Taproot promoters cause tissue specific gene expression within the storage root of sugar beet.
The storage root (taproot) of sugar beet (Beta vulgaris L.) originates from hypocotyl and primary root and contains many different tissues such as central xylem, primary and secondary cambium, secondary xylem and phloem, and parenchyma. It was the aim of this work to characterize the promoters of three taproot-expressed genes with respect to their tissue specificity. To investigate this, promoters for the genes Tlp, His1-r, and Mll were cloned from sugar beet, linked to reporter genes and transformed into sugar beet and tobacco. Reporter gene expression analysis in transgenic sugar beet plants revealed that all three promoters are active in the storage root. Expression in storage root tissues is either restricted to the vascular zone (Tlp, His1-r) or is observed in the whole organ (Mll). The Mll gene is highly organ specific throughout different developmental stages of the sugar beet. In tobacco, the Tlp and Mll promoters drive reporter gene expression preferentially in hypocotyl and roots. The properties of the Mll promoter may be advantageous for the modification of sucrose metabolism in storage roots.
Oltmanns
Heiko
H
PLANTA Angewandte Pflanzengenetik und Biotechnologie, GmbH, Grimsehlstrasse 31, 37555 Einbeck, Germany.
Kloos
Dorothee U
DU
Briess
Waltraud
W
Pflugmacher
Maike
M
Stahl
Dietmar J
DJ
Hehl
Reinhard
R
D027461:Beta vulgaris / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018546:Hypocotyl / Q000033:anatomy & histology / Q000378:metabolism; D008156:Luciferases / Q000032:analysis; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000033:anatomy & histology / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014026:Nicotiana / Q000033:anatomy & histology / Q000235:genetics
D010940:Plant Proteins; D008156:Luciferases