REGULAR ARTICLE Differential functional traits underlying the contrasting salt tolerance in Lepidium species R. Hajiboland & S. Bahrami-Rad & N. Zeinalzade & E. Atazadeh & H. Akhani & C. Poschenrieder Received: 30 August 2019 /Accepted: 21 January 2020 # Springer Nature Switzerland AG 2020 Abstract Aims To explore the mechanisms responsible for salt tolerance in Brassicaceae species, a multifactorial ap- proach was used to clarify the functional traits underly- ing the differential salt tolerance in two Lepidium spe- cies, namely the halophyte L. latifolium and its glycophyte relative, L. sativum. Methods Parameters related to photosynthesis, nitrogen assimilation, ion accumulation, water relations and suc- culence, osmotic adjustment, phenolics metabolism, an- tioxidative defense, nitric oxide (NO) level and the expression of Na + antiporter (SOS1 and NHX) were analyzed in plants grown under salt stress in hydroponics. Results In addition to significant differences regarding the majority of salt tolerance indicators, a characteristic early boost, 52 h after exposure to salt, was observed in the concentration of H 2 O 2 and NO in the halophyte, which was almost absent in the glycophyte. Following the application of detrended component analysis, dis- crimination between the glycophyte and halophyte could only be performed via temporal curves in the antioxdative components and NO, and less effectively, by phenolics metabolism. Conclusion H 2 O 2 and NO signaling and the adaptive modification of phenolics metabolism play crucial roles in determining the halophytic behavior of L. latifolium. These data may result in new insights concerning the studies on halophytism in the Brassicaceae. Keywords Hydrogen peroxide . Leaf succulence . Lepidiumlatifolium . Nitric oxide . Phenoliccompounds . Stomatal density Abbreviations APX ascorbate peroxidase MDA malondialdehyde NR nitrate reductase NO nitric oxide POD peroxidase PAL phenylalanine ammonia lyase PPO polyphenol oxidase ROS reactive oxygen species SOD superoxide dismutase Plant Soil https://doi.org/10.1007/s11104-020-04436-0 Responsible Editor: Wieland Fricke. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11104-020-04436-0) contains supplementary material, which is available to authorized users. R. Hajiboland (*) : S. Bahrami-Rad : E. Atazadeh Department of Plant Science, University of Tabriz, Tabriz 51666-16471, Iran e-mail: ehsan@tabrizu.ac.ir N. Zeinalzade Department of Biology, University of Tabriz, Tabriz 51666-16471, Iran H. Akhani Halophytes and C4 Plants Research Laboratory, Department of Plant Science, School of Biology, University of Tehran, P.O.Box 14155-6455, Tehran, Iran C. Poschenrieder Plant Physiology Laboratory, Bioscience Faculty, Universidad Autónoma de Barcelona, 08193 Bellaterra, Spain