title: Complete inventory of soybean NAC transcription factors: sequence conservation and expression analysis uncover their distinct roles in stress response.
abstract: We performed an inventory of soybean NAC transcription factors, in which 101 NAC domain-containing proteins were annotated into 15 different subgroups, showing a clear relationship between structure and function. The six previously described GmNAC proteins (GmNAC1 to GmNAC6) were located in the nucleus and a transactivation assay in yeast confirmed that GmNAC2, GmNAC3, GmNAC4 and GmNAC5 function as transactivators. We also analyzed the expression of the six NAC genes in response to a variety of stress conditions. GmNAC2, GmNAC3 and GmNAC4 were strongly induced by osmotic stress. GmNAC3 and GmNAC4 were also induced by ABA, JA and salinity but differed in their response to cold. Consistent with an involvement in cell death programs, the transient expression of GmNAC1, GmNAC5 and GmNAC6 in tobacco leaves resulted in cell death and enhanced expression of senescence markers. Our results indicate that the described soybean NACs are functionally non-redundant transcription factors involved in response to abiotic stresses and in cell death events in soybean.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Laboratório de Biologia Molecular de Plantas, BIOAGRO, Universidade Federal de Viçosa, 36570.000, Viçosa, Minas Gerais, Brazil.
authors.forename: Guilherme L
authors.initials: GL
authors.lastname: Pinheiro
authors.forename: Carolina S
authors.initials: CS
authors.lastname: Marques
authors.forename: Maximiller D B L
authors.initials: MD
authors.lastname: Costa
authors.forename: Pedro A B
authors.initials: PA
authors.lastname: Reis
authors.forename: Murilo S
authors.initials: MS
authors.lastname: Alves
authors.forename: Claudine M
authors.initials: CM
authors.lastname: Carvalho
authors.forename: Luciano G
authors.initials: LG
authors.lastname: Fietto
authors.forename: Elizabeth P B
authors.initials: EP
authors.lastname: Fontes
mesh_terms: D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant; D009997:Osmotic Pressure; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism*; D013312:Stress, Physiological; D014026:Nicotiana / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors