Aflatoxin B1 (AFB1) is a potent mycotoxin threatening food and feed safety. Here, we report the identification and characterization of a Bacillus safensis-derived multicopper oxidase (BsaMCO) capable of efficient AFB1 detoxification. Recombinant BsaMCO exhibited robust in vitro activity, achieving >78% degradation of AFB1 under 24 h incubation at 37 °C. Optimization experiments revealed that enzyme concentration, pH, temperature, metal ions, and electron acceptors significantly influenced degradation efficiency, defining an operational window suitable for practical applications. LC–MS profiling suggested the presence of transformation products tentatively consistent with oxidative demethylation to aflatoxin P1 (AFP1) and with the formation of AFG2a-like products through subsequent hydration- and oxidation-related transformations. Molecular docking and 100 ns all-atom molecular dynamics (MD) simulations demonstrated stable binding of AFB1 in the T1 copper pocket. Van der Waals and electrostatic interactions, together with a persistent hydrogen bond at Gly323, facilitated single-electron transfer through the intramolecular T2/T3 copper cluster. Principal component and Gibbs free energy analyses confirmed a low-energy, stable conformational ensemble. HepG2 cell assays indicated that BsaMCO-degraded products substantially reduced cytotoxicity and apoptosis compared with native AFB1. Simulated feed experiments further validated enzymatic AFB1 degradation, with approximately 53% reduction after 24 h. Collectively, these findings establish BsaMCO as a safe and effective biocatalyst for AFB1 detoxification, providing mechanistic, structural, and cellular evidence supporting its application in food and feed safety.

Three taxa of R. rugosa (Chinese Group), three taxa of R. centifolia, and one R. × damascena (Worldwide Group) were used to detect their volatile organic compound (VOC) contents using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. A total of 146 VOCs were detected, including 73 terpenoids, 18 phenylpropanoids/benzenoids, 50 fatty acid derivatives, and 5 other compounds. The contents of terpenoids were increasing with flower development, while the contents of fatty acid derivatives were decreasing. Heatmap cluster analysis (HCA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) revealed that seven roses can be divided into Chinese and Worldwide groups, and α-farnesene, 9-nonadecene, 3-methyl-2-(2-methyl-2-butenyl)-furan, heptadecane, methyleugenol, β-myrcene, α-pinene, propanoic acid, 2-methyl-,1-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester, pentadecane, and 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate were the marker compounds for two groups. Sensory and incense tone compound evaluation showed that the aromas were mainly composed of floral, rosy, and sweet notes. However, the aroma of seven roses had a stronger spicy, woody, and citrus note in buds (S3) or full-blooming flower stages (S5), which were mainly caused by high contents of methyleugenol, β-myrcene, and β-pinene. In this study, the VOC profile and aromatic characteristics of oil-bearing roses were systematically compared between Chinese and Worldwide genotypes using metabolic pathway analysis and aroma evaluation, providing a more comprehensive reference for fragrant rose breeding.

Background Continuous cropping obstacles in cut chrysanthemum, which are characterized by soil nutrient imbalance, reduced enzyme activities, and disrupted rhizosphere microbial communities, restrict the development of its industry. This study investigated the regulatory effects of crop rotation on soil properties and microbial communities, and compared the mitigation efficiency of different rotation patterns.Results At 60 days of growth, cut chrysanthemums under crop rotation systems exhibited significant increases in stem diameter, as well as fresh and dry weights of both aboveground and underground biomass, compared to continuous cropping. Rotation significantly increased soil total nitrogen, hydrolyzable nitrogen, and available phosphorus, with cabbage rotation exhibiting the most prominent phosphorus accumulation effect. The activities of soil catalase, alkaline phosphatase, and sucrase were higher in rotation groups, whereas the activity of urease decreased with successive planting cycles. Bacterial richness increased with planting cycles, while fungal diversity declined. Notably, rotation reduced the relative abundance of pathogenic Fusarium by 17.1-28.1%. Multivariate analyses indicated that soil nitrogen and phosphorus were closely correlated with bacterial community structure, while phosphorus was the most influential factor on fungal communities. Critically, the two crop rotation systems exhibited distinct mechanisms: maize primarily exerts regulatory effects on soil microbial community structure and enzyme activities, while cabbage focuses on optimizing soil nutrient element status.Conclusion Crop rotation with maize or cabbage alleviates continuous cropping obstacles by improving soil nutrient status, enhancing enzyme activities, and optimizing rhizosphere microbial communities. Maize rotation excels in regulating soil enzyme activities and bacterial communities, whereas cabbage rotation is more effective in promoting plant biomass during the vegetative growth stage, accumulating soil phosphorus, and inhibiting pathogenic fungi. This study provides a theoretical basis for sustainable cut chrysanthemum production via rotation management strategies designed to enhance soil microbial and physicochemical properties.

