Gibberellin and abscisic acid regulate GAST1 expression at the level of transcription

Citation
Lf. Shi et Ne. Olszewski, Gibberellin and abscisic acid regulate GAST1 expression at the level of transcription, PLANT MOL B, 38(6), 1998, pp. 1053-1060
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT MOLECULAR BIOLOGY
ISSN journal
0167-4412 → ACNP
Volume
38
Issue
6
Year of publication
1998
Pages
1053 - 1060
Database
ISI
SICI code
0167-4412(199812)38:6<1053:GAAARG>2.0.ZU;2-V
Abstract
Both gibberellic acid (GA(3)) and abscisic acid (ABA) regulate the expressi on of the GAST1 gene of tomato. Treatment with GA(3) increases the abundanc e of GAST1 RNA while treatment with ABA blocks this effect. In this study, the effects of GA(3) and ABA on the rate of transcription of the GAST1 gene and the stability of GAST1 RNA were examined. Nuclear run-on analyses dete cted an increase in transcription of the GAST1 gene 1 h after GA(3) treatme nt with transcription increasing to a maximum at 9 h after treatment. The h alf-life of GAST1 RNA in GA(3)-treated leaves was similar to that in contro l leaves. In addition, the extent of overexpression of GAST1 RNA in transge nic tomato plants containing the CaMV 35S promoter driving the expression o f the GAST1 transcribed region was largely unaffected by GA(3). These resul ts suggest that GA(3) stimulates the expression of the GAST1 gene by acting only at the level of transcription. ABA treatment dramatically reduced the abundance of GAST1 RNA in gib1 shoots through an effect at the level of tr anscription and did not appear to affect the stability of this RNA. Midcour se ABA addition to the GA(3)-incubated shoots reversed the GA(3)-mediated i ncrease in the transcription of GAST1 gene within 15 min. Transgenic plants that either overexpressed or underexpressed GAST1 RNA exhibited no phenoty pic differences from wild type.