Search Results (285)

The vegetative insecticidal protein Vip3Aa from Bacillus thuringiensis (Bt) has become a key plant-incorporated protectant (PIP) in transgenic crops targeting lepidopteran pests, particularly as resistance increasingly compromises the efficacy of Cry protein PIPs. More than a decade after its commercial deployment, Vip3Aa performance remains efficacious but increasingly vulnerable. Field screens have detected unexpectedly high baseline frequencies of Vip3Aa-resistant alleles and have produced highly resistant strains in several major pests, including Helicoverpa spp., Spodoptera spp., and Mythimna separata. Although structure–function experiments and studies on resistance to Vip3Aa have identified altered midgut processing and impaired receptor binding as candidate resistance mechanisms, the underlying genetic determinants remain poorly understood. Moreover, resistance to Vip3Aa appears to diverge from canonical Cry protein resistance pathways, underscoring the need for dedicated mechanistic studies. This review critically examines the available experimental evidence on Vip3Aa resistance mechanisms, highlighting major knowledge gaps and proposing research priorities to inform resistance monitoring and extend the durability of Vip3Aa-based pest control. Full article

Blue light is a significant environmental cue influencing plant photomorphogenesis and regulating plant growth and development. The COP9 signaling complex (CSN), a multi-subunit protein complex, plays a pivotal role in regulating photomorphogenesis, with CSN2 being identified as a key subunit essential for the assembly and function of the CSN. This study investigated the role of OsCSN2 in rice under blue-light conditions. Utilizing OsCSN2 knockout (KO) mutant plants and transgenic overexpression (OE) lines for wild-type (WT) and mutated versions of OsCSN2, we observed significant suppression of the overall seedling phenotype under blue light, indicating that OsCSN2 acts as a negative regulator of blue light-mediated morphogenesis. Further analysis revealed that exogenous application of gibberellin (GA₃) and the GA synthesis inhibitor paclobutrazol (PAC) modulated seedling elongation in response to blue light, particularly affecting plant height, coleoptile, and first incomplete leaf length without altering root growth. This suggests that OsCSN2 mediates the inhibitory effects of blue light on aboveground development through the gibberellin signaling pathway. On day 9, the analyses of endogenous GA₃ levels combined with Western blotting (WB) and quantitative real-time PCR (qRT-PCR) revealed that OsCSN2 senses blue light signals through cryptochrome 2 (CRY2), influences the expression of COP1 and BBX14, and highlights its role in the photoreceptive signaling pathway. This regulation ultimately influences the degradation of SLR1 within the GA signaling pathway, affecting rice seedling growth and development. Our findings also highlight the differential roles of OsCSN1 and OsCSN2 within the CSN in modulating rice seedling photomorphogenesis, thereby providing new insights into the intricate regulatory mechanisms governing plant responses to blue light. Full article

Cryptochrome is an important class of blue-light receptors involved in various physiological activities such as photomorphogenesis and abiotic stress regulation in plants. In order to investigate the molecular mechanism of blue-light-induced color change in Chimonobambusa sichuanensis, we screened and cloned the gene encoding the blue-light receptor Cryptochrome. In order to investigate the molecular mechanism of blue-light-induced color change in Chimonobambusa sichuanensis, we screened and cloned the gene encoding the blue-light receptor Cryptochrome in Ch.sichuanensis, and analyzed the expression characteristics of the Cryptochrome gene in Ch.sichuanensis under different light intensities, light quality, and temperatures by qRT-PCR. Through homologous cloning, a total of four CsCRY genes were obtained in the Ch.sichuanensis genome, namely, CsCRY1a, CsCRY1b, CsCRY2, and CsCRY3. Structural domain analyses of the encoded proteins of the four genes revealed that all CsCRYs proteins had the typical photoreceptor structural domain, PRK (protein kinase C-related kinase). Phylogenetic tree analyses revealed that the four genes CsCRY1a, CsCRY1b, CsCRY2, and CsCRY3 could be categorized into three subfamilies, with CsCRY1a and CsCRY1b clustered in subfamily I, CsCRY2 classified in subfamily II, and CsCRY3 belonging to subfamily III. All CsCRYs proteins lacked signal peptides and the instability index was higher than 40, among which the isoelectric points of CsCRY1a, CsCRY1b, and CsCRY2 were around five. qRT-PCR analysis revealed that the expression of all four CsCRYs genes was up-regulated at 75 µmol·m⁻²·s⁻¹ blue-light illumination for 4 h. In addition, under treatments of different light quality, the expression of CsCRY2 genes was significantly higher under blue light than under red light and a mixture of red light and blue light with a light intensity of 1:1; the expression of CsCRY1a and CsCSY1b was significantly higher in the mixed light of red and blue light than in the single light treatment, while under different temperature gradients, CsCRYs genes were highly expressed under low-temperature stress at −5 °C and 0 °C. This study provides a basis for further research on blue-light-induced color change in Ch.sichuanensis and expands the scope of Cryptochrome gene research. Full article

