Antioxidant and prooxidant effects of lanthanum ions on Vicia faba L. seedlings under cadmium stress, suggesting ecological risk

Abstract

The present study combined chemical analyses and biological measurements to investigate biphasic effects of La on Cd stress in leaves of Vicia faba seedlings, which were hydroponically cultivated for 15 d in the combination of 6 µM CdCl(2) and 2 to 480 µM La(NO(3))(3), respectively. The results showed that contents of Cd first elevated above and then declined below the 6 µM single Cd treatment when 2 to 30 µM extraneous La were combined. Contents of mineral nutrients altered differentially and became imbalanced. No distinct band was observed in catalase (CAT), guaiacol peroxidase (GPX), or ascorbate peroxidase (APX) patterns, but in superoxide dismutase (SOD) isozymes by the supplementation with 8 to 480 µM of extraneous La. Superoxide dismutase and APX activities changed as a U-shaped curve; however, CAT and GPX changed as an inverted U-shaped curve along with increasing La. Moreover, heat shock protein 70 (HSP 70) production was reduced below the single treatment of Cd at 2 to 8 µM of extraneous La and enhanced thereafter. Thus, La at lower concentrations promoted antioxidation against Cd stress; La at higher concentrations turned to prooxidant effects, implicating potential ecological risk. Heat shock protein 70, combined with the antioxidant enzymes, constitutes an integrative defense system, which can be used to estimate the degree of antioxidation or prooxidation of extraneous La to Cd-induced oxidative stress in the seedlings.

Lanthanum Affects Bell Pepper Seedling Quality Depending on the Genotype and Time of Exposure by Differentially Modifying Plant Height, Stem Diameter and Concentrations of Chlorophylls, Sugars, Amino Acids, and Proteins

“…Indeed, Kawano et al (2002) found that La may trigger oxidative stress in a time- and dose-dependent manner in tobacco ( Nicotiana tabacum ) BY-2 cells, which is a typical effect of REE inducing hormetic dose-responses in plants. Accordingly, Wang et al (2012b) reported that La at low concentrations (i.e., 2–8 μM LaCl 3 ) promoted antioxidation against Cd stress in soybean seedlings, whereas at high concentrations (i.e., 30–480 μM LaCl 3 ) it resulted in prooxidant effects, implying potential ecological risk. Moreover, Fashui et al (2000, 2005) found that increasing the synthesis of ROS decreases the protein concentration.…”

Rare Earth Elements in the Soil Environment

“…There are also studies that correlate the presence of REE to a higher activity of the antioxidant enzymatic system [112,117,119,130,131,150]. , and 10…”

“…This survey was further refined by entering the keyword Bpollution^(rare earth elements AND soil AND pollution), leading to a subset of 260 references. Again, the great majority of the references (~57 %) were published in recent years (since 2010), and half of them (130) came from China, Japan, Germany, and France. By replacing the third keyword with Bplant^(rare earth elements AND soil AND plant), we collected 369 references, and when we added pollution to this last refinement (rare earth elements AND soil AND plant AND pollution), we have recovered only 91 references from the previous search, with~57 % published since 2010.…”

Lanthanum ions intervened in enzymatic production and elimination of reactive oxygen species in leaves of rice seedlings under cadmium stress

“…After being taken up by plant roots, Cd could disturb various metabolic processes and physiological activities (e.g., photosynthesis, mineral nutrition, membrane structure, cell respiration, and plant growth) [2,5,6]. Thus, some chemical methods were adopted to alleviate oxidative stress and damage on cultivars exposed to Cd or other heavy metals [1,7].…”

“…Rare earth elements have been proved to have resistance to heavy metals and thus relieve oxidative damage in plants [1,9]. Previous studies demonstrated that La 3þ at lower concentrations reduced ROS accumulation and promoted antioxidation in V. faba L. seedlings under Cd stress [1,7] and at higher doses inhibited antioxidant enzymes and physiological function in roots and leaves of soybean seedlings [14]. As is well known, Cd can cause reactive oxygen species (ROS) burst, oxidative stress, macromolecule damage, and cell death in plants [12,13].…”