Melatonin Promotes Iron Reactivation and Reutilization in Peach Plants under Iron Deficiency.

The yellowing of leaves due to iron deficiency is a prevalent issue in peach production. Although the capacity of exogenous melatonin (MT) to promote iron uptake in peach plants has been demonstrated, its underlying mechanism remains ambiguous. This investigation was carried out to further study the effects of exogenous MT on the iron absorption and transport mechanisms of peach (Prunus persica) plants under iron-deficient conditions through transcriptome sequencing. Under both iron-deficient and iron-supplied conditions, MT increased the content of photosynthetic pigments in peach leaves and decreased the concentrations of pectin, hemicellulose, cell wall iron, pectin iron, and hemicellulose iron in peach plants to a certain extent. These effects stemmed from the inhibitory effect of MT on the polygalacturonase (PG), cellulase (Cx), phenylalanine ammonia-lyase (PAL), and cinnamoyl-coenzyme A reductase (CCR) activities, as well as the promotional effect of MT on the cinnamic acid-4-hydroxylase (C4H) activity, facilitating the reactivation of cell wall component iron. Additionally, MT increased the ferric-chelate reductase (FCR) activity and the contents of total and active iron in various organs of peach plants under iron-deficient and iron-supplied conditions. Transcriptome analysis revealed that the differentially expressed genes (DEGs) linked to iron metabolism in MT-treated peach plants were primarily enriched in the aminoacyl-tRNA biosynthesis pathway under iron-deficient conditions. Furthermore, MT influenced the expression levels of these DEGs, regulating cell wall metabolism, lignin metabolism, and iron translocation within peach plants. Overall, the application of exogenous MT promotes the reactivation and reutilization of iron in peach plants.

Effects of intercropping with two Solanum species on the growth and cadmium accumulation of Cyphomandra betacea seedlings.

The contamination of orchard by cadmium (Cd) has recently increased in severity. To decrease the Cd content in fruit tree, a pot-based experiment was conducted to study the effects of intercropping with two Solanum species (Solanum alatum and Solanum diphyllum) on the growth and Cd accumulation of Cyphomandra betacea seedlings. The data revealed that intercropping with two Solanum species significantly increased the biomass, photosynthetic pigment contents, antioxidant enzyme activities, and soluble protein contents of C. betacea seedlings under Cd stress condition. The intercropping significantly decreased the Cd content in C. betacea seedlings. However, the intercropping significantly decreased the S. alatum and S. diphyllum biomasses, while increased the Cd content and accumulation in the roots and shoots of two Solanum species, and the Cd uptake by S. alatum was lower than that of S. diphyllum. Therefore, intercropping with these two Solanum species, especially S. diphyllum, may promote the growth and decrease the Cd content in C. betacea.

Effects of reciprocal hybridization on cadmium accumulation in F1 hybrids of two Solanum photeinocarpum ecotypes.

In this study, farmland and mining ecotypes of Solanum photeinocarpum (a potential cadmium (Cd) hyperaccumulator plant) were reciprocally hybridized each other, and the Cd accumulation characteristics of the F1 hybrids were studied. In pot experiments, higher biomasses and Cd extraction abilities were found for two S. photeinocarpum F1 hybrids than for the parents, but the Cd contents in various organs were lower in the hybrids than the parents. However, the differences between the Cd contents in the two hybrids were not significant. The antioxidant enzyme (superoxide dismutase and peroxidase) activities were higher for the S. photeinocarpum F1 hybrids than the parents. Less DNA methylation was found in the hybrids than the parents because more demethylation occurred in the hybrids than the parents. The biomass, Cd content, and Cd extraction ability effects in field experiments were similar to the effects in the pot experiments. It was concluded that reciprocally hybridizing different S. photeinocarpum ecotypes improved the ability of S. photeinocarpum to be used to phytoremediate contaminated land.

Effect of micronutrient pack on micronutrient status and antioxidant capacities among institutional older adults in Shanghai, China.

BACKGROUND AND OBJECTIVES: Older adults are at increased risk of micronutrient deficiency, disrupting the balance of oxidation/antioxidation system and leading to serious health burdens. This study aimed to investigate the effect of micronutrient pack on micronutrient status and oxidative/antioxidative biomarkers in institutional older adults. METHODS AND STUDY DESIGN: Subjects aged 65-100 years were randomly assigned to either intervention group or control group (n=49 each), providing a package of micronutrient pack or placebo daily for three months. The concentrations of micronutrients, malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were detected both at baseline and at the end of the study. RESULTS: The changes in concentrations of serum folate (21.1±1.6 vs 0.6±0.5 nmol/L), vitamin B-1 (3.4±0.4 vs -0.2±0.3 nmol/L), vitamin B-2 (11.5±3.3 vs 2.3±1.4 nmol/L), vitamin B-12 (128.8±34.8 vs 13.3±16.0 pmol/L), 25-hydroxyvitamin D (17.8±1.3 vs -0.8±0.5 ng/mL) and plasma zinc (0.6±1.8 vs -9.6±1.9 µmol/L) over 3-months were significantly increased in the intervention group compared with the control group (all p<0.05). While the prevalence of folate, vitamin B-12 and vitamin D deficiencies were significantly decreased after 3-months intervention (all p<0.05). Moreover, changes in serum MDA level (-1.5±0.2 vs 0.2±0.3 nmol/mL) were remarkably reduced, and the activities of serum GSH-Px (1.3±0.3 vs 0.3±0.2 ng/mL) and plasma SOD (14.3±2.4 vs -2.1±2.4 U/mL) were increased in the intervention group than those of in the control group (all p<0.01). CONCLUSIONS: The micronutrient pack among institutional older adults was well-accepted with good compliance and tolerance. The 3-month intervention may improve micronutrient status and enhance antioxidative capacities.