Phosphate solubilization and mobilization: bacteria-mycorrhiza interactions.

Area of Science:

• Agricultural Science
• Microbiology
• Soil Science

Background:

• Phosphorus (P) is vital for plant growth but often exists in insoluble forms.
• Inaccessible soil phosphorus limits plant development and agricultural productivity.
• Phosphate-solubilizing microorganisms (PSMs) are key players in the soil phosphorus cycle.

Purpose of the Study:

• To review the capabilities of PSMs in solubilizing insoluble phosphorus.
• To highlight the potential of PSMs as biofertilizers for improving phosphorus availability.
• To discuss the mechanisms and factors influencing P solubilization by PSMs.

Main Methods:

• Review of literature on phosphate-solubilizing microorganisms (bacteria and fungi).
• Analysis of mechanisms involved in organic and inorganic phosphorus solubilization.
• Examination of the role of specific genes and microbial species in P cycling.
• Inclusion of arbuscular mycorrhizal fungi as enhancers of P uptake.

Main Results:

• PSMs effectively convert insoluble P into plant-accessible forms.
• Mechanisms include organic acid production, proton extrusion, siderophore, and exopolysaccharide secretion.
• Enzymatic activity mineralizes organic P, while inorganic P is solubilized via various microbial processes.
• Arbuscular mycorrhizal fungi significantly enhance plant phosphorus uptake.

Conclusions:

• PSM inoculants show promise as biofertilizers to improve soil P availability.
• Optimizing application conditions (timing, inoculum form, dosage) is crucial for maximizing effectiveness.
• Further research is essential to fully harness the potential of PSMs in sustainable agriculture.