A GLUCOCORTICOID-MEDIATED TRANSCRIPTIONAL INDUCTION SYSTEM IN TRANSGENIC PLANTS

Authors
Citation
T. Aoyama et Nh. Chua, A GLUCOCORTICOID-MEDIATED TRANSCRIPTIONAL INDUCTION SYSTEM IN TRANSGENIC PLANTS, Plant journal, 11(3), 1997, pp. 605-612
Citations number
33
Categorie Soggetti
Plant Sciences",Biology
Journal title
ISSN journal
09607412
Volume
11
Issue
3
Year of publication
1997
Pages
605 - 612
Database
ISI
SICI code
0960-7412(1997)11:3<605:AGTISI>2.0.ZU;2-#
Abstract
A novel chemical induction system for transcription in plants has been developed, taking advantage of the regulatory mechanism of vertebrate steroid hormone receptors. A chimeric transcription factor, designate d GVG was constructed, consisting of the DNA-binding domain of the yea st transcription factor GAL4, the transactivating domain of the herpes viral protein VP16, and the receptor domain of the rat glucocorticoid receptor (GR). The GVG gene was introduced into transgenic tobacco an d Arabidopsis together with a luciferase (Luc) gene which was transcri bed from a promoter containing six tandem copies of the GAL4 upstream activating sequence. Induction of luciferase activity was observed whe n the transgenic tobacco plants were grown on an agar medium containin g dexamethasone (DEX), a strong synthetic glucocorticoid. Induction le vels of the luciferase activity were well correlated with DEX concentr ations in the range from 0.1 to 10 mu M and the maximum expression lev el was over 100 times that of the basal level. Analysis of the inducti on kinetics by Northern blot analysis showed that the Luc mRNA was fir st detected 1 h after DEX treatment and increased to the maximum level in 4 h. The stationary induction level and the duration of the induct ion varied with the glucocorticoid derivative used. The GVG gene activ ity can also be regulated by DEX in transgenic Arabidopsis plants. The results indicate that a stringent chemical control of transcription c an be achieved in plants with the GVG system. Advantages and potential uses of this system are also discussed.