Guivarc'h, Anne and Rembur, Jacques and Goetz, Marc and Roitsch, Thomas and Noin, Michele and Schmuelling, Thomas and Chriqui, Dominique (2002) Local expression of the ipt gene in transgenic tobacco (Nicotiana tabacum L. cv. SR1) axillary buds establishes a role for cytokinins in tuberization and sink formation. JOURNAL OF EXPERIMENTAL BOTANY, 53 (369). pp. 621-629. ISSN 0022-0957
Full text not available from this repository. (Request a copy)Abstract
The developmental characteristics of a transgenic tobacco line (BIK62) expressing the ipt cytokinin-biosynthetic gene under the control of a tagged promoter were analysed. In situ hybridization and cytokinin immunocytochemistry revealed that the ipt gene was mainly expressed in the axillary buds after the floral transition. The ipt-expressing axillary buds presented morphological alterations such as short and narrow scale-leaflets, and swollen internodes filled with starch grains, giving rise to short and tuberized lateral branches. In addition, the modification of the endogenous cytokinin balance in the axillary meristems resulted in a fast rate of leaf initiation and cytokinins accumulated mostly in the lateral zones of the reactivated axillary meristems, suggesting a role in leaf organogenesis. Cell cycle analysis revealed that the reactivated axillary meristems were characterized by predominant S+G2 nuclei. Terminal internodes displayed low levels of hexose and sucrose concomitant with starch accumulation. Extracellular invertases (EC 3.1.26) were also present in higher amounts in the tuberizing internodes compared to the axillary buds of wild-type tobacco. These results underline the role of cytokinins in cell cycle regulation and in the creation of a sink-source effect. They also provide new information about cytokinin involvement in the process of tuberization and their overproduction in axillary buds giving rise to tuberized lateral branches in a naturally non-tuberizing species.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | TISSUE-SPECIFIC EXPRESSION; EXTRACELLULAR INVERTASE; ARABIDOPSIS-THALIANA; CHENOPODIUM-RUBRUM; SOLANUM-TUBEROSUM; PLANT DEVELOPMENT; LEAF SENESCENCE; T-DNA; POTATO; AGROBACTERIUM; apical dominance; axillary bud; cytokinins; ipt gene; tuberization |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften > Lehrstuhl für Zellbiologie und Pflanzenphysiologie (Prof. Dr. Klaus Grasser) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Nov 2021 14:17 |
| Last Modified: | 02 Nov 2021 14:17 |
| URI: | https://pred.uni-regensburg.de/id/eprint/40426 |
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