Nuclides pollution and its biological effects are of great concern, especially for bryophytes during their terrestrial adaptation. Understanding PSII activity and electron transport response is vital for comprehending moss abiotic stress reactions. However, little is known about the photosynthetic performance of moss under nuclide treatment. Therefore, this study aimed to evaluate the chlorophyll fluorescence of Racomitrium japonicum L. The moss was subjected to Sr²⁺ solutions at concentrations of 5, 50, and 500 mg/L to evaluate chlorophyll a fluorescence using the OJIP test. Moderate and high Sr²⁺ stress led to inner cell membrane dissolution and reduced chlorophyll content, indicating impaired light energy absorption. At 5 mg/L Sr²⁺, fluorescence kinetics showed increased light energy capture, energy dissipation, and total photosynthetic driving force, thus stimulating transient photosynthetic activity of PSII and improving PSI reduction. Linear electron transfer and PSII stability significantly decreased under moderate and high Sr²⁺ stress, indicating potential photosynthetic center damage. Cyclic electron transfer (CEF) alleviated photosynthetic stress at 5 mg/L Sr²⁺. Thus, low Sr²⁺ levels stimulated CEF, adjusting energy flux and partitioning to protect the photosynthetic apparatus. Nevertheless, significant damage occurred due to inefficient protection under high Sr²⁺ stress.

Roots are fundamental to plant growth, with their development being profoundly influenced by water, mineral nutrients, and notably, plant hormones. Citrus, a leading horticultural crop cultivated globally, holds immense economic value. This study tried to investigate the roles and mechanisms effect of foliar spray 1.0 μmol/L ethephon (ETH) of ethylene and 5.0 μmol/L AgNO3 (an ethylene inhibitor) its inhibitor with auxin on root growth and mineral nutrients content levels in trifoliate orange under sand culture conditions for 45 days. Our findings indicate that ethephon treatment significantly boosted the number of lateral roots, root fresh weight, and enhanced the mineral nutrient content (N, P, K, B, Ca, Mg, Fe, Mn, and Zn, with the exception of Cu) in both root and shoot tissues. In contrast, the inhibitors notably reduced the length of lateral roots and decreased the content of P, and Fe in both root and shoot, whilst elevating Zn contents. Furthermore, ETH incited the up-regulation of auxin biosynthesis and transportation genes, leading to an increased endogenous auxin content in the lateral root-hair region. whereas, the inhibitors produced an opposite effect. We thus conclude that ethylene modulates auxin transportation and biosynthesis. This activity stimulates the auxin signaling pathway locally-specifically, in the root hair zone in the lateral root, which in turn, regulates root growth and mineral nutrient content.

Broussonetia papyrifera (L.) L’Hér. ex Vent., a dioecious tree species that belongs to the Moraceae family, is a perennial plant found extensively throughout China. Its leaves are rich in essential trace elements such as copper, molybdenum, manganese, and iron, as well as various biologically active compounds, including amino acids, polysaccharides, proteins, as well as flavonoids, phenylpropanoids, and other polyphenolic compounds. These compounds exhibit significant pharmacological effects, such as antioxidant, lipid-lowering, heat-clearing, detoxifying, blood-cooling, diuretic, and immunomodulatory activities. In recent years, B. papyrifera has gained attention for its medicinal potential; however, breeding efforts, especially those aimed at increasing the flavonoid content, have lagged. This study reviews the progress in research on the active medicinal ingredients of B. papyrifera, with a focus on identification methods, classification criteria, and enrichment technologies for its medicinal components. The biosynthesis of structural genes and transcription factors in flavonoids has been investigated in B. papyrifera. The pharmacological effects of the secondary metabolites of B. papyrifera were systematically examined, aiming to offer strategies for enhancing the flavonoid content and promoting its medicinal value.

Introduction: Formaldehyde is a common gaseous pollutant emitted by buildings and decorative materials. In recent years, growing concerns have been raised regarding its harmful effects on health in indoor air. Therefore, this study aims to investigate the physiological and photosynthetic response mechanisms of Racomitrium japonicum under formaldehyde stress.Methods: R. japonicum was exposed to dynamic fumigation with formaldehyde for 7 days, with each day comprising an 8-h exposure period within a sealed container. The effects on plant structure, pigment content, photosynthetic efficiency, and reactive oxygen species (ROS) generation were assessed.Results and discussion: Our findings revealed that formaldehyde stress caused structural damage, reduced pigment content, decreased photosynthetic efficiency, and increased ROS production in R. japonicum. Significantly, distinct stress-response pathways were observed at different formaldehyde concentrations. In response to low and moderate formaldehyde concentrations, R. japonicum activated its antioxidant enzyme system to mitigate ROS accumulation. In contrast, the high-concentration treatment group demonstrated suppressed antioxidant enzyme activity. In response, R. japonicum used nonphotochemical quenching and activated cyclic electron flow to mitigate severe cellular damage. This study provides an in-depth understanding of the physiological changes in R. japonicum under formaldehyde stress, elucidating its response mechanisms. The findings offer valuable insights for developing effective indoor formaldehyde monitoring and purification methods.

Background: Selenium (Se) deficiency poses significant health risks to human populations globally, necessitating effective biofortification strategies. Amaranth (Amaranthus retroflexus), a nutrient-dense vegetable with demonstrated capacity for Se accumulation in seleniferous soils, represents a promising biofortification vehicle. Critically, arbuscular mycorrhizal fungi (AMF) enhance rhizospheric Se mobilization, yet their synergistic effects on plant energy metabolism remain unexplored. Results: This pot study investigated the influence of exogenous selenium (Se) treatment on energy metabolism in amaranth colonized by the arbuscular mycorrhizal fungus Glomus mosseae. Using LC–MS/MS-based targeted metabolomics with OPLS-DA and KEGG analysis, we identified 14 differentially expressed metabolites (8 up-/6 down-regulated) in Se-exposed plants. These metabolites mapped to glycolysis, TCA cycle, pentose phosphate pathway, electron transport chain, and amino acid/pyruvate metabolism. Activity assays of key enzymes, including PGI, SDH, G6PDH, 6PGDH, and CCO, revealed potential multi-pathway perturbations in energy metabolism under Se treatment. Conclusions: Based on these results, it can be concluded that selenium addition significantly affected amaranth energy metabolism. Graphical