Search Results (565)

Chitin deacetylases (CDAs) are carbohydrate esterases associated with chitin metabolism and the conversion of chitin into chitosan. Studies have demonstrated that chitin deacetylation is essential for chitin organization and compactness and therefore influences the mechanical and permeability properties of chitinous structures, such as the peritrophic membrane (PM) and cuticle. In the present study, two genes (ApCDA5a and ApCDA5b) encoding CDA protein isoforms were identified and characterized in Chinese oak silkworm (Antheraea pernyi) larvae. Although five signature motifs were identified, CDA5 proteins only have the chitin-deacetylated catalytic domain. Spatiotemporal expression pattern analyses revealed that both transcripts presented the highest abundance in the anterior region of the midgut during the feeding period after molting, suggesting their role in chitin turnover and PM assembly. The down-regulation of ApCDA5a and ApCDA5b via RNA interference (RNAi) was correlated with the breakage of chitin microfibrils in the PM, suggesting that group V CDAs were essential for the growth and assembly of the chitinous layer. Additionally, ApCDA5a and ApCDA5b may have non-overlapping functions that regulate the morphological characteristics of PM chitin construction in different ways. Larvae injected with double-stranded RNA (dsRNA) against ApCDA5a and ApCDA5b transcripts were less resistant to infection by N. pernyi than those in the control groups. These results revealed that down-regulating ApCDA5a and ApCDA5b had independent effects on the PM structure and undermined the intactness of the PM, which disrupted the function of the PM against microsporidia infection per os. Our data provide new evidence for differentiating CDA functions among group V CDAs in lepidopteran insects. Full article

Bursaphelenchus xylophilus is one of the most destructive quarantine pests, causing irreversible damage to pine trees. However, the unexpected identification of pine wilt disease in Northern China indicates that Bursaphelenchus xylophilus can survive under low temperatures. In this study, we analyzed the reproductivity variations among 18 different isolates, and SC13 was identified to have excellent low temperature resistance. Subsequent molecular analysis of SC13 indicated its distinct gene expression under low temperatures. The epidermal growth factor, nematode cuticle collagen and G-protein-coupled receptor genes with environmental adaptation functions were demonstrated to be differentially expressed under low temperatures. Meanwhile, morphological observations also indicated that SC13 contained significantly more lipid drops in low-temperature treatments. Generally, the identification of representative Bursaphelenchus xylophilus isolates will facilitate relevant studies in the future, and the discovery of the gene expression and morphological changes of Bursaphelenchus xylophilus under low temperatures could expand the current understanding of the environmental adaption abilities of such invasive nematodes. Full article

Entomopathogenic fungi (EPFs) can infect and kill a diverse range of arthropods, including ticks (Acari: Ixodidae) that can transmit various diseases to animals and humans. Consequently, the use of EPFs as a biocontrol method for managing tick populations has been explored as an alternative to chemical acaricides, which may have harmful effects on the environment and non-target species. This review summarizes studies conducted on EPFs for tick control between 1998 and 2024, identifying 9 different EPF species that have been used against 15 different species of ticks. One of the most well-known and widely researched EPFs used against ticks is Metarhizium anisopliae, a fungus known for its ability to infect and kill various arthropods. When applied to tick-infested areas, M. anisopliae spores attach to the tick’s cuticle, germinate, and penetrate through the cuticle, leading to the eventual death of the tick due to the fungal infection. Whilst a number of studies support the potential of this and other EPF species against ticks, this review suggests that limitations to their effective use may include factors such as heat, humidity, and ultraviolet light (UV-A and UV-B). This comprehensive review aims to provide an overview of the literature on the potential of EPFs in tick control, focusing on their mode of action, previous field successes/failures, advantages, potential applications, and prospects for future practical developments. Full article

