Impact of motility and chemotaxis features of the rhizobacterium Pseudomonas chlororaphis PCL1606 on its biocontrol of avocado white root rot

Autors/ores

  • Álvaro Polonio Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC. Departamento de Microbiología, Facultad de Ciencias, Campus de Teatinos, 29071 Málaga, Spain
  • Carmen Vida Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC. Departamento de Microbiología, Facultad de Ciencias, Campus de Teatinos, 29071 Málaga, Spain
  • Antonio de Vicente Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC. Departamento de Microbiología, Facultad de Ciencias, Campus de Teatinos, 29071 Málaga, Spain
  • Francisco M. Cazorla Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC. Departamento de Microbiología, Facultad de Ciencias, Campus de Teatinos, 29071 Málaga, Spain

Paraules clau:

Pseudomonas chlororaphis, Rosellinia necatrix, avocado white root rot, multitrophic interactions, rhizosphere

Resum

The biocontrol rhizobacterium Pseudomonas chlororaphis PCL1606 has the ability to protect avocado plants against white root rot produced by the phytopathogenic fungus Rosellinia necatrix. Moreover, PCL1606 displayed direct interactions with avocado roots and the pathogenic fungus. Thus, nonmotile (flgK mutant) and non-chemotactic (cheA mutant) derivatives of PCL1606 were constructed to emphasize the importance of motility and chemotaxis in the biological behaviour of PCL1606 during the biocontrol interaction. Plate chemotaxis assay showed that PCL1606 was attracted to the single compounds tested, such as glucose, glutamate, succinate, aspartate and malate, but no chemotaxis was observed to avocado or R. necatrix exudates. Using the more sensitive capillary assay, it was reported that smaller concentrations (1 mM) of single compounds elicited high chemotactic responses, and strong attraction was confirmed to avocado and R. necatrix exudates. Finally, biocontrol experiments revealed that the cheA and fglK derivative mutants reduced root protection against R. necatrix, suggesting an important role for these biological traits in biocontrol by P. chlororaphis PCL1606. [Int Microbiol 20(2):94-104 (2017)]

Keywords: Pseudomonas chlororaphis · Rosellinia necatrix · avocado white root rot · multitrophic interactions · rhizosphere

Descàrregues

Número

Secció

Articles