Peptidoglycan recognition proteins (PGRPs) are essential for innate immune recognition and regulation from insects to mammals. However, the specific role of PGRPs in responding to Bacillus thuringiensis (Bt) infection and maintaining midgut microbial homeostasis in Plutella xylostella remains poorly understood. In this study, we identified and characterized a PGRP gene from P. xylostella, designated PxPGRP4. The spatiotemporal expression analysis revealed that PxPGRP4 is predominantly expressed in the midgut of naïve larvae and at adult stages. A homozygous mutant strain featuring a four-base pair nucleotide deletion was successfully generated through CRISPR/Cas9-mediated knockout of PxPGRP4. The bioassay results indicated that the susceptibility of P. xylostella larvae to Cry1Ac protoxin was significantly increased by the loss of PxPGRP4 expression. Furthermore, 16S rRNA sequencing and qPCR analysis revealed that the PxPGRP4 mutants exhibited a significantly reduced total bacterial load and altered microbiota composition in the midgut compared to the wild-type strain, with a shift in the dominant bacterial family from Enterobacteriaceae to Enterococcaceae. Additionally, the knockout of PxPGRP4 resulted in significant alterations in the expression of midgut immune-related genes. These findings highlight the crucial role of PxPGRP4 as a modulator of midgut microbiota and immune responses and provide valuable insights into Bt resistance management. Full article

Camellia’s ornamental value is constrained by its natural winter–spring flowering period. Although the discovery of Camellia azalea provides important germplasm resources for developing cultivars with year-round flowering, the molecular mechanisms underlying flowering time variation remain unclear. Here, we investigated three germplasms with distinct flowering patterns: winter–spring flowering Camellia japonica ‘Tieke Baozhu’, summer–autumn flowering Camellia azalea, and their hybrid Camellia ‘Lingnan Yuanbao’ inheriting the latter’s flowering traits. Integrated transcriptomic and metabolomic analyses revealed that differentially expressed genes (DEGs) and metabolites (DAMs) were mainly enriched in the pathways related to photoperiod regulation, plant hormone synthesis and signal transduction and flavonoid synthesis. The transcription factor (TF) analysis revealed that the bHLH and MYB TF families were significantly differentially expressed in different Camellia germplasm, suggesting their potential involvement in the regulation of flowering time through the plant hormone signal transduction and photoperiod pathway. Meanwhile, photoperiod regulation related genes, including Cryptochrome circadian regulator (CRY), Timing of CAB expression 1 (TOC1), and phytochrome interacting factor 3 (PIF3), showed significant expression differences, further confirming the photoperiod pathway’s crucial regulatory function. In terms of plant hormone levels, there were significant differences in the levels of gibberellin (GA), abscisic acid (ABA), and jasmonic acid (JA) among Camellia germplasm. The differential expression characteristics of DELLA (Asp-Glu-Leu-Leu-Ala) proteins indicated that the GA signal transduction pathway was one of the key factors regulating flowering time in Camellia. Additionally, metabolomics analyses showed significant differences in flavonoid metabolite content among Camellia germplasm, which was significantly correlated with the different developmental stages of the buds. Our findings provide a theoretical basis for the molecular breeding of everblooming Camellia cultivars, advancing the understanding of flowering regulation mechanism in ornamental species. Full article

Bacillus thuringiensis (Bt) is an efficacious biocontrol bacterium known for producing various toxins, such as crystal toxins, which disrupt the midgut epithelium of pest larvae, leading to larval mortality. However, the development of resistance to Bacillus thuringiensis in pests poses a significant threat to the widespread application of Bt corn. Consequently, we employed high-throughput sequencing of the midgut bacterial 16S ribosomal RNA to characterize the midgut bacteria in four Bt-resistant strains. Specifically, Bt-resistant strains (ACB-FR and ACB-AcR) exhibited lower bacterial diversity compared to ACB-AbR and ACB-IeR. Multivariate analyses and statistical evaluations further demonstrated that the microbiota communities in Bt-resistant pests (AbR, AcR, IeR, and FR) were distinct from those in Bt-susceptible strains. Notably, the genus Klebsiella predominated in BtS, whereas Enterococcus was the genus with peak enrichment in AbR, AcR, IeR, and FR. Bioassays subsequently revealed that Enterococcus enhances the Cry1Ab resistance of ACB larvae. Our investigations indicate that treatment with Bt protein alters the midgut microbiota community of O. furnacalis, and these microbiota differences may potentially modulate the Bt-induced lethality mechanism. Full article

