To identify controlling cis acting promoter regions in the B. napus extA extensin gene, expression in transgenic tobacco of 5′ −159, −433, −664, −789 and −940 bp promoter truncations linked to the uidA (B-glucuronidase) reporter coding sequence were analysed. The −159 and −433 bp truncations directed non specific expression in all cell types within the plant. An activator region which increased expression levels 10 fold in all cell types was located between −159 to −433 bp. A repressor region was found between −664 to −789 bp; removal of this region resulted in a 15 fold increase in expression. Histochemical analysis showed that transgenics containing the −664, −789 and −940 bp truncations directed expression of the fusion gene only in the phloem. A negative regulatory region located between −433 to −664 bp repressed expression in non-phloem cell types. In areas of the plant subject to tensile stress, the repression exerted by the negative regulatory region was overcome, allowing expression in all cell types. The quantitative repressor and activator regions which controlled absolute expression levels in all cell types were seperate from the negative regulatory region which controlled cell type specific expression in response to tensile stress. A wound responsive region was found to be located between −940 to −3500 bp. Thus, the extA gene is under complex control, being regulated by 4 sets of positively and negatively acting cis regions, which control wound inducibility, activation in response to tensile stress, and quantitative expression levels.
Plant Molecular Biology – Springer Journals
Published: Oct 6, 2004
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud