Physiological and Biochemical Changes in Lettuce under High Temperature Stress after Exogenous Salicylic Acid Treatments

摘要

Exogenous salicylic acid (SA) of different concentrations (0mmol·L-1,0.1mmol.L-1,0.2mmol·L-1,0.4mmol·L-1 and0.6mmol·L-l) was applied to lettuce seedlings before submitting to high temperature stress.Results showed that the activities of catalase (CAT) and peroxidase (POD) were enhanced; the contents of soluble proteins and proline increased,while malondialdehyde (MDA) content and relative electric conductivity decreased by pretreatments of SA.The optimal effects resulted from the SA concentrations of 0.2mmol·L-1 and 0.4 mmol·L-1.