Book with abstracts from the COST Action 0905 meeting in ... - UMB

TRANSPORT AND DEPOSITION OF IRON AND ZINC IN THE WHEAT
AND BARLEY GRAIN
IDENTIFICATION OF THE TRANSCRIPTOME CORRELATED WITH HEAVY
METAL TRANSPORT GENE MANIPULATION FOR IMPROVED NUTRITIONAL
VALUE OF THE WHEAT AND BARLEY GRAIN
Søren Borg, Behrooz Darbani, Birgitte Tauris, Shahin Noeparvar, Preben B. Holm
The University of Aarhus, Faculty of Science and Technology, Department of Molecular
Biology and Genetics, Research Centre Flakkebjerg, DK-4200 Slagelse, Denmark
The research area comprises molecular characterization of genes encoding zinc and
iron transporters and genes involved in zinc and iron binding and deposition in the developing
barley grain and the manipulation of these genes by transformation to improve the zinc and
iron content of the barley endosperm. We have previously performed microarray studies based
on laser capture microdissection and have established the first roadmap for zinc and iron
transport into the barley grain (Tauris et al.2009; Borg et al.2009). We have as one of our
primary goals to develop this roadmap further by introducing next generation sequencing on
laser capture microdissected tissues comprising the transport pathway from the vegetative
tissues into the endosperm. Our second objective is to use this knowledge to improve iron and
zinc content and bioavailability of the endosperm by gene manipulation by transformation.
Our hypothesis is that it is possible to increase the content of essential minerals in the wheat
endosperm by transgenic modulation of mineral transporters and deposition in the endosperm.
Gene manipulation:
• Bypass the normal deposition of zinc in the protein storage vacuole of the aleurone by
tissue-specific down-regulation of the vacuolar zinc transporter, MTP1.
• Generate barley plants over expressing the HvHMA2 zinc transporter using unloading
zone specific promoters.
• Generation of transgenic wheat overexpressing the wheat TaFer1 gene under the
control of the wheat high molecular weight glutenine 1Dx5 promoter in modern
CIMMYT wheat lines.
• Bypass the normal deposition of iron in the protein storage vacuole of the aleurone by
tissue-specific down-regulation of vacuolar iron transporter, Vit1.
• Cross the transgenic lines with lines expressing phytase to improve the bioavailability
of divalent mineral cations in the digestive tract of humans and livestock
The work is supported by HarvestPlus, 2033 K Street, NW, Washington DC 20006-1002,
USA
References
Borg S, Brinch-Pedersen H, Tauris B and Holm P B 2009 Iron transport, deposition and
bioavailability in the wheat and barley grain. Plant and Soil 325, 15-24.
Tauris B, Borg S, Gregersen P L and Holm P B 2009 A roadmap for zinc trafficking in the
developing barley grain based on laser capture microdissection and gene expression profiling.
Journal of Experimental Botany 60, 1333-1347.