Regulation of Cell Shape in <i>Euglena gracilis</i>

Lonergan, Thomas A.

doi:10.1104/pp.71.4.719

Cited by 47 publications

(23 citation statements)

References 30 publications

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“…Since D. salina cells lack a rigid polysaccharide cell wall, their cytoplasmic membranes allow the cells to adjust their volume and shape rapidly in response to the environmental changes (Maeda and Thompson, 1986). Although early studies have reported rhythmic changes in cell shapes of Euglena gracilis (Lonergan, 1983), the mechanism in E. gracilis is different to that in D. salina reported in this study. E. gracilis cell shape is under direct control of the biological clock and thus even under continuous light, the daily rhythm of cell shape remains.…”

Section: Discussioncontrasting

confidence: 92%

The influence of photoperiod and light intensity on the growth and photosynthesis of Dunaliella salina (chlorophyta) CCAP 19/30

Ibrahim

Harvey

2016

Plant Physiology and Biochemistry

131

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The green microalga Dunaliella salina survives in a wide range of salinities via mechanisms involving glycerol synthesis and degradation and is exploited for large amounts of nutraceutical carotenoids produced under stressed conditions. In this study, D. salina CCAP 19/30 was cultured in varying photoperiods and light intensities to study the relationship of light with different growth measurement parameters, with cellular contents of glycerol, starch and carotenoids, and with photosynthesis and respiration. Results show CCAP 19/30 regulated cell volume when growing under light/dark cycles: cell volume increased in the light and decreased in the dark, and these changes corresponded to changes in cellular glycerol content. The decrease in cell volume in the dark was independent of cell division and biological clock and was regulated by the photoperiod of the light/dark cycle. When the light intensity was increased to above 1000 μmol photons m−2 s−1, cells displayed evidence of photodamage. However, these cells also maintained the maximum level of photosynthesis efficiency and respiration possible, and the growth rate increased as light intensity increased. Significantly, the intracellular glycerol content also increased, >2-fold compared to the content in light intensity of 500 μmol photons m−2 s−1, but there was no commensurate increase in the pool size of carotenoids. These data suggest that in CCAP 19/30 glycerol stabilized the photosynthetic apparatus for maximum performance in high light intensities, a role normally attributed to carotenoids.

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Section: Discussioncontrasting

confidence: 92%

The influence of photoperiod and light intensity on the growth and photosynthesis of Dunaliella salina (chlorophyta) CCAP 19/30

Ibrahim

Harvey

2016

Plant Physiology and Biochemistry

131

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“…E. gracilis displays diverse cell shapes, which change rapidly in response to environmental cues, external stimuli, and the biological circadian clock (38)(39)(40)(41). Interestingly, treatment with exogenous IAA and cocultivation with V. natriegens also changed the cell shape of E. gracilis to a more rounded form (Fig.…”

Section: Discussionmentioning

confidence: 99%

Improvement of Euglena gracilis Paramylon Production through a Cocultivation Strategy with the Indole-3-Acetic Acid-Producing Bacterium Vibrio natriegens

Kim

Jeon

et al. 2019

Appl Environ Microbiol

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We investigated the putative effects on the growth and paramylon production of Euglena gracilis of cocultivation with Vibrio natriegens. E. gracilis heterotrophically cocultivated with V. natriegens displayed significant increases in biomass productivity and paramylon content. In addition, the effects of the bacterial inoculum density and the timing of inoculation on the growth of E. gracilis were examined, to determine the optimal conditions for cocultivation. With the optimal deployment of V. natriegens, biomass productivity and paramylon content were increased by more than 20% and 35%, respectively, compared to those in axenic E. gracilis cultures. Interestingly, indole-3-acetic acid biosynthesized by V. natriegens was responsible for these enhancements of E. gracilis. The morphology of cocultured E. gracilis cells was assessed. Paramylon granules extracted from the cocultivation were significantly larger than those from axenic culture. Our study showed that screening for appropriate bacteria and subsequent cocultivation with E. gracilis represented an effective way to enhance biomass and metabolite production. IMPORTANCE Euglena gracilis has attracted special interest due to its ability to excessively accumulate paramylon. Paramylon is a linear β-1,3-glucan polysaccharide that is the principal polymer for energy storage in E. gracilis. The polysaccharide features high bioactive functionality in the immune system. This study explored a new method to enhance the production of paramylon by E. gracilis, through cocultivation with the indole-3-acetic acid-producing bacterium Vibrio natriegens. The enhanced production was achieved indirectly with the phytohormone-producing bacteria, instead of direct application of the hormone. The knowledge obtained in this study furthers the understanding of the effects of V. natriegens on the growth and physiology of E. gracilis.

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“…Circadian changes in cell morphology have been documented for a wide range of cell types and organisms including photoreceptors in vertebrates (Basinger et al 1976;La Vail 1976;Behrens and Wagner 1996) and invertebrates (Barlow 2001), pinealocytes (Vollrath and Spiwoks-Becker 1996), and even the single cell organism Euglena gracilis (Lonergan 1983). We propose the term "circadian plasticity" for circadian changes in the morphology of neurons.…”

Section: Circadian Plasticity As a New Type Of Neuronal Plasticitymentioning

confidence: 98%

Circadian rhythms in the morphology of neurons in Drosophila

Mehnert

Cantera

2011

Cell Tissue Res

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Neurons have an enormous capacity to adapt to changing conditions through the regulation of gene expression, morphology, and physiology. In the fruit fly Drosophila melanogaster, this plasticity includes recurrent changes taking place within intervals of a few hours during the day. The rhythmic alterations in the morphology of neurons described so far include changes in axonal diameter, branching complexity, synapse numbers, and the number of synaptic vesicles. The cycles of these changes have larger amplitude when the fly is exposed to light, but they persist in constant darkness and require the expression of the clock genes period and timeless, leading to the concept of circadian plasticity. The molecular mechanisms driving these cycles appear to require the expression of these genes either inside the neurons themselves or in other peripheral pacemaker cells. Loss-of-function mutations in period and timeless not only abolish the morphological rhythms, but also often cause abnormal axonal branching suggesting that circadian plasticity is relevant for the maintenance of normal morphology. Research into whether (1) circadian plasticity is a common feature of neurons in all animals and (2) our own neurons change shape between day and night will be of interest.

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Regulation of Cell Shape in Euglena gracilis

Cited by 47 publications

References 30 publications

The influence of photoperiod and light intensity on the growth and photosynthesis of Dunaliella salina (chlorophyta) CCAP 19/30

The influence of photoperiod and light intensity on the growth and photosynthesis of Dunaliella salina (chlorophyta) CCAP 19/30

Improvement of Euglena gracilis Paramylon Production through a Cocultivation Strategy with the Indole-3-Acetic Acid-Producing Bacterium Vibrio natriegens

Circadian rhythms in the morphology of neurons in Drosophila

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