P450 Genes Research Articles

Identification of the cytochrome P450 gene AccCYP6A13 in Apis cerana cerana and its response to environmental stress

Cytochrome P450 plays a crucial role in regulating insect growth, development, and resisting a variety of stresses. Insect metamorphosis and response to external stress are altered by deleting CYP450 genes. In this study, we identified and analyzed a novel gene of CYP450 family, AccCYP6A13, from Apis cerana cerana, and explored its role in the response of Apis cerana cerana to adverse external stressors. It was found that the expression of AccCYP6A13 was spatiotemporal specificity. The expression level increased with age and reached its highest value in the adult stage. The primarily expressiong location were legs, brain, and epidermis of honeybees. Stress conditions can affect the expression of AccCYP6A13 depending on treatment times. RNA interference experiments have shown that knocking down AccCYP6A13 reduces antioxidant activity and deactivates detoxification enzymes, resulting in oxidative damage accumulation and a decline in detoxification capability in bees, as well as inhibiting numerous antioxidant genes. Additionally, knockdown of the AccCYP6A13 gene in Apis cerana cerana resulted in increased sensitivity to pesticides and increased mortality when treated with neonicotinoid pesticides such as thiamethoxam. AccCYP6A13 overexpression in a prokaryotic system further confirmed its role in resistance to oxidative stress. To summarize, AccCYP6A13 may play an essential role in the normal development and response to environmental stress in Apis cerana cerana. Furthermore, this study contributed to the theoretical understanding of bee resistance biology.

Overexpression of cytochrome P450 gene CYP6K1 is associated with pyrethroid resistance in German cockroaches (Blattodea: Ectobiidae) from California.

We investigated the expression of 4 cytochrome P450 genes (CYP4G19, CYP6J1, CYP6K1, and CYP4C21) in 4 field-collected strains (WM, RG386, CDR, and Ryan) of the German cockroach, Blattella germanica (L.), collected from California. The UCR susceptible strain was used as a comparison. Topical assays using a diagnostic dose (3× LD95) of deltamethrin revealed decreased sensitivity in all field-collected strains with mortality ranging from 0% to 58%, and the addition of PBO before deltamethrin treatment increased mortality to 52.5%-87.5%. Using qPCR to investigate the expression levels of CYP4G19, CYP4C21, CYP6J1, and CYP6K1, we found that only CYP6K1 was significantly overexpressed (2.1-5.8× higher) in all field-collected strains when compared to the UCR strain. Next, we investigated the role of the CYP6K1 gene by performing gene knockdown using RNAi. After dsCYP6K1 treatment, the expression levels of CYP6K1 in WM and Ryan strains were significantly reduced (P < 0.01) by 91%-94% vs. those treated with dsEGFP (control) on the third and sixth day posttreatment. RG386, CDR, and Ryan strains were more susceptible compared to their respective controls to topically applied deltamethrin 6 days after treatment with dsCYP6K1. This study provides evidence of the involvement of the P450 CYP6K1 gene in pyrethroid resistance in some populations of German cockroaches.

Mesoporous silica nanospheres-mediated insecticide and antibiotics co-delivery system for synergizing insecticidal toxicity and reducing environmental risk of insecticide

Mesoporous silica nanoparticles (MSNs) are efficient carriers of drugs, and are promising in developing novel pesticide formulations. The cotton aphids Aphis gossypii Glover is a world devastating insect pest. It has evolved high level resistance to various insecticides thus resulted in the application of higher doses of insecticides, which raised environmental risk. In this study, the MSNs based pesticide/antibiotic delivery system was constructed for co-delivery of ampicillin (Amp) and imidacloprid (IMI). The IMI@Amp@MSNs complexes have improved toxicity against cotton aphids, and reduced acute toxicity to zebrafish. From the 16S rDNA sequencing results, Amp@MSNs, prepared by loading ampicillin to the mesoporous of MSNs, greatly disturbed the gut community of cotton aphids. Then, the relative expression of at least 25 cytochrome P450 genes of A. gossypii was significantly suppressed, including CYP6CY19 and CYP6CY22, which were found to be associated with imidacloprid resistance by RNAi. The bioassay results indicated that the synergy ratio of ampicillin to imidacloprid was 1.6, while Amp@MSNs improved the toxicity of imidacloprid by 2.4-fold. In addition, IMI@Amp@MSNs significantly improved the penetration of imidacloprid, and contributed to the amount of imidacloprid delivered to A. gossypii increased 1.4-fold. Thus, through inhibiting the relative expression of cytochrome P450 genes and improving penetration of imidacloprid, the toxicity of IMI@Amp@MSNs was 6.0-fold higher than that of imidacloprid. The greenhouse experiments further demonstrated the enhanced insecticidal activity of IMI@Amp@MSNs to A. gossypii. Meanwhile, the LC50 of IMI@Amp@MSNs to zebrafish was 3.9-fold higher than that of IMI, and the EC50 for malformation was 2.8-fold higher than IMI, respectively, which indicated that the IMI@Amp@MSNs complexes significantly reduced the environmental risk of imidacloprid. These findings encouraged the development of pesticide/antibiotic co-delivery nanoparticles, which would benefit pesticide reduction and environmental safety.

