Salt tolerant Methylobacterium mesophilicum showed viable colonization abilities in the plant rhizosphere

Area of Science:

• Microbiology
• Plant Pathology
• Environmental Science

Background:

• Understanding opportunistic pathogens' adaptation to environmental stress is crucial for epidemiology.
• The survival mechanisms of plant-associated microbes under abiotic stress remain poorly understood.

Purpose of the Study:

• To investigate the salt tolerance of Methylobacterium mesophilicum.
• To determine the colonization ability of M. mesophilicum in plant roots and shoots under drought and salt stress.

Main Methods:

• Gnotobiotic sand system and saline soil pots were used to study plant colonization.
• Bacterial colonization in the rhizosphere of cucumber, tomato, and paprika was quantified.
• Antibiotic resistance and salt tolerance (up to 6% NaCl) of the bacterial strain were assessed.

Main Results:

• M. mesophilicum successfully colonized the rhizosphere of multiple plant species under normal and salt stress conditions.
• Colonization levels reached up to 6.4 × 10^4 CFU/g root.
• The strain exhibited resistance to several antibiotics and tolerance to significant salinity stress.

Conclusions:

• M. mesophilicum demonstrates remarkable salt tolerance and colonization capabilities in plants.
• These traits are vital for the pathogen's persistence on plant surfaces in challenging environments.
• This study provides foundational data on M. mesophilicum's behavior and survival strategies.