Lead (Pb) stress affects hormone-mediated responses (e.g., reproduction) in insects. In this study, the effects of Pb stress (12.5-50 mg Pb/kg in larval artificial diets) on the reproduction of the common cutworm Spodoptera litura (Lepidoptera: Noctuidae) were investigated after 7 generations. The results showed that Pb stress did not reduce the longevity of adult females, but 50 mg Pb/kg significantly reduced the longevity of adult males, regardless of the generation. After 50 mg Pb/kg stress for one or 7 generations, the peak time of egg-laying was delayed, and egg production and hatchability were decreased significantly. The vitellin content in eggs was significantly inhibited by Pb stress. The S. litura vitellogenin (Vg) gene promoter was cloned and analyzed. Multiple putative transcription factors were predicted for the 2321 bp Vg promoter region, including the TATA box, GATA, basic helix-loop-helix (bHLH) transcription factor, Broad-Complex (BR-C) binding sites, etc. The fragment from -2222 to -211 bp of the Vg promoter was the activation domain for Vg, whereas the region from -211 to -55 bp repressed the activity of the Vg promoter. The construct promoter (-782/+76) in Trichoplusia ni (Hi5) cells significantly improved Vg expression, which was not affected by Pb stress (1 or 10 mg/ml). Therefore, Pb stress significantly inhibited the reproduction of S. litura but not by regulating the Vg promoter.

We executed a pot experiment to examine the differences of absorption, chemical forms, subcellular distribution, and toxicity of Cd between two cultivars of Chinese flowering cabbage Brassica campestris [Lvbao701 (low-Cd cultivar) and Chicaixin No.4 (high-Cd cultivar)]. Compared to Chicaixin No.4, the presence of Lvbao701 enhanced the proportion of insoluble Cd forms in soil, Lvbao701 roots and leaves had higher proportion of Cd converted into insoluble phosphate precipitates and pectate-or protein-bound forms and lower proportion of inorganic Cd, which result in low accumulation and toxicity of Cd to Lvbao701 and cutworm Spodoptera litura fed on Lvbao701 leaves. Instead of total Cd, Cd transfer and toxicity in B. campestris-S. litura system depend on chemical Cd forms in soil and cabbages and subcellular Cd distributions in cabbages and insects, and the proportions of them were not the highest among all chemical forms and subcellular distributions of Cd. Although exchangeable Cd was major Cd chemical form in cabbage planted soil, Cd bound to iron and manganese oxides and to organic matter were significantly correlated with growth indices and photosynthesis parameters of cabbages. Despite major part of Cd was precipitated in cell wall of roots, Cd in organelle fraction was closely associated with the fitness of cabbages. Metal-rich granules, not cytosolic fraction (the major subcellular Cd distribution), affected the food utilization of S. litura. Therefore, cabbage cultivars significantly affected Cd transfer and toxicity in B. campestris-S. litura system, and the use of Lvbao701 in Cd polluted soil could reduce potential risks for Cd entering food chains.

Background/Objectives: Fissidens crispulus Brid. is a dioicous moss with conspicuous axillary hyaline nodules and serrulate leaf margins. It features Neoamblyothallia-type peristome teeth and serves as an ecologically significant model for studying adaptation in the hyperdiverse genus Fissidens (>440 species). Methods: In this study, the complete chloroplast genome of F. crispulus was sequenced and de novo assembled, enabling detailed comparative genomic, phylogenetic, and codon usage bias studies. Results: As the third fully sequenced member of Fissidentaceae, this study deciphers its 124,264–124,440 bp quadripartite genome encoding 129 genes (83 CDS, 32 tRNAs, 8 rRNAs). Repeat analysis identified 125–127 SSRs, dominated by mono-/di-nucleotide A/T repeats (>70%), and dispersed repeats predominantly forward (F) and palindromic (P) (>85%), confirming profound AT-biased composition (GC content: 28.7%). We established 7 hypervariable loci (matK, ycf2, etc.) as novel Dicranidae-wide phylogenetic markers. Codon usage exhibited significant A/U-ending preference, with 12 optimal codons (e.g., GCA, UGU, UUU) determined. Maximum likelihood analyses resolved F. crispulus and F. protonematicola as sister groups with high support value (MBP = 100%). Conclusions: This work provides the foundational cpDNA resource for Fissidens, filling a major gap in bryophyte chloroplast genomics and establishing a framework for resolving the genus’s infrageneric conflicts. Furthermore, it offers critical insights into bryophyte plastome evolution and enables future codon-optimized biotechnological applications.

The contamination of farmland soil with cadmium (Cd) poses a significant threat to the safety and quality of agricultural products. Herbivorous pests may develop adaptations to survive in Cd-contaminated farmland over time, potentially leading to population outbreaks. The gut microbiota plays a crucial role in this adaptation process, though the mechanisms involved remain unclear. This study examined the effects of two pepper cultivars of Capsicum annuum (Chiyan, CY, and Tianlanse, TLS) under Cd contamination on larval growth, development, food utilization, and gut microbiota of Spodoptera litura larvae. The inherent toxicity of TLS is higher than that of CY, as evidenced by a significant reduction in larvae survival rate in the control. In CY, Cd had a positive effect on larvae at low concentrations and a negative effect at high concentrations. Briefly, 5 mg/kg Cd of CY increased the efficiency of conversion of ingested food (ECI) and relative growth rate (RGR), whereas 10 mg/kg Cd decreased larvae growth and nutritional indices [higher relative consumption rate (RCR), approximate digestibility (AD), and lower efficiency of conversion of digested food (ECD)]. In TLS, Cd had a significant, dose-dependent, negative effect on larvae weight, ECD, and relative growth rate (RGR). Cd thus increased the negative effects of the plant toxins on the larvae. Meta-barcode sequencing of the 16S rRNA gene revealed that microbial diversity was affected by pepper cultivar but not Cd concentration. In larvae fed on CY, the most frequent bacterial genera were Enterococcus and Pluralibacte, whereas Enterococcus was the predominant genus in TLS larvae. Our findings reveal variations in how Cd impacts S. litura larvae across different pepper cultivars and imply that alterations in gut microbial communities could play a role in the joint detoxification of Cd and plant-derived toxins.