The interactions between microorganisms sharing the same phyllosphere
environment can be highly relevant for plant health. Although such interactions are
ubiquitous in nature, the possible interaction between the incoming pathogen and the
resident microbial flora, as well as the impact of these interactions on disease
development/suppression, are unknown and not understood. To assess this, we will use in
this study the olive knot disease as a model system. This disease is caused by the bacterium
Pseudomonas savastanoi pv. savastanoi (Psv), that produced knots, mainly on olive tree
twigs and young branches.
Endophytic and epiphytic bacterial were isolated from asymptomatic twigs and knots
of olive trees from two cultivars with different susceptibilities to olive knot (cv. Verdeal-
Transmontana - susceptible; cv. Cobrançosa - tolerant). Bacterial isolates obtained were
molecularly identified through sequencing of V1 - V4 regions from 16S rDNA. Overall, 73
species belonging to 37 genera were identified. The composition of bacterial community
colonizing asymptomatic twigs changed drastically when becomes diseased. A set of
bacterial was showed to be highly associated with either asymptomatic twigs or knot of each
cultivar, suggesting that they might h
also to be extremely different between cultivars, suggesting an effect of the cultivar in
bacterial community assemblage. Future research should be carried out in order to identify
it these bacterial-bacterial and bacterial-plant interactions can be really part of host defense
against olive knot disease.This work is funded by FEDER funds through COMPETE (Programa Operacional
Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia)
in the framework of the project EXCL/AGR-PRO/0591/2012. D. MINA thanks the Fundação para a
Ciência e Tecnologia (FCT), Portugal for the Ph.D. grant SFRH/BD/105341/2014info:eu-repo/semantics/publishedVersio
