Stimulation of plant metabolism is a research direction for increasing the nutritional and functional value of food. In a two-year field experiment with spring wheat, eight inducers from different groups (bio- and abiotic; exo- and endogenous) were used. The tested inducers had varied and significant effects on wheat grain yield and quality. Hydrogen peroxide, chitin, and chitosan hydrochloride increased phenolic content and antioxidant activity (by 13.7%, 15.7%, and 10.1%, respectively, compared to control). Analysis of the amino acid composition of caryopses flour showed a significant increase in the content of aspartic acid, alanine, phenylalanine, and arginine after the application of hydrogen peroxide. Application of chitosan hydrochloride, L-phenylalanine, and chitin resulted in an increase in APX gene expression, while sodium hypochlorite significantly decreased CAT gene expression. Potassium iodide and sodium hypochlorite significantly reduced grain yield (by 10.6% and 14.4%, respectively, compared to control) and also worsened quality parameters of grain. Hydrogen peroxide, chitin, and chitosan hydrochloride showed the greatest stimulatory potential, as their application did not worsen, and in some cases improved, yield parameters and increased the phenolic content and antioxidant activity of grain. Hydrogen peroxide further improved the amino acid composition of grains. However, further research is needed to understand the mechanisms of effects on plants and to optimize the use of these inducers in agricultural practice.
Biszczak et al. (Mon,) studied this question.