title: Cold-adapted and rhizosphere-competent strain of Rahnella sp. with broad-spectrum plant growth-promotion potential.
abstract: A phosphate-solubilizing bacterial strain isolated from Hippophae rhamnoides rhizosphere was identified as Rahnella sp. based on its phenotypic features and 16S rRNA gene sequence. The bacterial strain showed the growth characteristics of a cold-adapted psychrotroph, with the multiple plant growth-promoting traits of inorganic and organic phosphate solubilization, 1-aminocyclopropane-1- carboxylate-deaminase activity, ammonia generation, and siderophore production. The strain also produced indole- 3-acetic acid, indole-3-acetaldehyde, indole-3-acetamide, indole-3-acetonitrile, indole-3-lactic acid, and indole-3- pyruvic acid in tryptophan-supplemented nutrient broth. Gluconic, citric and isocitric acids were the major organic acids detected during tricalcium phosphate solubilization. A rifampicin-resistant mutant of the strain exhibited high rhizosphere competence without disturbance to the resident microbial populations in pea rhizosphere. Seed bacterization with a charcoal-based inoculum significantly increased growth in barley, chickpea, pea, and maize under the controlled environment. Microplot testing of the inoculum at two different locations in pea also showed significant increase in growth and yield. The attributes of coldtolerance, high rhizosphere competence, and broad-spectrum plant growth-promoting activity exhibited the potential of Rahnella sp. BIHB 783 for increasing agriculture productivity.
authors.affiliation: Plant Pathology and Microbiology Laboratory, Hill Area Tea Sciences, Institute of Himalayan Bioresource Technology, Council of Scientific and Industrial Research, P.O. Box No. 6, Palampur-176 061, Himachal Pradesh, India.
authors.forename: Pratibha
authors.initials: P
authors.lastname: Vyas
authors.forename: Robin
authors.initials: R
authors.lastname: Joshi
authors.forename: K C
authors.initials: KC
authors.lastname: Sharma
authors.forename: Praveen
authors.initials: P
authors.lastname: Rahi
authors.forename: Ashu
authors.initials: A
authors.lastname: Gulati
authors.forename: Arvind
authors.initials: A
authors.lastname: Gulati
mesh_terms: D000641:Ammonia / Q000378:metabolism; D029863:Cicer / Q000254:growth & development / Q000382:microbiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D031281:Hippophae / Q000254:growth & development / Q000382:microbiology*; D001467:Hordeum / Q000254:growth & development / Q000382:microbiology; D007211:Indoles / Q000378:metabolism*; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020638:Rahnella / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D017262:Siderophores / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007211:Indoles; D010710:Phosphates; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; D017262:Siderophores; D000641:Ammonia; C001446:indoleacrylic acid