title: Putrescine is involved in Arabidopsis freezing tolerance and cold acclimation by regulating abscisic acid levels in response to low temperature.
abstract: The levels of endogenous polyamines have been shown to increase in plant cells challenged with low temperature; however, the functions of polyamines in the regulation of cold stress responses are unknown. Here, we show that the accumulation of putrescine under cold stress is essential for proper cold acclimation and survival at freezing temperatures because Arabidopsis (Arabidopsis thaliana) mutants defective in putrescine biosynthesis (adc1, adc2) display reduced freezing tolerance compared to wild-type plants. Genes ADC1 and ADC2 show different transcriptional profiles upon cold treatment; however, they show similar and redundant contributions to cold responses in terms of putrescine accumulation kinetics and freezing sensitivity. Our data also demonstrate that detrimental consequences of putrescine depletion during cold stress are due, at least in part, to alterations in the levels of abscisic acid (ABA). Reduced expression of NCED3, a key gene involved in ABA biosynthesis, and down-regulation of ABA-regulated genes are detected in both adc1 and adc2 mutant plants under cold stress. Complementation analysis of adc mutants with ABA and reciprocal complementation tests of the aba2-3 mutant with putrescine support the conclusion that putrescine controls the levels of ABA in response to low temperature by modulating ABA biosynthesis and gene expression.
authors.affiliation: Unitat de Fisiologia Vegetal, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Spain.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Cuevas
authors.forename: Rosa
authors.initials: R
authors.lastname: López-Cobollo
authors.forename: Rubén
authors.initials: R
authors.lastname: Alcázar
authors.forename: Xavier
authors.initials: X
authors.lastname: Zarza
authors.forename: Csaba
authors.initials: C
authors.lastname: Koncz
authors.forename: Teresa
authors.initials: T
authors.lastname: Altabella
authors.forename: Julio
authors.initials: J
authors.lastname: Salinas
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Tiburcio
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferrando
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D000064:Acclimatization; D000704:Analysis of Variance; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000235:genetics; D005615:Freezing; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016254:Mutagenesis, Insertional; D009154:Mutation; D011700:Putrescine / Q000378:metabolism* / Q000494:pharmacology; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018749:RNA, Plant; C036483:T-DNA; D000040:Abscisic Acid; D011700:Putrescine