Harnessing selenium nanoparticles to mitigate the harmful impact of <i>Orobanche aegyptiaca</i> on growth and metabolic activity in <i>Cicer arietinum</i>

Abstract

BACKGROUND: Orobanche aegyptiaca is a devastating parasitic weed that severely constrains chickpea production. This study investigated the protective role of selenium nanoparticles (SeNPs) in alleviating the detrimental effects of O. aegyptiaca infection on chickpea (Cicer arietinum L.) growth, photosynthetic efficiency, and metabolic responses. RESULTS: Infection with O. aegyptiaca significantly reduced chickpea biomass and impaired photosynthetic capacity. It also decreased starch, sucrose, and fructose content, and increased amylase and invertase activity. Infection also lowered amino acid levels and impaired anthocyanin metabolism. Application of SeNPs alleviated these negative effects by improving biomass accumulation and photosynthetic efficiency. Selenium nanoparticles increased total soluble sugars, which reduced the parasite's sink strength, and improved the accumulation of key amino acids (proline, glutamic acid, arginine, and ornithine) along with the activation of their biosynthetic enzymes Glutamine synthetase (GS), pyrroline-5-carboxylate dehydrogenas (P5CDH), pyrroline-5carboxylate reductase (P5CR), and ornithine aminotransferase (OAT). Selenium nanoparticles also upregulated anthocyanin metabolism by increasing the activity of chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL), and elevating the levels of phenylalanine, cinnamate, coumarin, total flavonoids, and anthocyanins. Treated infected plants also showed elevated phenolic and flavonoid contents and exhibited strong antibacterial activity. CONCLUSION: Selenium nanoparticles effectively mitigate the harmful impacts of O. aegyptiaca on chickpea by improving growth, modulating primary and secondary metabolism, and enhancing the plant's defensive responses. These results highlight the use of SeNPs as a promising strategy for managing parasitic weed stress in chickpea. © 2026 Society of Chemical Industry.