Plastidic (Pho1-type) phosphorylase isoforms in potato (Solanum tuberosum L.) plants: expression analysis and immunochemical characterization
| Autor: | Jens Schneider-Mergener, Anja Lode, Anke Koch, Tanja Albrecht, Martin Steup, Burkhard Greve |
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| Rok vydání: | 2001 |
| Předmět: |
Gene isoform
DNA Complementary Phosphorylases Molecular Sequence Data Plant Science Biology Gene Expression Regulation Enzymologic Epitopes Glycogen phosphorylase Cytosol Gene Expression Regulation Plant Gene expression Genetics Amino Acid Sequence Plastids Plastid Peptide sequence Gene Institut für Biochemie und Biologie Solanum tuberosum Regulation of gene expression Sequence Homology Amino Acid food and beverages Starch Immunohistochemistry Molecular biology Isoenzymes Biochemistry Organ Specificity |
| Zdroj: | Planta. 213:602-613 |
| ISSN: | 1432-2048 0032-0935 |
| DOI: | 10.1007/s004250100525 |
| Popis: | Higher plants contain two types of phosphorylase (EC 2.4.1.1). One type is plastidic (Phol) and the other resides in the cytosol (Pho2). For Solanum tuberosum L., two highly homologous Pho1-type sequences (designated as Pho1a and Pho1b, respectively) have been described that occur both in a homodimeric, (Pho1a)2, and a heterodimeric, Pho1a-Pho1b, state [U. Sonnewald et al. (1995) Plant Mol Biol 27:567 576; T. Albrecht et al. (1998) Eur J Biochem 251:981-991]. We present a spatial and temporal analysis of the expression patterns of the Pho1-type phosphorylases in S. tuberosum. Expression was analyzed at transcript, protein and activity levels. The specificity of both the probes and the antibodies used was carefully determined to ensure selectivity of detection. For both the Pho1a and Pho1b probes the degree of cross-hybridization was estimated. Peptide scanning identified the epitopes of the anti-Pho 1a and anti-Pho 1b antibodies. Expression of the two Pho1-type genes was analyzed in various organs of the potato plant. In all organs studied the Pho1a transcript levels exceeded those of Pho1b. Furthermore, leaves of a given developmental stage were sampled during the light period and were analyzed for transcript and protein levels and for various carbohydrate pools as well. The data show that in leaves the Pho1a gene expression closely corresponds to starch accumulation, suggesting that the enzyme fulfils a metabolic function within the process of starch biosynthesis. In tubers, Pho1a is constitutively expressed in the parenchyma cells whereas expression of the Pho1b, gene is restricted to cells in close vicinity of the vascular tissue. |
| Databáze: | OpenAIRE |
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