Search results for "plastid"
showing 10 items of 54 documents
Vipp1: a very important protein in plastids?!
2011
As a key feature in oxygenic photosynthesis, thylakoid membranes play an essential role in the physiology of plants, algae, and cyanobacteria. Despite their importance in the process of oxygenic photosynthesis, their biogenesis has remained a mystery to the present day. A decade ago, vesicle-inducing protein in plastids 1 (Vipp1) was described to be involved in thylakoid membrane formation in chloroplasts and cyanobacteria. Most follow-up studies clearly linked Vipp1 to membranes and Vipp1 interactions as well as the defects observed after Vipp1 depletion in chloroplasts and cyanobacteria indicate that Vipp1 directly binds to membranes, locally stabilizes bilayer structures, and thereby ret…
A single primer pair gives a specific ortholog amplicon in a wide range of Cyanobacteria and plastid-bearing organisms: applicability in inventory of…
2010
The scarcity of universally applied molecular markers for algae has resulted in the development of multiple, independent and not easily comparable systems. The goal of this work is to increase the number of available molecular markers and to generate easily comparable systems. Thereby, we have designed a primer pair capable of amplifying a broad range of organisms: Cyanobacteria, Chlorophyta, Chlorarachniophyta, Cryptophyta, Euglenida, Glaucophyta, Rhodophyta, Stramenopiles and Streptophyta including plants. This primer pair can amplify a portion of the 23S rRNA gene with sufficient variability to identify reference material form collections across a broad range of taxa and perform phylogen…
The never-ending story of geologically ancient DNA: was the model plantArabidopsisthe source of Miocene Dominican amber?
2013
Studies characterizing geologically ancient DNA in plants are rare, and all have reportedly obtained plastid DNA sequences from Miocene fossils in a remarkable state of preservation. Recently, a group made the extraordinary claim of having amplified a geologically ancient Miocene plastid DNA fragment (the rbcL gene) from Dominican amber nuggets, and the organismal source of this DNA was identified as Hymenaea protera (Fabaceae), the plant that produced the fossilized Dominican amber. Assuming that the Miocene sequence is error-free, reanalysis of the sequence indicates it is probably a technical artifact or an rbcL pseudogene. Furthermore, BLAST similarity searches and phylogenetic analyses…
Midbiotics: conjugative plasmids for genetic engineering of natural gut flora.
2019
ABSTRACT The possibility to modify gut bacterial flora has become an important goal, and various approaches are used to achieve desirable communities. However, the genetic engineering of existing microbes in the gut, which are already compatible with the rest of the community and host immune system, has not received much attention. Here, we discuss and experimentally evaluate the possibility to use modified and mobilizable CRISPR-Cas9-endocing plasmid as a tool to induce changes in bacterial communities. This plasmid system (briefly midbiotic) is delivered from bacterial vector into target bacteria via conjugation. Compared to, for example, bacteriophage-based applications, the benefits of …
Phylogenetics of Anthyllis (Leguminosae: Papilionoideae: Loteae): Partial incongruence between nuclear and plastid markers, a long branch problem and…
2010
Abstract Phylogenetic relationships in the genus Anthyllis (Leguminosae: Papilionoideae: Loteae) were investigated using data from the nuclear ribosomal internal transcribed spacer regions (ITS) and three plastid regions (psbA–trnH intergenic spacer, petB–petD region and rps16 intron). Bayesian and maximum parsimony (MP) analysis of a concatenated plastid dataset recovered well-resolved trees that are topologically similar, with many clades supported by unique indels. MP and Bayesian analyses of the ITS sequence data recovered trees that have several well-supported topological differences, both among analyses, and to trees inferred from the plastid data. The most substantial of these concer…
The Plastidial Glyceraldehyde-3-Phosphate Dehydrogenase Is Critical for Viable Pollen Development in Arabidopsis
2010
Plant metabolism is highly coordinated with development. However, an understanding of the whole picture of metabolism and its interactions with plant development is scarce. In this work, we show that the deficiency in the plastidial glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPCp) leads to male sterility in Arabidopsis (Arabidopsis thaliana). Pollen from homozygous gapcp double mutant plants (gapcp1gapcp2) displayed shrunken and collapsed forms and were unable to germinate when cultured in vitro. The pollen alterations observed in gapcp1gapcp2 were attributed to a disorganized tapetum layer. Accordingly, the expression of several of the genes involved in tapetum development was d…
Dissimilar molecular and morphological patterns in an introgressed peripheral population of a sand dune species ( Armeria pungens , Plumbaginaceae)
2019
Introgression is a poorly understood evolutionary outcome of hybridisation because it may remain largely undetected whenever it involves the transfer of small parts of the genome from one species to another. Aiming to understand the early stages of this process, a putative case from the southernmost border of the Armeria pungens range from its congener A. macrophylla is revisited following the discovery of a subpopulation that does not show phenotypic signs of introgression and resembles typical A. pungens. We analysed morphometrics, nuclear ribosomal DNA ITS and plastid DNA (trnL‐trnF) sequences, genome size, 45S and 5S rDNA loci‐FISH data and nrDNA IGS sequences. Within the study site, mo…
Microtubule distribution in gravitropic protonemata of the mossCeratodon
1990
Tip cells of dark-grown protonemata of the moss Ceratodon purpureus are negatively gravitropic (grow upward). They possess a unique longitudinal zonation: (1) a tip group of amylochloroplasts in the apical dome, (2) a plastid-free zone, (3) a zone of significant plastid sedimentation, and (4) a zone of mostly non-sedimenting plastids. Immunofluorescence of vertical cells showed microtubules distributed throughout the cytoplasm in a mostly axial orientation extending through all zones. Optical sectioning revealed a close spatial association between microtubules and plastids. A majority (two thirds) of protonemata gravistimulated for > 20 min had a higher density of microtubules near the lowe…
The effect of light intensities on the transcript level of proteins involved in photosynthesis in mustard plants
1996
Summary The influence of light quantity on the steady-state levels of plastid encoded transcripts was examined during the development of primary leaves from mustard ( Sinapis alba ) plants. RbcL mRNA, petA mRNA, and psbA mRNA, which encode the large subunit (LSU) of Rubisco, Cyt f of the Cyt b6/f complex, and D1 protein of PS II were investigated in leaves grown under high-light (HL) or low-light (LL) conditions. Additionally, the nuclear encoded 25 S rRNA was quantified. As a proportion of total RNA, the levels of 25 S rRNA, rbcL mRNA, petA mRNA, and psbA mRNA did not differ substantially in the HL versus LL plants. During leaf ontogenesis, though, the proportion of psbA mRNA in total RNA …
Isoprenoid biosynthesis in eukaryotic phototrophs: a spotlight on algae.
2011
Isoprenoids are one of the largest groups of natural compounds and have a variety of important functions in the primary metabolism of land plants and algae. In recent years, our understanding of the numerous facets of isoprenoid metabolism in land plants has been rapidly increasing, while knowledge on the metabolic network of isoprenoids in algae still lags behind. Here, current views on the biochemistry and genetics of the core isoprenoid metabolism in land plants and in the major algal phyla are compared and some of the most pressing open questions are highlighted. Based on the different evolutionary histories of the various groups of eukaryotic phototrophs, we discuss the distribution an…