Background: Zinc is a vital trace element required by plants for numerous cellular activities. Application of nano-fertilizers in the form of Zn-O nanoparticles was evaluated in this study to describe the changes in CDDP fingerprints and selected WRKY genes expression in two Glycine max L. varieties.

Methods: Foliar dispersions of ZnO nanoparticles were applied by handheld sprayer with the nanoparticle concentrations 1.4 mg L^-1, 14 mg L^-1 and 140 mg L^-1 plus control plants. Four primer combinations of conserved parts of plant WRKY genes were used in CDDP fingerprinting and four WRKY genes were evaluated for their expression changes.

Result: Polymorphic CDDP profiles were generated for three primer combination. No unique amplicons were obtained, but the generated fingerprint profiles differ in control plants of both varieties. The ability of used primer combinations to detect polymorphism was comparable only for combinations F1R2b and F1R3a. No significant changes of expression were obtained in the case of 1.4 mg L^-1 foliar application of ZnO nanoparticles for WRKY11, WRKY106 and WRKY149 genes. The highest applied concentration of ZnO nanoparticles resulted in the relevant upregulation of all the analysed WRKY genes with the values from 5 times (Adelfia, WRKY 90) up to the 80 times (Mentor, WRKY 106).