Anthocyanins, which accumulate in fruits, flowers, and vegetative organs, play a critical role in plant reproduction, disease resistance, stress tolerance, and promoting human health. Although light significantly influences the development of various fruit pigments, the specific mechanisms through which it regulates anthocyanin accumulation during fruit ripening are not yet fully understood. This study aimed to investigate the role of light in anthocyanin biosynthesis using Aft tomato fruits, which accumulate pigments in the epidermis. To explore the effects of light on anthocyanin biosynthesis, half of each fruit was covered with aluminum foil to establish light-exposed and bagged conditions for comparative analysis. The results showed that the bagged treatment led to a significant decrease in the total anthocyanin content of the fruits. Transcriptome analysis revealed a notable upregulation of several structural genes involved in the anthocyanin biosynthetic pathway, specifically Sl4CL, SlCHS, SlCHI, SlF3H, SlDFR, and Sl3GT in the light-exposed fruits. Additionally, the expression levels of light-responsive genes and transcription factors, such as SlCRY1, SlSPA, SlUVR3, SlHY5, SlBBX24, SlMYB11, MADS-box transcription factor 23, SlHD-ZIP I/II, SlAN2-like, SlbHLH and SlWD40 proteins, were significantly higher in the light-exposed samples compared to those subjected to the bagged treatment. Weighted Gene Co-Expression Network Analysis (WGCNA) demonstrated a strong association between light-induced gene expression such as SlPAL, SlCHS1, SlDFR, SlF3H, SlF3′5′H, SlANS, SlHY5, and SlAN2-like quantified by qRT-PCR analysis and anthocyanin biosynthesis. Moreover, as the fruit matured, both anthocyanin accumulation and the expression of genes related to its biosynthetic pathway increased. These findings contribute to a foundational understanding of the regulatory network that influences light-induced processes and fruit development impacting anthocyanin accumulation, which will facilitate in-depth study of the functions of these identified genes and provide a foundation for breeding anthocyanin-rich tomato varieties. Full article

Resistance to HER2 tyrosine-kinase inhibitor Lapatinib (Lap) is one of the leading causes of cancer treatment failure in HER2+ breast cancer (BC), associated with an aggressive tumor phenotype. Cryptotanshinone (Cry) is a natural terpene molecule that could function as a chemosensitizer by disturbing estrogen receptor (ERα) signaling and inhibiting the protein translation factor-4A, eIF4A. Therefore, we evaluated Cry dual regulation on eIF4A and ERα. This study aimed to elucidate the underlying mechanisms of Lap chemoresistance and the impact of Cry on them. We generated two Lap-resistant BT474 cell HER2+ variants named BT474^LapRV1 and BT474^LapRV2 with high chemoresistance levels, with 7- and 11-fold increases in EC₅₀, respectively, compared to BT474 parental cells. We found a PDCD4-p70S6Kβ axis association with Lap chemoresistance. However, a concomitant down-regulation of the RAF-MEK-ERK cell survival pathway and NF-κB was found in the chemoresistant cell variants; this phenomenon was exacerbated by joint treatment of Cry and Lap under a Lap plasmatic reported concentration. Optimized calcium management was identified as a compensatory mechanism contributing to chemoresistance, as determined by the higher expression of calcium pumps PMCA1/4 and SERCA2. Contrary to expectations, a combination of Lap and Cry did not affect the chemoresistance despite the ERα down-regulation; Cry-eIF4A binding possibly dampens this condition. Results indicated the pro-survival eIF4A/STAT/Bcl-xl pathway and that the down-regulation of the MAPK-NF-κB might function as an adaptive mechanism; this response may be compensated by calcium homeostasis in chemoresistance, highlighting new adaptations in HER2+ cells that lead to chemoresistance. Full article

