Reference "Distinct Expression and Function of Three Ammonium Transporter Genes (OsAMT1;1

Reference ID

7935

Title

Distinct Expression and Function of Three Ammonium Transporter Genes (OsAMT1;1 - 1;3) in Rice

Source

Plant & cell physiology, 2003, vol. 44, pp. 726-734

Authors (5)

Sonoda-Y	Ikeda-A
Saiki-S	Yamaya-T
Yamaguchi-J

Abstract

To study the regulation of ammonium uptake into rice roots, three ammonium
transporter genes (OsAMT1;1, 1;2 and 1;3; Oryza sativa ammonium transporter)
were isolated and examined. OsAMT1s belong to AMT1 family, containing 11
putative transmembrane-spanning domains. Southern blot analysis and screening of
the rice genome database confirmed that with OsAMT1;1-1;3 the complete AMT1
family of rice had been isolated. Heterologous expression of OsAMT1s in the
yeast Saccharomyces cerevisiae mutant 31019b showed that all three OsAMT1s
exhibit ammonium transport activity. Northern blot analysis showed a distinct
expression pattern for the three genes; more constitutive expression in shoots
and roots for OsAMT1;1, root-specific and ammonium-inducible expression for
OsAMT1;2, and root-specific and nitrogen-derepressible expression for OsAMT1;3.
In situ mRNA detection revealed that OsAMT1;2 is expressed in the central
cylinder and cell surface of root tips. This gene expression analysis revealed a
distinct nitrogen-dependent regulation for AMTs in rice, differing from that in
tomato or ARABIDOPSIS: