title: DNA profiling, telomere analysis and antioxidant properties as tools for monitoring ex situ seed longevity.
abstract: OBJECTIVE
  The germination test currently represents the most used method to assess seed viability in germplasm banks, despite the difficulties caused by the occurrence of seed dormancy. Furthermore, seed longevity can vary considerably across species and populations from different environments, and studies related to the eco-physiological processes underlying such variations are still limited in their depth. The aim of the present work was the identification of reliable molecular markers that might help in monitoring seed deterioration.
  
  
  METHODS
  Dry seeds were subjected to artificial ageing and collected at different time points for molecular/biochemical analyses. DNA damage was measured using the RAPD (random amplified polymorphic DNA) approach while the seed antioxidant profile was obtained using both the DPPH (1,1-diphenyl, 2-picrylhydrazyl) assay and the Folin-Ciocalteu reagent method. Electron paramagnetic resonance (EPR) provided profiles of free radicals. Quantitative real-time polymerase chain reaction (QRT-PCR) was used to assess the expression profiles of the antioxidant genes MT2 (type 2 metallothionein) and SOD (superoxide dismutase). A modified QRT-PCR protocol was used to determine telomere length.
  
  
  RESULTS
  The RAPD profiles highlighted different capacities of the two Silene species to overcome DNA damage induced by artificial ageing. The antioxidant profiles of dry and rehydrated seeds revealed that the high-altitude taxon Silene acaulis was characterized by a lower antioxidant specific activity. Significant upregulation of the MT2 and SOD genes was observed only in the rehydrated seeds of the low-altitude species. Rehydration resulted in telomere lengthening in both Silene species.
  
  
  CONCLUSIONS
  Different seed viability markers have been selected for plant species showing inherent variation of seed longevity. RAPD analysis, quantification of redox activity of non-enzymatic antioxidant compounds and gene expression profiling provide deeper insights to study seed viability during storage. Telomere lengthening is a promising tool to discriminate between short- and long-lived species.
authors.affiliation: Dipartimento di Biologia e Biotecnologie L. Spallanzani, Laboratori di Genetica e Microbiologia, Via Ferrata 1, 27100 Pavia, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Donà
authors.forename: A
authors.initials: A
authors.lastname: Balestrazzi
authors.forename: A
authors.initials: A
authors.lastname: Mondoni
authors.forename: G
authors.initials: G
authors.lastname: Rossi
authors.forename: L
authors.initials: L
authors.lastname: Ventura
authors.forename: A
authors.initials: A
authors.lastname: Buttafava
authors.forename: A
authors.initials: A
authors.lastname: Macovei
authors.forename: M E
authors.initials: ME
authors.lastname: Sabatini
authors.forename: A
authors.initials: A
authors.lastname: Valassi
authors.forename: D
authors.initials: D
authors.lastname: Carbonera
mesh_terms: D000531:Altitude; D000975:Antioxidants / Q000378:metabolism*; D016172:DNA Fingerprinting / Q000379:methods*; D017931:DNA Primers / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000235:genetics; D010636:Phenols / Q000378:metabolism; D010802:Phylogeny; D010936:Plant Extracts / Q000378:metabolism; D019105:Random Amplified Polymorphic DNA Technique; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000254:growth & development*; D029751:Silene / Q000235:genetics* / Q000254:growth & development*; D016615:Telomere / Q000378:metabolism*; D059505:Telomere Homeostasis / Q000235:genetics
chemical_list: D000975:Antioxidants; D017931:DNA Primers; D016166:Free Radical Scavengers; D010636:Phenols; D010936:Plant Extracts; D017382:Reactive Oxygen Species