Subcellular compartmentation of the cytokinin (CK) metabolic network is crucial in determining levels of active hormone. Over-expression of Zm-p60.1, a maize b-glucosidase capable of releasing active CK from O-glucosides, leads to a disruption of zeatin metabolism. This protein can be used as a tool to understand subcellular compartmentation of reversible conjugation. Analysis of the phenotypes of transgenic tobacco plants over-expressing different subcellular variants of Zm-p60.1 is likely to yield crucial information regarding the mechanisms of homeostasis - at the cellular level - of active CK levels. Crosses between transgenic plants over-expressing Zm-p60.1 and those over-expressing the Phaseolus zeatin-O-glucosyltransferase ZOG1, and other crosses we have available will be analyzed with the objective of elucidating the processes regulating reversible CK conjugation. To overcome the problems associated with constitutive overexpression, and lack of suitable markers, transgenic Arabidopsis with inducible over-expression will be constructed and their phenotypes analyzed. (en)
Charakterizace subcellulárních variant Zm-p60.1 a jejich odpovědi na cytokininy. Testování odpovědi všech variant na ostatní fytohormony, komponenty živného média a fotoperiodu. Příprava a charakterizace transgenní Arabidopsis nadprodukující Zm-p60.1 pod konstitutivním a inducibilním promotorem.