Khodakovskaya M., Zhao D., Smith W., Li Y., McAvoy R.
В журнале Plant Cell Reports
Год: 2006 Том: 25 Страницы: 1181-1192
Cytokinins play important roles in regulating plant growth and development. A new genetic construct for regulating cytokinin content in plant cells was cloned and tested. The gene coding for isopentenyl transferase (ipt) was placed under the control of a 0.821 kb fragment of the 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase gene promoter from Lycopersicon esculentum (LEACO1) and introduced into Nicotiana tabacum (cv. Havana). Some LEACO10.821kb-ipt transgenic plant lines displayed normal shoot morphology but with a dramatic increase in the number of flower buds compared to nontransgenic plants. Other transgenic lines produced excessive lateral branch development but no change in flower bud number. Isolated leaves of transgenic tobacco plants showed a significantly prolonged retention of chlorophyll under dark incubation (25°C for 20 days). Leaves of nontransformed plants senesced gradually under the same conditions. Experiments with LEACO10.821kb-gus transgenic tobacco plants suggested auxin and ethylene involvement in induction of LEACO10.821kb promoter activity. Multiple copies of nucleotide base sequences associated with either ethylene or auxin response elements were identified in the LEACO10.821kb promoter fragment. The LEACO10.821kb-ipt fusion gene appears to have potential utility for improving certain ornamental and agricultural crop species by increasing flower bud initiation and altering branching habit. © 2006 Springer-Verlag.
