Cadmium-induced ultrastructural changes in Euglena cells

Duret, S.; Bonaly, J.; Bariaud, A.; Vannereau, A.; Mestre, Jean-Charles

doi:10.1016/s0013-9351(86)80011-1

Cited by 27 publications

(7 citation statements)

References 13 publications

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“…Among various environmental stresses, heavy metal accumulation and resistance in Euglena are widely studied. Under Cd treatment, mitochondria and chloroplasts were altered in shape, and thylakoid arrangement was changed, and osmiophilic plastoglobuli was increased (Duret et al, 1986 ). Cd causes cellular damage to Euglena , including DNA strand breaks and intracellular membrane damage, as a result of reactive oxygen stress (Watanabe and Suzuki, 2002 ).…”

Section: Discussionmentioning

confidence: 99%

Metabolic Responses of a Model Green Microalga Euglena gracilis to Different Environmental Stresses

Liu

et al. 2021

Front. Bioeng. Biotechnol.

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Euglena gracilis, a green microalga known as a potential candidate for jet fuel producers and new functional food resources, is highly tolerant to antibiotics, heavy metals, and other environmental stresses. Its cells contain many high-value products, including vitamins, amino acids, pigments, unsaturated fatty acids, and carbohydrate paramylon as metabolites, which change contents in response to various extracellular environments. However, mechanism insights into the cellular metabolic response of Euglena to different toxic chemicals and adverse environmental stresses were very limited. We extensively investigated the changes of cell biomass, pigments, lipids, and paramylon of E. gracilis under several environmental stresses, such as heavy metal CdCl2, antibiotics paromomycin, and nutrient deprivation. In addition, global metabolomics by Ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) was applied to study other metabolites and potential regulatory mechanisms behind the differential accumulation of major high-valued metabolites. This study collects a comprehensive update on the biology of E. gracilis for various metabolic responses to stress conditions, and it will be of great value for Euglena cultivation and high-value [154mm][10mm]Q7metabolite production.

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Section: Discussionmentioning

confidence: 99%

Metabolic Responses of a Model Green Microalga Euglena gracilis to Different Environmental Stresses

Liu

et al. 2021

Front. Bioeng. Biotechnol.

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“…Indeed, several studies have reported the presence of larger and more numerous plastoglobules in chloroplasts from plants grown under diverse stress conditions [39][40][41][42][43][44][45][46][47].…”

Section: Involvement Of Plastoglobules In Stress Responsementioning

confidence: 99%

Plastoglobules: versatile lipoprotein particles in plastids

Bréhélin

Kessler

Wijk

2007

Trends in Plant Science

244

157

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Plastoglobules are plastid-localized lipoprotein particles that contain tocopherols and other lipid isoprenoidderived metabolites, as well as structural proteins named plastoglobulins. Surprisingly, recent publications show that plastoglobules contain enzymes involved in the metabolism of these secondary metabolites, as well as enzymes of unknown function. The size and number of plastoglobules vary during plastid development and differentiation, and strongly increase during light stress, senescence and in mutants blocked in thylakoid formation. Given that plastoglobules are contiguous with the outer lipid leaflet of the thylakoid membrane, it is highly plausible that a function of plastoglobules is the active channeling of lipid molecules and lipid breakdown products. Understanding the function of plastoglobules should provide a foundation for improving the nutritional value and yield of plants.History of plastoglobule research and discovery Early electron microscopic studies revealed the presence of 'osmiophilic globuli' inside chloroplasts ( Figure 1) and chromoplasts, as well as other plastid types [1]. The diameter of these bodies, later termed plastoglobules, ranges from 30 nm to 5 mm. These plastoglobules could be conveniently isolated by flotation density centrifugation because of their relatively high lipid content [1,2]. The lipid composition of plastoglobules has been determined in several plant species -it consists mainly of prenyl-quinones and neutral lipids. Plastoglobules qualify as lipoprotein particles because they have been reported to associate with proteins. Members of the plastoglobulin family (also called fibrillin or PAP for plastid lipid-associated protein) [3], were the first known genuine plastoglobule protein components. In addition to vascular plants, plastoglobules are found in non-vascular species such as moss [4] and algae [5,6]. Interestingly, carotenoid-rich plastoglobule-like structures constitute the eyespot structure of Chlamydomonas reinhardtii, the proteome of which has been shown to contain members of the plastoglobulin family [6]. In cyanobacteria, the presence of 'lipid droplets' among the thylakoids has been reported [7]. The exact identity of these lipid droplets has not been defined; however, the presence of at least two plastoglobulin homologs in the genome of Synechocystis PCC6803 suggests that they could be plastoglobules.Although plastoglobules were largely viewed as passive lipid and carotenoid storage particles, their varying size in different species, plastid types and developmental stages suggested a more dynamic role. Moreover, correlative evidence suggested that plastoglobules are involved in thylakoid development as well as disassembly: (i) etioplasts with poorly developed thylakoids have more plastoglobules than are found in chloroplasts, but the plastoglobule abundance decreased during thylakoid biogenesis [8-10]; (ii) in senescent chloroplasts, during thylakoid disassembly, plastoglobules enlarge and accumulate [9,11,12]; (iii) several thylakoid biogenesis...