Lilac plants (Syringa spp.) are extensively valued in landscaping and human health for their colorful cultivars and significantly medicinal and edible properties. The current works mainly focus on the anthocyanidin-induced pigmentation or the flavonoid-driven antioxidant activity, respectively. Nevertheless, the genetic and metabolic panorama of flavonoids, especially the metabolic flux partitioning of anthocyanidin and other flavonoids, remains ambiguous in the Syringa vulgaris plants. In this study, integrating phenotypic, RNA sequencing, and metabolomic data, this study delineates the metabolic flux partitioning of flavonoids underlying floral pigmentation and antioxidant capacity across three S. vulgaris cultivars (blue, purple, and white). A core regulatory module of seven genes governs the biosynthesis of four flavonoid metabolites (kaempferol-3,7-diglucoside, kaempferol-3-sophorose-7-glucoside, kaempferol-3-rutinoside, and rutin) and two anthocyanidin metabolites (cyanidin-4-rutinoside and delphinidin-3-rutinoside), while shikimate acyltransferase gene (SvHCT-4) acted as a pivotal node directing flux toward cyanidin-4-rutinoside and delphinidin-3-rutinoside accumulation. These flavonoids and anthocyanidins in S. vulgaris cultivars orchestrated stage-specific modulation of floral pigmentation and differentially enhanced the scavenging capacities of 2,2-Diphenyl-2-picrylhydrazyl radical (DPPH·) and hydroxyl radical (OH·). SvHCT-4 functions as a critical metabolic branch point governing metabolic flux partitioning from non-anthocyanin flavonoids to anthocyanin biosynthesis in the blue and purple cultivars of S. vulgaris, thereby enhancing floral pigmentation and antioxidant activity. The findings not only provided valuable insights into the intricate regulatory networks governing floral pigmentation and antioxidant capacity but also offered potential targets for future genetic engineering and breeding efforts aimed at enhancing these desirable traits in horticultural crops.

BackgroundChrysanthemum (Chrysanthemum morifolium) is a globally important ornamental and economic crop that is susceptible to cold stress, which can present challenges for its large-scale cultivation. Plant AT-rich sequence and zinc-binding (PLATZ) transcription factors are key regulators of plant perception and response to cold and other abiotic stresses; however, the role of these factors in the cold tolerance of chrysanthemum remains unclear.ResultsIn this study, we identified 41 CmPLATZ genes through a genome-wide analysis. We systematically investigated the structural features, chromosomal localization, phylogenetic relationships, promoter cis-acting elements, and cold-responsive transcriptional profiles of these genes. Additionally, the tissue-specific expression and cold-inducible patterns of key members were analyzed in 11 chrysanthemum accessions with divergent cold tolerance. The 41 CmPLATZ genes were distributed across 21 chromosomes and clustered into six groups. The expansion of CmPLATZ was primarily driven by whole-genome duplication (WGD) events. Ka/Ks analysis indicated that the duplicated genes have been subjected to purifying selection, which resulted in limited functional divergence. Synteny analysis revealed that the evolutionary relationships of CmPLATZ genes are more complex than those of PLATZ gene families in the related species C. makinoi and C. seticuspe. Based on the analysis of promoter elements and transcriptome profiling, we observed that multiple CmPLATZ members respond to low-temperature stress and we identified CmPLATZ1a and CmPLATZ4a as key candidate regulators. Subcellular localization experiments confirmed the nuclear localization of these proteins, and heterologous functional validation demonstrated that overexpression of CmPLATZ1a in Arabidopsis significantly enhanced cold tolerance, suggesting the potential involvement of this gene in regulating conserved cold-response pathways.ConclusionsThis study provides the first genome-wide characterization of the CmPLATZ family, offering new insights into the cold-response regulatory network of chrysanthemum, and providing a theoretical basis and candidate gene resources for the extension of the cultivation range.

