Search results for "Plastids"
showing 10 items of 23 documents
Organelle protein changes in arbuscular mycorrhizal Medicago truncatula roots as deciphered by subcellular proteomics
2019
Prod 2020-8c SPE IPM INRA UB CNRS; The roots of most land plants can enter a symbiotic relationship with arbuscular mycorrhizal (AM) soil‐borne fungi belonging to the phylum Glomeromycota, which improves the mineral nutrition of the host plant. The fungus enters the root through the epidermis and grows into the cortex where it differentiates into a highly branched hyphal structure called the arbuscule. The role of the plant membrane system as the agent for cellular morphogenesis and signal/nutrient exchanges is especially accentuated during AM endosymbiosis. Notably, fungal hyphae are always surrounded by the host membrane, which is referred to as the perifungal membrane around intracellula…
Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms.
2015
International audience; Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies prin…
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…
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…
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…
PHOSPHOROUS SEED COATING AFFECT TO GERMINATION, PHOTOSYNTHETIC PIGMENTS AND YIELD OF RAPE
2005
Rape (Brassica napus L. var. napus) is long ago-known vegetable of Brassicaceae in agriculture. It is important and valuable oil, forage, green-fertiliser and nectar plant. The experience of last years shows that rape is suitable for growing in conditions of Latvia, but investigations about its cultivars and growing technologies are not wide enough.The phosporus-fertilizer adding in the rape plantations is of great importance for increasing of its productivity. With the aim to reduce the expenses the phosphorus treated rape seeds are made use.In our investigations the velocity of seeds germination, germinating viability, germinating vigour, green pigments” quantity in seed-lobes and seeds” …
Ancient recruitment by chromists of green algal genes encoding enzymes for carotenoid biosynthesis.
2008
Chromist algae (stramenopiles, cryptophytes, and haptophytes) are major contributors to marine primary productivity. These eukaryotes acquired their plastid via secondary endosymbiosis, whereby an early-diverging red alga was engulfed by a protist and the plastid was retained and its associated nuclear-encoded genes were transferred to the host genome. Current data suggest, however, that chromists are paraphyletic; therefore, it remains unclear whether their plastids trace back to a single secondary endosymbiosis or, alternatively, this organelle has resulted from multiple independent events in the different chromist lineages. Both scenarios, however, predict that plastid-targeted, nucleus-…
Functional characterization of the plastidial 3-phosphoglycerate dehydrogenase family in Arabidopsis.
2013
This work contributes to unraveling the role of the phosphorylated pathway of serine (Ser) biosynthesis in Arabidopsis (Arabidopsis thaliana) by functionally characterizing genes coding for the first enzyme of this pathway, 3-phosphoglycerate dehydrogenase (PGDH). We identified two Arabidopsis plastid-localized PGDH genes (3-PGDH and EMBRYO SAC DEVELOPMENT ARREST9 [EDA9]) with a high percentage of amino acid identity with a previously identified PGDH. All three genes displayed a different expression pattern indicating that they are not functionally redundant. pgdh and 3-pgdh mutants presented no drastic visual phenotypes, but eda9 displayed delayed embryo development, leading to aborted emb…