Cucumber target leaf spot, caused by Corynespora cassiicola, is an emerging disease with a high incidence that causes severe damage to cucumbers on a global scale. Therefore, efforts need to be undertaken to limit the spread and infection of this pathogen, preferably by using environmentally friendly methods. In this study, the effects of temperature and moisture on the sporulation of C. cassiicola were investigated in vitro and in vivo. The novelty of our study refers to the observation of spore production and size as well as the revelation of a correlation between spore size and virulence. On potato dextrose agar (PDA) and cucumber−leaf extract agar (CEA), temperature played a critical role in spore production, which was strongly influenced by both temperature and moisture on detached leaves and cucumber seedlings. Maximum spore production was found at 30 °C on PDA and 25 °C on CEA, cucumber detached leaves and living plants. Lower spore productions were observed with a stepwise change of 5 °C. In addition, the largest spore production was found at 100% relative humidity (RH) in comparison to the other tested moisture. Moreover, moisture was found to be the most important factor affecting spore size, accounting for 83.09–84.86% of the total variance in length and 44.72–73.10% of the total variance in width. The longest−narrowest spores were formed at 100% RH, and the shortest−widest spores were formed at 75% RH. Furthermore, the result showed that larger spores of C. cassiicola were more virulent and small spores were avirulent. Our findings will contribute to the development of new strategies for the effective alleviation and control of cucumber target leaf spot.

Introduction: The Cactaceae family exhibits remarkable adaptation to arid environments, yet mitochondrial genomic resources remain extremely scarce for this lineage. Lophophora williamsii (peyote) is an ecologically and culturally significant cactus species native to the Chihuahuan Desert, but its mitochondrial genome has never been characterized. Methods: We assembled and annotated the first complete mitochondrial genome of L. williamsii using PacBio HiFi long-read sequencing, and conducted comprehensive analyses including repeat identification, codon usage, RNA editing prediction, intracellular gene transfer detection, phylogenetic reconstruction, selection pressure assessment, and synteny comparison. Results: The assembled mitogenome is exceptionally large (2,422,778 bp) and structurally complex, comprising 57 contigs that resolve into five linear molecules. It encodes 33 core and 13 variable protein-coding genes, three rRNA genes, and 49 tRNA genes. A total of 587 simple sequence repeats (SSRs), 124 tandem repeats, and 5,519 interspersed repeats (≥30 bp) were identified. Codon usage bias is predominantly driven by natural selection. We predicted 431 C-to-U RNA editing sites across 32 PCGs and detected 18 chloroplast-derived DNA fragments (31,614 bp) containing 19 intact genes. Phylogenetic analysis based on 30 conserved mitochondrial PCGs placed L. williamsii as sister to Mammillaria huitzilopochtli . Most mitochondrial genes are under purifying selection, whereas atp8 and matR exhibit positive selection. Synteny analysis revealed extensive collinear blocks decreasing with phylogenetic distance. Discussion: This first complete mitogenome of L. williamsii provides a fundamental genomic resource for understanding mitochondrial evolution in Cactaceae, offers high-resolution molecular markers for species identification and forensic authentication, and supports conservation genetics for this threatened species.

