Effects of different concentrations of sodium chloride on plant growth and glucosinolate content and composition in pakchoi

Pakchoi (Brassica campestris L. ssp. chinensis var. communis) is one of the most important Brassica vegetables in China, and the consumption of Brassica vegetables reduces the risk of cancer occurrence. The aim of this study was to investigate the contents and composition of glucosinolates in pakchoi shoots exposed to 0, 50 and 100 mM sodium chloride (NaCl) for two weeks. The results showed that salt stress significantly decreased the fresh weight of whole plant and the dry weight of shoots and roots of pakchoi, as compared to the control. Under 50 mM NaCl, the contents of total glucosinolates, aliphatic and indole glucosinolates were significantly increased, however, under 100 mM NaCl, the content of indole glucosinolates was significantly increased and aromatic glucosinolate (gluconasturtiin) content was significantly decreased. For individual glucosinolates, the contents of glucoalyssin, gluconapin, glucobrassicin and neglucobrassicin were significantly enhanced under 50 mM NaCl, however, only significant increases in the contents of gluconapin and glucobrassicin were observed under 100 mM NaCl. It could be concluded that NaCl stress considerably influenced the glucosinolate content and composition in pakchoi shoots.