Effects of UV-B on motility and photobehavior in the green flagellate, Euglena gracilis

1985 ◽  
Vol 141 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Donat-P. H�der
Keyword(s):  
Euglena Gracilis ◽  
Green Flagellate

Evaluation of the adverse effects of two commonly used fertilizers, DAP and urea, on motility and orientation of the green flagellate Euglena gracilis

2011 ◽  
Vol 74 ◽  
pp. 140-150 ◽  
Author(s):  
Azizullah Azizullah ◽  
Adeel Nasir ◽  
Peter Richter ◽  
Michael Lebert ◽  
Donat-Peter Häder
Keyword(s):  
Adverse Effects ◽  
Euglena Gracilis ◽  
Green Flagellate

scholarly journals The cryptic plastid of Euglena longa defines a new type of non-photosynthetic plastid organelles

2019 ◽  
Author(s):  
Zoltán Füssy ◽  
Kristína Záhonová ◽  
Aleš Tomčala ◽  
Juraj Krajčovič ◽  
Vyacheslav Yurchenko ◽  
...  
Keyword(s):  
Euglena Gracilis ◽  
Physiological Role ◽  
Redox Status ◽  
Secondary Endosymbiosis ◽  
Metabolic Functions ◽  
Green Algal ◽  
Photosynthetic Eukaryotes ◽  
Algal Groups ◽  
New Type ◽  
Green Flagellate

AbstractMost secondarily non-photosynthetic eukaryotes have retained residual plastids whose physiological role is often still unknown. One such example is Euglena longa, a close non-photosynthetic relative of Euglena gracilis harbouring a plastid organelle of enigmatic function. By mining transcriptome data from E. longa we finally provide an overview of metabolic processes localized to its elusive plastid. The organelle plays no role in biosynthesis of isoprenoid precursors and fatty acids, and has a very limited repertoire of pathways concerning nitrogen-containing metabolites. In contrast, the synthesis of phospholipids and glycolipids has been preserved, curiously with the last step of sulfoquinovosyldiacylglycerol synthesis being catalysed by the SqdX form of the enzyme so far known only from bacteria. Notably, we show that the E. longa plastid synthesizes tocopherols and a phylloquinone derivative, the first such report for non-photosynthetic plastids studied so far. The most striking attribute of the organelle is the presence of a linearized Calvin-Benson (CB) pathway including RuBisCO yet lacking the gluconeogenetic part of the standard cycle, together with ferredoxin-NADP+ reductase (FNR) and the ferredoxin/thioredoxin systems. We hypothesize that FNR passes electrons to the ferredoxin/thioredoxin systems from NADPH to activate the linear CB pathway in response to the redox status of the E. longa cell. In effect, the pathway may function as a redox valve bypassing the glycolytic oxidation of glyceraldehyde-3-phosphate to 3-phosphoglycerate. Altogether, the E. longa plastid defines a new class of relic plastids that is drastically different from the best studied organelle of this category, the apicoplast.ImportanceColourless plastids incapable of photosynthesis evolved in many plant and algal groups, but what functions they perform is still unknown in many cases. Here we study the elusive plastid of Euglena longa, a non-photosynthetic cousin of the familiar green flagellate Euglena gracilis. We document an unprecedented combination of metabolic functions that the E. longa plastid exhibits in comparison with previously characterized non-photosynthetic plastids. For example, and truly surprisingly, it has retained the synthesis of tocopherols (vitamin E) and a phylloquinone (vitamin K) derivative. In addition, we offer a possible solution of the long-standing conundrum of the presence of the CO2-fixing enzyme RuBisCO in E. longa. Our work provides a detailed account on a unique variant of relic plastids, the first among non-photosynthetic plastids that evolved by secondary endosymbiosis from a green algal ancestor, and suggests that it has persisted for reasons not previously considered in relation to non-photosynthetic plastids.

Organization of the Pellicle and the Muciferous Glands in Euglena Gracilis

1970 ◽  
Vol 28 ◽  
pp. 104-105
Author(s):  
Hilton H. Mollenhauer ◽  
W. Evans
Keyword(s):  
Plasma Membrane ◽  
Euglena Gracilis ◽  
Complex Forms ◽  
Secondary Periodicity

The pellicular structure of Euglena gracilis consists of a series of relatively rigid strips (Fig. 1) composed of ridges and grooves which are helically oriented along the cell and which fuse together into a common junction at either end of the cell. The strips are predominantly protein and consist in part of a series of fibers about 50 Å in diameter spaced about 85 Å apart and with a secondary periodicity of about 450 Å. Microtubules are also present below each strip (Fig. 1) and are often considered as part of the pellicular complex. In addition, there may be another fibrous component near the base of the pellicle which has not yet been very well defined.The pellicular complex lies underneath the plasma membrane and entirely within the cell (Fig. 1). Each strip of the complex forms an overlapping junction with the adjacent strip along one side of each groove (Fig. 1), in such a way that a certain amount of sideways movement is possible between one strip and the next.

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

Three-dimensional distribution of ribulose-1, 5-bisphosphate carboxylase/oxygemase during the early development of proplastids in dark-grown Euglena cells transferred to an inorganic medium

1990 ◽  
Vol 48 (3) ◽  
pp. 906-907
Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase
Keyword(s):  
Cell Suspension ◽  
Euglena Gracilis ◽  
Carbon Materials ◽  
Three Dimensional ◽  
Peripheral Region ◽  
Plastid Development ◽  
Bisphosphate Carboxylase ◽  
Inorganic Medium ◽  
Ribulose 1 ◽  
Dimensional Distribution

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.

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