A sustainable solution for eucalyptus cultivation under environmental stresses: novel Pseudomonas species with plant growth-promoting traits

Background and aims

Eucalyptus has unique wood properties and great economic value, but traditional yield-increasing methods rely on chemicals and harm the environment. Plant growth-promoting rhizobacteria (PGPR) are a good solution to this problem, and Pseudomonas is a typical example. The study aims to explore sustainable, eco-friendly alternatives to minimize chemical pollution of the environment by screening and characterizing Pseudomonas with the potential to promote the growth of eucalyptus.

Methods

The Salkowski colorimetric method and various selective media were used to screen for bacteria with growth-promoting functions. Genes associated with growth-promoting functions were identified by genome annotation. A combination of phylogenetic, comparative genomic, morphological, physiological and biochemical methods was used to classify and identify the strains.

Results

Genomic annotation identified genes associated with growth-promoting functions (e.g., ppk for phosphate solubilization, trpA/B/C for IAA synthesis), consistent with the results of plate experiments, further confirming their growth-promoting potential. The two strains were classified as new species within the Pseudomonas genus, and named Pseudomonas eucalyptica sp. nov. and Pseudomonas eucalyptoterra sp. nov.

Conclusion

This study provides new ideas for the development of green, non-polluting biofertilizers and adds to our knowledge of Pseudomonas diversity.