Upstream sequences regulating legumin gene expression in heterologous transgenic plants.
We have previously isolated a legumin gene LeB4 from Vicia faba and shown that a 4.7 kb DNA fragment containing the gene leads to seed-specific expression in transgenic tobacco plants. Here we report that the 2.4 kb upstream sequence alone, when fused to either the neomycin phosphotransferase II (nptII) gene or the beta-glucuronidase (uidA) gene, leads to high enzyme levels in transgenic seeds of both tobacco and Arabidopsis. beta-Glucuronidase (GUS) activity is especially intense in the cotyledons fading out towards the embryonal root tip, a result confirmed by in situ hybridization. Staining of endosperm cells is consistent in both species. Analysis of a series of promoter deletion mutants fused to the nptII gene and introduced into tobacco plants revealed that about 1 kb of 5'-flanking sequence is sufficient for high-level expression but indirect evidence suggests the presence of weak positive regulatory elements further upstream. Deletions leaving only 0.2 kb of upstream sequence reduce enzyme levels to less than 10%. A deletion which destroys the legumin box with its seed protein gene-specific CATGCATG motif has no obvious effects on expression levels.
Bäumlein
H
H
Zentralinstitut für Genetik und Kulturpflanzenforschung, Akademie der Wisssenschaften, Gatersleben, Federal Republic of Germany.
Boerjan
W
W
Nagy
I
I
Panitz
R
R
Inzé
D
D
Wobus
U
U
D015139:Blotting, Southern; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D009693:Nucleic Acid Hybridization; D009928:Organ Specificity / Q000235:genetics; D010940:Plant Proteins; D014674:Plant Proteins, Dietary / Q000235:genetics*; D010944:Plants / Q000235:genetics*; D010947:Plants, Toxic; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014026:Nicotiana / Q000235:genetics*; D000097793:Legumins
D010940:Plant Proteins; D014674:Plant Proteins, Dietary; D000097793:Legumins