Late embryogenesis abundant (LEA) proteins play an essential role in plant growth under various abiotic stresses. In this study, we identified 23 RcLEA genes in Rosa chinensis ‘Old Blush’ and subsequently grouped them into eight clades according to phylogenetic relationships and conserved domain features by bioinformatics methods. And conserved protein motifs and gene structure are also analyzed. The cis-regulatory elements of RcLEA promoter are enriched with cis-regulatory elements relevant to abiotic stress adaptation. Comparative transcriptomics between two species revealed tissue-specific and cold-induced expression differences, highlighting distinct functional roles of LEA genes in growth and abiotic stress tolerance between Rosa chinensis ‘Old Blush’ and Rosa beggeriana. Furthermore, Quantitative Real-Time PCR (qRT-PCR validation confirmed divergent cold-responsive expression profiles of LEA genes in R. chinensis ‘Old Blush’ compared with the highly cold-tolerant R. beggeriana in four LEA homologous genes. These findings indicated that LEA acts as a cold-response gene in roses and provide foundation to breed cold-tolerant varieties of roses.

Low temperatures can significantly affect the growth of ornamental plants, emphasizing the importance of improving their cold tolerance. However, comparative studies on the photosynthetic responses of sun and shade plants to low temperatures remain limited. In this study, gas exchange, chlorophyll fluorescence in Photosystem II (PSII) and Photosystem I (PSI), the antioxidant system, the osmoregulator substance, and lipid peroxidation were investigated in the shade plant Helleborus viridis (Hv) and the sun plant Lupinus polyphyllus (Lp) during cold acclimation (CA) and the freezing-thaw recovery (FTR). The CA treatment significantly declined the net photosynthetic rate (Pn) and the maximum photochemical efficiency of PSII (Fv/Fm) in Hv and Lp, indicating the photoinhibition occurred in both species. However, Hv exhibited a much better photosynthetic stability to maintain Pn, Fv/Fm, and carboxylation efficiency (CE) than Lp during CA, suggesting that Hv had a greater photosynthetic resilience compared to Lp. Furthermore, Hv preferred to maintain Pn, Fv/Fm, the actual photosynthetic efficiency of PSII (Y(II)), and the actual photosynthetic efficiency of PSI (Y(I)) to consistently provide the necessary energy for the carbon assimilation process, while Lp tended to divert and dissipate excess energy by thermal dissipation and cyclic electron flow during CA. Moreover, there were higher soluble sugar contents in Hv in comparison to Lp. These traits allowed Hv to recover photosynthetic efficiency and maintain cellular integrity better than Lp after the freezing stress. In conclusion, CA significantly reduced the photosynthetic capacity and led to the divergent photosynthetic strategies of both species, which finally resulted in a different freezing tolerance after the freezing-thaw recovery. These findings provide insights into the divergent photoprotective strategies of sun and shade plants in response to cold temperatures.

