Plant diseases caused by fungal, bacterial, and viral pathogens represent a major constraint to global agricultural productivity. Plants rely on a complex and highly regulated defense system in which defense-related enzymes play central roles in restricting pathogen invasion and disease progression. This review provides a comprehensive overview of the enzymatic components of plant disease resistance, with a particular focus on key defense-related enzymes, including phenylalanine ammonia-lyase, peroxidases, chitinases, β-1,3-glucanases, and polyphenol oxidase. The biochemical functions of these enzymes in reinforcing cell walls, generating antimicrobial compounds, and regulating reactive oxygen species are discussed in relation to their contribution to plant immunity. Furthermore, the molecular regulation of defense-related enzymes is examined, emphasizing the roles of pathogen recognition, phytohormone-mediated signaling pathways, transcriptional control, and signal cross-talk. Recent advances in omics technologies are highlighted as powerful tools for elucidating regulatory networks underlying enzyme-mediated defense responses. In addition to molecular mechanisms, this review explores the agricultural and biotechnological applications of defense-related enzymes, including their use as biochemical markers in breeding programs, targets for genetic improvement, and key components of induced resistance strategies. Current challenges, such as growth–defense trade-offs and environmental influences on enzyme activity, are also addressed, along with future perspectives for integrating molecular insights into sustainable disease management and crop improvement. Overall, this review underscores the importance of defense-related enzymes as major contributors to plant disease resistance and their potential contribution to resilient and sustainable agricultural systems.

Plants, being immobile, are constantly exposed to various biotic and abiotic stresses, leading to the generation of reactive oxygen species (ROS) which disrupt cellular homeostasis and cause oxidative damage. To combat this, plants have evolved various enzymatic and non-enzymatic antioxidant mechanisms. This study investigates the enzymatic activities of key antioxidants in Polygala vulgaris L., a species within the Polygalaceae known for its medicinal properties. The enzymatic activities of), catalase (CAT), superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD) and phenol oxidase (PO) were measured. Additionally, the content of malondialdehyde (MDA), a marker for oxidative stress, was determined. The methanol extract of P. vulgaris L. was analyzed using GC-MS to identify bioactive compounds, and molecular docking studies were conducted to assess the interactions and binding energies of these compounds with the lysosomal integral membrane protein-2 (LIMP 2). LIMP 2 interaction of the extract suggested that it may trigger Parkison’s disease and at the same time protect the organism from enterovirus invasion. Results indicated significant antioxidant activity in P. vulgaris L., with potential implications for its use in mitigating oxidative stress-related cellular damage. The study provides a comprehensive overview of the antioxidant defense mechanisms in P. vulgaris L. and underscores its potential for future pharmacological applications.

Mammillaria elongata is a species of Cactaceae family, native to central Mexico. In Turkey, it is grown as cultivated plant. The succulent plants have pink and red fruits. In this study, we investigated the protein content, sugar content, anti-bacterial and anti-fungal effect in fruit extract. According to the results, in the fruit with a total wet weight of 0.252 g 15.5215 mg protein was found with Lowry method. Besides, the extract contains high amounts of reducing sugar such as glucose. Bacterial growth (Escherichia coli and Pseudomonas aeruginosa on bloody agar) and fungal colonization (Fusarium oxysporum, Rhizoctonia solani, Sclerotinia sclerotiorum on PDA) were not affected by plant extract. However, in all control media, that contain only plant extract, pink colored organism growth was observed. After DNA ısolation and 18S rRNA PCR from this organism, its species name determined as Rhodotorula glutinis according to % 100 sequence similarity.