Bioaugmentation with copper tolerant endophyte Pseudomonas lurida strain EOO26 for improved plant growth and copper phytoremediation by Helianthus annuus

• Published in: Chemosphere (Oxford) Vol. 266; p. 128983
• Main Authors: Kumar, Adarsh, Tripti, Voropaeva, Olga, Maleva, Maria, Panikovskaya, Ksenia, Borisova, Galina, Rajkumar, Mani, Bruno, L. Benedict
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2021
• Subjects: Biodegradation, Environmental; Copper - analysis; Copper uptake; Drought tolerance; Endophytes - genetics; Helianthus; IAA production; Phosphate solubilization; Plant growth promoting bacteria; Plant Roots - chemistry; Pseudomonas; RNA, Ribosomal, 16S - genetics; Soil Microbiology; Soil Pollutants - analysis; pH; Plant growth promoting bacteria; IAA production; Phosphate solubilization; Copper uptake; Drought tolerance
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.128983

Organic fertilizers became a better alternative to chemical fertilizers in modern agricultural practices however, contamination of copper (Cu) from organic fertilizer is still a major concern for the globe. Plant growth promoting (PGP) microorganisms showed their efficiency to combat with this problem and thus Cu tolerant PGP endophytes from roots of Odontarrhena obovata (Alyssum obovatum) growing on Cu smelter contaminated serpentine soil were explored in present study. Out of twenty-four isolates, Pseudomonas lurida strain EOO26 identified by 16s rRNA gene sequencing was selected to check its efficacy for Cu-remediation. The strain EOO26 showed multi-metal tolerance, drought resistance and exhibited PGP attributes such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophore and ammonia production. Significant production of indole-3-acetic acid and phosphate-solubilization under different Cu concentration (0–100 mg L−1) at varying pH (5.0–8.0) suggests potentiality of this strain to work effectively under wide range of abiotic stress conditions. Plant growth experiment (pH 6.8 ± 0.3) in copper spiked soil suggested a significant increase in length and dry weight of root and shoot of sunflower (Helianthus annuus) after inoculation with strain EOO26. Plants inoculated with strain EOO26 resulted in increase in Cu uptake by 8.6-fold for roots and 1.9-fold for leaves than uninoculated plants. The total plant uptake in inoculated Cu treatment was 2.6-fold higher than uninoculated one, which is much higher than the previously reported Cu accumulating plants. The excellent adaptation abilities and promising metal removal efficiency strongly indicate superiority of strain EOO26 for phytoremediation of Cu-contamination and may work effectively for Cu removal from contaminated soils. •Pseudomonas lurida strain EOO26 is a potential metal and drought tolerant endophyte.•EOO26 showed various PGP traits and Cu enhances IAA production over control.•Produces IAA and solubilizes phosphate under wide range of pH and Cu content.•EOO26 improved biometric growth parameters of Helianthus annuus.•EOO26 enhanced Cu accumulation in roots and leaves, and total Cu uptake.