Zinc stress and ROS and RNS metabolism of roots

Zinc (Zn) is an essential micronutrient naturally present in soils, but anthropogenic activities can lead to accumulation in the environment and resulting damage to plants. Heavy metals such as Zn can induce oxidative stress and the generation of reactive oxygen and nitrogen species (ROS and RNS), which can reduce growth and yield in crop plants.

Microscopic images of Brassica root tips stained with Schiff’s reagent.
Microscopic images of Brassica root tips stained with Schiff’s reagent. The pink coloration indicates lipid peroxidation. Scale bar = 200 µm. Image from Feigl et al.

Feigl et al. examine markers of oxidative and nitrosative stress to evaluate the relative sensitivities of Brassica napus (oilseed rape) and B. juncea (Indian mustard) to zinc toxicity. Declines in the primary root length, total root fresh weight and root meristem cell viability of B. napus show it is substantially more sensitive to increasing zinc concentrations than B. juncea. This sensitivity of B. napus is underscored by considerable lipid peroxidation in the roots as well as accumulation of superoxide, which is not seen in B. juncea. By contrast, markers of nitrosative stress do not discriminate the sensitivities of the two species.

This article appears in the special issue ROS and NO Reactions in Plants.