Mating behavior is essential for sexual reproduction, and it is often modulated by key chemical cues.  In many moth species, males find compatible mates through the reception of sex pheromones which are released by females.  Pheromone receptors (PRs) are key elements in sensing these chemical signals.  Concurrently, male moths emit a complex blend of volatile compounds during courtship; however, the mechanisms for recognizing putative male pheromones remain poorly understood.  Here, we employed gas chromatography coupled with electroantennographic detection and mass spectrometry to analyze the volatile compounds produced by males of the cotton bollworm, Helicoverpa armigera.  Three candidate male sex pheromones were identified, with (Z)-7-dodecen-1-yl acetate (Z7-12:OAc) eliciting the most pronounced electrophysiological response in the male antenna.  The olfactory receptor neuron (ORN) ORN-a in Type A trichoid sensilla was shown to respond to Z7-12:OAc by conducting single sensillum recording (SSR) assays.  Additionally, we found that the OR13s from five Heliothinae species responded to Z7-12:OAc by using the Xenopus oocyte expression system and two-electrode voltage-clamp recording.  Our findings identified a candidate for evaluation in future behavioral studies of the poorly understood chemosensory recognition mechanisms underlying male sex pheromones.  If its relevance is supported by behavioral data, this knowledge may facilitate the design of novel olfactory regulators for effective pest control strategies involving mating disruption.

The trade-off between yield and environmental effects caused by nitrogen fertilizer application is an important issue in wheat production.  A reduction in fertile florets is one of the main reasons for the lower yields under low nitrogen application rates.  Brassinosteroids (BRs) have been found to play a role in nitrogen-induced rice spikelet degeneration.  However, whether BRs play a role in wheat floret development and the mechanisms involved are not clear.  Therefore, a nitrogen gradient experiment and exogenous spraying experiment were conducted to investigate the role and mechanism of BRs in wheat floret development under low nitrogen stress.  The results showed that as the nitrogen application decreased, the endogenous BRs content of the spikes decreased, photosynthesis weakened, and total carbon, soluble sugar and starch in the spikes decreased, leading to a reduction in the number of fertile florets.  Under low nitrogen stress, exogenous spraying of 24-epibrassinolide promoted photosynthesis, and stimulated stem fructan hydrolysis and the utilization and storage of sucrose in spikes, which directed more carbohydrates to the spikes and increased the number of fertile florets.  In conclusion, BRs mediate the effects of nitrogen fertilizer on wheat floret development, and under low nitrogen stress, foliar spraying of 24-epibrassinolide promotes the flow of carbohydrates from the stem to the spikes, alleviating wheat floret degeneration.

Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.  In the laboratory, we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A. gossypii populations with different basal insecticide resistance levels, and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance, as well as differences in fitness.  Under the same selection pressure, Yarkant A. gossypii (with low basal insecticide resistance) evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A. gossypii (with high basal insecticide resistance), and the evolution of A. gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe, Xingjiang, China.  The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid, imidacloprid, thiamethoxam and pymetrozine; while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor, imidacloprid, thiamethoxam, pymetrozine, and chlorpyrifos.  The relative fitness of A. gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.  The relative fitness levels of the sulfoxaflor-resistant strains (Yarkant-SulR and Jinghe-SulR) were lower than those of the acetamiprid-resistant strains (Yarkant-AceR and Jinghe-AceR).  In addition, the relative fitness levels of sulfoxaflor- and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.  In summary, basal insecticide resistance of A. gossypii and insecticide type affected the evolution of resistance to insecticides in A. gossypii, as well as cross-resistance to other insecticides.  The sulfoxaflor- and acetamiprid-resistant A. gossypii strains had obvious fitness costs.  The results of this work will contribute to the insecticide resistance management and integrated management of A. gossypii.

Spodoptera frugiperda is a highly destructive pest that has become a global problem due to its robust reproductive and migratory capabilities.  Transient receptor potential (TRP) channels, which constitute a vast ion channel family, play pivotal roles in sensing the external environment and maintaining internal homeostasis in insects.  TRP channels have been widely investigated for their critical roles in regulating various insect behaviors in recent years.  In this study, we identified 15 TRP gene loci encoding 26 transcripts in the genome of S. frugiperda and analyzed their expression profiles at different developmental stages.  The results revealed that S. frugiperda possesses four TRPC genes, six TRPA genes, one TRPM gene, two TRPV genes, one TRPN gene, and one TRPML gene, while a canonical TRPP is absent.  Moreover, the SfruTRPA1 was functionally characterized using the Xenopus oocyte expression system.  The results showed that SfruTRPA1 is activated by temperature increases from 20 to 45°C, and there is no significant desensitization after repeated stimuli within the same temperature range.  Additionally, SfruTRPA1 is activated by certain natural chemicals, including allyl isothiocyanate (AITC) and cinnamaldehyde (CA).  These findings provide valuable insights to the TRP genes in S. frugiperda.

