ORIGINAL ARTICLE Potential production of polyphenols, carotenoids and glycoalkaloids in Solanum villosum Mill. under salt stress Saoussen Ben-Abdallah 1,2 & Walid Zorrig 3 & Lisa Amyot 2 & Justin Renaud 2 & Abdelali Hannoufa 2 & Mokhtar Lachâal 1 & Najoua Karray-Bouraoui 1 Received: 7 March 2018 /Accepted: 15 November 2018 /Published online: 29 November 2018 Abstract Changes in the antioxidant defence systems were investigated in many aromatic and medicinal plants grown under salinity; however, no study is available about its effects on Solanum villosum Mill. In this study, we investigated the response of S. villosum to sodium chloride (NaCl), especially the impacts of NaCl on secondary metabolites production (phenolic com- pounds, carotenoids, and glycol-alkaloids). For this purpose, a hydroponic culture experiment was conducted on seedlings subjected to 0, 50, 100, or 150 mM NaCl. NaCl affected the growth of S. villosum in terms of plant height and dry weight, however, it increased the water content of the leaves. Although leaf Na + concentration was significantly increased under salt stress, the leaves K + , Ca 2+ and Mg 2+ concentration were enhanced and/ or not significantly affected. The adaptation of S. villosum to NaCl stress was also reflected by the maintain of chlorophyll levels under different NaCl treatments. Additionally, leaf caffeic acid, lutein, and beta-carotene contents were considerably increased under 100 mM NaCl treatment, along with the up regulation of some related phenolic (phenylalanine ammonialyase and flavonol synthase), and carotenoid genes (phytoene synthase 1, phytoene synthase 2, and b-lycopene cyclase). The leaf contents of β-solamargine and α-solasonine also increased significantly with increasing salinity. The present study is the first to through some light on the medicinal quality of S. villosum that would be quite helpful for production of secondary metabolites under salt-stressed conditions. Keywords Salinity . Solanum villosum . Phenolic compounds . Carotenoid . Gene expression Highlights • Solanum villosum is an economically important medicinal plant worldwide and represents an invaluable source of health-related com- pounds. • In this study we aim to characterize salinity tolerance of this species and its ability to improve its antioxidant pool. • Under salt stress conditions, we demonstrated that Solanum villosum lost more than 50% of its dry matter. This species as a glycophyte plant with high ability to accumulate less Na + in its aerial part. • The dose response manner of Solanum villosum to salinity, through preventing the oxidative damage, was a qualitative and quantitative trait with increased cafeic acid and carotenoids and glycolakaloids contents under moderate and high salt stress levels. * Saoussen Ben-Abdallah saoussen.iris@gmail.com 1 Laboratoire de productivité végétale et contraintes environnementales, Département de Biologie. Faculté des Sciences de Tunis, Universite de Tunis El Manar, Campus Universitaire, 2092 Tunis El Manar, Tunisia 2 Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3, Canada 3 Laboratory of Extremophile Plants, Centre of Biotechnology of Borj-Cedria, BP 901, 2050 Hammam-Lif, Tunisia Biologia (2019) 74:309–324 https://doi.org/10.2478/s11756-018-00166-y # Institute of Molecular Biology, Slovak Academy of Sciences 2018