title: Nicotianamine synthase gene family as central components in heavy metal and phytohormone response in maize.
abstract: Nicotianamine (NA) is an important divalent metal chelator and the main precursor of phytosiderophores. NA is synthesized from S-adenosylmethionine in a process catalyzed by nicotianamine synthase (NAS). In this study, a set of structural and phylogenetic analyses have been applied to identify the maize NAS genes based on the maize genome sequence release. Ten maize NAS genes have been mapped; seven of them have not been reported to date. Phylogenetic analysis and expression pattern from microarray data led to their classification into two different orthologous groups. C-terminal fusion of ZmNAS3 with GFP was found in the cytoplasm of Arabidopsis leaf protoplast. Expression analysis by reverse transcription polymerase chain reaction revealed ZmNAS genes are responsive to heavy metal ions (Ni, Fe, Cu, Mn, Zn, and Cd), and all 10 ZmNAS genes were only observed in the root tissue except of ZmNAS6. The promoter of ZmNAS genes was analyzed for the presence of different cis-element response to all kinds of phytohormones and environment stresses. We found that the ZmNAS gene expression of maize seedlings was regulated by jasmonic acid, abscisic acid, and salicylic acid. Microarray data demonstrated that the ZmNAS genes show differential, organ-specific expression patterns in the maize developmental steps. The integrated comparative analysis can improve our current view of ZmNAS genes and facilitate the functional characterization of individual members.
authors: School of Life and Basic Sciences, Sichuan Agricultural University, Yaan, Sichuan 625014, People's Republic of China.
authors: Mei-Liang
authors: ML
authors: Zhou
authors: Lei-Peng
authors: LP
authors: Qi
authors: Jun-Feng
authors: JF
authors: Pang
authors: Qian
authors: Q
authors: Zhang
authors: Zhi
authors: Z
authors: Lei
authors: Yi-Xiong
authors: YX
authors: Tang
authors: Xue-Mei
authors: XM
authors: Zhu
authors: Ji-Rong
authors: JR
authors: Shao
authors: Yan-Min
authors: YM
authors: Wu
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D055162:Biocatalysis / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000201:enzymology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics*; D019216:Metals, Heavy / Q000633:toxicity*; D008958:Models, Molecular; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D012436:S-Adenosylmethionine / Q000737:chemistry / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D040681:Structural Homology, Protein; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*
chemical_list: D019216:Metals, Heavy; D010937:Plant Growth Regulators; D012436:S-Adenosylmethionine; D019883:Alkyl and Aryl Transferases; C118230:nicotianamine synthase