The Effect of Foliar Selenium (Se) Treatment on Growth, Photosynthesis, and Oxidative-Nitrosative Signalling of Stevia rebaudiana Leaves

作者：Péter Borbély, Árpád Molnár, Emil Valyon, Attila Ördög, Klára Horváth-Boros, Dezső Csupor, Attila Fehér, Zsuzsanna Kolbert · 发表于：Antioxidants · 年份：2021 · DOI：10.3390/antiox10010072 · 被引用次数：38 · 研究领域：Selenium in Biological Systems、Plant Stress Responses and Tolerance、Plant Micronutrient Interactions and Effects

Selenium (Se) enrichment of Stevia rebaudiana Bertoni can serve a dual purpose, on the one hand to increase plant biomass and stress tolerance and on the other hand to produce Se fortified plant-based food. Foliar Se spraying (0, 6, 8, 10 mg/L selenate, 14 days) of Stevia plantlets resulted in slightly decreased stevioside and rebaudioside A concentrations, and it also caused significant increment in stem elongation, leaf number, and Se content, suggesting that foliar Se supplementation can be used as a biofortifying approach. Furthermore, Se slightly limited photosynthetic CO2 assimilation (AN, gsw, Ci/Ca), but exerted no significant effect on chlorophyll, carotenoid contents and on parameters associated with photosystem II (PSII) activity (FV/FM, F0, Y(NO)), indicating that Se causes no photodamage in PSII. Further results indicate that Se is able to activate PSI-cyclic electron flow independent protection mechanisms of the photosynthetic apparatus of Stevia plants. The applied Se activated superoxide dismutase (SOD) isoenzymes (MnSOD1, FeSOD1, FeSOD2, Cu/ZnSOD1, Cu/ZnSOD2) and down-regulated NADPH oxidase suggesting the Se-induced limitation of superoxide anion levels and consequent oxidative signalling in Stevia leaves. Additionally, the decrease in S-nitrosoglutathione reductase protein abundance and the intensification of protein tyrosine nitration indicate Se-triggered nitrosative signalling. Collectively, these results suggest that Se supplementation alters Stevia sho...