title: Assessment of the genetic diversity of Frankia microsymbionts of Elaeagnus angustifolia L. plants growing in a Tunisian date-palm oasis by analysis of PCR amplified nifD-K intergenic spacer.
abstract: Diversity of Frankia microsymbionts of non-native Elaeagnus angustifolia L. plants spontaneously growing in a Tunisian desertic retreat area, the date-palm oasis of Tozeur, was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-sequencing techniques targeting the nifD-K intergenic spacer. Three PCR-RFLP haplotypes (I, II, and III) were detected among collected nodules. Haplotype I was detected at all five sampling sites and dominated the other haplotypes present at these sites. This haplotype was also exhibited by strain BMG5.10, which was isolated by a plant-capturing assay in 1998 from soil collected in the same locality, qualifying it to be the most competitive haplotype in the edapho-climatic condition of the studied desertic date-palm oasis. nifD-K sequences of the three haplotypes formed a closely related phylogenetic subgroup. These results suggest that Frankia variability is constrained by severe edapho-climatic conditions of retreated desert in Tunisian area.
authors.affiliation: Laboratoire Microorganismes et Biomolécules Actives, Département de Biologie, Faculté des Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisia. maher.gtari@fst.rnu.tn
authors.forename: Maher
authors.initials: M
authors.lastname: Gtari
authors.forename: Daniele
authors.initials: D
authors.lastname: Daffonchio
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous
mesh_terms: D028023:Arecaceae / Q000254:growth & development*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D003889:Desert Climate; D031263:Elaeagnaceae / Q000254:growth & development / Q000382:microbiology*; D040161:Frankia / Q000145:classification* / Q000235:genetics; D014644:Genetic Variation; D006239:Haplotypes; D009586:Nitrogen Fixation / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012988:Soil Microbiology; D014416:Tunisia
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer