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

EXPRESSING NcZNT1 AND NcZTP1 FROM NOCCAEA (THLASPI)
CAERULESCENS ENHANCE Zn AND Cd TOLERANCE AND
ACCUMULATION IN ARABIDOPSIS THALIANA
Zeshan Hassan 1 , Sangita Talukdar 1 , Henk Schat 2 and Mark G.M. Aarts 1
1 Lab of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB,, Wageningen,
The Netherlands
2 Ecology and Physiology of Plants, Faculty of Biology, Vrije Universiteit, De Boelelaan
1085, 1081 HV Amsterdam, The Netherlands
Keywords: Biofortification, Cadmium (Cd), hyperaccumulation, Noccaea
caerulescens, Zinc (Zn).
Zinc is a vital part of human nutrition and there is a global Zn deficiency in human diet
being reported. Biofortification is an important tool to improve the nutritional value of
food crops by using plant breeding and biotechnology. Noccaea (Thlaspi) caerulescens is a
model metal hyperaccumulator species that can accumulate up to 3% of zinc, but also high
amounts of nickel and cadmium. NcZNT1 is a member of IRT1 like protein family in N.
caerulescens and is localized to plasma membrane while NcZTP1 is a member of the CDF
gene family, predicted to localize to the vacuolar membrane. We have expressed both these
genes separately into Arabidopsis thaliana under the control of constitutive CaMV 35S
promoter to investigate their role in Zn accumulation and tolerance. Transgenic plants with
high expression of the transgenes were grown hydroponically under high Zn, Cd, or low Fe
supply. Transgenic plants were more tolerant to high Zn, Cd and low Fe, and accumulate
more Zn and Cd. We conclude that the over expression of NcZNT1 and NcZTP1 play a role
in high Zn, Cd and low Fe tolerance and enhanced Zn and Cd accumulation probably
through enhanced Zn uptake inside cells and compartmentalization in the vacuole
respectively. This can be one step further towards the progress of a viable GMO-based
Biofortification technology.