Endófitos bacterianos y su potencial en biotecnología agrícola: el caso de pseudomonas fluorescens PICF7

Trabajo presentado en el VI Simposio Nacional de Bacteria Fitopatógenas, el V Simposio Internacional de Bacterias Fitopatógenas (2016) II Simposio de Bacterias Benéficas de las Plantas (2016), celebrados en guadalajara (México) del 22 al 24 de septiembrel de 2016.Endophytes, from the Greek ‘endon’ (inside) + ‘phyton’ (plant), are microorganisms (mainly bacteria and fungi) that can be detected at any moment within the tissues of healthy plants without producing any visible symptom. Phytopathogenic microorganisms, nitrogen-fixing nodule-producing bacteria and mycorrhizal fungi also exhibit endophytism during part of their life cycle, but they will not be considered in this presentation. Moreover, the focus will be on endophytic bacteria. Most of the components of plant-associated microbiomes colonize and persist on the surface of plant tissues/organs or in the rhizosphere, but some are also able to establish themselves as non-deleterious endophytes. It is now generally accepted that all plants harbor an amazing diversity of endophytic communities which play relevant roles, poorly understood though, in the development, growth and health of the host. They also help the plant to cope with diverse types of (a)biotic stresses. Powerful metagenomics and cultureindependent approaches are revealing that the plant inner microbiome is more diverse and complex than the rather partial portrait obtained by traditional culture-dependent methods. It must be emphasized that the ability of a given bacterium to internally colonize plant tissues must be verified by microscopy techniques, along with the demonstration of its capacity to recolonize plant tissues (e.g. from inoculation of disinfected seeds). Therefore, the mere isolation from surface-disinfected tissues is not enough to claim true endophytism.Research supported by grants P07-CVI02624 and P12-AGR667 (Junta de Andalucía, Spain), co-financed by ERDF from the EU.N