Effects of the Protein Hydrolysate Pretreatment on Cucumber Plants Exposed to Chilling Stress

This study aimed to evaluate the effects of the protein hydrolysate Naturamin WSP on the antioxidant defense system and oxidation-related damage of young cucumber plants exposed to chilling stress. Low positive temperatures have a negative effect on plant growth and performance, and besides visible alterations, such as inhibited growth, significant changes occur at the cellular level. Plants grown at low temperature typically suffer from oxidative damage, which leads to increased lipid peroxidation. Moreover, chilling-stressed plants accumulate more proline to protect their cell membranes. The application of biostimulants such as the protein hydrolysate Naturamin WSP can alleviate some of the adverse effects caused by low temperature. Our results indicated an increased activity of guaiacol peroxidase (GPOD) in all plants treated with the biostimulant regardless of the temperature of cultivation. The mitigation of damages caused by chilling stress might be explained by an enhanced anti-oxidative defense, as demonstrated by the activity of guaiacol peroxidases and increased proline concentrations in Naturamin WSP-treated plants.