Demonstrating the potential of abiotic stress-tolerant Jeotgalicoccus huakuii NBRI 13E for plant growth promotion and salt stress amelioration

Abstract

The present study aimed to demonstrate the potential of abiotic stress-tolerant Jeotgalicoccus huakuii NBRI 13E for plant growth promotion and salt stress amelioration. NBRI 13E was characterized for abiotic stress tolerance and plant growth-promoting (PGP) attributes under normal and salt stress conditions. Phylogenetic comparison of NBRI 13E was carried out with known species of the same genera based on 16S rRNA gene. Plant growth promotion and rhizosphere colonization studies were determined under greenhouse conditions using maize, tomato, and okra. Field experiment was also performed to assess the ability of NBRI 13E inoculation for improving growth and yield of maize crop in alkaline soil. NBRI 13E demonstrated abiotic stress tolerance and different PGP attributes under in vitro conditions. Phylogenetic and differential physiological analysis revealed considerable differences in NBRI 13E as compared with the reported species for Jeotgalicoccus genus. NBRI 13E colonizes in the rhizosphere of the tested crops, enhances plant growth, and ameliorates salt stress in a greenhouse experiment. Modulation in defense enzymes, chlorophyll, proline, and soluble sugar content in NBRI 13E-inoculated plants leads to mitigate the deleterious effect of salt stress. Furthermore, field evaluation of NBRI 13E inoculation using maize was carried out with recommended 50 and 100% chemical fertilizer controls, which resulted in significant enhancement of all vegetative parameters and total yield as compared to respective controls. Jeotgalicoccus huakuii NBRI 13E is reported for the first time for its ability to develop a bioinoculant formulation for stress amelioration and improved crop productivity.