Expression of SULTR2;2, encoding a low-affinity sulphur transporter, in the Arabidopsis bundle sheath and vein cells is mediated by a positive regulator.


Type
Article
Change log
Authors
Kirschner, Sandra 
Woodfield, Helen 
Prusko, Katharina 
Koczor, Maria 
Gowik, Udo 
Abstract

The bundle sheath provides a conduit linking veins and mesophyll cells. In the C3 plant Arabidopsis thaliana, it also plays important roles in oxidative stress and sulphur metabolism. However, the mechanisms responsible for the patterns of gene expression that underpin these metabolic specializations are poorly understood. Here, we used the Arabidopsis SULTR2;2 gene as a model to better understand mechanisms that restrict expression to the bundle sheath. Deletion analysis indicated that the SULTR2;2 promoter contains a short region necessary for expression in the bundle sheath and veins. This sequence acts as a positive regulator and is tolerant to multiple consecutive deletions indicating considerable redundancy in the cis-elements involved. It is highly conserved in SULTR2;2 genes of the Brassicaceae and is functional in the distantly related C4 species Flaveria bidentis that belongs to the Asteraceae. We conclude that expression of SULTR2;2 in the bundle sheath and veins is underpinned by a highly redundant sequence that likely represents an ancient and conserved mechanism found in families as diverse as the Asteraceae and Brassicaceae.

Description
Keywords
Arabidopsis, Base Sequence, Gene Expression Regulation, Plant, Plant Leaves, Plant Vascular Bundle, Sequence Alignment
Journal Title
J Exp Bot
Conference Name
Journal ISSN
0022-0957
1460-2431
Volume Title
69
Publisher
Oxford University Press (OUP)
Sponsorship
BBSRC PhD studentship Deutsche Forschungsgemeinschaft