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An excess of selenium (Se) can cause toxicity to plants. Treatment with melatonin (MT) can alleviate the stress conditions in plants. Limited research exists on the impact of MT on Se stress and uptake in fruit trees. To address Se stress and enhance Se accumulation in Cyphomandra betacea Sendt. (Solanum betaceum Cav.), the effects of exogenous MT (50–200 µmol L−1) on C. betacea growth and Se accumulation under Se stress were studied. MT increased the biomass, photosynthetic pigments levels, and peroxidase activity of C. betacea under Se stress. Only at concentrations of 150 and 200 µmol L−1 did MT increase superoxide dismutase and catalase activities, as well as soluble protein content in C. betacea leaves. MT treatment also boosted the Se content and bioconcentration factor of C. betacea under Se stress while reducing the translocation factor. The dose of MT was directly related to the Se content, and the highest levels of Se in roots and shoots were observed at 150 µmol L−1, which was an increase of 114% and 60%, respectively, compared with the control. In addition, correlation, principal component, cluster, grey, and path analyses revealed a strong correlation between root Se content and shoot biomass with the shoot Se content. Therefore, MT treatment can mitigate Se stress and enhance Se uptake in C. betacea, and the most effective dose of MT is 150 µmol L−1. [ABSTRACT FROM AUTHOR]

The content of selenium (Se) in most horticultural crops is low. To improve Se uptake in fruit trees, we investigated the impact of water extract derived from Nasturtium officinale R. Br. straw on the growth and Se uptake of peach seedlings under Se‐enriched soil by a pot experiment. The water extract of N. officinale straw exhibited notable effects on various growth parameters and Se accumulation in peach seedlings, with the most significant outcomes observed at a 200‐fold dilution. Specifically, the extract led to substantial enhancements in biomass, photosynthetic pigment content, antioxidant enzyme activity, and soluble protein content in peach seedlings. Remarkably, the 200‐fold dilution of N. officinale straw extract resulted in a 60.78% increase in root biomass and a 31.26% increase in shoot biomass when compared to the control. Moreover, the water extract augmented the levels of total Se, inorganic Se, and organic Se, along with the activities of Se metabolism‐related enzymes in peach seedlings. Among various tested dilutions, the 300‐fold and 400‐fold dilutions of N. officinale straw extract exhibited the highest total Se contents in roots and shoots, respectively, indicating increments of 97.26% and 44.08% over their respective controls. Additionally, correlation and gray relational analyses unveiled significant associations between peroxidase activity, soluble protein content, chlorophyll a content, chlorophyll a/b ratio, and the total shoot Se content. In conclusion, the water extract of N. officinale straw holds substantial potential for promoting the growth and Se uptake in peach seedlings, with the best concentration of 300‐fold dilution. [ABSTRACT FROM AUTHOR]

To promote the selenium (Se) uptakes in fruit trees under Se-contaminated soil, the effects of water extract of Fagopyrum dibotrys (D. Don) Hara straw on the Se accumulation in peach seedlings under selenium-contaminated soil were studied. The results showed that the root biomass, chlorophyll content, activities of antioxidant enzymes, and soluble protein content of peach seedlings were increased by the F. dibotrys straw extract. The different forms of Se (total Se, inorganic Se, and organic Se) were also increased in peach seedlings following treatment with the F. dibotrys straw extract. The highest total shoot Se content was treated by the 300-fold dilution of F. dibotrys straw, which was 30.87% higher than the control. The F. dibotrys straw extract also increased the activities of adenosine triphosphate sulfurase (ATPS), and adenosine 5'-phosphosulfate reductase (APR) in peach seedlings, but decreased the activity of serine acetyltransferase (SAT). Additionally, correlation and grey relational analyses revealed that chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se content. Overall, this study shows that the water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration. The water extract of Fagopyrum dibotrys (D. Don) Hara straw promoted the selenium (Se) uptake in peach seedlings under selenium-contaminated soil. The concentration of F. dibotrys straw extract showed a quadratic polynomial regression relationship with the total root and shoot Se. Furthermore, chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se. This study shows that water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration. [ABSTRACT FROM AUTHOR]

