Metabolome and transcriptome reprogramming underlying tomato drought resistance triggered by a Pseudomonas strain

Area of Science:

• Plant Science
• Microbiology
• Biochemistry

Background:

• Plant Growth Promoting Rhizobacteria (PGPR) are known to alleviate drought stress.
• The precise molecular and metabolic mechanisms behind PGPR-mediated drought tolerance are not fully understood.

Purpose of the Study:

• To elucidate the drought-attenuating mechanisms of tomato plants inoculated with a specific PGPR strain, Pseudomonas putida SAESo11.
• To integrate transcriptomic and metabolomic data for a comprehensive understanding.

Main Methods:

• Transcriptomic analysis to identify differentially expressed genes.
• Untargeted metabolomics to profile metabolite accumulation.
• Morpho-physiological assessments to evaluate drought stress mitigation.

Main Results:

• Inoculation with P. putida SAESo11 resulted in a less disturbed plant transcriptome under drought stress.
• Metabolomic analysis revealed reduced metabolic reprogramming and lower accumulation of stress-related metabolites in inoculated plants.
• Key drought-attenuating mechanisms include redox state modulation, enhanced nitrogen assimilation, altered amino acid metabolism, and induced phenylpropanoid biosynthesis.

Conclusions:

• P. putida SAESo11 inoculation confers systemic benefits, enhancing tomato seedling growth and drought stress tolerance.
• Mechanisms involve metabolic and regulatory functions, including hormonal signaling and carbon metabolism regulation.
• Specific molecules like aspartate, myo-inositol, and glutamate, along with genes for trehalose, tryptophan, and cysteine synthesis, are key indicators of this drought priming.