Salt stress poses a significant challenge to plant growth and restricts agricultural development. To delve into the intricate mechanisms involved in soybean’s response to salt stress and find targets to improve the salt resistance of soybean, this study integrated transcriptomic, proteomic, and metabolomic analyses to explore the regulatory networks involved in soybean salt tolerance. Transcriptomic analysis revealed significant changes in transcription factors, hormone-related groups, and calcium ion signaling. Notably, the biosynthetic pathways of cutin, suberine, and wax biosynthesis play an important role in this process. Proteomic results indicated salt-induced DNA methylation and the enrichment of phosphopyruvate hydrase post-salt stress, as well as its interaction with enzymes from various metabolic pathways. Metabolomic data unveiled the synthesis of various metabolites, including lipids and flavonoids, in soybean following salt stress. Furthermore, the integrated multiomics results highlighted the activation of multiple metabolic pathways in soybean in response to salt stress, with six pathways standing out prominently: stilbenoid, diarylheptanoid, and gingerol biosynthesis; carotenoid biosynthesis; carbon fixation in photosynthetic organisms; alanine, aspartate, and glutamate metabolism; thiamine metabolism; and pyruvate metabolism. These findings not only offer valuable insights into leveraging multiomics profiling techniques for uncovering salt tolerance mechanisms but also identify candidate genes for soybean improvement. Full article

Hair straighteners are among the most technically complex products to be safely and effectively developed, and this challenge has increased even more with the higher incidence of resistant hair among consumers. This underscores the importance of studying new active ingredients, combinations and carrier formulations to improve performance without compromising safety. In this research, we compared eight hair-straightening formulations with different active ingredients and/or concentrations to develop new, safer and more effective texture modifiers. Eight formulations were developed and compared with each other and to controls (virgin and bleached hair) regarding mechanical and thermal resistance, cuticle morphology, hair shine and fiber diameter. Results showed that all formulations were safe and effective at straightening hair. Specifically, 13.3% and 9.4% ammonium thioglycolate (G03 and G04) were more suitable for wavy and curly hair, 12.5% and 7.9% amino methyl propanol thioglycolate (G05 and G06) for finer or chemically processed hair, 5% and 4% sodium cysteamine (G07 and G08) for curly and tight curly hair to control volume, and 2% and 1% of a combination of ammonium thioglycolate with sodium thioglycolate (G09 and G10) for more resistant wavy and curly hair. Full article

Brown planthoppers (BPHs, Nilaparvata lugens Stål) are a major threat to rice cultivation in Asia, necessitating the development of pest-resistant varieties for effective management. However, the adaptability of BPHs has resulted in the development of virulent populations, such as biotype Y BPHs, which exhibit significant virulence against the rice variety YHY15 that harbors the resistance gene Bph15. The various response mechanisms of BPH populations to resistant rice varieties are critical yet underexplored. Via RNA sequencing, the present study identified distinct transcriptional profiles in avirulent (biotype 1) and virulent (biotype Y) BPH nymphs both before and after feeding on YHY15 rice. Our findings revealed differential expression patterns of gene clusters involved in protein synthesis, hydrolysis, fatty acid biosynthesis, metabolism, cuticle composition, and translocation. Further analysis elucidated changes in the expression of genes associated with longevity and structural components of cuticles, highlighting specific disruptions in both biotype 1 and biotype Y BPHs. Moreover, the two biotypes showed differences in the expression level of genes involved in ATP-binding cassette (ABC) transporters. A functional assessment of ABC transporter genes revealed a role of NlABCG14 in the honeydew production of biotype Y BPHs to YHY15 rice, without impacting their survival and developmental dynamics. These insights deepen our understanding of the mechanisms of virulent BPHs response to resistant rice varieties and highlight potential targets for improving pest management strategies. Full article

