Isolation and characterization of endophytic plant growth-promoting (PGPB) or stress homeostasis-regulating (PSHB) bacteria associated to the halophyte Prosopis strombulifera.
This study was designed to isolate and characterize endophytic bacteria from halophyte Prosopis strombulifera grown under extreme salinity and to evaluate in vitro the bacterial mechanisms related to plant growth promotion or stress homeostasis regulation. Isolates obtained from P. strombulifera were compared genotypically by BOX-polymerase chain reaction, grouped according to similarity, and identified by amplification and partial sequences of 16S DNAr. Isolates were grown until exponential growth phase to evaluate the atmospheric nitrogen fixation, phosphate solubilization, siderophores, and phytohormones, such as indole-3-acetic acid, zeatin, gibberellic acid and abscisic acid production, as well as antifungal, protease, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. A total of 29 endophytic strains were grouped into seven according to similarity. All bacteria were able to grow and to produce some phytohormone in chemically defined medium with or without addition of a nitrogen source. Only one was able to produce siderophores, and none of them solubilized phosphate. ACC deaminase activity was positive for six strains. Antifungal and protease activity were confirmed for two of them. In this work, we discuss the possible implications of these bacterial mechanisms on the plant growth promotion or homeostasis regulation in natural conditions.
Sgroy
Verónica
V
Laboratorio de Fisiología Vegetal. Facultad de Ciencias Exactas, Universidad Nacional de Río Cuarto, CP 5800 Río Cuarto, Córdoba, Argentina.
Cassán
Fabricio
F
Masciarelli
Oscar
O
Del Papa
María Florencia
MF
Lagares
Antonio
A
Luna
Virginia
V
D000397:Air Pollution; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D018556:Crops, Agricultural / Q000254:growth & development; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000235:genetics; D055864:Droughts; D004926:Escherichia coli / Q000235:genetics; D005784:Gene Amplification; D005838:Genotype; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000032:analysis; D009700:Nucleoside Deaminases / Q000378:metabolism; D010575:Pesticides / Q000032:analysis; D010937:Plant Growth Regulators / Q000737:chemistry / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D029862:Prosopis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012987:Soil / Q000032:analysis
D017931:DNA Primers; D004269:DNA, Bacterial; D018744:DNA, Plant; D004275:DNA, Ribosomal; D019216:Metals, Heavy; D010575:Pesticides; D010937:Plant Growth Regulators; D012987:Soil; D009700:Nucleoside Deaminases