Preliminary Analysis Of Salt Stress-responsive Glucosinolate Profile In Thellungiella Halophila

Here we report glucosinolates composition and content of Thellungiella halophila under different salt stress conditions. We investigated the dynamic change of glucosinolate-myrosinase system under salt stress.First, seven glucosinolates in T. halophila were unambiguously identified by high performance liquid chromatography (HPLC), including aliphatic glucosinolates allylglucosinolate (Allyl),3-ethylsulphinylpropylglucosinolate (3MSOP),10-methylsulfinyldecyl-glucosinolate (10MSD) and 3-methylthiopropylglucosinolate (3MTP), indole glucosinolates indolyl-3-methylglucosinolate (I3M) and 4-methoxy-3-indolylmethylglucosinolate (4MOI3M), aromatic glucosinolate 2-phenylethylglucosinolate (2PE). The composition of glucosinolates varied considerably among different tissues, with seven compounds identified in roots (except bolting stage), flowers and siliques, six in stems, cauline leaves and petioles, five in rosette leaves. The total contents of glucosinolates in different organs at various developmental stages also displayed significant variations.Second, in the experimental system, the plants are exposed to NaCl solutions (0,200,300, 400,500 mmol/L) for 24 h. Low and moderate level of salt stress (200 and 300 mmol/L NaCl treatment) do not significantly varied the physiology of T. halophila. Relative high level of salt stress (400 and 500 mmol/L NaCl treatment) significantly increased relative conductivity and reduced relative tissue water content.Third, the glucosinolate-myrosinase system in different organs displayed significant variations when response to NaCl stress. At bolting stage, the contents of total and aromatic glucosinolates decreased and then increased with increasing NaCl concentrations in the roots. The aromatic glucosinolates accounted for nearly 50% of the total glucosinolates. The myrosinase activity do not varied significantly in roots after treatment. In the flowers, the contents of total and indole glucosinolates increased with increasing NaCl concentrations. The indole glucosinolates accounted for nearly 98% of the total glucosinolates. The myrosinases activities were higher than control after NaCl stress.Fourth, the glucosinolate-myrosinase system of roots at various developmental stages also displayed significant variations when response to NaCl stress. At young seedling stage, the contents of total glucosinolates increased and then decreased with increasing NaCl concentrations. The myrosinases activities significantly increased after 500 mmol/L NaCl treated. At the seedling stage, the contents of total glucosinolates decreased and then increased with increasing NaCl concentrations. The myrosinases activities decreased and then increased to the level of control with increasing NaCl concentrations.