Number of the records: 1
Altered cytokinin metabolism affects cytokinin, auxin, and abscisic acid contents in leaves and chloroplasts, and chloroplast ultrastructure in transgenic tobacco
- 1.
SYSNO ASEP 0305980 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Ostatní články Title Altered cytokinin metabolism affects cytokinin, auxin, and abscisic acid contents in leaves and chloroplasts, and chloroplast ultrastructure in transgenic tobacco Title Altered cytokinin metabolism affects cytokinin, auxin, and abscisic acid contents in leaves and chloroplasts, and chloroplast ultrastructure in transgenic tobacco Author(s) Polanská, Lenka (UEB-Q)
Vičánková, Anna (UEB-Q)
Nováková, Marie (UEB-Q)
Malbeck, Jiří (UEB-Q) RID, ORCID
Dobrev, Petre (UEB-Q) RID, ORCID
Brzobohatý, Břetislav (BFU-R) RID, ORCID
Vaňková, Radomíra (UEB-Q) RID, ORCID
Macháčková, Ivana (UEB-Q)Source Title Journal of Experimental Botany. - : Oxford University Press - ISSN 0022-0957
Roč. 58, č. 3 (2007), s. 637-649Number of pages 13 s. Language eng - English Country GB - United Kingdom Keywords abscisic acid ; auxin ; chloroplast ultrastructure Subject RIV EF - Botanics R&D Projects GA206/03/0369 GA ČR - Czech Science Foundation (CSF) GA206/06/1306 GA ČR - Czech Science Foundation (CSF) IAA600040612 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) Next source Other public resourcesOther public resources CEZ AV0Z50380511 - UEB-Q (2005-2011) AV0Z50040507 - BFU-R (2005-2011) DOI 10.1093/jxb/erl235 Annotation Cytokinins (CKs) are involved in the regulation of plant development including plastid differentiation and function. Partial location of CK biosynthetic pathways in plastids suggests the importance of CKs for chloroplast development. The impact of genetically modified CK metabolism on endogenous CK, indole-3-acetic acid, and abscisic acid contents in leaves and isolated intact chloroplasts of Nicotiana tabacum was determined by liquid chromatography/mass spectrometry and two-dimensional high-performance liquid chromatography, and alterations in chloroplast ultrastructure by electron microscopy. Ectopic expression of Sho, a gene encoding a Petunia hybrida isopentenyltransferase, was employed to raise CK levels. The increase in CK levels was lower in chloroplasts than in leaves. CK levels were reduced in leaves of tobacco harbouring a CK oxidase/dehydrogenase gene, AtCKX3. The total CK content also decreased in chloroplasts, but CK phosphate levels were higher than in the wild type. In a transformant overexpressing a maize beta-glucosidase gene, Zm-p60.1, naturally targeted to plastids, a decrease of CK-O-glucosides in chloroplasts was found. In leaves, the changes were not significant. CK-O-glucosides accumulated to very high levels in leaves, but not in chloroplasts, of plants overexpressing a ZOG1 gene, encoding trans-zeatin-O-glucosyltransferase from Phaseolus lunatus. Manipulation of the CK content affected levels of indole-3-acetic and abscisic acid. Chloroplasts of plants constitutively overexpressing Sho displayed ultrastructural alterations including the occasional occurrence of crystalloids and an increased number of plastoglobuli. The other transformants did not exhibit any major differences in chloroplast ultrastructure. The results suggest that plant hormone compartmentation plays an important role in hormone homeostasis and that chloroplasts are rather independent organelles with respect to regulation of CK metabolism. Workplace Institute of Experimental Botany Contact David Klier, knihovna@ueb.cas.cz, Tel.: 220 390 469 Year of Publishing 2008
Number of the records: 1