β-Radiation Stress Responses on Growth and Antioxidative Defense System in Plants: A Study with Strontium-90 in Lemna minor

• Published in: International journal of molecular sciences Vol. 16; no. 7; pp. 15309 - 15327
• Main Authors: Van Hoeck, Arne, Horemans, Nele, Van Hees, May, Nauts, Robin, Knapen, Dries, Vandenhove, Hildegarde, Blust, Ronny
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 07.07.2015; MDPI AG
• Subjects: abiotic stress; Antioxidants - metabolism; Araceae - drug effects; Araceae - enzymology; Araceae - metabolism; Araceae - radiation effects; Beta Particles; dosimetry; Lemna minor; Metabolome - radiation effects; oxidative stress; radiation responses; Radiometry; Stress, Physiological - drug effects; Stress, Physiological - radiation effects; Strontium Radioisotopes - pharmacology; strontium-90; Time Factors; Lemna minor; radiation responses; dosimetry; strontium-90; oxidative stress; abiotic stress
• ISSN: 1422-0067; 1422-0067
• DOI: 10.3390/ijms160715309

In the following study, dose dependent effects on growth and oxidative stress induced by β-radiation were examined to gain better insights in the mode of action of β-radiation induced stress in plant species. Radiostrontium (⁹⁰Sr) was used to test for β-radiation induced responses in the freshwater macrophyte Lemna minor. The accumulation pattern of 90Sr was examined for L. minor root and fronds separately over a seven-day time period and was subsequently used in a dynamic dosimetric model to calculate β-radiation dose rates. Exposing L. minor plants for seven days to a ⁹⁰Sr activity concentration of 25 up to 25,000 kBq·L⁻¹ resulted in a dose rate between 0.084 ± 0.004 and 97 ± 8 mGy·h⁻¹. After seven days of exposure, root fresh weight showed a dose dependent decrease starting from a dose rate of 9.4 ± 0.5 mGy·h⁻¹. Based on these data, an EDR10 value of 1.5 ± 0.4 mGy·h⁻¹ was estimated for root fresh weight and 52 ± 17 mGy·h⁻¹ for frond fresh weight. Different antioxidative enzymes and metabolites were further examined to analyze if β-radiation induces oxidative stress in L. minor.