title: Diversity of auxin-producing bacteria associated to Pseudomonas savastanoi -induced olive knots.
abstract: Forty three strains were isolated from knots induced by Pseudomonas savastanoi in different olive cultivars. All the selected bacteria were shown to produce variable amounts of the plant growth hormone indole-3-acetic acid (IAA). Amplification of the intergenic transcribed spacers (ITS) between 16S and 23S rDNA genes, allowed the clustering of the isolates into seven distinct groups. All isolates from ITS group 1 were positive to the Pseudomonas savastanoi pv. savastanoi specific iaa L gene as shown by PCR. Partial sequencing of 16S rDNA gene confirmed the identity of these isolates to Pseudomonas savastanoi strains and allowed to tentatively assign the other isolates from the remaining ITS groups to Pantoea oleae/agglomerans, Burkholderia cepacia, Pseudomonas putida, Stenotrophomonas maltophilia and Hafnia alvei. Identification of endophytic knot-derived isolates revealed association of various saprophytic and putative human pathogenic bacteria with P. savastanoi pv. savastanoi in knot environment of olive infected trees.
authors.affiliation: Laboratoire Microorganismes et Biomolécules Actives, Département de Biologie, Faculté des Sciences de Tunis, Tunisia. imene.ouzari@fst.rnu.tn
authors.forename: Hadda
authors.initials: H
authors.lastname: Ouzari
authors.forename: Amel
authors.initials: A
authors.lastname: Khsairi
authors.forename: Noura
authors.initials: N
authors.lastname: Raddadi
authors.forename: Leila
authors.initials: L
authors.lastname: Jaoua
authors.forename: Abdennaceur
authors.initials: A
authors.lastname: Hassen
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Zarrouk
authors.forename: Daniele
authors.initials: D
authors.lastname: Daffonchio
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Boudabous