Effects of zinc stress on growth and antioxidant enzyme responses of Kandelia obovata seedlings

Abstract

This study evaluated the tolerance and accumulation potential in the mangrove Kandelia obovata under moderate and high levels of external Zn. A greenhouse experiment was conducted to investigate the effects of a range of external Zn concentrations (0–400 mg L⁻¹) on the growth of this species by counting the lateral root number and measuring the root length, leaf area, and total dry biomass. We also determined the Zn accumulation in plant tissues. K. obovata survived with external Zn concentrations of up to 400 mg L⁻¹, although the excess metal resulted in a biomass reduction of 34%. A significant increase in antioxidant enzyme activities occurred in roots of plants under high-level Zn stress, suggesting that K. obovata seedlings could tolerate up to 200 mg L⁻¹ zinc treatment.

Keywords:

• antioxidant enzyme
• growth
• mangrove
• Kandelia obovata
• zinc

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the grant from the Natural Science Foundation of China (NSFC) [No. 41001189]; the Natural Science Foundations of the Anhui Bureau of Education [KJ2015KJ006]; and the Natural Science Foundations of Fuyang Normal College [2013FSKJ04ZD].