The combination of logging, burning, and livestock farming has been the main driver of European landscape sustainability for thousands of years. Whether or not livestock could keep these habitats on their own is under debate when extensive livestock grazing is kept understory in forests of high environmental value that, in turn, are affected by global warming. In this work, the impact of beef cattle on the diversity, shrub cover, and primary production of the Atlantic Pyrenean oak (Quercus pyrenaica Willd.) in northern Spain has been evaluated. The research studied their feeding habits using the faecal cuticle micro histological analysis in dung samples. Then, the effects of cattle grazing on the cover and alpha diversity of woody plants were evaluated. Finally, oaks’ primary production and phenology in grazed and control areas were compared. The results show that cattle feed on woody (an average of 30% of non-leguminous woody) and annual plant species (more than 20% of forbs) but do not affect plant cover or alpha diversity of vegetation. However, oak phenology differed between grazed and ungrazed treatments, probably due to the spatial variability of grazed forests. It can be concluded that understory grazing in Pyrenean oak forests could be considered a sustainable silvopastoral activity with a neutral impact on forest integrity. Full article

Commercial mango growers commonly spray potassium nitrate (KNO₃) solution to enhance flowering and fruit quality, yet there is limited information on the uptake efficiency of nitrogen (N) by mango cultivars through leaf cuticles. The study aimed to assess N uptake efficiency (NUpE) from foliar application of KNO₃ solution and compare NUpE among mango varieties. Mango cultivars were ‘Kensington Pride’ (‘KP’), ‘B74’ (‘Calypso^®’), and ‘NMBP 1201’ (‘AhHa!^®’), ‘NMBP 1243’ (‘Yess!^®’), and ‘NMBP 4069’ (‘Now^®’) grafted onto ‘KP’ seedlings. Leaves of six-month-old seedlings were dipped in ¹⁵N-enriched KNO₃ solution and analyzed for total N and ¹⁵N contents. A significant correlation was observed between the leaf area and the amount of solution retained after dipping the leaves in the KNO₃ solution. Moreover, leaves treated with the KNO₃ solution had higher ¹⁵N levels than the natural ¹⁵N abundance, indicating successful N uptake from the KNO₃ solution. The NUpE ranged from 27% to 44% and varied with variety. Cultivar ‘NMBP 4069’ had the highest NUE (44%) which was comparable with that of ‘B74’ (40%). ‘NMBP 1201’ showed the lowest (27%) NUpE which was comparable with that of ‘NMBP 1243’ (30%) and ‘KP’ (33%). These data on ¹⁵N uptake through the mango leaf cuticle demonstrates the effectiveness of foliar application as a method of supplying N to mango trees, highlighting important varietal differences in foliar ¹⁵N uptake efficiency. Considering these differences in NUpE among mango varieties will help in making informed decisions about cultivar selection and N management strategies for sustainable mango production. Full article

Waxy cuticle covers plant aerial organs and protects plants against environmental challenges. Although improved cuticle-associated traits are aimed at the wheat breeding programs, the mechanism governing wheat cuticular wax biosynthesis remains to be elucidated. Herein, wheat WW domain-containing protein TaCFL1 is characterized as a negative regulator of wax biosynthesis. The knockdown of TaCFL1 expression results in a 15% increase in wax accumulation and decreased leaf cuticle permeability in bread wheat. Furthermore, wheat class IV homeodomain transcription factors TaHDG1.1 and TaHDG1.2 are identified as partially redundant activators of wax biosynthesis. The silencing of TaHDG1.1 or TaHDG1.2 expression leads to an 11% reduction in epidermal wax accumulation and an increase in leaf cuticle permeability wax, while the co-silencing of TaHDG1.1 and TaHDG1.2 results in a 31% reduction in epidermal wax accumulation and a further increase in wax in the leaf cuticle permeability. Moreover, wheat 3-Ketoacyl-CoA synthase TaKCS10 is isolated as an essential component of the wax biosynthetic machinery. The silencing of TaKCS10 expression results in a 22% reduction in wax accumulation and increased leaf cuticle permeability. In addition, we demonstrated that the TaKCS10 expression is activated by TaHDG1.1 and TaHDG1.2, and that TaCFL1 attenuates the TaHDG1-mediated transcriptional activation of TaKCS10. This evidence supports that the WW domain-containing protein TaCFL1 negatively regulates wax biosynthesis via attenuating the transcriptional activation of the TaKCS10 gene mediated by HD-ZIP IV transcription factor TaHDG1. Full article

