Cadmium-Induced Physiological Response in Lonicera japonica Thunb.

Phytoremediation of Cd-contaminated soil using hyperaccumulators has become a new promising technique. Lonicera japonica Thunb. has been reported as a new Cd-hyperaccumulator. In this study, the effect of Cd stress duration on growth, photosynthesis and mineral nutrition of L. japonica was investigated. At 30 days after Cd stress, there was not any visual leaf symptoms in L. japonica, and an obvious stimulating effect of 10mgkg1 Cd on net photosynthesis rate (PN) was well correlated to photosynthetic pigment contents and mineral nutrition (Mg and Fe) concentrations. With Cd stress time extended, no significant differences of shoots and total biomass and PN compared with the control was observed, indicating that L. japonica could develop effective tolerance mechanisms to avoid Cd-induced damage to photosynthesis and growth. The photosynthetic performance remained functional through stomatal and non-stomatal adjustments, and mineral nutrition responses. The improved growth based on shoots and total biomass and PN by 10mgkg1 Cd, as suggested by hormesis, may be beneficial to enhance the potential for phytoremediation, because it typically faced the low Cd concentrations in actual Cd-contaminated soils. The study results indicated that L. japonica could be used for phytoremediation contaminated soils by Cd.