Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Nov;1(6):290-2.
doi: 10.4161/psb.1.6.3590.

Deoxymugineic Acid synthase: a gene important for fe-acquisition and homeostasis

Khurram Bashir  1 , Naoko K Nishizawa
Affiliations

Deoxymugineic Acid synthase: a gene important for fe-acquisition and homeostasis

Khurram Bashir et al. Plant Signal Behav. 2006 Nov.

Abstract

Plants can be classified in two groups based on Iron (Fe) acquiring strategy. Graminaceous plants (Strategy II) acquire iron through mugineic acid family phytosiderophores (MAs). All MAs are synthesized from L-Met, sharing the same pathway from L-Met to 2'-deoxymugineic acid (DMA) and the subsequent steps may differ depending on plant specie and cultivar. DMA is synthesized through the reduction of a 3''-keto intermediate by deoxymugineic acid synthase (DMAS). Previously, all the genes involved in the synthesis of DMA have been cloned with the exception of DMAS. Recently we have reported the isolation of DMAS genes from rice, wheat, maize and barley. The DMAS belongs to aldo-keto reductase superfamily (AKR). The expression of each of the above DMAS genes is upregulated under Fe-deficient conditions in root tissue, and that of OsDMAS1 and TaDMAS1 are upregulated in shoot tissue. It seems that the expression of DMAS is not regulated at posttranscriptional level. Analysis of OsDMAS1 promoter-GUS transgenic rice suggested that DMA may have role in Fe homeostasis in rice. The cloning of DMAS genes is an important step to develop transgenic rice with increased biosynthesis and section of DMA and ultimately resistant to Fe-deficiency in calcareous soils.

Keywords: Aldo-Keto reductase; MAs; deoxymugineic acid; iron.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Biosynthetic pathway of mugineic acid family phytosiderophores. Three molecules of S-adenosyl methionine are combined by NA synthase (NAS) to form nicotianamine (NA). The amino group of NA is transferred by NA aminotransferase (NAAT), and the resultant 3″-keto intermediate is reduced to 2′-deoxymugineic acid (DMA) by deoxymugineic acid synthase (DMAS). The subsequent steps differ with the plant species and cultivar.
Figure 2
Figure 2
Phylogenetic characterization of DMAS genes. Unrooted phylo-genetic tree of the aldo-keto reductase superfamily (AKR4). The details and accession numbers of the AKR proteins are at www.med.upenn.edu/akr/members.html. AK102609 is a homolog of OsDMAS1 that lacks DMAS activity.
See this image and copyright information in PMC

Comment on

References

    1. Marschner H. Mineral nutrition of higher plants. New York: Academic Press; 1995.
    1. Marschner H, Römheld V, Kissel M. Different strategies in higher plants in mobilization and uptake of iron. J Plant Nutr. 1986;9:695–713.
    1. Takagi S. Naturally occurring iron-chelating compounds in oat and rice root washing. I. Activity measurement and preliminary characterization. Soil Sci Plant Nutr. 1976;22:423–433.
    1. Takagi S, Nomoto K, Takemoto S. Physiological aspect of mugineic acid, a possible phytosiderophore of graminaceous plants. J Plant Nutr. 1984;7:469–477.
    1. Römheld V, Marschner H. Evidence for a specific uptake system for iron phytosiderophores in roots of grasses. Plant Physiol. 1986;70:175–180. - PMC - PubMed

LinkOut - more resources