Cerium improves the vase life of Lilium longiflorum cut flowers through ascorbate-glutathione cycle and osmoregulation in the petals

The present study investigated the role of cerium nitrate (Ce(NO3)3) in regulating the ascorbate-glutathione (AsA-GSH) cycle, the relative water content (RWC), and the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), soluble sugar and proline in the petals, and the contents of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Car) in the leaves of Lilium longiflorum cut flowers. The findings showed that Ce(NO3)3 markedly improved the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR), the ratios of AsA/DHA and GSH/GSSG, RWC, and the contents of proline and soluble sugar in the petals, and markedly reduced the contents of MDA and H2O2 in the petals, compared with the control. Meanwhile, Ce(NO3)3 markedly improved the contents of Chl a, Chl b and Car in the leaves. Among different concentrations of Ce(NO3)3, 40 μM Ce(NO3)3 is the most effective treatment for the improvement of the vase life of Lilium longiflorum cut flowers. Above results indicated that Ce(NO3)3 improves the vase life of Lilium longiflorum cut flowers by enhancing the AsA-GSH cycle and water retaining capacity.