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Title: Protein synthesis during the initial phase of the temperature-induced bleaching response in Euglena gracilis

Growing cultures of photoheterotrophic Euglena gracilis experience an increase in chlorophyll accumulation during the initial phase of the temperature-induced bleaching response suggesting an increase in the synthesis of plastid components at the bleaching temperature of 33{degree}C. A primary goal of this work was to establish whether an increase in the synthesis of plastid proteins accompanies the observed increase in chlorophyll accumulation. In vivo pulse-labeling experiments with ({sup 35}S)sodium sulfate were carried out with cells grown at room temperature or at 33{degree}C. The synthesis of a number of plastid polypeptides of nucleocytoplasmic origin, including some presumably novel polypeptides, increased in cultures treated for 15 hours at 33{degree}C. In contrast, while synthesis of thylakoid proteins by the plastid protein synthesis machinery decreased modestly, synthesis of the large subunit of the enzyme ribulosebisphosphate carboxylase was strongly affected at the elevated temperature. Synthesis of novel plastid-encoded polypeptides was not induced at the bleaching temperature. It is concluded that protein synthesis in plastids declines during the initial phase of the temperature response in Euglena despite an overall increase in cellular protein synthesis and an increase in chlorophyll accumulation per cell.
Authors:
 [1]
  1. (Univ. of Oklahoma, Norman (USA))
Publication Date:
OSTI Identifier:
5962873
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plant Physiology; (USA); Journal Volume: 93:1
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ALGAE; TEMPERATURE EFFECTS; PROTEINS; BIOSYNTHESIS; CARBON-CARBON LYASES; CHLOROPHYLL; POLYPEPTIDES; SODIUM SULFATES; SULFUR 35; TRACER TECHNIQUES; ALKALI METAL COMPOUNDS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CARBOXYLIC ACIDS; DAYS LIVING RADIOISOTOPES; ENZYMES; EVEN-ODD NUCLEI; HETEROCYCLIC ACIDS; HETEROCYCLIC COMPOUNDS; ISOTOPE APPLICATIONS; ISOTOPES; LIGHT NUCLEI; LYASES; NUCLEI; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; OXYGEN COMPOUNDS; PEPTIDES; PHYTOCHROMES; PIGMENTS; PLANTS; PORPHYRINS; RADIOISOTOPES; SODIUM COMPOUNDS; SULFATES; SULFUR COMPOUNDS; SULFUR ISOTOPES; SYNTHESIS 550201* -- Biochemistry-- Tracer Techniques