Transgenic crops have been commercially cultivated for nearly three decades, leading to increasing concerns about their environmental safety, particularly their effects on non-target organisms. This study investigated the underlying mechanisms behind the lack of impact of the Cry1Ab1 protein on the Myzus persicae. The Cry1Ab1 protein showed no significant impact on the survival and development of M. persicae. Compared to other Cry protein, fewer Cry1Ab1-binding proteins were identified including beta-actin, ATP synthase subunit alpha, and GPN-loop GTPase 2. Transcriptomic analysis showed that a small set of pathways, mainly involved in immune defense, were temporarily enriched at 24 h after exposure to the Cry1Ab1 protein, while no significant pathways were enriched at 48 h in M. persicae. The results suggest that the Cry1Ab1 protein has a transient and minimal impact on M. persicae. Further structural comparisons between Cry1Ab1 and other Cry proteins (e.g., Cry1Ac) revealed significant differences in Domain III, which likely reduced the binding efficiency and impact on M. persicae’s metabolism and biological traits. This study provides valuable insights into the molecular and functional mechanisms behind the ineffectiveness of Cry1Ab1 on M. persicae and contributes to the safety evaluation of Bt for non-target organisms. Full article

Aphids (Hemiptera: Aphididae) are cosmopolitan generalist pests of many agricultural crops. Their ability to reproduce rapidly through parthenogenesis allows them to quickly reach population sizes that are difficult to control. Their damage potential is further exacerbated when they act as vectors for plant pathogens, causing diseases in plants. Aphids are typically managed through the widespread use of insecticides, increasing the likelihood of short-term insecticide resistance. However, for the past few decades, entomopathogenic bacteria have been used as an alternative management strategy. Entomopathogenic bacteria have demonstrated their effectiveness for biologically suppressing insect pests, including aphids. In addition to identifying bacterial species that are pathogenic to aphids, research has been conducted on toxins such as Cry, Cyt, Vip, recombinant proteins, and other secondary metabolites with insecticidal activity. Most studies on aphids have been conducted in vitro, exposing them to an artificial diet contaminated with entomopathogenic bacteria or bacterial metabolites for periods ranging from 24 to 96 h. The discovery of new bacterial species with insecticidal potential, as well as the possibility of biotechnological applications through the genetic improvement of crops, will provide more alternatives for managing these agricultural pests in the future. This will also help address challenges related to field application. Full article

The red palm weevil (RPW; Coleoptera: Curculionidae) is a destructive pest affecting palms worldwide, capable of causing significant economic losses and ecological damage in managed palm ecosystems. Current management heavily relies on synthetic insecticides, but their overuse fosters resistance. Bacillus thuringiensis (Bt) offers a promising alternative, producing toxins selective against various insect orders, including Coleoptera. However, no specific Bt toxin has yet been identified for RPW. This study investigates the toxicity against RPW larvae of the Bt Cry1Ia protoxin, known for its dual activity against Lepidoptera and Coleoptera. A laboratory RPW colony was reared for two generations, ensuring a reliable insect source for bioassays. Cry1Ia was expressed as a 6xHis-tagged fusion protein in Escherichia coli and purified using nickel affinity. Incubation with RPW larval gut proteases for 24 h produced a stable core of ~65 kDa. Diet-incorporation bioassays revealed high Cry1Ia toxicity in neonate larvae. In contrast, the lepidopteran-active Cry1Ac protoxin, used as a robust negative control, was completely degraded after 24 h of in vitro proteolysis and showed no toxicity in bioassays. Cry1Ia-fed larvae exhibited significant midgut cell damage, characteristic of Bt intoxication. These findings highlight Cry1Ia’s strong potential for integration into RPW management programs. Full article

We investigated the transcription of circadian clock genes in publicly available datasets of gene expression in medulloblastoma (MB) tissues using the R2 Genomics Analysis and Visualization Platform. Differential expression of the core clock genes among the four consensus subgroups of MB (defined in 2012 as Group 3, Group 4, the SHH group, and the WNT group) included the core clock genes (CLOCK, NPAS2, PER1, PER2, CRY1, CRY2, BMAL1, BMAL2, NR1D1, and TIMELESS) and genes which encode proteins that regulate the transcription of clock genes (CIPC, FBXL21, and USP2). The over-expression of several clock genes, including CIPC, was found in individuals with the isochromosome 17q chromosomal aberration in MB Group 3 and Group 4. The most significant biological pathways associated with clock gene expression were ribosome subunits, phototransduction, GABAergic synapse, WNT signaling pathway, and the Fanconi anemia pathway. Survival analysis of clock genes was examined using the Kaplan–Meier method and the Cox proportional hazards regression model through the R2 Genomics Platform. Two clock genes most significantly related to survival were CRY1 and USP2. The data suggest that several clock proteins, including CRY1 and USP2, be investigated as potential therapeutic targets in MB. Full article

