Present address, Heidelberger Institut für Pflanzenwissenschaften, Universität Heidelberg, Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany.
Ectopic expression of nicotianamine synthase genes results in improved iron accumulation and increased nickel tolerance in transgenic tobacco
Article first published online: 9 DEC 2004
Plant, Cell & Environment
Volume 28, Issue 3, pages 365–374, March 2005
How to Cite
DOUCHKOV, D., GRYCZKA, C., STEPHAN, U. W., HELL, R. and BÄUMLEIN, H. (2005), Ectopic expression of nicotianamine synthase genes results in improved iron accumulation and increased nickel tolerance in transgenic tobacco. Plant, Cell & Environment, 28: 365–374. doi: 10.1111/j.1365-3040.2005.01273.x
- Issue published online: 9 DEC 2004
- Article first published online: 9 DEC 2004
- Received 22 June 2004; received in revised form 25 August 2004; accepted for publication 27 September 2004
- nicotianamine synthase;
- transgenic plants
Heavy metals are essential for basic cellular processes but toxic in higher concentrations. This requires the precise control of their intracellular concentrations, a process known as homeostasis. The metal-chelating, non-proteinogenous amino acid nicotianamine (NA) is a key component of plant metal assimilation and homeostasis. Its precise function is still unknown. Therefore, this article aims to contribute new information on the in vivo function of NA and to evaluate its potential use for plant nutrition and crop fortification. For this purpose, a nicotianamine synthase gene of Arabidopsis thaliana was ectopically expressed in transgenic tobacco plants. The presence of extra copies of the nicotianamine synthase gene co-segregated with up to 10-fold elevated levels of NA in comparison with wild type. The increased NA level led to: (a) a significantly increased iron level in leaves of adult plants; (b) the accumulation of zinc and manganese, but not copper; (c) an improvement of the iron use efficiency in adult plants grown under iron limitation; and (d) an enhanced tolerance against up to 1 m m nickel. Taken together, the data predict that NA may be a useful tool for improved plant nutrition on adverse soils and possibly for enhanced nutritional value of leaf and seed crops.