Osmoregulation and antioxidant production in maize under combined cadmium and arsenic stress

Abstract

An investigation was carried out to examine the combined and individual effects of cadmium (Cd) and arsenic (As) stress on osmolyte accumulation, antioxidant activities, and reactive oxygen species (ROS) production at different growth stages (45, 60, 75, 90 days after sowing (DAS)) of two maize cultivars viz., Dong Dan 80 and Run Nong 35. The Cd (100 μM) and As (200 μM) were applied separately as well as in combination (Cd + As) at 30 DAS. Results revealed pronounced variations in the behavior of antioxidants, osmolytes, and ROS in both maize cultivars under the influence of Cd and As stress. Activities of enzymatic (SOD, POD, CAT and APX, GPX, GR) and non-enzymatic (GSH and AsA) antioxidants, generation of ROS, and accumulation of osmolytes were enhanced with the passage of time; therefore, the maximum values for these attributes were observed at 90 DAS for both cultivars. Exposure of plants to Cd or As stress considerably enhanced the antioxidant activities, ROS, and osmolyte accumulation compared with control, while combined application of Cd + As was more devastating in reducing plant biomass of both maize cultivars. Among cultivars, Dong Dan 80 was better able to negate the heavy metal-induced oxidative damage, which was associated with higher antioxidant activities, greater osmolytes accumulation, and lower ROS production in this cultivar.

Integration of Cadmium Accumulation, Subcellular Distribution, and Physiological Responses to Understand Cadmium Tolerance in Apple Rootstocks

“…In agreement with lower accumulation of ROS and MDA, the increases in total soluble sugars in bark, and starch in roots and leaves of M. baccata under Cd exposure may contribute to osmotic regulation and oxidant detoxification. Similar results were also found in maize (Anjum et al, 2016) and poplar (He et al, 2013a). In comparison with M. hupehensis and M. robusta , the constructive higher concentration of starch in roots, bark and leaves of M. baccata could be considered as an important Cd tolerance mechanism.…”

“…In recent years, remarkable progress has been made on elucidating Cd tolerance in crop plants at the physiological levels (Romero-Puertas et al, 2012; Clemens et al, 2013; Zhang et al, 2013; Choppala et al, 2014; Anjum et al, 2016). Cd stress leads to decrease in photosynthesis, chlorophyll contents and thereby resulted in decline in total soluble sugars and starch which are required to provide energy to cope with Cd stress (Nagajyoti et al, 2010; He et al, 2013a).…”

Modulation of arsenic-induced oxidative stress and protein metabolism by diphenyleneiodonium, 24-epibrassinolide and proline in Glycine max L.

“…Further, being an oxidizing agent, ROS disturbs membrane integrity drastically, consequentially enhancing the leakage of cellular constituents. A similar change in free radical generation and related electrolyte leakage under As-stress has been observed in Oryza sativa L. (Begum et al 2016) and Zea mays L. (Anjum et al 2016). The results of the present study indicate that the As-induced oxidative damage in Glycine max L. was compensated for remarkably by exogenous DPI, EBL or Pro, by limiting ROS production and electrolyte release.…”

Exogenous application of plant growth regulators (PGRs) induces chilling tolerance in short-duration hybrid maize

“…Different abiotic stresses affect maize growth and yield and bring changes in physio-biochemical attributes (Anjum et al 2016c;Anjum et al 2016d;Anjum et al 2016e) as well as photosynthesis and gas exchange attributes (Anjum et al 2016a). Among different abiotic stresses, suboptimal temperature (≤12°C) is one of the serious constraints to maize production which damage macromolecules and cellular structures, by production of reactive oxygen species (ROS) (Apel and Hirt 2004).…”