title: Molecular characterization of stress-inducible GmNAC genes in soybean.
abstract: Drought is detrimental to plant growth and development, and often results in significant losses to the yields of economically important crops such as soybeans (Glycine max L.). NAC transcription factors (TFs), which consist of a large family of plant-specific TFs, have been reported to enhance drought tolerance in a number of plants. In this study, 31 unigenes that contain the complete open reading frames encoding GmNAC proteins were identified and cloned from soybean. Analysis of C-terminal regulatory domain using yeast one-hybrid system indicated that among 31 GmNAC proteins, 28 have transcriptional activation activity. Expression analysis of these GmNAC genes showed that they are differentially expressed in different organs, suggesting that they have diverse functions during plant growth and development. To search for the drought-inducible GmNAC genes, we prescreened and re-confirmed by quantitative real-time PCR analysis that nine GmNAC genes are induced by dehydration stress with differential induction levels in both shoot and root. The expression profiles of these nine GmNAC genes were also examined under other stresses such as high salinity, cold and with abscisic acid hormone treatments. Phylogenetic analysis of the GmNAC proteins with previously reported drought-inducible NAC proteins of Arabidopsis and rice revealed that the nine drought-inducible GmNAC proteins belong to the "stress-inducible" NAC group. The results of this systematic analysis of the GmNAC family will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars.
authors.affiliation: Division of Plant Sciences, National Center for Soybean Biotechnology, University of Missouri, Columbia, MO 65211, USA. tran@psc.riken.jp
authors.forename: Lam-Son Phan
authors.initials: LS
authors.lastname: Tran
authors.forename: Truyen N
authors.initials: TN
authors.lastname: Quach
authors.forename: Satish K
authors.initials: SK
authors.lastname: Guttikonda
authors.forename: Donavan L
authors.initials: DL
authors.lastname: Aldrich
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Anjanasree
authors.initials: A
authors.lastname: Neelakandan
authors.forename: Babu
authors.initials: B
authors.lastname: Valliyodan
authors.forename: Henry T
authors.initials: HT
authors.lastname: Nguyen
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003681:Dehydration; D055864:Droughts; D017343:Genes, Plant; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D016366:Open Reading Frames; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D014157:Transcription Factors; D000040:Abscisic Acid