Events Surrounding the Early Development of <i>Euglena</i> Chloroplasts

Schwartzbach, Steven D.; Schiff, Jerome A.; Goldstein, Neil

doi:10.1104/pp.56.2.313

Cited by 63 publications

(23 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…On full aeration of these cells, a large part of the development of the proplastid that was previously thought to be light-dependent can take place in darkness using the energy and carbon provided by oxidative degradation of the wax. Since the degradation of paramylum is strictly light dependent in three day resting cells of W3BUL Euglena (10) and is seen to decrease on illumination of three day resting cells of W3BUL lacking wax (6) it is likely that the reason why the development of the proplastid remnant is light dependent in cells lacking wax, is that development is dependent on energy and carbon released from paramylum in the light . Thus, the early stages in the development of the proplastid remnant require energy and intermediates from the breakdown of either wax (in aerated cells) or paramylum (in illuminated cells).…”

Section: And Discussionmentioning

confidence: 99%

Light-independent and dependent phases of proplastid development in Euglena gracilis W3BUL.

Osafune¹,

Schiff

Hase

1987

Cell Struct. Funct.

View full text Add to dashboard Cite

ABSTRACT. Cells of Euglena gracilis Klebs var. bacillaris Cori mutant W3BUL grown in darkness on Hutner's pH 3.5 medium without agitation accumulate wax ester. These cells have undeveloped proplastid remnants characteristic of this mutant. If these cells are transferred to an inorganic medium and bubbled with 2-3 % CO2 in air, the wax disappears and the proplastid expands and develops in darkness to form prolamellar bodies and membrane vessicles within 96 h. No further development takes place in darkness, but if these cultures are illuminated at 96 h formation of prothylakoids is observed. Thus the wax ester accumulated during growth can be used subsequently to support proplastid development up to the prolamellar body stage, but the formation of prothylakoids is strictly light-dependent. Development in this system takes place at a slower rate than in cells grown with shaking and lacking wax which are transferred to resting medium. As previously shown, all of proplastid development requires light under these conditions. It is suggested that the oxygen-requiring utilization of wax in darkness can provide energy and metabolites for a part of proplastid development but the later steps in these cells, or the entire development in cells lacking wax is supported by paramylum degradation which is strictly light-dependent. However, a specific light reaction required for prothylakoid organization is not ruled out.Mutant W3BUL derived from Euglena gracilis var. bacillaris contains a rudimentary proplastid remnant when grown in darkness and placed on a resting medium for 72 h to permit cell division to cease. On exposure of these 3 day resting cells to light, the proplastid remnant expands, internal vaculoes are formed, and this is followed by the formation of a prolamellar body and rudimentary prothylakoids over the course of the subsequent 3-5 days (6). Studies with wild-type cells of the Z strain of E. gracilis grown in darkness indicate that, under appropriate conditions, wax can be caused to accumulate which, under subsequent aeration of the cells, can be * Permanent address:

show abstract

Section: And Discussionmentioning

confidence: 99%

Light-independent and dependent phases of proplastid development in Euglena gracilis W3BUL.

Osafune¹,

Schiff

Hase

1987

Cell Struct. Funct.

View full text Add to dashboard Cite

show abstract

“…These findings compel us to conclude that what is limiting in the dark is reducing power ordinarily supplied from outside the plastid under control of the ubiquitous blue light receptor. Since this cytoplasmic receptor is known to control paramylon breakdown (25), it is likely that the breakdown of paramylon via early glycolysis in the cytoplasm would provide glyceraldehyde-3-P which could be used by NADP triose-P dehydrogenase to reduce NADP. This reduced NADP would react with ferredoxin-NADP reductase and ferredoxin to reduce CM.…”

Section: Discussionmentioning

confidence: 99%

Events Surrounding the Early Development of Euglena Chloroplasts

Vaisberg

Schiff²,

Li³

et al. 1976

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Exposure of dark grown resting cells to light induces the degradation of the storage carbohydrate paramylum ( Smillie 1970, 1971;Freyssinet et al 1972;Schwartzbach et al 1975;Sumida et al 1987), the degradation of cellular lipids (Rosenberg and Pecker 1964) and increases the rate of cellular respiration (Fong and Schiff 1977;Schiff 1963). Chloroplast development is blocked by respiratory inhibitors and uncouplers (Evans 1971;Fong and Schiff 1977;Klein et al 1972) while inhibitors of photosynthesis have little effect on chlorophyll synthesis in resting cells during the first 24 h of light exposure but are inhibitory after this time Smillie 1970, 1971;Freyssinet et al 1984a, b;Horrum and Schwartzbach 1981;Schiff et al 1967) when the majority of paramylum has been consumed.…”

Section: Control Of Mitochondrial Developmentmentioning

confidence: 98%

Photo and Nutritional Regulation of Euglena Organelle Development

Schwartzbach

2017

Advances in Experimental Medicine and Biology

Self Cite

View full text Add to dashboard Cite

Euglena can use light and CO, photosynthesis, as well as a large variety of organic molecules as the sole source of carbon and energy for growth. Light induces the enzymes, in this case an entire organelle, the chloroplast, that is required to use CO as the sole source of carbon and energy for growth. Ethanol, but not malate, inhibits the photoinduction of chloroplast enzymes and induces the synthesis of the glyoxylate cycle enzymes that comprise the unique metabolic pathway leading to two carbon, ethanol and acetate, assimilation. In resting, carbon starved cells, light mobilizes the degradation of the storage carbohydrate paramylum and transiently induces the mitochondrial proteins required for the aerobic metabolism of paramylum to provide the carbon and energy required for chloroplast development. Other mitochondrial proteins are degraded upon light exposure providing the amino acids required for the synthesis of light induced proteins. Changes in protein levels are due to increased and decreased rates of synthesis rather than changes in degradation rates. Changes in protein synthesis rates occur in the absence of a concomitant increase in the levels of mRNAs encoding these proteins indicative of photo and metabolic control at the translational rather than the transcriptional level. The fraction of mRNA encoding a light induced protein such as the light harvesting chlorophyll a/b binding protein of photosystem II, (LHCPII) associated with polysomes in the dark is similar to the fraction associated with polysomes in the light indicative of photoregulation at the level of translational elongation. Ethanol, a carbon source whose assimilation requires carbon source specific enzymes, the glyoxylate cycle enzymes, represses the synthesis of chloroplast enzymes uniquely required to use light and CO as the sole source of carbon and energy for growth. The catabolite sensitivity of chloroplast development provides a mechanism to prioritize carbon source utilization. Euglena uses all of its resources to develop the metabolic capacity to utilize carbon sources such as ethanol which are rarely in the environment and delays until the rare carbon source is no longer available forming the chloroplast which is required to utilize the ubiquitous carbon source, light and CO.

show abstract

Events Surrounding the Early Development of Euglena Chloroplasts

Abstract: ABSTRACT

Cited by 63 publications

References 32 publications

Light-independent and dependent phases of proplastid development in Euglena gracilis W3BUL.

Light-independent and dependent phases of proplastid development in Euglena gracilis W3BUL.

Events Surrounding the Early Development of Euglena Chloroplasts

Photo and Nutritional Regulation of Euglena Organelle Development

Contact Info

Product

Resources

About