PGPR-mediated expression of salt tolerance gene in soybean through volatiles under sodium nitroprusside

• Published in: Journal of basic microbiology Vol. 56; no. 11; pp. 1274 - 1288
• Main Authors: Vaishnav, Anukool, Kumari, Sarita, Jain, Shekhar, Varma, Ajit, Tuteja, Narendra, Choudhary, Devendra Kumar
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 01.11.2016
• Subjects: biofilm; Biofilms - growth & development; catalase; Catalase - genetics; catechol oxidase; chemotaxis; electrolytes; gas chromatography-mass spectrometry; GC-MS; gene expression; gene expression regulation; Gene Expression Regulation, Plant; genes; Germination - drug effects; Glycine max - drug effects; Glycine max - genetics; Glycine max - growth & development; Glycine max - microbiology; linoleate 13S-lipoxygenase; Lipid Peroxidation; metabolism; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Donors - metabolism; nitrite reductase; Nitrite Reductases - genetics; nitroprusside; Nitroprusside - metabolism; Nitroprusside - pharmacology; peroxidase; Peroxidase - genetics; plant growth-promoting rhizobacteria; Plant Roots - microbiology; potassium; Pseudomonas; Pseudomonas - metabolism; Pseudomonas simiae; qRT-PCR; quantitative polymerase chain reaction; quinoline; Quinolines - metabolism; reverse transcriptase polymerase chain reaction; Rhizosphere; Rhizospheric colonization; root exudates; Salinity; salt stress; salt tolerance; Salt Tolerance - genetics; seed germination; seedlings; Seedlings - drug effects; Seedlings - growth & development; Seedlings - microbiology; sodium chloride; Sodium Chloride - metabolism; Soil Microbiology; soybeans; Stress, Physiological; transcription (genetics); volatile organic compounds; Volatile Organic Compounds - metabolism; GC-MS; Pseudomonas simiae; Rhizospheric colonization; Nitric oxide; qRT-PCR; Salinity
• ISSN: 0233-111X; 1521-4028; 1521-4028
• DOI: 10.1002/jobm.201600188

Increasing evidence shows that nitric oxide (NO), a typical signaling molecule plays important role in development of plant and in bacteria‐plant interaction. In the present study, we tested the effect of sodium nitroprusside (SNP)‐a nitric oxide donor, on bacterial metabolism and its role in establishment of PGPR‐plant interaction under salinity condition. In the present study, we adopted methods namely, biofilm formation assay, GC‐MS analysis of bacterial volatiles, chemotaxis assay of root exudates (REs), measurement of electrolyte leakage and lipid peroxidation, and quantitative reverse transcription–polymerase chain reaction (qRT–PCR) for gene expression. GC‐MS analysis revealed that three new volatile organic compounds (VOCs) were expressed after treatment with SNP. Two VOCs namely, 4‐nitroguaiacol and quinoline were found to promote soybean seed germination under 100 mM NaCl stress. Chemotaxis assay revealed that SNP treatment, altered root exudates profiling (SS‐RE), found more attracted to Pseudomonas simiae bacterial cells as compared to non‐treated root exudates (S‐RE) under salt stress. Expression of Peroxidase (POX), catalase (CAT), vegetative storage protein (VSP), and nitrite reductase (NR) genes were up‐regulated in T6 treatment seedlings, whereas, high affinity K+ transporter (HKT1), lipoxygenase (LOX), polyphenol oxidase (PPO), and pyrroline‐5‐carboxylate synthase (P5CS) genes were down‐regulated under salt stress. The findings suggest that NO improves the efficiency and establishment of PGPR strain in the plant environment during salt condition. This strategy may be applied on soybean plants to increase their growth during salinity stress.