title: Overexpression of the activated form of the AtAREB1 gene (AtAREB1ΔQT) improves soybean responses to water deficit.
abstract: Abscisic acid-responsive element binding protein (AREB1) is a basic domain/leucine zipper transcription factor that binds to the abscisic acid (ABA)-responsive element motif in the promoter region of ABA-inducible genes. Because AREB1 is not sufficient to direct the expression of downstream genes under non-stress conditions, an activated form of AREB1 (AREB1ΔQT) was created. Several reports claim that plants overexpressing AREB1 or AREB1ΔQT show improved drought tolerance. In our studies, soybean plants overexpressing AREB1ΔQT were characterized molecularly, and the phenotype and drought response of three lines were accessed under greenhouse conditions. Under conditions of water deficit, the transformed plants presented a higher survival rate (100%) than those of their isoline, cultivar BR 16 (40%). Moreover, the transformed plants displayed better water use efficiency and had a higher number of leaves than their isoline. Because the transgenic plants had higher stomatal conductance than its isoline under well-watered conditions, it was suggested that the enhanced drought response of AREB1ΔQT soybean plants might not be associated with altered transpiration rates mediated by ABA-dependent stomatal closure. However, it is possible that the smaller leaf area of the transgenic plants reduced their transpiration and water use, causing delayed stress onset. The difference in the degree of wilting and percentage of survival between the 35S-AREB1ΔQT and wildtype plants may also be related to the regulation of genes that protect against dehydration because metabolic impairment of photosynthesis, deduced by an increasing internal CO2 concentration, was not observed in the transgenic plants.
authors.affiliation: Departamento de Biologia Aplicada à Agricultura, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP, Brasil.
authors.forename: J P
authors.initials: JP
authors.lastname: Leite
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: E G G
authors.initials: EG
authors.lastname: Barbosa
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: S R R
authors.initials: SR
authors.lastname: Marin
authors.affiliation: Departmento de Biologia Geral, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: J P
authors.initials: JP
authors.lastname: Marinho
authors.affiliation: Laboratório de Ecofisiologia Vegetal, Embrapa Soja, Londrina, Brasil.
authors.forename: J F C
authors.initials: JF
authors.lastname: Carvalho
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: R F
authors.initials: RF
authors.lastname: Pagliarini
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: A S
authors.initials: AS
authors.lastname: Cruz
authors.affiliation: Departmento de Biometria, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: M C N
authors.initials: MC
authors.lastname: Oliveira
authors.affiliation: Laboratório de Ecofisiologia Vegetal, Embrapa Soja, Londrina, Brasil.
authors.forename: J R B
authors.initials: JR
authors.lastname: Farias
authors.affiliation: Laboratório de Ecofisiologia Vegetal, Embrapa Soja, Londrina, Brasil.
authors.forename: N
authors.initials: N
authors.lastname: Neumaier
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil.
authors.forename: F C M
authors.initials: FC
authors.lastname: Guimarães
authors.affiliation: Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kanamori
authors.affiliation: Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakashima
authors.affiliation: Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
authors.forename: K Y
authors.initials: KY
authors.lastname: Shinozaki
authors.affiliation: Departamento de Biologia Aplicada à Agricultura, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP, Brasil.
authors.forename: J A
authors.initials: JA
authors.lastname: Desidério
authors.affiliation: Laboratório de Biotecnologia Vegetal, Embrapa Soja, Londrina, PR, Brasil alexandre.nepomuceno@embrapa.br.
authors.forename: A L
authors.initials: AL
authors.lastname: Nepomuceno
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020218:Response Elements; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism; D019076:Transgenes; D014867:Water / Q000378:metabolism*
chemical_list: D000040:Abscisic Acid; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D014867:Water; C508877:At1g45249 protein, Arabidopsis