In barley having adherent hulls, an irreversible connection between the pericarp with both palea and lemma is formed during grain maturation. A mutation in the NUDUM 1 (NUD1) gene prevents this connection and leads to the formation of barley with non-adherent hulls. A genetic model of two isogenic lines was used to elucidate the genetic mechanisms of hull adhesion: a doubled haploid line having adherent hulls and its derivative with non-adherent hulls obtained by targeted mutagenesis of the NUD1 gene. Comparative transcriptomics analysis of the grain coats was performed at two stages of development: the milk stage, when the hulls can still be easily detached from the pericarp, and the dough stage when the hull adhesion process occurs. It was shown that the main differences in the transcriptomes lie in the genes related to DNA replication and chromatin assembly, cell wall organization, and cuticle formation. Meanwhile, genes involved in lipid biosynthesis mostly show minor differences in expression between stages and genotypes and represent a limited set of active genes. Among the 3-ketoacyl-CoA synthase (KCS) genes active during grain development, candidates for key enzymes responsible for very long-chain fatty acid elongation were identified. Full article

The promotion of natural beauty has empowered women with textured hair to embrace their natural hair texture and opt for bleaching as a means of style variation. However, bleaching exacerbates the inherent fragility of this hair type, necessitating treatments to partially restore its mechanical properties. Vegetable oils, renowned for their strengthening properties, were evaluated regarding (I) their ability to penetrate both virgin and bleached textured hair using Matrix-Assisted Laser Desorption Ionization (MALDI) time-of-flight (TOF) analysis, and (II) their effects by way of tensile and fatigue tests. The MALDI–TOF results revealed groups of oil molecules in the cortical region of the bleached textured hair. The tensile test results, in turn, showed that the oil treatments were unable to alter the mechanical properties of the hair. Conversely, the fatigue test showed an increase in resistance in the virgin hair, most likely attributed to a lubrication effect in the outermost portions of the cortex and cuticles. In the bleached hair, a reduction in resistance was noted following the treatment with the oils. Comparative analysis with a previous study on straight hair by our group suggests that external molecules diffuse more homogeneously in straight hair than in textured hair. The unique cortical structure of textured hair creates two areas with distinct diffusion zones, resulting in the irregular distribution of external materials and different effects compared to straight hair. Full article

The majority of insects reproduce sexually. Among the many factors involved in controlling the reproductive process, cuticular lipids play an important role as unique chemical signatures of species, developmental stage, and sex, and participate in mate recognition. An understanding of the sex- and metamorphosis-related fluctuations in the cuticular lipid profiles of harmful insects is necessary to hamper their reproductive process. A GC/MS analysis of the cuticular lipids of the beehive pest Galleria mellonella Linnaeus (Lepidoptera: Pyralidae) revealed 11 FFAs in the male pupae (C8:0, C9:0, C14:0, C15:0, C16:1, C16:0, C17:0, C18:1, C18:0, C20:1, and C21:1) together with another two in the females (C10:0 and C17:1). As metamorphosis progressed, some FFAs disappeared from the pupal cuticle (C8:0 and C17:0 in both sexes, and C10:0, C17:1, and C20:1 only in female pupae) and the levels of the others changed. In adult virgin males and females, C8:0, C17:1, and C17:0 reappeared and two FFAs absent in pupae (C6:0 and C11:0) appeared. In virgin males, C13:0 also appeared (absent in pupae). Copulation resulted in the disappearance of C13:0 and C17:1, decreased the concentrations of C9:0, C11:0, C18:1, and C18:0, and elevated the amounts of C14:0, C16:1, and C16:0 in mated males. In mated females, the concentrations of C11:0, C14:0, C15:0, C16:0, C17:1, and C18:1 increased while C18:1 decreased. Copulation reduced cholesterol levels in mated females, and increased those in males. Full article