Personalized approach to outpatient management of patients taking tamoxifen by gynecologists

BACKGROUND: 30% of women with luminal breast cancer receiving adjuvant tamoxifen experience disease recurrence within 15 years. This demonstrates the wide variability in clinical response to tamoxifen. Both nongenetic (age, gender, body mass index, duration of drug use) and genetic factors have been described to influence the high variability of response to tamoxifen. Differences in the genes encoding the enzymes CYP2D6, CYP2C, and CYP3A (CYP2D6*4, CYP3A5*3, CYP2C9*2, CYP2C9*3, CYP2C19*2, CYP2C19*3) and the ABCB1 gene (C3435T) may also be the main factors of susceptibility to the occurrence of undesirable effects when taking tamoxifen, which in turn may lead to decreased patient adherence to therapy.&#x0D; AIM: The aim of this study was to create a concept and an algorithm for a personalized approach to outpatient management of patients taking tamoxifen by a gynecologist in connection with the carriage of polymorphisms of cytochrome P450 and drug transporter genes.&#x0D; MATERIALS AND METHODS: In 2017–2018, the outpatient records of 230 patients with breast cancer were analyzed retrospectively. A single-stage pharmacogenetic study of 120 women with stage I–III luminal breast cancer taking tamoxifen was conducted prospectively for the presence of cytochrome P450 gene polymorphisms using the polymerase chain reaction method and assessing associations with adverse drug reactions, and 54 patients were interviewed after five-year follow-up to assess adherence and satisfaction with medical supervision.&#x0D; RESULTS: The likelihood of developing endometrial hyperplasia has been shown to increase while taking tamoxifen with increasing average age, body mass index, duration of tamoxifen use, and postmenopause. Significant associations have been identified between the carriage of the CYP2D6, CYP2C9, CYP2C19, CYP3A5, and ABCB1 gene polymorphisms and the development of adverse drug reactions. Predictive models have been developed to determine the risk of adverse drug reactions. All studied adverse drug reactions associated with various genetic polymorphisms predominated in the group of patients who stopped taking tamoxifen due to poor intolerance. Gynecologists regularly observed 57.4% of patients. Moreover, the higher the adherence to therapy was, the higher was the regularity of observation by a gynecologist.&#x0D; CONCLUSIONS: A plan for outpatient management of patients receiving adjuvant endocrine therapy with tamoxifen by a gynecologist has been developed.

Knockdown of one cytochrome P450 gene CYP6DW4 increases the susceptibility of Bemisia tabaci to dimpropyridaz, a novel pyridazine pyrazolecarboxamide insecticide

Bemisia tabaci is a formidable insect pest worldwide, and it exhibits significant resistance to various insecticides. Dimpropyridaz is a novel pyridazine pyrazolecarboxamide insecticide used against sucking insect pests, but there is little information regarding its metabolic detoxification in arthropods or cross-resistance with other insecticides. In this study, we found that dimpropyridaz shows no cross-resistance with three other popular insecticides, namely abamectin, cyantraniliprole, and flupyradifurone. After treatment of B. tabaci adults with a high dose of dimpropyridaz, higher cytochrome P450 monooxygenase (P450) activity was detected in the survivors, and the expression of the P450 gene CYP6DW4 was highly induced. Cloning and characterization of the full-length amino acid sequence of CYP6DW4 indicated that it contains conserved domains typical of P450 genes, phylogenetic analysis revealed that it was closely related to a B. tabaci protein, CYP6DW3, known to be involved in detoxification of imidacloprid. Silencing of CYP6DW4 by feeding insects with dsRNA significantly increased the susceptibility of B. tabaci to dimpropyridaz. In addition, homology modeling and molecular docking analyses showed the stable binding of dimpropyridaz to CYP6DW4, with binding free energy of −6.65 kcal/mol. Our findings indicate that CYP6DW4 plays an important role in detoxification of dimpropyridaz and possibly promotes development of resistance in B. tabaci.

