Abstract
Selenium (Se) is an essential micronutrient for humans. Increasing Se content in food crops offers an effective approach to enhance the consumption of Se in human diets. A thoroughly understanding of the effects of Se on plant growth is important for Se biofortification in food crops. Given that Se is an analog of sulfur (S) and can be toxic to plants, its effect on plant growth is expected to be greatly affected by S nutrition. However, this remains to be further understood. Here, we evaluated the influence of Se treatments on broccoli (Brassica oleracea L. var. italica) growth when S was withheld from the growth nutrient solution. We found that Se was highly toxic to plants when S nutrition was poor. In contrast to Se treatments with adequate S nutrition that slightly reduced broccoli growth, the same concentration of Se treatments without S supplementation dramatically reduced plant sizes. Higher Se toxicity was observed with selenate than selenite under low S nutrition. We examined the bases underlying the toxicity. We discovered that the high Se toxicity in low S nutrition was specifically associated with an increased ratio of Se in proteins verse total Se level, enhanced generation of reactive oxygen species, elevated lipid peroxidation causing increased cell membrane damage, and reduced antioxidant enzyme activities. Se toxicity could be counteracted with increased supplementation of S, which is likely through decreasing non-specific integration of Se into proteins and altering the redox system. The present study provides information for better understanding of Se toxicity and shows that adequate S nutrition is important to prevent Se toxicity during biofortification of crops by Se fertilization.
Highlights
Selenium (Se) is an essential micronutrient for humans and animals
To examine the toxicity of Se to plant growth and the role of S in protecting plants from Se toxicity, two broccoli cultivars were grown in Hoagland nutrient solution and treated with increased amounts of Na2SeO4 or Na2SeO3 in the presence or absence of 1 mM Na2SO4 supplementation for 2 weeks
The selenite treatment at 40 μM showed similar biomass as selenate at 20 μM (Figure 2B). These results indicate that selenate is more toxicity than selenite when S nutrition was low and S can protect plants from Se toxicity
Summary
Selenium (Se) is an essential micronutrient for humans and animals. Selenium Toxicity in Broccoli to increase the consumption of Se in human diets (Alfthan et al, 2015). Previous reports show that the monomethylated forms of Se, such as Se-methylselenocysteine and γ-glutamyl-Se-methylselenocysteine, have potent cancer chemopreventive activity (Ip et al, 2000; Dong et al, 2001). These anticarcinogenic compounds are enriched in the Se-biofortified Brassica crops (Lyi et al, 2005; Ramos et al, 2011b; Ávila et al, 2013, 2014). A better understanding of Se metabolism is important for Se biofortification and enrichment in food crops
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
