Abstract
Background: Applications of bioinoculants for improving crop productivity may be an eco-friendly alternative to chemical fertilizers. Rhizosphere or soil-inhabiting beneficial microbes can enhance plant growth and productivity through direct and indirect mechanisms, i.e., phosphate solubilization, nutrient acquisition, phytohormone production, etc. Objective: This study is based on the hypothesis that diseases resistant plants can act as a source of potential microbes that can have good plant growth-promoting traits and bio-control potential. Methods: In this study, we have isolated the rhizobacterial strains (AKAD 2-1, AKAD 2-10, AKAD 3-5, AKAD 3-9) from the rhizosphere of a disease-resistant variety of soybean (JS-20-34) (Glycine max (L.) Merr.). These bacterial strains were further screened for various plant growth-promoting traits (phosphate solubilization, indole acetic acid (IAA), ammonia, biofilm, HCN, Exopolysaccharide (EPS), and enzyme production activity (catalase, cellulase, and chitinase)). Results: Among four, only bacterial strain AKAD 3-5 has shown plant-growth-promoting and biocontrol (98%) activity against Fusarium oxysporum. Morphological, biochemical, and molecular characterization (16S rRNA) revealed that this rhizobacterial isolate AKAD 3-5 closely resembles Micrococcus luteus (Gene bank accession: MH304279). Conclusion: Here, we conclude that this strain can be utilized to promote soybean growth under varied soil stress conditions.
Highlights
Soybean has turned out to be a major oilseed crop in India, and a good source of protein supplement, wherein more than 40% population suffers from energy-protein malnutrition [1, 2]
The study conducted by Zahedi and Abbasi [27, 28] investigated the effect of inoculation of three beneficial bacterial strains Azotobacter chroococcum, Azospirillum brasilense, and Rhizobium japonicum, and their combination on polyamines and phytohormones of soybean growing under different irrigation systems
Previous studies conducted on Micrococcus luteus were majorly focused on exploring its plant growth-promoting attributes [29 - 32], but plants under stress conditions are susceptible to different kinds of disease
Summary
Soybean has turned out to be a major oilseed crop in India, and a good source of protein supplement, wherein more than 40% population suffers from energy-protein malnutrition [1, 2]. Several plant growth-promoting (PGP) microbes help to increase the availability of nutrients, like nitrogen (N), phosphorus (P), iron (Fe), as well as produce metabolites that can regulate growth and defense responses in plants [10, 23]. Groups of some plant growth-promoting (PGP) microbes produce some defensive molecules, like melatonin, proline, and carotenoids which play a defensive role under abiotic stress conditions. Previous studies conducted on Micrococcus luteus were majorly focused on exploring its plant growth-promoting attributes [29 - 32], but plants under stress conditions are susceptible to different kinds of disease. We have isolated, identified, and screened a potential isolate Micrococcus luteus, from a disease-resistant variety of soybean (JS-20-34), with their effective plant growth-promoting, desiccation-tolerant, antifungal, and antagonistic activity against Fusarium oxysporum. Rhizosphere or soilinhabiting beneficial microbes can enhance plant growth and productivity through direct and indirect mechanisms, i.e., phosphate solubilization, nutrient acquisition, phytohormone production, etc
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
