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.

Diesel spills and nuclides pollution cause global ecosystem and human health problems. The remediation of contaminated soil using woody plants has received considerable attention. Differences in plant species and sex can lead to differences in tolerance to various stressors. We aimed to investigate the response of male and female seedlings of Populus cathayana and Salix babylonica to diesel and Sr²⁺ stress and to compare the enrichment characteristics of Sr²⁺ in trees. Male and female seedlings of P. cathayana and S. babylonica were treated with diesel fuel and 0, 10 (low), and 100 (high) mg Kg⁻¹ of Sr²⁺. Results showed that P. cathayana and S. babylonica had good enrichment characteristics and tolerance. S. babylonica had a more robust tolerance and ability to remediate contaminated soil than P. cathayana. The defense mechanisms of both female seedlings in response to stress were similar, while males showed different defense strategies. Male trees had higher Sr²⁺ enrichment capacity, antioxidant enzymes, soil enzyme activity, and soluble matter content, indicating that males had higher tolerance capacity than females. Under diesel stress alone, the reduced photosynthetic rate of male seedlings of P. cathayana was mainly limited by stomatal factors, and their photosynthetic system was more tolerant to diesel. POD and APX activities, as well as alkaline phosphatase and urease activities in the soil, were significantly higher in S. babylonica seedlings than in P. cathayana, indicating that S. babylonica seedlings were more resistant to diesel pollution. At low concentrations of the Sr²⁺ complex, diesel and Sr²⁺ showed antagonistic effects in reducing the damage caused by stress. As the Sr²⁺ concentration increased, damage to the plants manifested primarily through synergistic enhancement. The results of this study provide a scientific basis for the remediation of diesel fuel and nuclides contaminated soils using woody plants.

Background: Asthma with a childhood-onset is found to be associated with increased risk of severe mental illnesses in later life. However, the causal relationships between childhood-onset asthma and major mental disorders remained unclear. Methods: We conducted a two-sample Mendelian randomization (MR) analysis to investigate the causal effects of childhood-onset asthma (n=327,670) on six major mental illnesses, including major depressive disorders (n=143,265), bipolar disorder (n=353,899), schizophrenia (n=130,644), anxiety (n=10,240), autism (n=46,350), and ADHD (n=225,534) using summary statistics of genome-wide association studies (GWAS). The inverse variance weighted (IVW) method, along with weighted median and MR-Egger were employed for the causal estimates. Multiple sensitivity analyses were conducted to examine the robustness of the estimates. Moreover, the direct effects of childhood-onset asthma on mental disorders after accounting for the effects of adult-onset asthma were evaluated through the multivariable MR (MVMR) analysis. Results: We found that genetically determined childhood-onset asthma significantly increased the risk of depression (IVW OR=1.059, 95%CI:1.025-1.095, p=5.72e-04) and bipolar disorder (IVW OR=1,065, 95%CI:1.027-1.105, p=6.75e-04), but not associated with other mental disorders. Further MVMR analysis indicated that the causal relationships remained significant with the adjustment of adult-onset asthma. Interestingly, we found that childhood-and adult-onset asthma exerted distinct causal effects on depression and bipolar disorders. No significant heterogeneity and horizontal pleiotropy were found to influence the causal estimates. Conclusions: MR analysis indicated a significant causal relationship between genetically determined childhood-onset asthma and increased risk of depression and bipolar disorder in later life. The causal effects of childhood-onset asthma were distinct to the adult-onset asthma. Further studies were warranted to investigate the mechanisms underlying the causal relationships.

Cesium (Cs) contamination has become an increasing environmental concern because of its high mobility, persistence, and ecological risks. Mosses have attracted considerable attention as bioindicators owing to their high environmental sensitivity; however, their responses to Cs remain poorly understood. In this study, the moss Hypnum plumaeforme was exposed to Cs⁺ (5, 50 and 500 mg L⁻¹) stress, and its morphological characteristics, antioxidant responses, photosynthetic performance and metabolomic alterations were comprehensively investigated. Low Cs⁺ exposure induced early oxidative signaling by increased H₂O₂ accumulation and slight stimulation of photosynthesis, whereas moderate stress triggered pronounced superoxide production and activation of antioxidant defenses. High Cs⁺ exposure caused severe cellular deformation, disruption of photosystem II, excessive hydroxyl radical accumulation, and collapse of the coordinated antioxidant–osmotic regulatory network. Untargeted LC–MS metabolomics further revealed substantial metabolic reprogramming under severe stress, including inhibition of carbon metabolism, significant enrichment of tryptophan metabolism, and accumulation of defensive secondary metabolites, indicating a shift in metabolic resources from growth toward stress defense. Collectively, these findings demonstrate the physiological responses of H. plumaeforme to Cs⁺ in a concentration-dependent manner. The high sensitivity of oxidative biomarkers, chlorophyll fluorescence parameters and metabolic signatures highlights the potential of H. plumaeforme as a bioindicator for assessment of cesium contamination.