title: Homeostatic control of polyamine levels under long-term salt stress in Arabidopsis: changes in putrescine content do not alleviate ionic toxicity.
abstract: Salt stress has been frequently studied in its first osmotic phase. Very often, data regarding the second ionic phase is missing. It has also been suggested that Putrescine or/and Spermine could be responsible for salt resistance. In order to test this hypothesis under long-term salt stress, we obtained Arabidopsis thaliana transgenic plants harboring pRD29A::oatADC or pRD29A::GUS construction. Although Putrescine was the only polyamine significantly increased after salt acclimation in pRD29A::oatADC transgenic lines, this rendered in no advantage to this kind of stress. The higher Spermine levels found in WT and transgenic lines when compared to control conditions along with no increment on Putrescine levels in WT plants under salt acclimation, leads us to analyze Spermine effect on pADC1 and pADC2 expression. Increasing levels of this polyamine inhibits these promoters expression while enhances pRD29A expression, making Spermine the polyamine responsible for salt acclimation, and the transgenic lines developed in this work suitable for studying Putrescine roles in conditions where its biosynthesis would be inhibited in the WT genotype.
authors.affiliation: Unidad de Biotecnología, IIB-INTECH (UNSAM-CONICET), Buenos Aires, Argentina.
authors.forename: Analía I
authors.initials: AI
authors.lastname: Alet
authors.forename: Diego H
authors.initials: DH
authors.lastname: Sánchez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferrando
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Tiburcio
authors.forename: Ruben
authors.initials: R
authors.lastname: Alcazar
authors.forename: Juan Cruz
authors.initials: JC
authors.lastname: Cuevas
authors.forename: Teresa
authors.initials: T
authors.lastname: Altabella
authors.forename: Francisco Marco
authors.initials: FM
authors.lastname: Pico
authors.forename: Pedro
authors.initials: P
authors.lastname: Carrasco-Sorli
authors.forename: Ana B
authors.initials: AB
authors.lastname: Menéndez
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Ruiz
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000064:Acclimatization; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018554:Avena / Q000235:genetics; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D006706:Homeostasis; D030821:Plants, Genetically Modified / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D054712:Salinity; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D011073:Polyamines; C520629:RD29a protein, Arabidopsis; D000040:Abscisic Acid; D002262:Carboxy-Lyases; C019722:arginine decarboxylase