Complex behavior of a copper-inducible gene expression system in transgenic poplar
2001
Mohamed, R. | Meilan, R. | Strauss, Steven H. (Oergon State University, Corvallis (USA). Department of Forest Science)
We studied a copper-inducible gene expression system first demonstrated in transgenic tobacco for its function in poplar (genus Populus). The system consists of a constitutively experessed, copper-activated transcription factor (ACEl), together with a hybrid promoter containing an ACE1 binding site (MRE) and the -90 fragment of the cauliflower mosaic virus 35S promoter (CaMV/35S/-90), both driving the GUS(beta-glucuronidase) reporter gene. A control construct lacked the ACEl gene. Surprisingly, GUS expression occurred at high levels in the absence of the ACEl gene in transgenic poplars. When the ACEl gene was present, GUS expression occurred even without added copper ion, and showed a parabolic dependence on copper concentration up to 50 microM, above which it inhibited expression. The system does not appear to provide useful copper-inducibility in poplar, possibly due to an endogenous factor that interacts with ACEl and high levels of basal transcription from the minimal 35S promoter used
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por Agricultural Knowledge and Innovation Institute