Growth and Oxidative Stress of Brittlewort (Nitella pseudoflabellata) in Response to Cesium Exposure

Abstract

The present study evaluated the impact of cesium ((133)Cs) at four concentrations (0, 0.001, 0.01, and 0.1 mg L(-1)) on growth, concentrations of chlorophyll and carotenoid pigments, and oxidative stress responses in the charophyte, Nitella pseudoflabellata, over 30 days. Oxidative stress was quantified by measuring anti-oxidant enzyme activities and H2O2 content. When compared with the control, significantly elevated activity levels of the anti-oxidative enzymes ascorbic peroxidase, catalase and guaiacol peroxidase were observed at 0.1 mg L(-1) (all p < 0.05), even though the H2O2 level was not significantly elevated. Carotenoid and chlorophyll a and b pigment levels were significantly reduced (all p < 0.05) at Cs exposures of 0.01 and 0.1 mg L(-1). Photosynthetic efficiency (i.e., Fv/Fm) was significantly reduced (p < 0.05) at Cs concentrations ≥0.001 mg L(-1). Significant reduction (p < 0.05) of plant growth (i.e., shoot length) was also observed after 1 week of exposure at Cs concentrations ≥0.001 mg L(-1). Our results suggested that Cs exposure reduced plant growth and affected plant functioning via activating the defense mechanism against oxidative stress in Nitella.

Two-step approach for assessing the health effects of environmental chemical mixtures: application to simulated datasets and real data from the Navajo Birth Cohort Study

“…Some of the findings are supported by previous literature while others are not directly mentioned or implicated in literature and warrant further investigation. Components of our findings on the associations between oxidative stress biomarkers and exposures to cesium, dimethylarsinic acid, barium, and thallium in the NBCS are supported by previous literature reports [44][45][46][47] in human and animal models. There is experimental evidence that oxidative stress can be induced either by redox-cycling metals such as barium or thallium through directly generating free radicals, or indirectly by non-redox cycling metals such as arsenic, lead or mercury [44,45].…”

“…Hanzel et al 2005 reported a link between thallium and oxidative stress through glutathione (GSH) metabolism and peroxide detoxification [46]. A recent study on plants reported that cesium exposure reduced plant growth via activating the defense mechanism against oxidative stress [47]. In a previous mouse model, cesium induced renal and liver damage through oxidative stress [49].…”

Maternal Urinary Metal and Metalloid Concentrations in Association with Oxidative Stress Biomarkers

“…To our knowledge, no human or animal studies have examined associations between Cs and oxidative stress. However, our findings of urinary Cs associated with higher levels of 8iso-PGF2α are in line with plant studies that show Cs can induce the formation of ROS and oxidative stress [71,72]. Further studies are needed to assess the mechanisms through which Cs can impact oxidative state in the human body.…”

Immediate response of Chara braunii exposed to zinc and hydrogen peroxide

“…25°C) with a light intensity of 20–40 μmol photons m −2 s −1 under a 12 h/12 h light/dark cycle (Atapaththu et al . 2016).…”

“…2010; Atapaththu et al . 2016). In contrast, we measured the immediate effect of zinc (Zn) and ROS (H 2 O 2 ) exposure to discriminate between direct effects of heavy metal contamination and indirect, ROS‐mediated effects in macrophytes.…”