title: Polyamine metabolism and biosynthetic gene expression in Arabidopsis thaliana under salt stress.
abstract: In the present study we analysed polyamine metabolism in Arabidopsis thaliana (ecotype Columbia) rosette leaves collected at vegetative and reproductive stages from plants germinated and grown under increasing salt stress (0-75 mM NaCl) conditions. The expression level of the different isoforms of polyamine biosynthetic enzymes was analysed by reverse transcriptase-polymerase chain reaction (RT-PCR) and the polyamine biosynthetic enzyme activities were determined both in supernatant and pellet fractions. Free and perchloric acid (PCA)-conjugated (soluble and insoluble) polyamines, were measured. At vegetative stage, plants were able to adapt up to 50 mM NaCl, showing a significant growth inhibition only at 75 mM NaCl. At this growth stage and NaCl concentration there was an up-regulation of spermine biosynthesis. At reproductive stage, plants were able to flower up to 50 mM NaCl, even if with a delay of 7 days. On the contrary, at 75 mM NaCl two different phenotypes were isolated: 75/01 (salt sensitive) and 75/02 (salt tolerant). The sensitive plants (75/01) showed a severely stressed phenotype, compared to the tolerant ones (75/02), and the polyamine metabolism was up-regulated, with the increase of free putrescine and spermine.
authors.affiliation: Department of Biology and Interdepartmental Centre for Biotechnology, University of Bologna, Via Irnerio 42, 40126, Bologna, Italy. bagninel@alma.unibo.it
authors.forename: N
authors.initials: N
authors.lastname: Bagni
authors.forename: K
authors.initials: K
authors.lastname: Ruiz-Carrasco
authors.forename: M
authors.initials: M
authors.lastname: Franceschetti
authors.forename: S
authors.initials: S
authors.lastname: Fornalè
authors.forename: R B
authors.initials: RB
authors.lastname: Fornasiero
authors.forename: A
authors.initials: A
authors.lastname: Tassoni
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D009997:Osmotic Pressure / Q000187:drug effects; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology*; D013096:Spermine / Q000096:biosynthesis*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D010940:Plant Proteins; D013096:Spermine; D012965:Sodium Chloride