Abstract
We studied the effects of prolonged dark growth on proplastids and etioplasts in cotyledons of sugar beet (Beta vulgaris L.) seedlings. Differentiation of proplastids into etioplasts occurred between d 4 and d 6 after imbibition, with the typical characteristics of increased synthesis of plastidial proteins, protein and carotenoid accumulation, size increase, development of plastid membranes and of the prolamellar body, and increase of the greening capacity. However, this situation of efficient greening capacity was short-lived. The greening capacity started to decline from d 6 after imbibition. This decline was due in part to reserve depletion and glucose limitation and also to irreversible damage to plastids. Indeed, electron microscopy observations in situ showed some signs of plastidial damage, such as accumulation of plastoglobuli and membrane alterations. The biochemical characterization of purified plastids also showed a decrease of proteins per plastid. Aminopeptidase activities, and to a lesser extent, neutral endopeptidase activities, were found to increase in plastids during this degenerative process. We identified two plastidial aminopeptidases showing a sharp increase of activity at the onset of the degenerative process. One of them, an alanyl aminopeptidase, was shown to be inactivated by exposure to light or addition of exogenous glucose, thus confirming the relationship with prolonged dark growth and indicating a relationship with glucose limitation.
Full Text
The Full Text of this article is available as a PDF (3.3 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Avelange M. H., Sarrey F., Rébillé F. Effects of Glucose Feeding on Respiration and Photosynthesis in Photoautotrophic Dianthus caryophyllus Cells: Mass Spectrometric Determination of Gas Exchange. Plant Physiol. 1990 Nov;94(3):1157–1162. doi: 10.1104/pp.94.3.1157. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baumgartner B. J., Rapp J. C., Mullet J. E. Plastid transcription activity and DNA copy number increase early in barley chloroplast development. Plant Physiol. 1989 Mar;89(3):1011–1018. doi: 10.1104/pp.89.3.1011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- Dahlin C., Cline K. Developmental Regulation of the Plastid Protein Import Apparatus. Plant Cell. 1991 Oct;3(10):1131–1140. doi: 10.1105/tpc.3.10.1131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dieuaide M., Brouquisse R., Pradet A., Raymond P. Increased Fatty Acid beta-Oxidation after Glucose Starvation in Maize Root Tips. Plant Physiol. 1992 Jun;99(2):595–600. doi: 10.1104/pp.99.2.595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Journet E. P., Douce R. Enzymic capacities of purified cauliflower bud plastids for lipid synthesis and carbohydrate metabolism. Plant Physiol. 1985 Oct;79(2):458–467. doi: 10.1104/pp.79.2.458. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klein R. R., Mullet J. E. Regulation of chloroplast-encoded chlorophyll-binding protein translation during higher plant chloroplast biogenesis. J Biol Chem. 1986 Aug 25;261(24):11138–11145. [PubMed] [Google Scholar]
- Liu X. Q., Jagendorf A. T. Neutral peptidases in the stroma of pea chloroplasts. Plant Physiol. 1986 Jun;81(2):603–608. doi: 10.1104/pp.81.2.603. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miyadai K., Mae T., Makino A., Ojima K. Characteristics of ribulose-1,5-bisphosphate carboxylase/oxygenase degradation by lysates of mechanically isolated chloroplasts from wheat leaves. Plant Physiol. 1990 Apr;92(4):1215–1219. doi: 10.1104/pp.92.4.1215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neuhaus H. E., Batz O., Thom E., Scheibe R. Purification of highly intact plastids from various heterotrophic plant tissues: analysis of enzymic equipment and precursor dependency for starch biosynthesis. Biochem J. 1993 Dec 1;296(Pt 2):395–401. doi: 10.1042/bj2960395. [DOI] [PMC free article] [PubMed] [Google Scholar]
- O'Farrell P. H. High resolution two-dimensional electrophoresis of proteins. J Biol Chem. 1975 May 25;250(10):4007–4021. [PMC free article] [PubMed] [Google Scholar]
- Orr M. D., Blakley R. L., Panagou D. Discontinuous buffer systems for analytical and preparative electrophoresis of enzymes on polyacrylamide gel. Anal Biochem. 1972 Jan;45(1):68–85. doi: 10.1016/0003-2697(72)90008-5. [DOI] [PubMed] [Google Scholar]
- Robinson C., Ellis R. J. Transport of proteins into chloroplasts. Partial purification of a chloroplast protease involved in the processing of important precursor polypeptides. Eur J Biochem. 1984 Jul 16;142(2):337–342. doi: 10.1111/j.1432-1033.1984.tb08291.x. [DOI] [PubMed] [Google Scholar]
- Taylor A. Aminopeptidases: towards a mechanism of action. Trends Biochem Sci. 1993 May;18(5):167–171. [PubMed] [Google Scholar]
- Thayer S. S., Choe H. T., Rausser S., Huffaker R. C. Characterization and subcellular localization of aminopeptidases in senescing barley leaves. Plant Physiol. 1988;87:894–897. doi: 10.1104/pp.87.4.894. [DOI] [PMC free article] [PubMed] [Google Scholar]