Salt-Affected Rocket Plants as a Possible Source of Glucosinolates

Abstract

Soil salinity can have various negative consequences on agricultural products, from their quality and production to their aesthetic traits. In this work, the possibility to use salt-affected vegetables, that otherwise would be discarded, as a source of nutraceuticals was explored. To this aim, rocket plants, a vegetable featuring bioactive compounds such as glucosinolates, were exposed to increasing NaCl concentrations in hydroponics and analysed for their content in bioactive compounds. Salt levels higher than 68 mM produced rocket plants that did not comply with European Union regulations and would therefore be considered a waste product. Anyway, our findings, obtained by Liquid Chromatography-High Resolution Mass Spectrometry, demonstrated a significant increase in glucosinolates levels in such salt-affected plants. opening the opportunity for a second life of these market discarded products to be recycled as glucosinolates source. Furthermore, an optimal situation was found at NaCl 34 mM in which not only were the aesthetic traits of rocket plants not affected, but also the plants revealed a significant enrichment in glucosinolates. This can be considered an advantageous situation in which the resulting vegetables still appealed to the market and showed improved nutraceutical aspects.

Effect of Lithium Slag Application on Saline–Alkali Soil Amelioration and Vegetable Growth

“…Radish is a root vegetable that belongs to the Brassicaceae family too. They have mild or moderate sensitivity to salt and are often chosen to study the salt stress mechanisms in highly saline environments [39][40][41][42][43]. Here they were selected due to their certain saline-alkali tolerance and relatively short harvest period (about 4-6 weeks).…”

“…However, the germination rate of radish seeds was not significantly affected by soil EC and soluble salt in this study due to its relatively higher tolerance to salt stress than roquette. Radish resists salt stress in a variety of ways, such as osmoregulation, hormone regulation, ion homeostasis regulation, reactive oxygen clearance and signal transduction [40,60]. In addition, salt stress could possibly weaken the activity of phosphorolytic enzymes which resulted in a decrease in seed germination [61].…”