title: Genetic diversity of bacterial communities of serpentine soil and of rhizosphere of the nickel-hyperaccumulator plant Alyssum bertolonii.
abstract: Serpentine soils are characterized by high levels of heavy metals (Ni, Co, Cr), and low levels of important plant nutrients (P, Ca, N). Because of these inhospitable edaphic conditions, serpentine soils are typically home to a very specialized flora including endemic species as the nickel hyperaccumulator Alyssum bertolonii. Although much is known about the serpentine flora, few researches have investigated the bacterial communities of serpentine areas. In the present study bacterial communities were sampled at various distances from A. bertolonii roots in three different serpentine areas and their genetic diversity was assessed by terminal restriction fragment length polymorphism (T-RFLP) analysis. The obtained results indicated the occurrence of a high genetic diversity and heterogeneity of the bacterial communities present in the different serpentine areas. Moreover, TRFs (terminal restriction fragments) common to all the investigated A. bertolonii rhizosphere samples were found. A new cloning strategy was applied to 27 TRFs that were sequenced and taxonomically interpreted as mainly belonging to Gram-positive and alpha-Proteobacteria representatives. In particular, cloned TRFs which discriminated between rhizosphere and soil samples were mainly interpreted as belonging to Proteobacteria representatives.
authors.affiliation: Dipartimento di Biologia Animale e Genetica, Università di Firenze, via Romana 17, I-50125, Firenze, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mengoni
authors.forename: E
authors.initials: E
authors.lastname: Grassi
authors.forename: R
authors.initials: R
authors.lastname: Barzanti
authors.forename: E G
authors.initials: EG
authors.lastname: Biondi
authors.forename: C
authors.initials: C
authors.lastname: Gonnelli
authors.forename: C K
authors.initials: CK
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Bazzicalupo
mesh_terms: D001419:Bacteria / Q000235:genetics*; D001483:Base Sequence; D019607:Brassicaceae / Q000382:microbiology*; D003001:Cloning, Molecular / Q000379:methods; D016000:Cluster Analysis; D017931:DNA Primers; D004262:DNA Restriction Enzymes / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D014644:Genetic Variation; D007558:Italy; D019216:Metals, Heavy / Q000032:analysis; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D025341:Principal Component Analysis; D017422:Sequence Analysis, DNA; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology
chemical_list: D017931:DNA Primers; D004275:DNA, Ribosomal; D019216:Metals, Heavy; D012987:Soil; D004262:DNA Restriction Enzymes