Open AccessIdentification and molecular characterization of the nicotianamine synthase gene family in bread wheat
Author(s) -
Bonneau Julien,
Baumann Ute,
Beasley Jesse,
Li Yuan,
Johnson Alexander A. T.
Publication year - 2016
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12577
Subject(s) - biology , gene , gene family , genome , chloroplast , biochemistry , amino acid , phylogenetic tree , genetics
Summary Nicotianamine ( NA ) is a non‐protein amino acid involved in fundamental aspects of metal uptake, transport and homeostasis in all plants and constitutes the biosynthetic precursor of mugineic acid family phytosiderophores ( MA s) in graminaceous plant species. Nicotianamine synthase ( NAS ) genes, which encode enzymes that synthesize NA from S‐adenosyl‐L‐methionine ( SAM ), are differentially regulated by iron (Fe) status in most plant species and plant genomes have been found to contain anywhere from 1 to 9 NAS genes. This study describes the identification of 21 NAS genes in the hexaploid bread wheat ( Triticum aestivum L.) genome and their phylogenetic classification into two distinct clades. The Ta NAS genes are highly expressed during germination, seedling growth and reproductive development. Fourteen of the clade I NAS genes were up‐regulated in root tissues under conditions of Fe deficiency. Protein sequence analyses revealed the presence of endocytosis motifs in all of the wheat NAS proteins as well as chloroplast, mitochondrial and secretory transit peptide signals in four proteins. These results greatly expand our knowledge of NAS gene families in graminaceous plant species as well as the genetics underlying Fe nutrition in bread wheat.