title: Putrescine accumulation in Arabidopsis thaliana transgenic lines enhances tolerance to dehydration and freezing stress.
abstract: Polyamines have been globally associated to plant responses to abiotic stress. Particularly, putrescine has been related to a better response to cold and dehydration stresses. It is known that this polyamine is involved in cold tolerance, since Arabidopsis thaliana plants mutated in the key enzyme responsible for putrescine synthesis (arginine decarboxilase, ADC; EC 4.1.1.19) are more sensitive than the wild type to this stress. Although it is speculated that the over-expression of ADC genes may confer tolerance, this is hampered by pleiotropic effects arising from the constitutive expression of enzymes from the polyamine metabolism. Here, we present our work using A. thaliana transgenic plants harboring the ADC gene from oat under the control of a stress-inducible promoter (pRD29A) instead of a constitutive promoter. The transgenic lines presented in this work were more resistant to both cold and dehydration stresses, associated with a concomitant increment in endogenous putrescine levels under stress. Furthermore, the increment in putrescine upon cold treatment correlated with the induction of known stress-responsive genes, and suggested that putrescine may be directly or indirectly involved in ABA metabolism and gene expression.
authors.affiliation: IIB-INTECH, Unidad de Biotecnología, Chascomús; Buenos Aires, Argentina.
authors.forename: Analía I
authors.initials: AI
authors.lastname: Alet
authors.forename: Diego H
authors.initials: DH
authors.lastname: Sanchez
authors.forename: Juan C
authors.initials: JC
authors.lastname: Cuevas
authors.forename: Secundino
authors.initials: S
authors.lastname: Del Valle
authors.forename: Teresa
authors.initials: T
authors.lastname: Altabella
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Tiburcio
authors.forename: Francisco
authors.initials: F
authors.lastname: Marco
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferrando
authors.forename: Fabiana D
authors.initials: FD
authors.lastname: Espasandín
authors.forename: María E
authors.initials: ME
authors.lastname: González
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Ruiz
authors.forename: Pedro
authors.initials: P
authors.lastname: Carrasco
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000064:Acclimatization; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D003681:Dehydration; D049308:Dioxygenases / Q000378:metabolism; D005615:Freezing; D010940:Plant Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C520629:RD29a protein, Arabidopsis; D000040:Abscisic Acid; D049308:Dioxygenases; C109043:9-cis-epoxy-carotenoid dioxygenase; D011700:Putrescine