title: Endophytic colonization and in planta nitrogen fixation by a diazotrophic Serratia sp. in rice.
abstract: Nitrogen fixing endophytic Serratia sp. was isolated from rice and characterized. Re-colonization ability of Serratia sp. in the rice seedlings as endophyte was studied under laboratory condition. For detecting the re-colonization potential in the rice seedlings, Serratia sp. was marked with reporter genes (egfp and Kmr) using transposon mutagenesis. The conjugants were screened for re-colonization ability and presence of nif genes using PCR. Further, the influence of flavonoids and growth hormones on the endophytic colonization and in planta nitrogen fixation of Serratia was also investigated. The flavonoids, quercetin (3 microg/ml) and diadzein (2 microg/ml) significantly increased the re-colonization ability of the endophytic Serratia, whereas the growth hormones like IAA and NAA (5 microg/ml) reduced the endophytic colonization ability of Serratia sp. Similarly, the in planta nitrogen fixation by Serratia sp. in rice was significantly increased due to flavonoids. The inoculation of endophytic diazotrophs increased the plant biomass and biochemical constituents.
authors.affiliation: Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore 641 003.
authors.forename: G S
authors.initials: GS
authors.lastname: Sandhiya
authors.forename: T C K
authors.initials: TC
authors.lastname: Sugitha
authors.forename: D
authors.initials: D
authors.lastname: Balachandar
authors.forename: K
authors.initials: K
authors.lastname: Kumar
mesh_terms: D018533:Biomass; D003470:Culture Media / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry; D017930:Genes, Reporter; D005819:Genetic Markers; D007210:Indoleacetic Acids / Q000494:pharmacology; D016296:Mutagenesis; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D009586:Nitrogen Fixation; D012275:Oryza / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018517:Plant Roots / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012705:Serratia / Q000378:metabolism*; D013997:Time Factors
chemical_list: D003470:Culture Media; D005419:Flavonoids; D005819:Genetic Markers; D007210:Indoleacetic Acids; D009280:Naphthaleneacetic Acids; D010937:Plant Growth Regulators; C034182:1-naphthaleneacetic acid; C030737:indoleacetic acid