Abstract 3578: A systematic NEN spheroid drug screen reveals a novel drug resistance mechanism in small bowel NETs

Abstract Neuroendocrine neoplasms (NENs) are rare cancers that arise from neuroendocrine cells. NENs are classified as well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Small bowel NETs (SBNETs) and pancreatic NETs (PNETs) are generally slow growing but they commonly metastasize to the liver and can become aggressive cancers. NECs are rapidly growing, and patients have poor prognosis. Little is known about the drug sensitivity profile of SBNETs, PNETs and NECs due to a paucity of cellular and animal models of these malignancies. We have successfully cultured NEN cells from clinical samples as patient-derived spheroids (PDS) and showed that they express appropriate tumor markers. We systematically screened 20 NEN (12 SBNET, 5 PNET, and 3 NEC) spheroid cultures against a library of 175 compounds (147 FDA-approved anti-cancer drugs, 8 lab selected compounds, and 20 structurally diverse molecules) and compared their drug sensitivity profiles to identify the most effective drug classes and to better understand the biology of each NEN subtype. Top drug hits were validated for their anti-tumor properties in NEN PDS and patient-derived xenograft (PDX) mouse models. Our NEN PDS cultures identified common and unique drug sensitivity profiles for each type of NEN. SBNET spheroids were more resistant to many classes of anti-cancer drugs, which was due to overexpression of cytochrome P450 genes. Consistent with clinical findings, PNET spheroids showed increased sensitivity to tyrosine kinase and mTOR/PI3K inhibitors compared to SBNET &amp; NEC spheroids. NEC spheroids showed the broadest sensitivity to many anti-neoplastic compounds. The top candidate drug identified from our screen was romidepsin, a histone deacetylase inhibitor. Romidepsin displayed anti-tumor properties in vitro and in vivo for all 3 NEN models and was highly synergistic with rapamycin, an mTOR inhibitor similar to the SBNET approved drug everolimus. Excitingly, low-dose romidepsin effectively inhibited tumor growth when combined with low-dose rapamycin in an SBNET PDX mouse model. These NEN PDS drug screens enabled direct drug testing in primary tumor cultures to identify promising drugs that could be used alone or in combination with currently approved-NEN therapies. Histone deacetylase inhibitors, such as romidepsin, may be effective against SBNETs. NEN PDS models also serve as a valuable resource for understanding the unique biology and mechanisms of drug resistance for specific NEN subtypes. Citation Format: Catherine G. Tran, Luis C. Borbon, Dane H. Tow, Jonathan Shilyansky, Guiying Li, James Egan, Scott K. Sherman, Ellen Abusada, Jing Tang, Ramaswamy govindan, Ryan C. Fields, Terry A. Braun, Carlos HF Chan, Chandrikha Chandrasekharan, Douglas Spitz, Dawn E. Quelle, Andrew M. Bellizzi, James R. Howe, Po Hien Ear. A systematic NEN spheroid drug screen reveals a novel drug resistance mechanism in small bowel NETs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3578.

Secondary metabolites in host pears defense against two fruit borers and cytochrome-P450-mediated counter-defense

Herbivorous insects have evolved metabolic strategies to survive the challenges posed by plant secondary metabolites (SMs). This study reports an exploration of SMs present in pears, which serve as a defense against invasive Cydia pomonella and native Grapholita molesta and their counter-defense response. The feeding preferences of fruit borers are influenced by the softening of two pear varieties as they ripen. The content of SMs, such as quercetin and rutin, increases due to feeding by fruit borers. Notably, quercetin levels only increase after C.pomonella feeding. The consumption of SMs affects the growth of fruit borer population differently, potentially due to the activation of P450 genes by SMs. These two fruit borers are equipped with specific P450 enzymes that specialize in metabolizing quercetin and rutin, enabling them to adapt to these SMs in their host fruits. These findings provide valuable insights into the coevolution of plants and herbivorous insects.

