The physiological and biochemical role of silicon in enhancing the resistance of maize to root‐lesion nematode

Abstract Silicon (Si) plays an important role in enhancing the tolerance of plants to biotic and abiotic stress in soil ecosystems. Root‐lesion nematodes ( Pratylenchus scribneri ; RLNs) cause root damage and diseases that result in quality deterioration and economic loss. This study investigated the effects of Si application on maize plants and its interaction with RLN infection. We set up different treatments to evaluate the role of silicon application in maize root growth and RLN resistance. This study conducted analysis by combining measurements of the metabolism and root activity of maize under different conditions. The results suggested that Si application (0.5 g/kg) significantly promoted fresh shoot weight, plant height, SPAD value (chlorophyll content), and root activity of maize, regardless of RLN inoculation. The highest SPAD value was observed in the Si treatment, which was significantly higher than in the control (CK) and RLN (N) treatments. Analysis of enzyme activity revealed that nematode inoculation reduced catalase (CAT) activity and increased malondialdehyde (MDA) concentration, while Si application increased CAT activity and decreased MDA concentration. In the SiN treatment, there was increased CAT activity at 0, 12, 48, 72 and 96 h compared with the N treatment. In parallel, nematode inoculation increased phenylalanine ammonia‐lyase (PAL), and polyphenol oxidase (PPO) activities, while SiN treatment further enhanced their activities. These findings indicate that Si application enhances maize resistance to nematode infection and improves plant growth and antioxidant defence mechanisms.