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Journal ArticleDOI

Events surrounding the early development of Euglena chloroplasts. I. Induction by preillumination.

01 Mar 1970-Plant Physiology (American Society of Plant Biologists)-Vol. 45, Iss: 3, pp 339-347
TL;DR: Although light is required for protochlorophyll(ide) conversion in chlorophyll synthesis, a brief preillumination seems to initiate the production of components in the subsequent dark period which, in nonpotentiated cells, are ordinarily synthesized during the lag period under continuous illumination.
Abstract: Preillumination, followed by a dark period prior to exposure of dark-grown nondividing cells of Euglena gracilis var. bacillaris to normal lighting conditions for chloroplast development, results in potentiation, or abolishment of the usual lag in chlorophyll accumulation. The degree of potentiation is a function of the length of the preillumination period, the intensity of preilluminating light, and the length of the dark period interposed before re-exposure to continuous light for development. The optimal conditions are found to be: 90 minutes of preillumination with white light at an intensity greater than 30 microwatts per square centimeter (14 foot candles) followed by a dark period of at least 12 hours. Reciprocity is not found between duration and intensity of preilluminating light. Preillumination with blue light and red light was found to be the most effective in promoting potentiation, and the ratio of effectiveness of blue to green to red is consistent with protochlorophyll-(ide) being the photoreceptor. Although red light is effective, there is no reversal by far red light, and these facts, taken together with the effectiveness of blue light, suggest that the phytochrome system is not involved. The amount of chlorophyll formed at the end of preillumination is proportional to the resulting potentiation, suggesting that the amount of protochlorophyll(ide) removed or chlorophyll(ide) formed regulates this phenomenon. Potentiated and nonpotentiated cells show comparable rates of protochlorophyll(ide) resynthesis, suggesting that this is not the limiting factor in nonpotentiated cells. Although light is required for protochlorophyll(ide) conversion in chlorophyll synthesis, a brief preillumination seems also to initiate the production of components in the subsequent dark period which, in nonpotentiated cells, are ordinarily synthesized during the lag period under continuous illumination. These components are necessary to sustain maximal rates of subsequent chlorophyll accumulation.

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Citations
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BookDOI
01 Jan 1982
TL;DR: Presented at the 7th Annual Meeting of the American Society for Photobiology, June 24-28, Pacific Grove, California.
Abstract: presented at the 7th Annual Meeting of the American Society for Photobiology, June 24-28, Pacific Grove, California. Programs and Abstracts, p. 175. 53. Schleider, N. R., Moskowitz, R. S., Cort, D. H., et a!. (1979): Effects of emollients on ultraviolet-radiation-induced erythema of the skin. Arch. Dermato!' 115: 1188-1191. 54. Frost, P., Horwitz, S. N., Caputo, R. V., et a!. (1979): Tar gel-phototherapy for psoriasis. Arch. DermalOl. 115:840-846. 55. Kaidbey, K. H., Grove, G. L., and Kligman, A. M. (1979): The influence of longwave ultraviolet radiation on sunburn cell production by UVB. J. Invest. Dermato!' 73:243-245. 56. Gschnait, F., Brenner, W., and Wolff, K. (1978): Photoprotective effect of a psoralen-UVAinduced tan. Arch. Dermatol. Res. 268: 181-188. 57. Kaidbey, K. H., and Kligman, A. M. (1979): The acute effects of longwave ultraviolet radiation on human skin. 1. Invest. Dermatol. 72: 253-256. 58. Parrish, J. A., Zaynoun, S., and Anderson, R. R. (1981): Cumulative effects of repeated subthreshold doses of ultraviolet radiation. J. Invest. Dermatol. 76:352-355. 59. Everett, M. A., Daffer, E., and Coffey, C. M. (1961): Coal tar and ultraviolet light. Arch. DermalOl. 84:473-476. 60. Ellis, C. C. (1948): The treatment of psoriasis with liquor carbonis detergens. J. Invest. Dermatol. 10:455. 61. Ingram, J. T. (1953): The approach to psoriasis. Br. Med. J. 2:591-594. Phototherapy of Skin Diseases 531 62. Comaish, S. (1965): Ingram method of treating psoriasis. Arch. Dermato!. 92:56-58. 63. Beierdorffer, H., and Wiskemann, A. (1978): Kombinierte Therapie der Psoriasis mit einem aromatischen Retinoid (RO 10-9359) und UYB-Bestrahlungen. Aktue!. Dermato!. 4: 183-187. 64. Steigleder, G. K., Orfanos, C. E., and Pullmann, H. (1978): Retinoid-SUP-Therapie der Psoriasis. Z. Hautkr. 54: 19-23. 65. Momtaz-T., K., and Parrish, J. A. (1981): Combination UYB and PUY A in the treatment of psoriasis. J. Invest. Dermato!' 76: 303. 66. Walter, J. F., Stoughton, R. B., and DeQuoy, P. R. (1978): Suppression of epidermal and proliferation by ultraviolet light, coal tar and anthralin. Br. J. Dermato!' 99:89-96. 67. Stoughton, R. B., DeQuoy, P., and Walter, J. F. (1978): Crude coal tar plus near ultraviolet light suppresses DNA synthesis in epidermis. Arch. Dermato!' 114:43-45. 68. Cecht, T., Pathak, M. A., and Biswas, R. K. (1979): An electron microscopic study of the photochemical cross-linking of DNA in guinea pig epidermis by psoralen derivatives. Biochim. Biophys. Acta 562:342-360. 69. Pathak, M. A., and Biswas, R. K. (1977): Skin photosensitization and DNA cross-linking ability of photochemotherapeutic agents (Abstract). J. Invest. Dermato!. 68:236. 70. Stern, R. S., Zierler, S., and Parrish, J. A. (1980): Skin carcinoma in patients with psoriasis treated with topical tar and artificial radiation. Lancet 1:732-735.

