Analysis of lipid peroxidation metabolism during florescence and senescence of Lily

Abstract

In order to explore the correlation between the level of membrane lipid peroxidation and the physiological mechanism of senescence at different developmental stages of lily, the soluble protein content, soluble sugar content, malondialdehyde (MDA) content, superoxide radical (O2-) production rate, hydrogen peroxide (H2O2) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, and peroxidase (POD) activity in petal of Lilium regale and Lilium leucanthum were measured at different developmental stages. The results showed that during flowering and senescence, soluble protein content in petal of L. regale changed with a single peak curve, while the content of soluble protein in petal of L. leucanthum decreased steadily. Soluble sugar content, SOD activity, and CAT activity of the two lilies increased first and then decreased. MDA content, H2O2 content,and O2- production rate continued to rise. POD activity of L. regale changed steadily, while POD activity of L. leucanthum increased significantly in the later stage. Therefore, the membrane lipid peroxidation caused by the accumulation of reactive oxygen species is one of the main physiological reasons for the senescence of lily.