Nowadays, the risk of oral intake of microplastics (MPs) and cadmium (Cd) by poultry is high. In some industrially polluted areas, the chicken feed samples contain 9.60 × 102 ± 1.09 × 102 MPs per kilogram (mean ± std) in wet weight, and the Cd content in chicken feed has been detected to reach up to 5.61 mg/kg. But scholars still focus more on the toxic effects of MPs and Cd on the liver and intestines of aquatic animals. There are few studies that use poultry as research animals and consider these two organs as an integrated system to investigate the toxicity of MPs and Cd on the gut-liver axis and the mechanisms of inflammation. Therefore, in this research, broilers were used as experimental subjects, and experimental models were established by single or combined exposure of MPs (100 mg/L) and Cd (140 mg/kg) to explore the effects of MPs and Cd on the intestinal mucosae and liver of broilers, as well as the mechanisms behind these toxic effects. In this study, the degree of adverse effects (decreased expression of tight junction proteins, changes in intestinal morphology, abundance and diversity of intestinal flora, liver inflammation) caused by the single exposure group was higher than that of the combined exposure group. The results showed that MPs and Cd induced intestinal damage and liver inflammation in broilers by interfering with the TLR4/MyD88/NF-κB pathway and intestinal flora homeostasis. The toxicity of combined exposure was lower than that of single exposure.

Mycotoxin contamination in food and feed poses a significant threat to human and animal health worldwide. OTA is a common mycotoxin. About 20–30% of global feed is contaminated with OTA, and the annual potential contamination amount exceeds 200 million tons, which has become a major problem of local feed safety. OTA shows strong nephrotoxicity and causes kidney damage in animals and humans. Growing evidence suggests that OTA-induced renal damage is closely associated with ferroptosis. Selenomethionine (SeMet), as the main chemical form of daily dietary selenium supplementation, has pharmacological properties such as anti-oxidation, anti-inflammatory, anti-mutagenic, anti-cancer, anti-viral and anti-bacterial, which can effectively inhibit the nephrotoxicity of OTA. This study aims to establish an OTA-induced broiler kidney injury model and implement selenium-containing methionine intervention. Utilizing transmission electron microscopy, qRT-PCR, and immunoblotting techniques, the research will analyze pathological changes in broiler kidneys, examine ultrastructural alterations, and evaluate gene/protein expressions of renal function indicators, ferroptosis biomarkers, inflammatory-related parameters, and Nrf2-GPX4 signaling pathway components. This study aimed to investigate whether SeMet alleviates OTA-induced kidney injury in broilers by regulating ferroptosis and to elucidate the underlying mechanisms. Results showed that OTA caused renal histopathological alterations, elevated serum concentrations of urea nitrogen (BUN), creatinine (CRE), uric acid (UA), and pro-inflammatory cytokines (IL-1β and IL-6). OTA also increased reactive oxygen species (ROS), malondialdehyde (MDA), and ferrous ion (Fe2+) levels while reducing total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and reduced glutathione/oxidized glutathione (GSH/GSSG). Additionally, OTA upregulated mRNA and protein levels of transferrin receptor 1 (TFR1) and kelch like ech-associated protein 1 (Keap1), while downregulating the nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), quinone oxidoreductase-1 (NQO1), glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and solute carrier family 7 member 11 (SLC7A11), thereby inducing lipid peroxidation and ferroptosis. By reversing the above changes induced by OTA, SeMet alleviated OTA-induced renal injury and inhibited OTA-induced lipid peroxidation and ferroptosis. These findings indicate that SeMet alleviates OTA-induced renal injury by inhibiting ferroptosis, suggesting that SeMet can be used as a feed additive in mycotoxin-contaminated environments.

