Changes of 45Ca2+ uptake and translocation in chinese cabbage (brassica pekinensis) at salt stress

Seedlings of Chinese cabbage were grown in the greenhouse at 0, 5 and 10 mS/cm NaCl. Membrane leakage, TTC reduction activity and MDA content of the roots were determined from one hour to ten hours after treatment as the index of root injury. Ca2+ uptake rate as a function of external [Ca2+] at 5 mS/cm and 10 mS/cm NaCl was much lower than that of control when the external [Ca2+] was more than 0.75 mmol/L. 45Ca2+ uptake was significantly inhibited 3 hours after exposed to 10 mS/cm and 5 hours after exposed to 5 mS/cm, respectively. Distribution of 45Ca2+ in roots, stems and leaves reveals that young leaves are the most sensitive part to salt stress in terms of the absorption of Ca2+, thus Ca deficiency occurs in young leaf margin when exposed to salt stress