Alleviating Effects of Slicylic Acid on Physiological Characteristics of Hibiscus syriacus L.under High Salt Stress

Yin Juan; Yang Xuejun; Liu Boxuan; Li Wenyang

doi:10.14083/j.issn.1001-4942.2025.02.008

Abstract：To improve the salt-tolerance of Hibiscus syriacus seedlings and to provide the scientific refer-ence for its planting in highly salinized soil,in this experiment,one-year-old seedlings of H.syriacus were used as materials,and four treatments of T0(0 NaCl+0 g/L salicylic acid),T1(1.0％NaCl+0 g/L salicylic acid),T2(0 NaCl+0.3 g/L salicylic acid)and T3(1.0％NaCl+0.3 g/L salicylic acid)were set.The effects of salicylic acid(SA)application on the growth and development of seedlings,the activity,osmotic adjust-ment and oxidative stress of roots,and the contents of SA in roots,stems and leaves of H.syriacus under high salt(1.0％NaCl stress)were studied.The results showed that the roots of H.syriacus seedlings were subjected to osmotic stress under high salt stress with the growth and development delayed,root activity decreased,and cellular oxidative stress level increased.Compared with T1 group,the plant growth and biomass in T3 group were increased,the root activity and contents of proline,soluble sugar and soluble protein were significantly increased,while the membrane permeability and malondialdehyde(MDA)content were significantly de-creased.Meanwhile,the activity of antioxidant enzymes in roots significantly increased on the 10th,20th,and 30th days after treatment in T3 group,among which,the superoxide dismutase(SOD)activity increased by 30.98％,30.48％and 183.09％;the catalase(CAT)activity increased by 20.97％,21.32％and 192.58％,and the peroxidase(POD)activity increased by 44.06％,42.66％and 146.92％,respectively.In addition,it was observed that the content of SA in the roots,stems and leaves of H.altissima were constantly changing dy-namically with the highest in leaves and the lowest in roots.In summary,SA had the ability to promote the growth of H.syriacus and to improve root osmotic regulation and antioxidant capacity under high salt stress,so as to alleviate the damage caused by high salt stress to roots.