Ochratoxin A (OTA), as a mycotoxin, can contaminate a variety of feeds and foods. Existing studies have shown that the main toxicity of OTA to organisms is nephrotoxicity, but the toxic mechanism to other organs is still worthy of further study. Whether OTA causes intestinal damage through the necroptosis pathway mediated by RIPK1/RIPK3/MLKL remains to be elucidated. Astaxanthin (AST), a feed additive with strong antioxidant properties, was used as an antidote to evaluate the alleviation effect on OTA-induced intestinal injury and the underlying mechanism in this research. Chickens are the most sensitive animals to OTA except pigs. Therefore, 70 white-feathered chickens (n = 15) and Chicken Small Intestinal Epithelial Cells (CSIECs) were used as experimental subjects. Experimental models were established by single or combined exposure of OTA (1.0 mg/kg on chickens for 21 d; 2 μM on CSIEC for 24 h) and AST (100 mg/kg on chickens for 21 d; 40 μM on CSIEC for 24 h). In this study, AST significantly ameliorated OTA-induced intestinal damage by restoring the expression of tight junction proteins (Occludin-1, Claudin-1, and ZO-1), attenuating severe histopathological alterations, mitigating the inflammatory response (elevated pro-inflammatory cytokines and reduced anti-inflammatory mediators), and suppressing necroptosis through downregulation of RIPK1, RIPK3 and MLKL expression. Combined evidence from animal experiments and cell culture experiments demonstrated that AST alleviated the necroptosis and inflammation caused by OTA in CSIECs and the intestine of chickens through the RIPK1/RIPK3/MLKL signaling pathway, thereby reducing the damage caused by OTA.

Ochratoxin A (OTA), a common mycotoxin contaminant, poses significant health risks through its multi-organ toxicity. While OTA is known to cause immune organ dysfunction leading to immunotoxicity, its precise mechanistic pathways remain unclear. The spleen is an important immune organ of the body and plays a key role in immune defense and homeostasis maintenance. Astaxanthin (AST), a potent antioxidant with demonstrated immunomodulatory properties, exhibits a broad therapeutic potential including anti-inflammatory, wound-healing, anti-aging, and hepatoprotective effects. Therefore, this study aimed to explore the mechanism by which AST attenuates OTA-induced immunotoxicity using a chicken OTA/AST treatment model. Sixty 1-day-old, white-feathered, sex-undifferentiated chicks were randomly allocated into four groups (n = 15): (1) Control, (2) OTA (1 mg/kg), (3) AST (100 mg/kg), and (4) OTA + AST (1 mg/kg OTA + 100 mg/kg AST). The experiment lasted for 21 days to establish the model. Subsequently, serum ELISA, antioxidant capacity assays, qRT-PCR, and western blot (WB) analyses were employed to explore the protective role of AST against immunotoxicity. The results showed that AST increased splenic organ coefficients and serum immunoglobulin (IgM and IgG) concentrations (p < 0.01) and decreased the expression of inflammatory factors (IL-8, IL-6, and IL-1β) (p < 0.01). We found that OTA was involved in the expression of the PTEN/PI3K/AKT signaling pathway (PTEN, PI3K, AKT, p-AKT (Ser473)) and apoptotic genes (Bcl-2, Bax, Caspase3, Caspase9). Notably, AST significantly attenuated OTA-induced oxidative damage (ROS, MDA, T-AOC) in the spleen (p < 0.05), upregulated the expression of PI3K and p-AKT (Ser473) (p < 0.05) and inhibited the expression of PTEN and apoptosis-related genes (p < 0.05). In summary, AST attenuates OTA-induced immunotoxicity by alleviating oxidative stress and modulating the PTEN/PI3K/AKT signaling pathway.

