Promoters from kin1 and cor6.6, two homologous Arabidopsis thaliana genes: transcriptional regulation and gene expression induced by low temperature, ABA, osmoticum and dehydration.
The Arabidopsis thaliana genes kin1 and cor6.6 belong to the same family and were expressed at higher levels following low temperature and ABA treatments. In an attempt to elucidate the mechanism of gene regulation by low temperature, the relationship between low-temperature- and abscisic acid (ABA)-induced gene expression and possible differential expression of the two genes, we have cloned a 5.3 kb genomic fragment harboring kin1 and cor6.6 and their respective 5' sequences. The putative promoters of both genes were fused to the beta-glucuronidase (GUS) coding sequence and GUS expression was analysed in transgenic tobacco and Arabidopsis plants. The cor6.6 promoter produced a higher basal level of expression than the kin1 promoter in transgenic tobacco. Enzyme assays of inducible GUS activity in transgenic Arabidopsis and tobacco plants showed that GUS activity directed by both kin1 and cor6.6 promoters was significantly induced by ABA, dehydration and osmoticum, but not by low temperature. Northern analysis revealed, in contrast, that GUS mRNA was significantly induced in these transgenic plants by low temperature. Further analysis showed that, at low temperature, GUS protein synthesis from the induced GUS mRNA was inhibited. Together these results reveal induction of kin1 and cor6.6 transcription by low temperature, exogenous ABA and dehydration. However, low-temperature expression is dramatically reduced at the translational level.
Wang
H
H
Plant Biotechnology Institute, National Research Council of Canada, Saskatoon.
Datla
R
R
Georges
F
F
Loewen
M
M
Cutler
A J
AJ
D000040:Abscisic Acid / Q000494:pharmacology; D021301:Antifreeze Proteins; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D003080:Cold Temperature; D004790:Enzyme Induction; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D017930:Genes, Reporter; D006023:Glycoproteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009997:Osmotic Pressure; D010750:Phosphoproteins / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins; D012689:Sequence Homology, Nucleic Acid; D014026:Nicotiana / Q000235:genetics; D014170:Transformation, Genetic
D021301:Antifreeze Proteins; D029681:Arabidopsis Proteins; D006023:Glycoproteins; C490208:KIN1 protein, Arabidopsis; D010750:Phosphoproteins; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C072392:COR6.6 protein, Arabidopsis; D000040:Abscisic Acid; D017346:Protein Serine-Threonine Kinases