320 citations

Journal ArticleDOI
TL;DR: The herbicide SAN 9789 blocks carotenoid synthesis in growing and resting cells of Euglena at concentrations of 20 to 100 mug/ml without affecting cell viability, and during 72 hours of light-induced plastid development in dark-grown resting cells, none of the usual carotanoids increase while phytoene accumulates, indicating that SAN 9790 blocks carotinoid synthesis at this point.
Abstract: The herbicide SAN 9789 (4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl-3- (2H)pyridazinone) blocks carotenoid synthesis in growing and resting cells of Euglena at concentrations of 20 to 100 μg/ml without affecting cell viability. Although the inhibition is immediate and complete, in resting cells no decrease in already synthesized carotenoids is found indicating a lack of turnover. In cells growing in the dark, carotenoids are diluted out as the cells divide. Cells dividing in the light in the presence of SAN 9789, eventually lose viability, presumably because of photooxidations usually prevented by carotenoids. During 72 hours of light-induced plastid development in dark-grown resting cells, none of the usual carotenoids increase while phytoene accumulates, indicating that SAN 9789 blocks carotenoid synthesis at this point. Chlorophyll synthesis and membrane formation are also blocked by the herbicide, but these inhibitions appear to be secondary to the inhibition of carotenoid synthesis. That carotenoid levels are strongly correlated with and may control the synthesis of chlorophyll and the formation of plastid membranes is suggested by the following data. (a) If dark-grown dividing cells are placed in the presence of the herbicide for various periods, rested and exposed to light in the presence of the drug, different amounts of carotenoids remain in the cells and the amount of chlorophyll finally synthesized is proportional to the amount of carotenoids present. (b) Photodestruction of chlorophyll is excluded, since the same amounts of chlorophyll are formed at intensities of 10 to 100 foot-candles of light. (c) Photoconversion of protochlorophyll(ide) to chlorophyll(ide) in dark-grown cells is not blocked by the herbicide. (d) Initial rates of chlorophyll synthesis are the same in treated and nontreated cells. (e) The extent of membrane formation appears to parallel the amount of carotenoids present as judged by electron microscopy.

136 citations

BookDOI
01 Jan 1977

135 citations


Cites background or methods from "Events surrounding the early develo..."

  • ...Thus, it appears indeed unlikely that the cyclopentenyl fatty acids are formed by cyclization of straight-chain fatty acids [53, 55]....

    [...]

  • ...Cauliflower buds Whole organelles 44 34 II 7 4 [53] Outer membrane 42 24 3 21 10 Inner membrane 41 37 14 5 3...

    [...]

  • ...The meso somes and thylakoids of certain bacteria appear to be in continuity with the plasma membrane of these protocytes and are to be regarded therefore as local specializations of the latter [53, 106]....

    [...]

  • ...Cauliflower mitochondria Outer membrane 50 4 20 8 18 [53] Inner membrane 14 9 13 62...

