Nano-selenium enhances the antioxidant capacity, organic acids and cucurbitacin B in melon (Cucumis melo L.) plants

• Published in: Ecotoxicology and environmental safety Vol. 241; p. 113777
• Main Authors: Kang, Lu, Wu, Yangliu, Zhang, Jingbang, An, Quanshun, Zhou, Chunran, Li, Dong, Pan, Canping
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.08.2022; Elsevier
• Subjects: Antioxidant activity; Biological resistance; Cucurbitacin B; Melon; Nano-selenium; Organic acids; Biological resistance; Nano-selenium; Antioxidant activity; Organic acids; Cucurbitacin B; Melon
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.113777

Pesticides are widely used in melon production causing safety issues around the consumption of melon and increasing pathogen and insect tolerance to pesticides. This study investigated whether a nano-selenium (Nano-Se) spray treatment can improve resistance to biological stress in melon plants, reducing the need for pesticides, and how this mechanism is activated. To achieve this, we examine the ultrastructure and physio-biochemical responses of two melon cultivars after foliar spraying with Nano-Se. Nano-Se treatment reduced plastoglobulins in leaf mesophyll cells, thylakoid films were left intact, and compound starch granules increased. Nano-Se treatment also increased root mitochondria and left nucleoli intact. Nano-Se treatment enhanced ascorbate peroxidase, peroxidase, phenylalanine ammonia lyase, β-1,3-glucanase, chitinase activities and their mRNA levels in treated melon plants compared to control plants (without Nano-Se treatments). Exogenous application of Nano-Se improved fructose, glucose, galactitol, stachyose, lactic acid, tartaric acid, fumaric acid, malic acid and succinic acid in treated plants compared to control plants. In addition, Nano-Se treatment enhanced cucurbitacin B and up-regulated eight cucurbitacin B synthesis-related genes. We conclude that Nano-Se treatment of melon plants triggered antioxidant capacity, photosynthesis, organic acids, and up-regulated cucurbitacin B synthesis-related genes, which plays a comprehensive role in stress resistance in melon plants. [Display omitted] •Nano-Se treatment improved antioxidant capacity in melon plants.•Photosynthesis of melon plants was enhanced by Nano-Se.•Nano-Se increased cucurbitacin B content to improve insect resistance of plants.•Nano-Se treatment of 5.0 mg·L−1 gave the best plant pathogen resistance effect.