Bioinsecticides based on the bacterium Bacillus thuringiensis (Bt) are widely used as safe alternatives to chemical insecticides. The insecticidal activity of Bt is occasioned by a protein toxin contained in parasporal crystals (Cry proteins) that are synthesized and laid down alongside the endospore during sporulation. The specificity of toxin action is associated with the subspecies of Bt and the individual Cry toxins they produce. Although a number of commercial Bt formulations are available to control moths, mosquitoes and beetles, there are none that control the red imported fire ant (RIFA) Solenopsis invicta. The present report is the first to describe the insecticidal activity of the Cry3A protein toxin, produced by Bacillus thuringiensis subsp. tenebrionis (Btt), against the RIFA as well as some of its key biochemical properties. Currently available commercial formulations of Btt are designed to control beetles such as the Colorado potato beetle, not ants. The Cry3A toxin (MW ~66 kDa) is embedded in a larger polypeptide (protoxin, MW ~73 kDa) and is released from the toxin enzymatically. Once activated, it can be administered to the RIFA as a soluble protein that most likely binds to an attendant receptor in the epithelial cells that line the wall of the larval ventriculus, killing the insect. Properly customized, the Cry3A toxin is a potential candidate for fire ant control. Full article

Objectives: To report the prevalence of invasive bacterial infection (IBI) in febrile infants ≤90 days presenting to hospital within 72 h of meningococcal B (MenB) immunisation. Methods: A secondary analysis of data from two previous multicentre studies of febrile infants conducted at UK and Irish hospitals. The first study was a retrospective study, conducted at six sites between 31 August 2018 and 1 September 2019. The second study was a prospective study conducted at 35 sites between 6 July 2022 and 31 August 2023. Febrile infants ≤90 days who had received the MenB vaccine within 72 h preceding presentation were included. Results: A total of 102 infants met the inclusion criteria, with a median age of 61 days and a male predominance of 65.7%. The most reported clinical features were an abnormal cry, decreased feeding and coryzal symptoms. In total, 68/102 (66.7%) were admitted to hospital; the median length of stay was 1 day. Median C-reactive protein (CRP) was 20.5 mg/L, mean white cell count was 13.7 × 10⁹/L, mean neutrophil count was 7.3 × 10⁹/L and mean lymphocyte count was 4.7 × 10⁹/L. In total, 38/102 (37.3%) had blood cultures performed, 26/102 (25.5%) had respiratory viral testing performed, 55/102 (53.9%) had urine culture performed and 14/102 (13.7%) had lumbar puncture performed. Additionally, 26/102 (25.5%) received parenteral antibiotics. There were no cases of IBI, and 3/102 (2.9%) cases of urinary tract infection. Conclusions: The rate of IBI is negligible in febrile infants following MenB immunisations. Current blood tests such as CRP are unreliable in this cohort, as many exhibit a moderate CRP rise above suggested international cut-offs for this age range. Full article

The cryptochromes are flavoproteins that either individually or synergistically respond to light and magnetic field directionality as well as are implicated in circadian rhythm entrainment and development. Single brief exposures (10 min) to low energy (1.5 mT) pulsed electromagnetic fields (PEMFs) were previously shown to enhance myogenesis by stimulating transient receptor potential canonical 1 (TRPC1)-mediated Ca²⁺ entry, whereby downwardly directed fields produced greater myogenic enhancement than upwardly directed fields. Here, we show that growth in the dark results in myoblasts losing their sensitivity to both magnetic field exposure and directionality. By contrast, overexpressing or silencing cryptochrome circadian regulator 2 (CRY2) in myoblasts enhances or reduces PEMF responses, respectively, under conditions of ambient light. Reducing cellular flavin adenine dinucleotide (FAD) content by silencing riboflavin kinase (RFK) attenuated responsiveness to PEMFs and inhibited selectivity for magnetic field direction. The upregulation of TRPC1 and cell cycle regulatory proteins typically observed in response to PEMF exposure was instead attenuated by upwardly directed magnetic fields, growth in the darkness, magnetic shielding, or the silencing of CRY2 or RFK. A physical interaction between CRY2 and TRPC1 was detected using coimmunoprecipitation and immunofluorescence, revealing their co-translocation into the nucleus after PEMF exposure. These results implicate CRY2 in an identified TRPC1-dependent magnetotransduction myogenic cascade. Full article