Urea-induced oxidative damage in Elodea densa leaves

Abstract

Urea being a fertilizer is expected to be less toxic to plants. However, it was found that urea at 100 mg L(-1) caused the oxidative stress in Elodea leaves due to the formation of reactive oxygen species (ROS) and lipid peroxidation that are known to stimulate antioxidant pathway. Urea at a concentration of 500 and 1000 mg L(-1) decreased low-molecular-weight antioxidants. In this case, the antioxidant status of plants was supported by the activity of antioxidant enzymes such as superoxide dismutase and guaiacol peroxidase. A significant increase in the soluble proteins and -SH groups was observed with high concentrations of urea (30-60 % of control). Thus, the increased activity of antioxidant enzymes, low-molecular-weight antioxidants, and induced soluble protein thiols are implicated in plant resistance to oxidative stress imposed by urea. We found that guaiacol peroxidase plays an important role in the removal of the peroxide in Elodea leaves exposed to 1000 mg L(-1)of urea.

Modulation of cadmium-induced phytotoxicity in Cabomba caroliniana by urea involves photosynthetic metabolism and antioxidant status

“…The data from AsA pretreated with 400 mg L −1 urea exposed plants indicated a drastic reduction (27%) in TBARS content and a marked increase in CAT (131%), GST (384%) and POD (55%) activity, which further corroborates the above findings that 400 mg L −1 urea caused oxidative damage in C. caroliniana. Similar finding have also been reported for other aquatic plants, including Elodea densa (Maleva et al, 2015). Furthermore, 400 mg L −1 urea enhanced Cd toxicity in C. caroliniana.…”

“…Our previous study found that certain concentrations of urea could stimulate the synthesis of photosynthetic pigments and increase photosynthesis in Cabomba caroliniana and Elodea nuttallii. However, high concentrations of urea impaired growth in the two aquatic species (Huang et al, 2016), which is consistent with the results for Elodea densa (Maleva et al, 2013(Maleva et al, , 2015. Excessive application of urea (more than 100 mg L −1 ) could decrease photosynthetic activity and the toxic mechanisms of urea on E. densa, based on the accumulation of ROS in leaves, which disturbs the balance and lead to oxidative stress (Maleva et al, 2013(Maleva et al, , 2015.…”

“…Investigations over the last several years present ample data regarding the separate influences of Cd or urea on the physiology of aquatic plants (Xu et al, 2012;Maleva et al, 2013Maleva et al, , 2015Chen et al, 2016;Huang et al, 2016). Due to excessive application, urea may be washed off from the agricultural fields, or move with water through leaching and erosion, enter and mix with Cd-loaded water bodies.…”

Antioxidant and Antiradical Activity of Beetroot (Beta vulgarisL. var.conditivaAlef.) Grown Using Different Fertilizers

“…At high concentration, urea leads to the depletion of a low molecular weight antioxidant pool. It is thought to be associated with increased oxidative stress and increased antioxidative protection of the plant [41,42]. Similar results were obtained in the application of fertilizers of nitrogen origin such as CAN, AN, and AS to the plant.…”

A New Lipid Rich Microalgal SP Scenedesmus Dimorphus Isolated: Nile Red Staining and Effect of Carbon, Nitrogen Sources on its Physio-Biochemical Components

“…Significant carbohydrates (P≤0.05) concentration have been found in beef extract. It is also reported that certain concentration of urea could stimulate the accumulation of photosynthetic pigments and intensify photosynthesis in Elodea densa (Maleva et al, 2015). However the protein concentration was found to be significant (P≤0.05) in yeast extract as comparison was made with other nitrogen source.…”