Functional characterization of Helicoverpa assulta CYP6B6 in insecticide metabolism

The oriental tobacco budworm Helicoverpa assulta (Lepidoptera: Noctuidae) is a specialist pest that may cause serious damages to important crops such as chili pepper and tobacco. Various man-made insecticides have been applied to control the infestation of this pest. To understand how this pest copes with insecticides, it is required to identify key players involved in insecticide transformation. In this study, a P450 gene of CYP6B subfamily was identified in the oriental tobacco budworm, and its expression pattern was revealed. Moreover, the activities of HassCYP6B6 against 12 insecticides were explored using recombinant enzymes produced in the facile Escherichia coli. Data from metabolic experiments showed that HassCYP6B6 was able to metabolize conventional insecticides including organophosporates (diazinon, malathion, phoxim), carbamate propoxur, and pyrethroid esfenvalerate, while no significant metabolism was observed towards new-type pesticides such as neonicotinoids (acetamiprid, imidacloprid), diamides (chlorantraniliprole, cyantraniliprole), macrocyclic lactone (emamectin benzoate, ivermectin), and metaflumizone. Structures of metabolites were proposed based on mass spectrometry analyses. The results demonstrate that HassCYP6B6 plays important roles in the transformation of multiple insecticides via substrate-dependent catalytic mechanisms including dehydrogenation, hydroxylation and oxidative desulfurization. The findings have important applied implications for the usage of insecticides.

Monitoring Aedes populations for arboviruses, Wolbachia, insecticide resistance and its mechanisms in various agroecosystems in Benin

Aedes mosquitoes are the main vectors of arboviruses in Benin. Cases of dengue have been reported in Benin with all four serotypes of the virus actively circulating in this region. Some agricultural settings are known to harbor Aedes vectors responsible for the transmission of arboviruses. The massive use of certain insecticides in agricultural settings has probably contributed to insecticide resistance in these vectors. In Benin, the susceptibility of arbovirus vectors to insecticides is poorly studied. In addition, the distribution of Wolbachia spp., which is used against some arboviruses is unknown. Moreover, there is limited information regarding the vectors responsible for the transmission of arboviruses in Benin. This present study monitored the species composition, arboviruses, and Wolbachia symbiont status, as well as the phenotypic and molecular insecticide resistance profile of Aedes populations from three agroecosystems in Benin. Aedes species identification was performed morphologically and confirmed using qPCR. (RT)-qPCR assay was applied for monitoring the presence of DENV, CHIKV, ZIKV, and WNV pathogens as well as for naturally occurring Wolbachia symbionts. Insecticide resistance was assessed phenotypically, by permethrin (0.75%) exposure of Adults (F0) using World Health Organization (WHO) bioassay protocols, and at the molecular level, using TaqMan (RT)-qPCR assays for assessing knock-down resistance (kdr) mutations (F1534C, V1016G/I, and S989P) and the expression levels of eight detoxification genes (P450s from the CYP9 and CYP6 families, carboxylesterases and glutathione-S-transferases). Aedes aegypti (Ae. aegypti) mosquitoes were the most abundant (93.9%) in the three agroecosystems studied, followed by Aedes albopictus (Ae. albopictus) mosquitoes (6.1%). No arboviruses were detected in the study's mosquito populations. Naturally occurring Wolbachia symbionts were present in 7 pools out of 15 pools tested. This could influence the effectiveness of vector control strategies based on exogenously introduced Wolbachia, all present in the three agroecosystems. Full susceptibility to permethrin was observed in all tested populations of Ae. albopictus. On the contrary, Ae. aegypti were found to be resistant in all three agroecosystem sites except for banana plantation sites, where full susceptibility was observed. Molecular analysis revealed that individual target site resistance kdr mutations F1534C and V1016G/I were detected in most Ae. aegypti populations. Additionally, double mutant (F1534C + V1016G/I) mosquitoes were found in some populations, and in one case, triple mutant (F1534C + V1016G/I + S989P) mosquitoes were detected. Metabolic resistance, as reflected by overexpression of three P450 genes (CYP6BB2, CYP9J26, and CYP9J32), was also detected in Ae. aegypti mosquitoes. Our study provides information that could be used to strategize future vector control strategies and highlights the importance of continuing vector surveillance. Future studies should assess the effect of piperonyl butoxide (PBO) on metabolic resistance and identify the different strains of Wolbachia spp., to choose the best vector control strategies in Benin.

RNA-seq analysis reveals narrow differential gene expression in MEP and MVA pathways responsible for phytochemical divergence in extreme genotypes of Thymus daenensis Celak

