2026-05-31T18:53:39Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/280152026-02-03T11:27:56Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Tienda Serrano, Sandra author Gutiérrez Barranquero, José Antonio author Padilla-Roji, Isabel author Arrebola-Díez, Eva María author De-Vicente-Moreno, Antonio author Cazorla-López, Francisco Manuel author 2023-10-19 Pseudomonas chlororaphis PCL1606 (PcPCL1606) is a model rhizobacterium used to study beneficial bacterial interactions with the plant rhizosphere. Many of its beneficial phenotypes depend on the production of the antifungal compound 2-hexyl, 5-propyl resorcinol (HPR). Transcriptomic analysis of PcPCL1606 and the dele-tional mutant in HPR production ΔdarB strain, assigned an additional regulatory role to HPR, and allowed the detection of differentially expressed genes during the bacterial interaction with the avocado rhizosphere. Interestingly, the putative genes phaG (PCL1606_46820) and phaI (PCL1606_56560), with a predicted role in polyhydroxyalkanoate biosynthesis, were detected to be under HPR control. Both putative genes were expressed in the HPR-producing wild-type strain, but strongly repressed in the derivative mutant ΔdarB, impaired in HPR production. Thus, a derivative mutant impaired in the phaG gene was constructed, characterized and compared with the wild-type strain PcPCL1606 and with the derivative mutant ΔdarB. The phaG mutant had strongly reduced PHA production by PcPCL1606, and displayed altered phenotypes involved in bacterial survival on the plant roots, such as tolerance to high temperature and hydrogen peroxide, and decreased root survival, in a similar way that the ΔdarB mutant. On the other hand, the phaG mutant does not have altered resistance to desiccation, motility, biofilm formation or adhesion phenotypes, as displayed by the HPR-defective ΔdarB mutant have. Interestingly, the mutant defective in PHA production also lacked a biocontrol phenotype against the soilborne pathogenic fungus Rosellinia necatrix, even when the derivative mutant still produced the antifungal HPR compound, demonstrating that the final biocontrol phenotype of PcPCL1606 first requires bacterial survival and adaptation traits to the soil and rhizosphere environment. Sandra Tienda, José Antonio Gutiérrez-Barranquero, Isabel Padilla-Roji, Eva Arrebola, Antonio de Vicente, Francisco M. Cazorla, Polyhydroxyalkanoate production by the plant beneficial rhizobacterium Pseudomonas chlororaphis PCL1606 influences survival and rhizospheric performance, Microbiological Research, Volume 278, 2024, 127527, ISSN 0944-5013, https://doi.org/10.1016/j.micres.2023.127527. https://hdl.handle.net/10630/28015 10.1016/j.micres.2023.127527 Aguacate - Cultivo Agentes de control biológico de plagas Raíces (Botánica) -- Enfermedades y plagas Aguacate - Efectos del estrés Polyhydroxyalkanoate production by the plant beneficial rhizobacterium Pseudomonas chlororaphis PCL1606 influences survival and rhizospheric performance