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  • ...The consecutive application of argentation chromatography and gas chromatography [61] if of great value when small amounts of the methyl esters of individual cyclopentenyl fatty acids are to be isolated in order to determine their structures [53] or their radioactivities [54]....

    [...]

Journal ArticleDOI
01 Aug 1975-Nature
TL;DR: An anomalous unicellular alga with a prokaryotic cellular organisation like that of a blue-green alga, but with a pigment composition characteristic of green algae and higher plants is reported.
Abstract: WE report an anomalous unicellular alga with a prokaryotic cellular organisation like that of a blue-green alga, but with a pigment composition characteristic of green algae and higher plants.

134 citations

Journal ArticleDOI
TL;DR: It is suggested that by providing an energy source, acetate stimulates cellular growth, cell cycle progression, and increased cabII-1 mRNA abundance by a blue lightstimulated mechanism which is independent of photosynthesis.
Abstract: In Chlamydomonas reinhardtii, the chlorophyll a/b-binding proteins of photosystem II are encoded in the nucleus by a small family of genes. We have studied the expression of one gene, which we call cabII-1, in a green-in-the-dark strain, which can synthesize chlorophyll in the dark or light, and in a yellow-in-the-dark mutant strain, which is able to make chlorophyll only in the light. In light/dark synchronized cultures of both strains, cabII-1 mRNA abundance increases during the first 6 h of a 12-h light phase, remains high for several hours, then declines. A variety of illumination conditions have been used to analyze the cabII-1 mRNA increase: continuous or intermittent red, blue, or white light, with or without 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II. Our results suggest that light induces increased cabII-1 transcript abundance in two ways: 1) by virtue of its role in the light reactions of photosynthesis and 2) by a blue lightstimulated mechanism which is independent of photosynthesis.

107 citations

References
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Journal ArticleDOI
TL;DR: Three species of DNA from wild-type cells of Euglena gracilis var bacillaris are described in this paper, including main band DNA (density = 1·707 g/cm3) most probably is assignable to the nucleus and is found in all strains examined.

162 citations

Journal ArticleDOI
TL;DR: The onset and kinetics of pigment formation, 02 evolution and CO2 fixation with the development of the proplastid into the mature chloroplast are correlated.
Abstract: Our studies with Euglena (2, 6, 14, 19, 20) have suggested that dark-grown cells contain approximately 30 proplastids which develop into about 10 chloroplasts when the cells are exposed to light. The existence of these proplastids, originally inferred from studies on ultraviolet inactivation and photoreactivation of chloroplast formation (14,19), was confirmed by fluorescence and electron microscopy (2, 6). Other workers have studied some of the initial steps involved when dark-grown cells are exposed to light, such as the conversion of protochlorophyll to chlorophyll (17). Other studies also exist of the related problem of the physiology of chloroplast development in higher plants (3, 7, 23, 27). Our earlier work (20) also showed that chloroplast development in Euglena could be separated experimentally into 2 phases: replication of the system which manufactures the chloroplast and development of the proplastid into the mature chlor6plast. In this study we correlate the onset and kinetics of pigment formation, 02 evolution and CO2 fixation with the development of the proplastid into the mature chloroplast. Materials and Methods

155 citations

Journal ArticleDOI
TL;DR: The evidence leads to the hypothesis that there are self-reproducing cytoplasmic entities in Euglena which contain nucleoprotein and which are responsible for chloroplast formation.

154 citations

Journal ArticleDOI
TL;DR: In this paper, an account of chlorophyll formation and its relation to simultaneously occurring changes in the sub-microscopic structure of the plastids is presented, and it is shown that the early development of the chloroplasts and their ability to synthesize the photosynthetic pigments are dependent on at least three light-driven reactions in the cell.
Abstract: SEVERAL photochemical reactions take part in the formation of the chloroplast pigments. There is now evidence that the early development of the chloroplasts and their ability to synthesize the photosynthetic pigments are dependent on at least three light-driven reactions in the cell, In the present paper an account of chlorophyll formation and its relation to simultaneously occurring changes in the sub-microscopic structure of the plastids is presented.

152 citations

Journal ArticleDOI
TL;DR: The photoreversible pigment which controls so many developmental responses of plants is demonstrated spectrophotometrically in intact corn coleoptiles and the spectra of intact lima bean seeds show spectral changes associated with germination processes.

141 citations