Effect of exogenous salicylic acid on salt tolerance of Hosta ensata

Salicylic acid (SA) plays a critical role in the response of plants to environmental stress. In this study, a pot experiment was utilized to study the effects of SA on the tolerance of Hosta ensata to salt. Seedlings were exposed to 0 (control) and 200 mM NaCl after a foliar spray of 0 (control), 0.25, 0.5, and 1.0 mM SA. The foliar spray of SA significantly improved the growth of H. ensata under NaCl stress compared with NaCl without SA. The plant height, dry weight, total chlorophyll content and Pn significantly increased, and the salt injury index decreased significantly. Moreover, the soluble sugar, soluble protein and proline contents of H. ensata treated with SA during NaCl stress significantly increased compared with NaCl without SA. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) increased, while the content of MDA significantly decreased. This study showed that the magnitude reached by the average subordinate function value was from the T2 treatment, which indicated that the salt tolerance of H. ensata was stronger in plants subjected to 0.5 mM SA. In conclusion, 0.5 mM SA can noticeably decrease the deleterious effects of NaCl stress on H. ensata.