Background/Objectives: The body color and patterns of insects play important roles in foraging, evading predators, mating, thermoregulation, and environmental adaptation. During the rearing of the QiufengN silkworm strain, a mutant with black pupal cuticle (QiufengNBP) was discovered. Preliminary map-based cloning and sequence analysis indicated that the ebony gene might significantly influence the formation of the black pupa mutant and the expression of 30K proteins. This study aims to determine the function of the ebony gene and its effect on the expression of the 30K protein during the pupal stage; Methods and Results: We employed CRISPR/Cas9 gene-editing technology to knock out the ebony gene in the Nistari strain, resulting in individuals with black pupae, named Nistari Black Pupa (NisBP). This confirmed that the ebony gene plays a crucial role in black pupa formation. Two-dimensional electrophoresis (2-DE) analysis of the pupal cuticle of NisBP and its wild-type Nistari found that the ebony gene has a significant impact on the expression of 30K proteins, which are vital for embryonic development and serve as key storage proteins; Conclusions: This study is the first to demonstrate that the ebony gene affects the expression of 30K proteins, laying the foundation for further research on their functions and providing insights into the developmental mechanisms of silkworms. Full article

Microscopic evidence demonstrated a strictly biotrophic lifestyle of the scab fungus Venturia inaequalis on growing apple leaves and characterised its hemibiotrophy as the combination of biotrophy and saprotrophy not described before. The pathogen–host interface was characterised by the formation of knob-like structures of the fungal stroma appressed to epidermal cells as early as 1 day after host penetration, very thin fan-shaped cells covering large parts of the host cell lumen, and enzymatic cuticle penetration from the subcuticular space limited to the protruding conidiophores. The V. inaequalis cell wall had numerous orifices, facilitating intimate contact with the host tissue. Pathogen-induced modifications of host cells included partial degradation of the cell wall, transition of epidermal cells into transfer cells, modification of epidermal pit fields to manipulate the flow of nutrients and other compounds, and formation of globular protuberances of mesophyll cells without contact with the pathogen. The non-haustorial biotrophy was characterised by enlarged areas of intimate contact with host cells, often mediated by a matrix between the pathogen and plant structures. The new microscopic evidence and information on the pathogens’ biochemistry and secretome from the literature gave rise to a model of the lifestyle of V. inaequalis, lacking a necrotrophic stage that covers and explains its holomorphic development. Full article

Russula, a prominent genus of ectomycorrhizal fungi, is notably abundant and diverse in China. We present here the findings from studies on various Chinese Russula collections. Two notable species within subg. Heterophyllinae, namely Russula leucoviridis and R. subswatica, were described and illustrated based on comprehensive morphological characteristics and molecular evidence. Morphologically, Russula leucoviridis is characterized by its pastel-green to green pileus center with light-yellow spots, a white to greenish-white pileus margin, and a cuticle that cracks and breaks into small green patches after maturation, whereas R. subswatica is distinguished by an infundibuliform pileus with a deeply depressed center after maturation, a light-orange to grayish-orange pileus center, and a yellowish-white to light-orange margin with a purplish to purplish-black hue, and a white to yellowish-white stipe that exhibits a purplish hue at the junction with the pileus. The phylogenetic analyses were conducted using a combined dataset of ITS, nrLSU, RPB2, and mtSSU. Relying on both morphological characteristics and multigene phylogeny, the former species is classified within subsect. Virescentinae, while the latter is affiliated with subsect. Griseinae. In this study, we provide new scientific data that enhance the comprehension of species diversity within the subgenus Heterophyllinae in China. Full article