Accurate understanding and modeling of soil hydrothermal dynamics in permafrost regions is essential for reliably assessing future permafrost changes and their impacts. However, the inadequate representation of soil water‒heat transport processes in current land surface models (LSMs) introduces large uncertainty in simulating permafrost dynamics, particularly on the Qinghai–Tibet Plateau (QTP). In this study, we modified the parameterizations of soil thermal conductivity, unfrozen water and soil evaporation resistance in version 5.0 of the Community Land Model (CLM5.0) and assessed their effects on soil hydrothermal dynamics in permafrost regions on the QTP using in-situ measurements at the depths of 10–40 cm. The results showed that soil temperature was more sensitive to the modified soil thermal conductivity and unfrozen water schemes, with average RMSE reduced by approximately 0.60 °C compared to the default CLM5.0. Soil moisture was mainly affected by the unfrozen water scheme during freezing and by the optimized soil evaporation resistance scheme during thawing, with maximum accuracy improvements of 8% and 25%, respectively. All three schemes significantly improved soil thermal conductivity simulations, reducing RMSE by over 80%. Overall, our modifications remarkably reduced simulation errors compared to the default schemes, improving the average accuracy of soil temperature, soil moisture and soil thermal conductivity by approximately 16%, 21% and 81% respectively. Additionally, this study emphasized the importance of accurately representing permafrost-related processes in LSMs, as they significantly affected simulation results. Specifically, soil thermodynamics is strongly sensitive to subtle changes in soil moisture transport processes, such as the hysteresis effect of unfrozen water content, and parameterizations of snowpack and vegetation. Therefore, future work should focus on enhancing the accurate representations of these processes and optimized parameters in LSMs to improve the simulation accuracy in permafrost regions on the QTP. This study enhanced the understanding of soil hydrothermal processes in LSMs and provided valuable insights for the future model development for permafrost regions under the context of climate change.

It is unknown why roses are terpene-rich, what the terpene biosynthetic pathways in roses are, and why only a few rose species produce the major components of rose essential oil. Here, we assembled two high-quality chromosome-level genomes for Rosa rugosa and Rosa multiflora. We also re-sequenced 132 individuals from the F1 progeny of Rosa chinensis and Rosa wichuraiana and 36 of their related species. Comparative genomics revealed that expansions of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and terpene synthases (TPSs) gene families led to the enrichment of terpenes in rose scent components. We constructed a terpene biosynthesis network and discovered a TPS-independent citronellol biosynthetic pathway in roses through gene functional identification, genome-wide association studies (GWASs), and multi-omic analysis. Heterologous co-expression of rose citronellol biosynthetic genes in Nicotiana benthamiana led to citronellol production. Our genomic and metabolomic analyses suggested that the copy number of NUDX1-1a determines the citronellol content in different rose species. Our findings not only provide additional genome and gene resources and reveal the evolution of the terpene biosynthetic pathways but also present a nearly complete scenario for terpenoid metabolism that will facilitate the breeding of fragrant roses and the production of rose oil.

Roses are one of the most important flowers applied to landscape, cut flowers, fragrance and food industries widely. As an effective method for plant reproduction, the regeneration via somatic embryos is the most promising method for breed improvement and genetic transformation of woody plants. However, lower somatic embryogenesis (SE) induction rates and genotypic constraints impede progress in genetic transformation in rose. This study describes a plant regeneration system for the famous red cut flower cultivar Rosa hybrida ‘Carola’. The stems without petioles cultured on Murashige and Skoog (MS) medium supplemented with 1.0 mg·L−1 6-benzylaminopurine (6-BA), 0.05 mg·L−1 a-naphthalene acetic acid (NAA) and 30 g·L−1 sucrose showed the maximum proliferation coefficient of shoots with 3.41 for the micropropagation system. We evaluated the effects of different plant growth regulators (PGRs) on the induction, proliferation and conversion of somatic embryos. The induction rate of calli reached 100% on MS medium supplemented with 2.0 g·L−1 NAA and 30 g·L−1 glucose. The highest induction rate of somatic embryos achieved a frequency of 13.33% on MS medium supplemented with 2.0 mg·L−1 zeatin (ZT), 0.1 mg·L−1 NAA and 30 g·L−1 glucose. The most suitable carbohydrate with 60 g·L−1 glucose resulted in a proliferation rate of somatic embryos (4.02) on MS medium containing 1.5 mg·L−1 ZT, 0.2 mg·L−1 NAA and 0.1 mg·L−1 gibberellic acid (GA3). The highest somatic embryos germination rate (43.33%) was obtained from the MS medium supplemented with 1.0 mg·L−1 6-BA, 0.01 mg·L−1 IBA and 30 g·L−1 glucose. Finally, the germinated somatic embryos successfully rooted on 1/2 MS medium containing 1.0 mg·L−1 NAA, 30 g·L−1 sucrose, and the vigorous plantlets were obtained after hardening-off culture. This study provided a stable and efficient protocol for plant regeneration via somatic embryos in R. hybrida ‘Carola’, which will be beneficial to the further theoretical study and genetic improvement in roses.

