Role of AtAMT1;2 in nitrogen uptake and plant growth.
Date
2008
Authors
Javadiyan, Shahrbanou
Editors
Advisors
Brent Kaiser
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Thesis
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Abstract
In Arabidopsis, six ammonium transporters mediate the movement of ammonium in or out of
cells. Uncertainty exists about their individual location and role, either in primary ammonium
uptake or in intercellular translocation of ammonium. Using the endogenous AMT1;2 promoter
to drive an AMT1;2:GFP fusion construct, it was shown that AMT1;2 is primarily localised to
root endodermal and cortical cells, while in shoots natural fluorescence in the leaves prevented
definitive localisation in cells and internal organelles (e.g. chloroplasts). A growth analysis of
amt1;2 and its corresponding wild type parental line revealed improved growth of an amt1;2 TDNA
insertion line in media containing 2 mM KNO3. No difference in growth was observed in
media containing 1 mM NH4NO3. Using 15N to measure net NH4
+ and NO3
- uptake suggested the
growth response in the amt1;2 line was not a result of improved nitrogen uptake. Furthermore,
examination of high affinity ammonium transport in the amt1;2 and WT lines revealed no
detectable difference in ammonium uptake in either N-starved or N-sufficient grown plants
respectively.
School/Discipline
School of Agriculture, Food and Wine : Plant and Food Science
Dissertation Note
Thesis (M.Bio (PB)) - University of Adelaide, School of Agriculture, Food and Wine, 2008
Provenance
Master of Biotechnology (Plant Biotechnology) by coursework