LAUSR

To explore aluminum (Al) tolerance in Ophiopogon japonicus, we used AlCl3 at the concentrations of 0 (control), 10, 20, 30, 40, 50, and 60 mmol/L to treat O. japonicas for detecting the growth and physiological indexes of the plant under AlCl3 stress. Compared with the control, fresh weight, dry weight, water content, contents of K, Mg, and Fe, activity of catalase in leaves and roots, Cacontent in roots, superoxide dismutase (SOD) activity, and root activity of O. japonicus roots showed a declining trend with the increase in the AlCl3 concentration. Meanwhile, the chlorophyll, Ca, and soluble protein (SP) contents of leaves, SOD activity and peroxidase (POD) activity of leaves and roots initially increased and then declined. However, the soluble sugar (SS) and Proline (Pro) contents of leaves slightly declined and then increased. The SS, SP, and Pro contents of roots, Al, free amino acid (FAA), superoxide anion (O2), and MDA contents, and plasma membrane permeability of leaves and roots showed a increasing trend. Therefore, low-concentration AlCl3 stress inhibited the growth ofO. japonicus, resulting in low water deficit and decline in root activity. Organic osmotica, such as SS, SP, Pro, and FAA, accumulated in leaves and roots, but no inorganic ions (including K, Ca, Mg, and Fe) were found. The antioxidant capacity decreased slightly, and the degree of oxidative damage was mild. High-concentration AlCl3 stress seriously inhibited the growth of O. japonicus, leading to a remarkable reduction in water deficit and root activity. Organic smallmolecule osmotica further accumulated in the plant, but inorganic ion deficit was aggravated. The antioxidant capacity decreased, whereas the degree of oxidative damage increased. Comprehensive analysis demonstrated that O. japonicus could endure AlCl3 stress ≤30mmol/L.