The system modulating ROS content in germinating seeds of two Brazilian savanna tree species exposed to As and Zn

The effects of increasing arsenic (0, 10, 50, 100 mg L−1) and zinc (0, 50, 80, 120, 200 mg L−1) doses on germination and oxidative stress markers (H2O2, MDA, SOD, CAT, APX, and GR) were examined in two Brazilian savanna tree species (Anadenanthera peregrina and Myracrodruon urundeuva) commonly used to remediate contaminated soils. The deleterious effects of As and Zn on seed germination were due to As- and Zn-induced H2O2 accumulation and inhibition of APX and GR activities, which lead to oxidative damage by lipid peroxidation. SOD and CAT did not show any As- and Zn-induced inhibition of their activities as was seen with APX and GR. We investigated the close relationships between seed germination success under As and Zn stress in terms of GR and, especially, APX activities. Increased germination of A. peregrina seeds exposed to 50 mg L−1 of Zn was related to increased APX activity, and germination in the presence of As (10 mg L−1) was observed only in M. urundeuva seeds that demonstrated increased APX activity. All the treatments for both species in which germination decreased or was inhibited showed decreases in APX activity. A. peregrina seeds showed higher Zn-tolerance than M. urundeuva, while the reverse was observed with arsenic up to exposures of 10 mg L−1

Adaptive Strategies of Plants Under Adverse Environment: Mitigating Effects of Antioxidant System

© Springer Nature Singapore Pte Ltd. 2020. Variation in plant adaptive strategies to the diversity and variability of the environmental factors is the key to plant developmental success. Climate change phenomenon may be considered as one of the important factors of the adverse environment since it may lead to visible changes in rainfall and temperature in the global as well as regional aspects. Under the conditions of such an unfavorable environment, plants increase the production of reactive forms of oxygen which further trigger disequilibrium between their production and removal. To control the production of reactive oxygen species (ROS), higher plants possess the ROS detoxification system which includes enzymatic and non-enzymatic antioxidant components that remove ROS and protect plant cells from oxidative damage. This chapter provides main information on ROS generation, redox balance, and plant protection in the view of ecophysiological adaptations to the adverse environment with a special focus on the antioxidant defense system