Physiological and transcriptome analyses demonstrate the silver nanoparticles mediated alleviation of salt stress in pearl millet (Pennisetum glaucum L). (1st February 2023)

• Record Type: Journal Article
• Authors: Khan, Imran; Awan, Samrah Afzal; Rizwan, Muhammad; Akram, Muhammad Adnan; Zia-ur-Rehman, Muhammad; Wang, Xiaosan; Zhang, Xinquan; Huang, Linkai
• Is Part Of: Environmental pollution. Volume 318(2023)
• Publication Date: 2023-02-01
• Subjects: Pearl millet -- Transcriptome -- Salt -- Nanoparticles -- Gene expression -- Amelioration; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2022.120863
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Pearl millet ( Pennisetum glaucum L.) is a highly nutritive-value summer-annual forage crop used for hay, silage, grazing, and green chop. However, abiotic stresses including salinity negatively affect its growth and productivity. Furthermore, the nanotechnology is attaining greater consideration to reduce the impact of environmental stresses in plants. In the present study, transcriptome responses of silver nanoparticles (AgNPs) in pearl millet under salinity were investigated. The treatments were given as Control, NaCl (250 mM), AgNPs (20 mg/L), and NaCl + AgNPs to pearl millet seedlings after thirteen days of seed sowing. After 1 h of given treatments, leaf samples were collected and subjected to physio-chemical examination and transcriptome analyses. Salt stress increased the hydrogen peroxide (H2 O2 ), malondialdehyde (MDA) content, and proline as compared to other treatments. In addition, the combined applications of NaCl + AgNPs ameliorated the oxidative damage by increasing antioxidant enzymes activities including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Furthermore, RNA sequencing data showed 6016 commonly annotated Differentially Expressed Transcripts (DETs) among various treated combinations. Among them, 427 transcripts were upregulated, and 136 transcripts were downregulated at nanoparticles vs control, 1469 upregulated and 1182 downregulated at salt vs control, 494 upregulated and 231 downregulated at salt + nanoparticles vs control, 783 upregulated and 523 downregulated at nanoparticles vs salt. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that Mitogen-activated protein kinase (MAPK) signaling pathway, biosynthesis of secondary metabolites, and plant hormonal signal transduction pathway were the enriched among all identified pathways. In addition, Reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR) showed that salinity up regulated the relative expression of DETs in pearl millet while, AgNPs optimized their expression that are associated with various molecular and metabolic functions. Overall, AgNPs treatments effectively improved the morphology, physiology, biochemistry, and gene expression pattern under salinity which could be attributed to positive impacts of AgNPs on pearl millet. Highlights: Salt stress negatively affects the growth and photosynthetic pigments in pearl millet. Silver nanoparticles (AgNPs) improve the growth and activities of antioxidant enzymes. Large no. of transcripts were upregulated by salinity and optimized by nanoparticles. GO and KEGG analysis show enrichment of transcript in various metabolic functions. AgNPs-mediated regulation of molecular pathways mitigate harmful impacts of salinity.