Thyme Essential Oil Reduces Disease Severity and Induces Resistance against Alternaria linariae in Tomato Plants

Abstract

Currently, the use of alternative tools for chemical control has become one of the most sustainable and eco-friendly options for crop protection against phytopathogens. Thus, the present study aimed to assess the effect of essential oils (EOs) on the control of tomato early blight (EB), a highly destructive disease of this crop. The antifungal activity and ability to induce resistance induction of the EOs of thyme (Thymus vulgaris), lemongrass (Cymbopogon citratus) and tea tree (Melaleuca alternifolia) were tested for control of A. linariae in tomato plants. In vitro, mycelial growth and conidial germination were strongly inhibited when thyme EO (TEO; 2000 ppm) and lemongrass (LGEO; 2000 ppm) were applied. The infected leaf area and final disease index were decreased by 47.78% and 39.00%, respectively, compared to the water treatment. Foliar spraying with TEO increased the activity of the defense-related enzymes peroxidase, polyphenol oxidase and β-1,3-glucanase. Furthermore, callose deposition and phenolic compound accumulation in tissues infected by A. linariae improved after TEO application. In conclusion, TEO stimulated the defense system of tomato plants infected by A. linariae, which was associated with a reduced severity of EB. These results indicate that TEO is a potential tool in tomato EB disease management.

Characterization and Control of Root Rot and Wilt Fungi of Geranium (Pelargonium graveolens L.) with Special Reference to First Record for Fusarium proliferatum as Wilt Pathogen on Geranium in Egypt

“…As plant becoming more vigorous and healthier this could help plant to be more tolerant and resist the fungal infection. These findings are consistent with other investigators (Imarah, 2005;Talha, 2011, andSaltos-Rezabala et al, 2022).…”

Defense Mechanisms Induced by Celery Seed Essential Oil against Powdery Mildew Incited by Podosphaera fusca in Cucumber

“…The treatment with CSEO also enhanced the activity of enzymes typically involved in the plant defense reaction against biotic stresses [57,[61][62][63][64]. Not surprisingly, a significant increase in β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase, peroxidase, and polyphenol oxidase activities in leaves of untreated cucumber seedlings infected with powdery mildew compared with healthy untreated seedlings was observed.…”

Harnessing Plant’s Arsenal: Essential Oils as Promising Tools for Sustainable Management of Potato Late Blight Disease Caused by Phytophthora infestans—A Comprehensive Review

“…Lastly, the lesser discussed benefits of EO in the frame of plant protection are known as eliciting and priming effects [215,216]. They consist of preparing crops to better fight pathogens or apprehend physiologic stresses by inducing plant defenses [217].…”