Polycyclic aromatic hydrocarbons (PAHs), primarily generated from incomplete combustion of fossil fuels and biomass, are ubiquitous persistent organic pollutants in contaminated soils and pose significant risks to plant growth and ecosystem stability. Among these, phenanthrene (PHE) and pyrene (PYR) are two representative PAHs frequently detected at elevated concentrations in contaminated sites. In this study, we systematically investigated the differential phytotoxicity of PHE and PYR to Leymus chinensis, a dominant grass species in temperate grasslands, by comprehensively analyzing plant morphology, physiological and biochemical responses, and molecular mechanisms under gradient concentrations of the two pollutants. Both PHE and PYR induced phenotypic damage and growth inhibition in L. chinensis, but PHE exhibited significantly stronger phytotoxicity than PYR. The PHE treatment led to a marked accumulation of osmotic regulatory substances, significant reduction in the content of photosynthetic pigments, restricted gas exchange capacity, and more severe accumulation of reactive oxygen species and lipid peroxidation of the cell membranes, particularly in the roots. These factors indicated the presence of intense oxidative stress. A fluorescence kinetic analysis revealed that PHE more severely disrupted the structure of the Photosystem II reaction center and stability of the electron transport chain. At the transcriptional level, PHE significantly suppressed the expression of photosynthesis-related genes, key carbon assimilation enzymes, and core antioxidant enzymes. In contrast, PYR- treated plants better maintained photosynthetic function and activating the metabolic pathways involved in detoxification. A Weighted Gene Co-expression Network Analysis (WGCNA) revealed a coordinated regulatory network between photosynthesis and antioxidant defense systems and indicated that imbalance in root-leaf interactions was a key factor in PHE- induced cell death. In conclusion, L. chinensis exhibited distinct organ-specific responses and metabolic partitioning to PHE and PYR: roots primarily engaged antioxidant and detoxification systems to cope with stress, while leaves prioritized maintaining photosynthetic function integrity. PHE exerted its stronger phytotoxicity mainly through disrupting photosynthetic system structure and suppressing antioxidant defense, whereas PYR was more effectively processed by the plant through detoxification metabolic pathways. These findings provide important theoretical support for ecological risk assessment of PAH contamination and optimization of phytoremediation strategies.

Etomidate is an ultrashort-acting imidazole-derived intravenous anesthetic. The non-medical abuse of etomidate as a new psychoactive substance has emerged as a critical public health challenge globally, particularly among adolescents, necessitating sensitive, rapid detection methods for forensic analysis. This study developed a quantum dot-based immunochromatographic test strip and a corresponding rapid detection method for the sensitive detection of etomidate acid in urine. CdSe/ZnS fluorescent quantum dot microspheres were used as labeling probes combined with specific monoclonal antibodies, and the detection protocol utilized a portable fluorescence reader. The method’s validation demonstrated a linear range of 10–2000 ng/mL (y = −0.231lnx + 0.5241, r = −0.991), with intra-batch and inter-batch coefficients of variation below 12%. The spike recovery rates ranged from 88.24% to 95.69%. Cross-reactivity testing against 12 common drugs and structural analogs showed no interference. The detection limit of 10 ng/mL represents a substantial improvement over conventional colloidal gold strips and approaches LC-MS/MS sensitivity. Assays of real urine specimens confirmed that the immunochromatographic test strip and detection method possess favorable accuracy and reliability. This fluorescent quantum dot-based immunochromatographic assay provides rapid, quantitative, and highly specific etomidate screening suitable for on-site forensic applications, effectively bridging front-end rapid testing with confirmatory laboratory analysis.

Lophophora diffusa is a psychoactive plant of Cactaceae, morphologically similar to the mescaline-rich Lophophora williamsii but with a distinct alkaloid profile, posing significant challenges for law enforcement. Here, we sequenced the complete chloroplast genome of L. diffusa using PacBio high-throughput sequencing technology. The chloroplast genome is 115,689 bp in length and exhibits a highly derived quadripartite structure, featuring a large single-copy (LSC) region of 79,403 bp, a small single-copy (SSC) region of 32,910 bp, and a pair of significantly reduced inverted repeat (IR) regions of 1,688 bp each. It encodes 100 unique genes and has a GC content of 36.52%. Phylogenetic analysis robustly resolved the position of L. diffusa, formed a monophyletic Lophophora clade that includes L. fricii and L. williamsii; under the current sampling, this clade was resolved as sister to a group containing Mammillaria species. This study provides a foundational genomic resource for future development of precise molecular tools to distinguish L. williamsii from its relatives, thereby supporting forensic botany and international narcotics control efforts.

Gazania rigens is a popular ornamental plant. This study deciphers its complete chloroplast genome. The genome is 150,688 bp in length and exhibits a typical circular quadripartite structure with a GC content of 37.54%. It encodes a total of 127 unique genes, including 79 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. Phylogenetic analysis based on this genome elucidates the evolutionary relationships of G. rigens among closely related taxa. This sequence provides a foundational resource for future biotechnological applications in this ornamental species.