Abstract: The effects of different concentrations of diterpenoids glaucocalyxin A (0, 20, 100 μmol·L^-1) on membrane permeability and osmotic adjustment of fiveArabidopsis thaliana lines (the ColombiaArabidopsis thaliana, and pla₁-1, pla₂-1, plc₁-1 and pldδ₂ phospholipase mutants) were examined. The results showed that the relative electrolyte leakage and malondialdehyde (MDA) contents were significantly increased by the application of glaucocalyxin A in five lines of A. thaliana. The contents of proline and soluble protein first increased and thendecreased, with a peak at 24 h. Different types of phospholipases played different roles in thephysiological regulation process. Our results suggest that the effects of glaucocalyxin A areassociated with the four types of phospholipids and that its allelopathic effects can be exerted byregulating phospholipases.

Key words: influence factor, substitution efficiency, SE-DEA, agro-chemical input intensity