IAA (indole-3-acetic acid), can regulate plant growth and development, and it can involve in regulation of abiotic stresses. In the present study, the effects of spraying different concentrations (0, 25, 50, 100 and 200 μmol/L) of IAA on the photosynthesis physiology in lettuce were investigated. The lettuce (Lactuca sativa) exposed to cadmium (Cd) exhibited a substantial change in photosynthetic pigment content and photosynthetic parameters. Spraying exogenous IAA resulted in alleviating the inhibitory of Cd toxicity to lettuce. The photosynthetic pigment content in shoot of lettuce increased by spraying with IAA compared with the Cd treatment alone. Cd stress caused reductions (P < 0.05) in Pn and Ls, respectively, whereas Gs, Ci, and Tr were increased, compared with the control. Spraying exogenous IAA resulted that the Pn increased and the Ls, Gs, Ci, Tr showed different trend. Therefore, spraying IAA effectively changed the photosynthetic pigment contents and photosynthesis parameters in lettuce.

Lettuce (Lactuca sativa) is one of the most common green leafy vegetables, which is widely cultivated all over the world, but extremely sensitive to cadmium (Cd) contaminated in soil. The effects of three hyperaccumulator plants straw (Solanum nigrum, Bidens pilosa and Galinsoga parviflora) on the antioxidant enzyme activities and osmotic regulators and malondialdehyde (MDA) content under Cd stress were studied by pot culture. Compared with no straw, three kinds of hyperaccumulator straw of S. nigrum straw, B. pilosa straw and G. parviflora straw increased the content of soluble protein and proline in lettuce, the activity of peroxidase (POD) and catalase (CAT) in lettuce was also increased, and the content of MDA was decreased. The stress resistance of lettuce was improved and the toxicity of Cd to lettuce was alleviated by using three kinds of hyperaccumulator plant straw.

Cadmium (Cd)‐contaminated soil has affected the fruit production safety. To decrease the Cd accumulation in the fruits, the effects of intercropping with the potential Cd‐hyperaccumulator Solanum photeinocarpum and its post‐grafting generations on the Cd uptake in cherry (Cerasus pseudocerasus) were studied by the pot experiments. Intercropping increased the biomass of cherry seedlings to some extent, and decreased the biomass of S. photeinocarpum and its post‐grafting generations. Intercropping decreased the Cd contents in cherry seedlings, and increased the Cd contents in S. photeinocarpum and its post‐grafting generations. Compared with their respective monoculture, intercropping decreased the shoot Cd content in cherry seedlings by 31.37%–60.70%, and increased the shoot Cd contents in S. photeinocarpum its post‐grafting generations by 18.50%–28.76%. In addition, intercropping also decreased the root‐to‐shoot Cd translocations in both plant species, and decreased the Cd content in the branches and fruits of fruiting cherry trees and the Cd extractions of S. photeinocarpum and its post‐grafting generations. Therefore, intercropping with S. photeinocarpum and its post‐grafting generations can be used to reduce Cd accumulation in cherry for fruit production safety. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination of orchard soils is a global problem that has been increasing. To decrease the Cd accumulation in fruits, intercropping the orchard crops with hyperaccumulator plants has been used for soil remediation. A pot and a field experiment were conducted to study the effects of intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat (Eriobotrya japonica) on the growth and Cd uptake of these two plant species. In the pot experiment, intercropping improved the biomass, Cd content, Cd extraction, and root-to-shoot Cd translocation in both species. Intercropping increased the DNA methylation levels, antioxidant enzyme activity, and soluble protein content of loquat seedlings. These results indicate that intercropping could improve the phytoremediation of S. photeinocarpum and its post-grafting generations and increase the Cd uptake in loquat seedlings. In the field experiment, intercropping increased the Cd contents in the old branches, while it decreased that in the young branches and fruits of loquat. These findings indicate that intercropping could increase the Cd uptake in old tissues but reduce the Cd uptake in young tissues and fruits of loquat. So, intercropping loquat with S. photeinocarpum and its post-grafting generations could be used in Cd-contaminated orchards. Intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat mutually promoted the growth of two plant species, and also promoted the cadmium uptakes in S. photeinocarpum and old branches of loquat, while inhibited the Cd uptake in the loquat young tissues (young branches and fruits). These results are the new findings of the intercropping. [ABSTRACT FROM AUTHOR]