Journal
MICROBIAL ECOLOGY
Volume 81, Issue 3, Pages 717-730Publisher
SPRINGER
DOI: 10.1007/s00248-020-01629-z
Keywords
Plant growth-promoting microorganisms; Antioxidant activity; Plant stress responses; Host adaptation
Categories
Ask authors/readers for more resources
The application of siderophore-producing microorganisms (SPMs) has been shown to enhance plant growth and survival under heavy metals toxicity, particularly in response to cadmium (Cd) stress. SPMs, including bacteria and fungi, were found to improve the fitness of alfalfa by increasing biomass and nutrient uptake, mitigating Cd-induced oxidative stress through enhanced antioxidant enzyme activities. Overall, plant-associated microbes present an efficient and environmentally friendly approach to help plants survive in Cd-contaminated soil.
Application of siderophore-producing microorganisms (SPMs), as an environmentally friendly approach, facilitates plant growth and survival under heavy metals toxicity. This study evaluated the effectiveness of SPMs, belonging to the bacterial genera Rhizobium and Pseudomonas and a root endophytic fungus (Piriformospora indica) to improve the fitness of alfalfa under cadmium (Cd) stress. A greenhouse experiment was performed as a randomized design with factorial arrangement of treatments. Treatments included microbial inoculations (Sinorhizobium meliloti, Pseudomonas fluorescence, and P. indica) and different Cd concentrations (0, 2, 5, 10 mg/kg) with three replications in potting media containing sand and sterile perlite (v/v, 2:1). The effect of Cd on plant growth and development, antioxidant enzymes activities, and accumulation of Cd and nutrients in alfalfa plant was investigated. Alfalfa inoculated with SPMs showed significantly higher biomass and nutrients uptake under both normal and Cd stress conditions than the controls. Under the highest Cd concentration (10 mg/kg), alfalfa plants inoculated with P. fluorescens and P. indica, either alone or in combination, showed the highest shoot dry weights. Cd-induced oxidative stress was mitigated by SPMs through enhanced antioxidant enzyme activities of catalase, ascorbate peroxidase, and guaiacol peroxidase. We showed that P. indica either alone or in combination with the siderophore producing bacteria (SPB) minimized the toxicity of Cd by enhanced growth rate and the lower Cd concentration in the shoots. In conclusion, metal-resistant SPMs could assist alfalfa to survive in Cd-contaminated soil by enhancing plant growth and development. Application of plant-associated microbes is an efficient, environmentally friendly approach to surmount the adverse effects of heavy metals toxicity on plants, animals, and humans.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available