Pseudomonas citronellolis; a multi-metal resistant and potential plant growth promoter against arsenic (V) stress in chickpea

• Published in: Plant physiology and biochemistry 2019-09, Vol.142, p.179-192
• Main Authors: Adhikary, Arindam, Kumar, Rajiv, Pandir, Ranjna, Bhardwaj, Pankaj, Wusirika, Ramakrishna, Kumar, Sanjeev
• Format: Article
• Language: English
• Subjects: Agricultural Inoculants; Arsenic; Arsenic - toxicity; Chlorophyll - metabolism; Cicer - drug effects; Cicer - growth & development; Cicer - microbiology; Drug Resistance, Multiple, Bacterial - drug effects; Electrolytes - metabolism; Environmental Pollution; Heavy metals; India; Malondialdehyde - metabolism; Metals, Heavy - toxicity; Minimum inhibitory concentrations (MIC); Phylogeny; Plant growth promoting bacteria; Plant Roots - drug effects; Plant Roots - growth & development; Plant Roots - microbiology; Plant Shoots - drug effects; Plant Shoots - growth & development; Pseudomonas; Pseudomonas - drug effects; Pseudomonas - isolation & purification; Pseudomonas - physiology; RNA, Ribosomal, 16S; Soil Microbiology
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2019.07.006

Soil micro-biota plays a vital role in maintaining plant growth and fitness under normal and adverse conditions. Pseudomonas is one of the most important free-living and copious genera in south-west Punjab and involved in plant growth promotion under heavy metal stress. In this study, we have studied microbial diversity of the agricultural and marginal land based on 16S rRNA gene and screened eight strains of Pseudomonas for its tolerances towards various heavy metals and for plant growth promoting properties (PGP). The best strain is tested in chickpea plants against Arsenic (As5+) stress. All the strains responded differently to heavy metals viz. Arsenic, (As5+ (0.3–0.5M) and As3+ (250 μg mL−1) Cadmium (Cd2+) (250–350 μg mL−1), Chromium (Cr2+) (200–350 μg mL−1) and Mercury (Hg2+) (1–2 μg mL−1). Out of eight strains, only two strains (KM594398 and KM594397) showed plant growth promoting characters, concurrently they were highly tolerant to Arsenic (As5+). Pseudomonas citronellolis (PC) (KM594397) showed the best results in terms of As5+ tolerance and plant growth promoting activity, hence further tested for actual plant growth response in chickpea (Cicer arietinum L.) under As5+ (10–160 mg kg−1) stress. Pseudomonas citronellolis enhanced plant growth and dry biomass under As5+ stress. High As5+ tolerance and plant growth promoting activity of Pseudomonas citronellolis in chickpea especially designate this strain suitable for marginal lands and heavy metals contaminated sites. •Pseudomonas was found to be the most copius genera in agricultural and abandoned land around Bathinda.•Isolated Pseudomonas showed tolerances towards non-essential heavy metals and metalloid such as Arsenic, Cadmium, Mercury, and Chromium.•Isolated Pseudomonas was found to possesses Plant growth promoting properties.•Application of isolate KM594397 (Pseudomonas citronellolis) showed improvement in Chickpea growth under Arsenic stress.