Abstract

The application of endophytes to mitigate stress in plants, particularly drought and salinity stress, has gained considerable attention, yet their role in rice remains underexplored. This study aimed to investigate the isolation and characterization of multi-stress-tolerant endophytic isolates with multiple plant growth-promoting attributes, including biocontrol potential against plant pathogens, from surface-sterilized leaf, stem, and root samples of various rice cultivars in Kerala. A total of 20 bacterial endophytes were isolated from rice plants and assessed for their plant growth-promoting (PGP) capabilities, biocontrol potential, and resilience to drought and salinity stress. Of these, 7 endophytic isolates exhibited notable PGP traits, and 3 demonstrated antifungal activity against Rhizoctonia solani and Fusarium oxysporum. Notably, only 3 endophytic isolates showed significant tolerance to drought conditions (−1.0 MPa) and salinity (150 mM), alongside strong growth-promoting abilities. The selected isolates significantly increased seed germination and seedling vigour (p ≤ 0.05), highlighting their effectiveness. Among these, the isolate CRI, identified as Bacillus rugosus through morphological, biochemical, and molecular (16S rRNA) analysis, stood out for its remarkable performance. Under stress conditions, rice seedlings treated with the multi-stress-tolerant CRI showed significant improved biomass, resilience, and enhanced biochemical processes, including better photosynthetic pigment levels and maintained membrane integrity. Field emission scanning electron microscopy (FE-SEM) confirmed the presence of these bacteria within the rice roots, underscoring their potential as a novel approach for enhancing stress tolerance and promoting rice growth. This study represents the first discovery of Bacillus rugosus as a potent multi-stress-tolerant endophyte, with dual benefits of promoting plant growth and exhibiting biocontrol activity. These findings pave the way for innovative strategies aimed at enhancing crop resilience and productivity, particularly in the face of increasing abiotic stressors in agricultural systems.

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

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.