Selenium Nanoparticles Mitigate Cadmium Stress in Tomato through Enhanced Accumulation and Transport of Sulfate/Selenite and Polyamines.

Accumulation of cadmium (Cd) ions in soil is an increasingly acute ecological problem in agriculture production. Selenium nanoparticles (SeNPs) can mediate Cd tolerance in plants; however, the underlying mechanisms remain unclear. Herein, we show that the foliar application of SeNPs improved the adaptive capacity of tomato plants to decrease Cd-induced damage. SeNPs induced more Cd in roots but not in shoots despite greater accumulation of selenium and sulfur in both tissues and high selenate influx. Additionally, SeNPs significantly increased thiol compounds, including glutathione, cysteine, and phytochelatins, contributing to enhanced Cd detoxification. Importantly, SeNPs induced the expression of sulfate transporters 1:3, S-adenosylmethionine 1 and polyamine transporter 3. Then, experiments with mutants of these genes showed that SeNP-reduced Cd stress largely relies on the levels and shoot-to-root transport of selenium/sulfur and polyamines. These findings highlight the potential of SeNPs to improve crop production and phytoremediation in heavy metal-contaminated soils.

Effects of exogenous sucrose and selenium on plant growth, quality, and sugar metabolism of pea sprouts.

BACKGROUND: Pea sprouts are considered a healthy food. Sucrose is a key nutritional factor affecting taste and flavor. Meanwhile, selenium (Se) is an essential micronutrient that plays multiple roles in wide variety of physiological processes and improves crop quality and nutritional value. Nonetheless, the effects of the combination of sucrose and Se treatment on growth, quality, and sugar metabolism of pea sprouts have not been explored. RESULTS: The results revealed that sucrose at 10 mg L-1 obviously increased fresh weight, vitamin C, soluble protein, soluble sugar, fructose, glucose, and sucrose contents. Se treatments also improved nutritional quality, but higher Se (2.5 mg L-1 ) significantly inhibited the growth of seedlings. Interestingly, the combined application of sucrose (10 mg L-1 ) and Se (1.25 mg L-1 ) could effectively promote vitamin C, sucrose, and fructose contents, especially the Se content, compared with Se application alone. Additionally, there were significant differences in the regulation of sugar metabolism between Se alone and combined application of sucrose and Se. Acid invertase and neutral invertase play a pivotal role in the accumulation of soluble sugar under Se treatments alone, and acid invertase might be the key enzyme to limit sugar accumulation under combined application of sucrose and Se. CONCLUSION: The moderate combined application of sucrose (10 mg L-1 ) and Se (1.25 mg L-1 ) more effectively regulated sugar metabolism and improved nutritional quality than Se application alone did. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.