Effect of Arthrobacter sp. Tg40 on Defense Gene Expression and Disease Severity in Pepper Infected with Rhizoctonia solani

Ünal F., Alakuş D. G., Divrik Ö., Sipahi H., Şahin S.

International Journal of Agriculture Forestry and Life Sciences, cilt.10, sa.1, ss.57-63, 2026 (Hakemli Dergi)

Özet

This study evaluated the biocontrol potential of Arthrobacter sp. Tg40 against Rhizoctonia solani in pepper plants and its influence on plant defense responses. The expression of selected defense-related genes (JERF3, POD, PR, and chitinase) was analyzed at 12, 24, 56, and 68 h using quantitative real-time PCR. Expression profiles varied depending on treatment and sampling time, indicating dynamic regulation of defense-related pathways. The combined application of R. solani and Arthrobacter sp. Tg40 enhanced the expression of several defense genes, particularly those associated with signaling, oxidative stress, and antifungal responses. Disease severity was highest in plants inoculated only with R. solani (95.2%), whereas it decreased to 16.8% in plants treated with R. solani + Arthrobacter sp. Tg40. The efficacy of Arthrobacter sp. Tg40 against R. solani was calculated as 82.35%. These results suggest that Arthrobacter sp. Tg40 may suppress disease development and contribute to the activation of defense-related mechanisms in pepper plants. Therefore, this bacterial strain may be considered a promising biological control agent for the management of soil-borne diseases in pepper production.