Čeština
EnglishEnhancement of flowering and branching phenotype in chrysanthemum by expression of ipt under the control of a 0.821 kb fragment of the LEACO1 gene promoter.
Khodakovskaya M., Vankova R., Malbeck J., Li A., Li Y., McAvoy R.
PLANT CELL REPORTS 28:: 1351-1362, 2009
Keywords: ipt, transgenic chrysanthemum, LEACO1-promoter, branching, number of flower buds, leaf senescence
Abstract: The cytokinin biosynthesis gene, isopentenyl transferase (ipt), under the control of a 821 bp fragment of the LEACO1 gene promoter (from Lycopersicon esculentum) was introduced into Dendranthema x grandiflorium ‘Iridon’ (chrysanthemum). LEACO10.821kb-ipt transgenic lines grown in the vegetative state, exhibited a range of branching habits and internode lengths. LEACO10.821kb-ipt transgenic lines grown in the generative state, exhibited flower bud counts that ranged from a number similar to the wild type up to 10-times higher. Dramatic increases in bud counts were observed even in transgenic lines that displayed a branching morphology similar to the wild type. Dramatic increases in flower number were associated with a delay of flower bud development and a decrease in flower bud diameter. Isolated leaves of transgenic chrysanthemum plants remained healthy and green after 14 days of dark incubation at 25oC and showed a significantly prolonged retention of chlorophyll compare with leaves from wild type plants. Analysis of ipt expression indicated a marked change in gene expression between the most extreme phenotypes observed in this study. Expression of ipt in transgenic lines correlated well with high concentrations of the sum total to bioactive cytokinins plus the glucosides and phosphate derivatives of these species, under both vegetative and generative growth conditions. In general, transgenic lines accumulated higher concentrations of both storage-form cytokinins (O-glucosides) and deactivated-from cytokinins (N-glucosides) in generative shoots of than in vegetative shoots. Based on observation of transgenic chrysanthemum lines that exhibited moderate increases in either flower bud number or lateral branch development, we conclude that the LEACO10.821kb-ipt gene appears to have great potential for use in ornamental crop improvement.
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IEB authors: Radomíra Vaňková
PLANT CELL REPORTS 28:: 1351-1362, 2009
Keywords: ipt, transgenic chrysanthemum, LEACO1-promoter, branching, number of flower buds, leaf senescence
Abstract: The cytokinin biosynthesis gene, isopentenyl transferase (ipt), under the control of a 821 bp fragment of the LEACO1 gene promoter (from Lycopersicon esculentum) was introduced into Dendranthema x grandiflorium ‘Iridon’ (chrysanthemum). LEACO10.821kb-ipt transgenic lines grown in the vegetative state, exhibited a range of branching habits and internode lengths. LEACO10.821kb-ipt transgenic lines grown in the generative state, exhibited flower bud counts that ranged from a number similar to the wild type up to 10-times higher. Dramatic increases in bud counts were observed even in transgenic lines that displayed a branching morphology similar to the wild type. Dramatic increases in flower number were associated with a delay of flower bud development and a decrease in flower bud diameter. Isolated leaves of transgenic chrysanthemum plants remained healthy and green after 14 days of dark incubation at 25oC and showed a significantly prolonged retention of chlorophyll compare with leaves from wild type plants. Analysis of ipt expression indicated a marked change in gene expression between the most extreme phenotypes observed in this study. Expression of ipt in transgenic lines correlated well with high concentrations of the sum total to bioactive cytokinins plus the glucosides and phosphate derivatives of these species, under both vegetative and generative growth conditions. In general, transgenic lines accumulated higher concentrations of both storage-form cytokinins (O-glucosides) and deactivated-from cytokinins (N-glucosides) in generative shoots of than in vegetative shoots. Based on observation of transgenic chrysanthemum lines that exhibited moderate increases in either flower bud number or lateral branch development, we conclude that the LEACO10.821kb-ipt gene appears to have great potential for use in ornamental crop improvement.
DOI: