Effects of ipt gene expression on the physiological and chemical characteristics of Artemisia annua L.

An isopentenyl transferase gene (ipt) from T-DNA was transferred into Artem isia annua L. via Agrobacterium tumefaciens. The ipt gene was placed in a b inary vector under the control of the CaMV 35S promoter. Leaf explants were infected with A. tumefaciens LBA4404 containing pBIipt to induce the buds. Nineteen shoot lines were selected, which were resistant to kanamycin. Pol ymerase chain reactions and Southern blotting confirmed that at least five shoot lines contained the foreign gene. The results of RT-PCR and Northern blotting analyses suggested that the foreign ipt gene of the transgenic sho ot was expressed. Cytokinins: chlorophyll and artemisinin contents were fou nd increased at different degree. Content of cytokinins (iPA and iP) was el evated 2- to 3-fold, chlorophyll increased 20-60% and artemisinin increased 30-70% compared with the control plants, respectively. A direct correlatio n was found between the contents of cytokinins, chlorophyll and artemisinin . This may be the first report on the relationship between endogenous cytok inin content and the production of secondary metabolites in plants. (C) 200 1 Elsevier Science Ireland Ltd. All rights reserved.