Zearalenone (ZEA) has adverse effects on human and animal health, and finding effective strategies to combat its toxicity is essential. The probiotic Bacillus velezensis A2 shows various beneficial physiological functions, including the potential to combat fungal toxins. However, the detailed mechanism by which the Bacillus velezensis A2 strain achieves this protective effect is not yet fully revealed. This experiment was based on transcriptome data to study the protective mechanism of Bacillus velezensis A2 against ZEA-induced damage to IPEC-J2 cells. The experiment was divided into CON, A2, ZEA, and A2+ZEA groups. This research used an oxidation kit to measure oxidative damage indicators, the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) method to detect cell apoptosis, flow cytometry to determine the cell cycle, and transcriptome sequencing to screen and identify differentially expressed genes. In addition, gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were adopted to screen out relevant signaling pathways. Finally, to determine whether A2 can alleviate the damage caused by ZEA to cells, the genes and proteins involved in inflammation, cell apoptosis, cell cycles, and related pathways were validated using a quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot methods. Compared with the CON group, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the ZEA group increased significantly (p < 0.01), while the levels of antioxidant enzyme activity, total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), and catalase (CAT) decreased significantly (p < 0.01). Compared with the ZEA group, the A2+ZEA group showed a significant decrease in ROS and MDA levels (p < 0.01), while the levels of T-SOD, GSH-PX, T-AOC, and CAT increased significantly (p < 0.01). TUNEL and cell cycle results indicated that compared with the ZEA group, the A2+ZEA group demonstrated a significant decrease in the cell apoptosis rate (p < 0.01), and the cell cycle was restored. Combining transcriptome data, qRT-PCR, and Western blot, the results showed that compared with the CON group, the mRNA and protein expression levels of Wnt10 and β-catenin increased significantly (p < 0.01), while the expression level of FRZB decreased significantly (p < 0.01); compared with the ZEA group, the expression levels of these mRNA and proteins were reversed. Bacillus velezensis A2 can increase the antioxidant level, reduce inflammatory damage, decrease cell apoptosis, and correct the cell cycle when that damage is being caused by ZEA. The protective mechanism may be related to the regulation of the Wnt/FRZB cell/β-catenin signaling pathway.

Aerides rosea (Orchidaceae) boasts high ornamental value due to its pleasant aroma, foxtail spike, and elegant floral morphology. Inducing A. rosea to become tetraploid enhances horticultural traits and facilitates fertile intergeneric hybrids through crosses with other market-available tetraploid species. The experimental design involved the application of colchicine at varying concentrations—0.05%, 0.1%, and 0.2%—to a solid medium. Exposure durations were 5, 10, and 15 days, with treatments conducted under sterile conditions on 6-week-old protocorms post-germination. Results indicated that the protocorms were sensitive to colchicine concentrations exceeding 0.05%, with high concentrations leading to a mortality rate exceeding 50%. Flow cytometry (FCM) with 4′,6-diamidino-2-phenylindole (DAPI) staining confirmed a doubling of chromosome numbers in tetraploid plants (2n = 4x = 76) compared to diploid controls (2n = 2x = 38). Induction efficiency was significantly influenced by colchicine concentration and treatment duration. A 10-day treatment with 0.2% colchicine yielded a 70.00% tetraploid induction rate; however, considering protocorm survival, a 5-day treatment with 0.05% colchicine was preferable, achieving a 63.55% survival rate and a 56.67% tetraploid induction rate. Tetraploid plants exhibited distinct morphological traits, such as a more compact growth habit, thicker leaves, and increased stem and root thickness. Leaf morphology changes included larger stomata with reduced density, denser spongy mesophyll, and more pronounced venation. Tetraploids also demonstrated a 1.94-fold increase in genome size compared to diploids. The tetraploid genotypes developed in this study hold significant potential for future Aerides breeding programs.

