title: Activation of a calcium-dependent protein kinase involved in the Azospirillum growth promotion in rice.
abstract: Rice seedlings (Oryza sativa) inoculated with the plant growth-promoting rhizobacteria Azospirillum brasilense FT326 showed an enhanced development of the root system 3 days after inoculation. Later on, a remarkable enlargement of shoots was also evident. An increase in the Ca2+-dependent histone kinase activity was also detected as a result of inoculation. The biochemical characterization and Western-blot analysis of the kinase strongly supports the hypothesis that it belongs to a member of the rice CDPK family. The fact that the amount of the protein did not change upon inoculation seems to indicate that a posttranslational activation is responsible for the change in the enzymatic activity. An in-gel kinase experiment identified a 46 kDa CDPK like protein kinase as a putative component of the signal transduction pathway triggered by Azospirillum inoculation. To our knowledge, this is the first report on the possible involvement of a Ca2+-dependent protein kinase in promotion of rice plants growth by A. brasilense.
authors.affiliation: Cátedra de Bioquímica, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina. ribaudo@agro.uba.ar.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Ribaudo
authors.affiliation: Cátedra de Bioquímica, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: José A
authors.initials: JA
authors.lastname: Curá
authors.affiliation: Cátedra de Bioquímica, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: María L
authors.initials: ML
authors.lastname: Cantore
mesh_terms: D016949:Azospirillum / Q000378:metabolism / Q000502:physiology*; D004789:Enzyme Activation; D008970:Molecular Weight; D012275:Oryza / Q000201:enzymology / Q000254:growth & development* / Q000382:microbiology; D010766:Phosphorylation; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D011494:Protein Kinases; C454865:calcium-dependent protein kinase, rice; D017871:Calcium-Calmodulin-Dependent Protein Kinases
keywords: Azospirillum; CDPK; Lateral roots growth promotion; Rice