Differential expression of cytosolic and plastid pyruvate kinase isozymes in tobacco
| العنوان: | Differential expression of cytosolic and plastid pyruvate kinase isozymes in tobacco |
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| المؤلفون: | Stephen D. Blakeley, David T. Dennis, Brian Miki, William C. Plaxton, Sylvia G. McHugh, Rajender S. Sangwan, Vicki L. Knowles |
| المصدر: | Physiologia Plantarum. 95:507-514 |
| بيانات النشر: | Wiley, 1995. |
| سنة النشر: | 1995 |
| مصطلحات موضوعية: | Messenger RNA, Physiology, Nicotiana tabacum, fungi, food and beverages, Leucoplast, Cell Biology, Plant Science, General Medicine, Biology, biology.organism_classification, Molecular biology, Isozyme, Biochemistry, Complementary DNA, Gene expression, Genetics, Northern blot, Pyruvate kinase |
| الوصف: | The expression of cytosolic and plastid pyruvate kinase (PK ; E.C. 2.7.1.40) in various tissues of tobacco (Nicotiana tabacum cv. Petit Havana SR1) was investigated. To facilitate this study, a cDNA clone for cytosolic pyruvate kinase (PK c ) was isolated from a tobacco seed cDNA expression library. This cDNA has an open reading frame capable of encoding a 508-amino acid polypeptide with a predicted molecular mass of 55.1 kDa. The deduced amino acid sequence has 76% identity with the sequence of potato PK c . Southem blot analysis shows that N. tabacum contains two copies of the PK c gene, each derived from the single gene found in its progenitors, N. tomentosiformis and N. sylvestris. Northern blots detected a 1.9-kb band in flower, seed, root, stem and leaf tissues of N. tabacum. Immunoblotting using anti-[castor oil seed (COS) PK c ]-immunoglobulin G (IgG) detected 58- and 56-kDa polypeptides in all tobacco tissues examined. In developing seeds, mRNA levels were low except for a peak at 8 days post anthesis (dpa), whereas the highest level of the PK c polypeptides was detected 10-16 dpa. The persistence of PK c well after the peak in mRNA levels suggests that PK c is stable in developing seeds. Our previous studies have shown that leucoplast PK (PK p ) mRNA could be detected throughout tobacco seed development as well as in somatic tissues. In developing seeds, steady state PK p mRNA levels showed a broad peak of accumulation from 8-20 dpa, reaching maximum levels at 16 dpa. In the present study, polypeptides of 63 and 60 kDa were detected on immunoblots probed with anti-(COS PK p )-IgG in developing tobacco seeds 10-20 dpa. The observed pattern of PK p protein accumulation closely correlated with the profile of steady state mRNA levels suggesting that this isoenzyme has a much greater rate of turnover than that of PK c . In contrast to PK c , there was no detectable accumulation of PK p protein at other times during seed development or in somatic tissues even though significant levels of PK p mRNA could be detected. The differences in the protein accumulation and mRNA expression patterns of PK c and PK p suggest that the tissue-specific and developmental expression of these isoenzymes in tobacco may be controlled by independent transcriptional and post-transcriptional mechanisms. |
| تدمد: | 1399-3054 0031-9317 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::17da16392c4a1aa2ea88f78c379adf16Test https://doi.org/10.1034/j.1399-3054.1995.950402.xTest |
| حقوق: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....17da16392c4a1aa2ea88f78c379adf16 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13993054 00319317 |
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