Passion fruit (Passiflora edulis Sims) is a vine of the Passiflora genus in the Passifloraceae family.  The extracted components include flavonoids and terpenoids, which have good anti-anxiety and anti-inflammatory effects in humans.  In this study, we analyzed the transcriptomes of four tissues of the ‘Zixiang’ cultivar using RNA-Seq, which provided a dataset for functional gene mining.  The de novo assembly of these reads generated 96 883 unigenes, among which 61 022 unigenes were annotated (62.99% yield).  In addition to its edible value, another important application of passion fruit is its medicinal value.  The flavonoids and terpenoids are mainly derivatives of luteolin, apigenin, cycloartane triterpenoid saponins and other active substances in leaf extracts.  A series of candidate unigenes in the transcriptome data that are potentially involved in the flavonoid and terpenoid synthesis pathways were screened using homology-based BLAST and phylogenetic analysis.  The results showed that the biosynthesis of triterpenoids in passion fruit comes from the branches of the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathways, which is different from the MVA pathway that is used in other fruit trees.  Most of the candidate genes were found to be highly expressed in the leaves and/or flowers.  Quantitative real-time PCR (qRT-PCR) verification was carried out and confirmed the reliability of the RNA-Seq data.  Further amplification and functional analysis of these putative unigenes will provide additional insight into the biosynthesis of flavonoids and terpenoids in passion fruit.

Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (mio16) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of mio16. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and mio16 was mapped in silico onto the physical position ranged from 229 965021 to 229 965409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of mio16 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of mio16 is alternated by Mu insertion.

Skeletal muscle satellite cells are stem cells that are known for their multipotency and ability to proliferate in vitro. However, primary skeletal muscle satellite cells have limited proliferative capacity in vitro, which hinders their study in poultry skeletal muscle. The emergence of immortalization techniques for cells has provided a useful tool to overcome this limitation and explore the functions of skeletal muscle satellite cells. In this study, we achieved the immortalization of chicken skeletal muscle satellite cells by transducing primary cells with TERT (Telomerase reverse transcriptase) amplified from chicken (chTERT) using a lentiviral vector through reconstitution of telomerase activity. The cells successfully bypassed replicative senescence but did not achieve true immortalization. Preliminary functional characterization of the established cell line revealed that the proliferative characteristics and cell cycle profile of the immortalized chicken skeletal muscle satellite cell lines (ICMS) were similar to those of chicken primary muscle satellite cells (CPMSCs). Serum dependency analysis and soft agar assays indicated that ICMS did not undergo malignant transformation. Induced differentiation results demonstrated that ICMS retained their capacity for differentiation. The cell lines established in this study provide an important basis for the establishment of immortalized poultry cell lines and a cell model for the study of poultry skeletal muscle-related functional genes.

Reducing nitrogen application rates can mitigate issues such as environmental degradation and resource wastage.  However, it can also exacerbate problems such as wheat floret degeneration, leading to reduced yields.  Therefore, investigating wheat floret degeneration mechanisms under low nitrogen stress and identifying mitigation measures are conducive to achieving high yields and sustainable development.  To investigate the physiological mechanism of low nitrogen stress affecting wheat floret degradation and whether exogenous brassinosteroids can alleviate this stress, three nitrogen application rates (N0, no nitrogen application; N1, 120 kg ha^-1 pure nitrogen; and N2, 240 kg ha^-1 pure nitrogen) and exogenous spraying experiments (N0CK, no nitrogen with water spraying; N0BR, no nitrogen with 24-epibrassinolide (an active brassinosteroids) spraying; and N1, 120 kg ha^-1 pure nitrogen with water spraying) were designed.  The results indicated that low nitrogen stress induced a large amount of reactive oxygen species generation.  Although wheat spikes synthesized flavonoids to combat oxidative stress, their energy metabolism (glycolysis and tricarboxylic acid cycle) and ascorbate-glutathione cycle were inhibited, keeping reactive oxygen levels elevated within the spike, inducing cell death and exacerbating floret degeneration.  Furthermore, brassinosteroids played a role in regulating wheat floret degeneration under low-nitrogen stress.  Exogenous foliar spraying of 24-epibrassinolide promoted energy metabolism and the ascorbate-glutathione cycle within the spike, enhancing energy charge and effectively mitigating a portion of reactive oxygen induced by low nitrogen stress, thereby alleviating floret degeneration caused by low nitrogen stress.  In summary, low-nitrogen stress disrupts the redox homeostasis of wheat spikes, leading to floret degeneration.  Brassinosteroids alleviate floret degeneration by improving the redox state of wheat spikes.  This research provides theoretical support for balancing the contradiction between high yields and sustainable development and is beneficial for the application of low nitrogen in production.

Chestnuts are important economic forest tree species with enormous application value in the wood, medicine, and chemical industries. Currently, the limited genome-wide SSR molecular marker information on chestnut resources significantly limits research on genetic diversity and identification of chestnut resources. To address this issue, we used GMATA to screen simple sequence repeat (SSR) markers throughout the Chinese chestnut genome. A total of 312,302 molecular markers were obtained with a density of 434.38/Mb. Subsequently, all SSR markers were examined for polymorphism using the HipSTR program and 138,208 polymorphic loci were finally obtained. To verify the identification ability of the developed SSR, we randomly selected 36 markers on 12 chromosomes to construct fingerprint maps of 96 ancient chestnut resources from the Yanshan Mountains. The results showed that only 6 pairs of primers were required to create a unique DNA fingerprint of the tested ancient trees, showing that the developed markers have high identification potential. We then evaluated the inter-specific universality and polymorphism of these markers using three species, including 91 chestnut plants. The molecular markers amplified 94% of the interspecies with a PIC value of 0.859. Cluster analysis revealed that testing resources using these developed markers can be well differentiated and these markers have been widely used to identify interspecific boundaries. These results proved that the developed molecular markers have the potential for genotypic diversity, which can provide references for genetic diversity research, variety identification, kinship analysis, selection of good products, and construction of core germplasm resources of chestnut and even chestnut plants. They lay a solid foundation for the molecular design of hybrids to improve breeding and develop germplasm resources.