title: The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments.
abstract: It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus.
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Rodríguez-Andrade
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Fuentes-Ramírez
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: Yolanda E
authors.initials: YE
authors.lastname: Morales-García
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: Dalia
authors.initials: D
authors.lastname: Molina-Romero
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: María R
authors.initials: MR
authors.lastname: Bustillos-Cristales
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México.
authors.forename: Rebeca D
authors.initials: RD
authors.lastname: Martínez-Contreras
authors.affiliation: Laboratorio Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas (CICM)-Instituto de Ciencias (IC), Benemérita Universidad Autónoma de Puebla (BUAP), Puebla, México. Electronic address: joymerre@yahoo.com.mx.
authors.forename: Jesús
authors.initials: J
authors.lastname: Muñoz-Rojas
mesh_terms: D041821:Gluconacetobacter / Q000302:isolation & purification*; D009584:Nitrogen / Q000008:administration & dosage*; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000382:microbiology*; D031786:Saccharum / Q000382:microbiology*
chemical_list: D009584:Nitrogen
keywords: Bacterial population; Bacterias promotoras del crecimiento de plantas; Caña de azúcar; Fertilización nitrogenada; G. diazotrophicus; Nitrogen fertilization; Plant growth promoting bacteria; Población bacteriana; Sugarcane