MF3 Protein Encapsulation in Biodegradable Poly-3-Hydroxybutyrate Improves Its Protective Action Against a Major Wheat Pathogen Parastagonospora Nodorum

Intensive use of pesticides results in environmental pollution and food contamination. Use of microbial elicitors, enhancing plant immunity, is a promising alternative to fungicidal treatments. MF3, an elicitor protein from Pseudomonas fluorescens, has a strong protective action toward a range of plant pathogens, but can be degraded by UV radiation and plant proteases under field conditions. MF3 encapsulation in biodegradable poly-3-hydroxybutyrate (PHB) protects it against the adverse external factors. Using a model plant-pathogen system, we demonstrated that the treatment of wheat leaf fragments with a MF3-PHB complex prior artificial inoculation with Parastagonospora nodorum, a major wheat pathogen, provides a higher suppression of the infection (41.5%) than the treatment with MF3 alone (28.9%) or PHB (2.5%). Thus, encapsulating this protein elicitor may provide prolonged and more efficient activity under field conditions and is able to promote the development of MF3-based biopesticides as an efficient alternative to commercial fungicides.