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“…Enlargement of plastoglobules was observed during ozone treatment in aspen and spruce trees [4]. Plastoglobule size also increases during drought [14] and in plants growing in the presence of heavy metals [15], [16].…”

Section: Introductionmentioning

confidence: 99%

Knockdown of FIBRILLIN4 Gene Expression in Apple Decreases Plastoglobule Plastoquinone Content

et al. 2012

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Fibrillin4 (FBN4) is a protein component of plastoglobules, which are antioxidant-rich sub-compartments attached to the chloroplast thylakoid membranes. FBN4 is required for normal plant biotic and abiotic stress resistance, including bacterial pathogens, herbicide, high light intensity, and ozone; FBN4 is also required for the accumulation of osmiophilic material inside plastoglobules. In this study, the contribution of FBN4 to plastoglobule lipid composition was examined using cultivated apple trees in which FBN4 gene expression was knocked down using RNA interference. Chloroplasts and plastoglobules were isolated from leaves of wild-type and fbn4 knock-down trees. Total lipids were extracted from chloroplasts and plastoglobules separately, and analyzed using liquid chromatography-mass spectrometry (LC–MS). Three lipids were consistently present at lower levels in the plastoglobules from fbn4 knock-down apple leaves compared to the wild-type as determined by LC-MS multiple ion monitoring. One of these species had a molecular mass and fragmentation pattern that identified it as plastoquinone, a known major component of plastoglobules. The plastoquinone level in fbn4 knock-down plastoglobules was less than 10% of that in wild-type plastoglobules. In contrast, plastoquinone was present at similar levels in the lipid extracts of whole chloroplasts from leaves of wild-type and fbn4 knock-down trees. These results suggest that the partitioning of plastoquinone between the plastoglobules and the rest of the chloroplast is disrupted in fbn4 knock-down leaves. These results indicate that FBN4 is required for high-level accumulation of plastoquinone and some other lipids in the plastoglobule. The dramatic decrease in plastoquinone content in fbn4 knock-down plastoglobules is consistent with the decreased plastoglobule osmiophilicity previously described for fbn4 knock-down plastoglobules. Failure to accumulate the antioxidant plastoquinone in the fbn4 knock-down plastoglobules might contribute to the increased stress sensitivity of fbn4 knock-down trees.

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Cadmium-induced ultrastructural changes in Euglena cells

Cited by 27 publications

References 13 publications

Metabolic Responses of a Model Green Microalga Euglena gracilis to Different Environmental Stresses

Metabolic Responses of a Model Green Microalga Euglena gracilis to Different Environmental Stresses

Plastoglobules: versatile lipoprotein particles in plastids

Knockdown of FIBRILLIN4 Gene Expression in Apple Decreases Plastoglobule Plastoquinone Content

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