The current spatial atmospheric forcing data cannot accurately depict the actual conditions of the Qinghai-Tibet Plateau (QTP), where monitoring stations are scarce and unevenly distributed. This deficiency in atmospheric data hinders accurate simulation of plateau permafrost changes on the plateau. In this study, we develop a new approach to evaluate regional permafrost changes, which does not rely on spatially distributed meteorological data but instead uses the regional climate change processes or temperature change rates. Centred on a transient heat conduction permafrost model, this approach was applied to the Qinghai Hoh Xil National Nature Reserve (referred to as Hoh Xil) within the QTP from 1960 to 2015, using the rate of air temperature change provided by the Wudaoliang Meteorological Station, the only national station in Hoh Xil. Simulation results showed that the difference between the simulated and observed change rates of mean annual ground temperature (MAGT) was less than 0.04 degrees C per decade from 2001 to 2015 at five long-term monitoring sites. The simulated ground temperature profiles in four boreholes from various permafrost zones revealed an error of less than 0.7 degrees C below 5 m in depth. Model validation demonstrates the reliability of this approach for predicting long-term permafrost changes. Future regional permafrost changes were further simulated based on the latest warming scenarios (BCC-CSM2-MR) from the Coupled Model Intercomparison Project Phase 6. Predictions revealed significant differences in the regional permafrost degradation rate under different climate warming scenarios. Under the most severe warming scenario (SSP58.5), permafrost in the study area is projected to still cover 72.2% of the total area by 2100, with most of the Hoh Xil's permafrost becoming warm (MAGT > 1 degrees C) permafrost. This approach not only facilitates the simulation of frozen ground changes in areas with few meteorological monitoring stations but also provides a new perspective for using coarse-resolution palaeoclimate data to investigate permafrost formation and evolution over long time scales.

[目的]切花菊生产中普遍存在施肥过量和施肥方式不当的问题,通过比较4种施肥处理对切花菊形态指标、品质和养分吸收的影响,筛选最适切花菊生产的施肥体系,为切花菊减肥增效栽培提供理论依据.[方法]以切花菊'白扇'为试材,设置分别在智能水肥一体化机设备和施肥罐机器下,追施水溶肥7次(S1、S2)和追施4次(T1、T2) 4个处理,每次追肥量相同(75 kg/hm2).在定植后35、62和85天,调查切花菊农艺指标、花部性状、植株氮磷钾含量及土壤氮磷钾含量.[结果]与施肥罐机器施肥(S2、T2处理)相比,定植62天时,采用智能水肥一体化机设备施肥 (S1、T1处理) 提高了切花菊的株高、茎粗、地上鲜重、地上干重、地下鲜重和地下干重,T1处理的效果又好于S1处理;定植85天时,T1处理切花菊株高高于S2和T2处理,花径和出花率与S1和S2处理无显著差异.定植35天时,T1处理的植株钾含量高于其他3个处理;定植62天时,T1处理植株茎叶中磷、钾含量高于其他3个处理;定植85天时,T1处理植株根中的磷、钾含量均最高.T1处理也增加了定植62和85天后土壤有效磷和速效钾含量.[结论]采用智能水肥一体化机设备条件下,将追施肥次数由7次减至4次,施肥量由525 kg/hm2降低到375 kg/hm2,改善了切花菊'白扇'的农艺性状和花部性状,促进了植株对养分的吸收利用,并提高了土壤有效磷和速效钾含量,而使用施肥罐机器的减肥增效效果不明显.因此,切花菊生产中应推广利用智能水肥一体化机设备,以实现减肥增效.