Biosynthesized iron oxide nanoparticles using Trichoderma harzianum with applications for phytopathogen control

Area of Science:

• Green Synthesis and Nanotechnology
• Mycology and Plant Pathology
• Materials Science

Background:

• Sustainable synthesis of nanomaterials is crucial for environmental applications.
• Biological synthesis offers controlled physicochemical properties of nanomaterials.
• Iron oxide nanoparticles have potential applications in agriculture and biocontrol.

Purpose of the Study:

• To biosynthesize Fe-based nanostructures using Trichoderma harzianum.
• To investigate the effect of iron precursor concentration and thermal treatment on nanostructure properties.
• To evaluate the biostimulant and biocontrol potential of biosynthesized iron oxide nanoparticles.

Main Methods:

• Biosynthesis of Fe-based nanostructures using Trichoderma harzianum with varying iron precursor concentrations (5 mM and 10 mM).
• Thermal treatment (annealing) of synthesized nanomaterials.
• Characterization using SEM, AFM, TEM, XRD, and XPS.
• Biological evaluation including biostimulant effects on T. harzianum and antagonistic activity against plant pathogens via dual-culture assays.

Main Results:

• Precursor concentration influenced particle size and aggregation; annealing led to phase transformation from Fe3O4 to α-Fe2O3.
• Thermal treatment removed capping biomolecules and oxidized Fe(II) to Fe(III).
• Biosynthesized iron oxide nanoparticles (Fe5 and Fe10) acted as biostimulants, enhancing T. harzianum growth, sporulation, and pigmentation.
• Both Fe5 and Fe10 significantly increased T. harzianum's antagonistic activity against Fusarium oxysporum, Fusarium verticillioides, and Phytophthora infestans.

Conclusions:

• Biosynthesis using Trichoderma harzianum provides a green route to Fe-based nanostructures with tunable properties.
• The resulting iron oxide nanoparticles exhibit dual functionality as biostimulants and biocontrol agents.
• These findings support the use of biosynthesized Fe oxide nanoparticles for sustainable crop protection strategies.