transcriptional a…

Calcium signaling in plant defense: involvement of subcellular compartments and glutamate receptorsCalcium signaling in plant defense: involvement of…

2012

Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)

1988

Notice présente dans BelInra (https://belinra.inra.fr/gestion/catalog.php?categ=isbd&id=90015); il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION; Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)

La stérilité male cytoplasmique du tournesol (Helianthus annuus L.) : caractérisation des ADN chloroplastiques

1984

Notice présente dans BelInra (https://belinra.inra.fr/gestion/catalog.php?categ=isbd&id=83503); il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION; La stérilité male cytoplasmique du tournesol (Helianthus annuus L.) : caractérisation des ADN chloroplastiques