Essential oil compounds modulate nutritional quality and stress response in Botrytis cinerea-infected grape (Vitis vinifera L. cv. ‘Karaerik’)

Abstract

Grapes, rich in vitamins and minerals, could offer a healthy alternative. However, their potential contamination by the fungus Botrytis cinerea poses serious health risks, necessitating cautious consumption, particularly among those on restricted diets, to mitigate adverse effects. Therefore, the study investigated the effects of individual and combined application of individual components of essential oils (EOs) such as thymol, eugenol, and 1,8-cineole on various parameters such as antioxidant enzymes, mineral elements, anthocyanins, and phenolic compounds in the treatment of B. cinerea infection in 'Karaerik' grapes. Our study provided important information about physiology and pathogen response, and results indicated that the pathogen-infected groups had higher levels of oxidative stress indicators, such as proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2). On the other hand, EOs elevate the activity of antioxidant enzymes, notably superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), whereas thymol treatments effectively reduced oxidative stress to levels comparable to the control group. Under thymol and eugenol treatments, nitrogen (N), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), sulfur (S), zinc (Zn), manganese (Mn), boron were significantly higher than the control groups. Increases were also determined in the concentrations of mineral elements such as (B) and copper (Cu). Anthocyanin profiles were preserved by EO treatments, with combined EO applications yielding higher anthocyanin profiles percentages compared to individual treatments. In our results, there were notable differences in the overall quantities of phenolic compounds, and the combination of EO applications caused higher levels of phenolic compounds, especially in the groups that include the fungal infection. Overall, the study showed how effective EO treatments are at reducing B. cinerea infections and maintaining grape quality, which has significance for long-term disease control plans and maintaining berry quality in viticulture.