title: Overexpression of Grain Amaranth (Amaranthus hypochondriacus) AhERF or AhDOF Transcription Factors in Arabidopsis thaliana Increases Water Deficit- and Salt-Stress Tolerance, Respectively, via Contrasting Stress-Amelioration Mechanisms.
abstract: Two grain amaranth transcription factor (TF) genes were overexpressed in Arabidopsis plants. The first, coding for a group VII ethylene response factor TF (i.e., AhERF-VII) conferred tolerance to water-deficit stress (WS) in transgenic Arabidopsis without affecting vegetative or reproductive growth. A significantly lower water-loss rate in detached leaves coupled to a reduced stomatal opening in leaves of plants subjected to WS was associated with this trait. WS tolerance was also associated with an increased antioxidant enzyme activity and the accumulation of putative stress-related secondary metabolites. However, microarray and GO data did not indicate an obvious correlation between WS tolerance, stomatal closure, and abscisic acid (ABA)-related signaling. This scenario suggested that stomatal closure during WS in these plants involved ABA-independent mechanisms, possibly involving reactive oxygen species (ROS). WS tolerance may have also involved other protective processes, such as those employed for methyl glyoxal detoxification. The second, coding for a class A and cluster I DNA binding with one finger TF (i.e., AhDof-AI) provided salt-stress (SS) tolerance with no evident fitness penalties. The lack of an obvious development-related phenotype contrasted with microarray and GO data showing an enrichment of categories and genes related to developmental processes, particularly flowering. SS tolerance also correlated with increased superoxide dismutase activity but not with augmented stomatal closure. Additionally, microarray and GO data indicated that, contrary to AhERF-VII, SS tolerance conferred by AhDof-AI in Arabidopsis involved ABA-dependent and ABA-independent stress amelioration mechanisms.
authors.affiliation: Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, C.P. 36821, Irapuato, Gto., México.
authors.forename: Julio A
authors.initials: JA
authors.lastname: Massange-Sánchez
authors.affiliation: Laboratorio de Biología Molecular, Instituto Tecnológico de Tlajomulco, Jalisco, km 10 Carretera a San Miguel Cuyutlán, CP 45640 Tlajomulco de Zúñiga, Jalisco, Mexico.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Palmeros-Suárez
authors.affiliation: Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Km 13.5 Carrretera Los Reyes-Texcoco, C.P. 56250, Coatlinchán Texcoco, Estado de México, México.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Espitia-Rangel
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, CP 36821, Irapuato, Gto., Mexico.
authors.forename: Isaac
authors.initials: I
authors.lastname: Rodríguez-Arévalo
authors.affiliation: Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, C.P. 36821, Irapuato, Gto., México.
authors.forename: Lino
authors.initials: L
authors.lastname: Sánchez-Segura
authors.affiliation: Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, C.P. 36821, Irapuato, Gto., México.
authors.forename: Norma A
authors.initials: NA
authors.lastname: Martínez-Gallardo
authors.affiliation: Conacyt Research Fellow-Colegio de Postgraduados, Campus Campeche. Carretera Haltunchen-Edzna Km 17.5, Sihochac, Champoton, 24450, Campeche, México.
authors.forename: Fulgencio
authors.initials: F
authors.lastname: Alatorre-Cobos
authors.affiliation: Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, C.P. 36821, Irapuato, Gto., México.
authors.forename: Axel
authors.initials: A
authors.lastname: Tiessen
authors.affiliation: Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, C.P. 36821, Irapuato, Gto., México.
authors.forename: John P
authors.initials: JP
authors.lastname: Délano-Frier
mesh_terms: D027721:Amaranthus / Q000378:metabolism*; D000595:Amino Acid Sequence; D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000502:physiology; D030821:Plants, Genetically Modified / Q000378:metabolism; D011765:Pyruvaldehyde / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance; D016415:Sequence Alignment; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D014157:Transcription Factors / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D004268:DNA-Binding Proteins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; C093680:ethylene-responsive element binding protein; D012965:Sodium Chloride; D011765:Pyruvaldehyde; D013482:Superoxide Dismutase