Expression of a phosphoenolpyruvate carboxylase promoter from Mesembryanthemum crystallinum is not salt-inducible in mature transgenic tobacco.
The 5' flanking region of a salt-stress-inducible, CAM-specific phosphoenolpyruvate carboxylase (PEPC) gene from the facultative halophyte Mesembryanthemum crystallinum, was fused to the beta-glucuronidase (GUS) reporter gene and introduced into Nicotiana tabacum SR1. The Ppc1 promoter displayed high levels of expression in transgenic tobacco quantitatively and qualitatively similar to a full-length 35S CaMV-GUS construct. Histochemical assays revealed that the full-length Ppc1-GUS fusions expressed GUS activity in all tissues except in root tips. While tobacco is capable of utilizing the Ppc1 cis-acting regulatory regions from M. crystallinum to yield high levels of constitutive expression, this glycophyte fails to direct a stress-inducible pattern of gene expression typical of this promoter in its native, facultative halophytic host.
Cushman
J C
JC
Department of Biochemistry, University of Arizona, Tucson 85721.
Meiners
M S
MS
Bohnert
H J
HJ
D001483:Base Sequence; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics; D008969:Molecular Sequence Data; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics*; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D014026:Nicotiana / Q000235:genetics; D014170:Transformation, Genetic
D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D005966:Glucuronidase; D010730:Phosphoenolpyruvate Carboxylase