BackgroundHere, we investigated the underlying transcriptional-level evidence behind phytochemical differences between two metabolically extreme genotypes of Thymus daenensis. The genotypes ‘Zagheh-11’ (thymol/carvacrol type, poor in essential oil [EO] [2.9%] but rich in triterpenic acids) and ‘Malayer-21’ (thymol type and rich in EO [3.8%]) were selected from an ongoing breeding program and then clonally propagated for further experimental use.Materials and methodsGC-MS, GC-FID, and HPLC-PDA were utilized to monitor the fluctuation of secondary metabolites at four phenological stages (vegetative, bud burst, early, and full-flowering stages). The highest phytochemical divergence was observed at early flowering stage. Both genotypes were subjected to mRNA sequencing (approximately 100 million paired reads) at the aforementioned stage. The expression patterns of four key genes involved in the biosynthesis of terpenoids were also validated using qRT-PCR.ResultsCarvacrol content in ‘Zagheh-11’ (26.13%) was approximately 23 times higher than ‘Malayer-21’ (1.12%). Reciprocally, about 10% higher thymol was found in ‘Malayer-21’ (62.15%). Moreover, the concentrations of three major triterpenic acids in ‘Zagheh-11’ were approximately as twice as those found in ‘Malayer-21’. Transcriptome analysis revealed a total of 1840 unigenes that were differentially expressed, including terpene synthases, cytochrome P450, and terpenoid backbone genes. Several differentially expressed transcription factors (such as MYB, bZIP, HB-HD-ZIP, and WRKY families) were also identified. These results suggest that an active cytosolic mevalonate (MVA) pathway may be linked to higher levels of sesquiterpenes, triterpenic acids, and carvacrol in ‘Zagheh-11’. The chloroplastic pathway of methyl erythritol phosphate (MEP) may have also contributed to a higher accumulation of thymol in Malayer-21. Indeed, ‘Zagheh-11’ showed higher expression of certain genes (HMGR, CYP71D180, β-amyrin 28-monooxygenase, and sesquiterpene synthases) in the MVA pathway, while some genes in the MEP pathway (including DXR, ispG, and γ-terpinene synthase) were distinctly expressed in Malayer-21. Future efforts in metabolic engineering of MVA/MEP pathways may benefit from these findings to produce increased levels of desired secondary metabolites at commercial scale.

Effects of Calamintha incana (Sm.) Helder Ethanolic Extract on the mRNA Expression of Drug-metabolizing cyp450s in the Mouse Livers.

Alteration in the expression and activity of drug-metabolizing enzymes (DMEs) can alter the pharmacokinetics and hence the response of the drug. Some chemicals found in herbs and fruits affect the expression of DMEs. Calamintha incana is commonly used in Middle Eastern Arabic countries. There is no report regarding the influence of Calamintha incana on the hepatic expression of DMEs. The current investigation aimed to investigate the effect of Calamintha incana consumption on the mRNA expression of major hepatic drug-metabolizing cytochrome (cyp) P450 genes in mice. The chemical composition of the ethanoic extract was analyzed using liquid chromatography/ mass spectrometry. Then, 21 BALB/c mice were used for the in vivo experiment. The mice were divided into three groups, each consisting of seven mice. The first group (low-dose group) was treated with 41.6 mg/kg of Calamintha incana extract and the second group was administered the high-dose (125 mg/kg) of the extract for one month. The mice in the third "control" group administrated the vehicle 20% polyethylene glycol 200. Then, the expression of cyp3a11, cyp2c29, cyp2d9, and cyp1a1 was analyzed using the real-time polymerase chain reaction. The relative liver weights of the mice and the hepatic pathohistological alterations were assessed. The ethanolic extract of Calamintha incana contained 27 phytochemical compounds. The most abundant compounds were linolenic acid, myristic acid, and p-cymene. It was found that the low dose of Calamintha incana extract upregulated significantly (P < 0.05) the expression of cyp3a11 by more than ten folds in the liver of treated mice. Furthermore, the histological analysis showed that low- and high-dose administration of the C. incana did not cause pathological alterations. It can be concluded from these findings that consumption of low doses of Calamintha incana upregulated the mRNA expression of mouse cyp3a11 without causing histopathological alterations in the livers. Further studies are needed to determine the influence of Calamintha incana on the pharmacokinetics and response of drugs metabolized by cyp3a11.

Genome-wide analysis of the cytochrome P450 superfamily suggests its roles in coumarin biosynthesis and salt stress response in Melilotus albus

Coumarin, a secondary metabolite from the plant phenylpropane pathway, was certified as an important natural product for plants in response to abiotic stresses. Cytochrome P450s represent the largest monooxygenase superfamily in kingdoms, participating in various biochemical processes including coumarin biosynthesis. Here, we reported a total of 290 P450 genes identified from the Melilotus albus genome, and these MaP450s were grouped into 9 clans. These genes were unevenly distributed in eight chromosomes and all of them contain highly conserved feature motifs of P450s. MaCYP82L1 was differentially expressed in JiMa46 and JiMa49, meanwhile up-regulated in response to NaCl treatment. The heterologous expression in yeast showed that the MaCYP82L1 transformed yeast cells exhibited obvious resistance under drought and salt stresses. Furthermore, overexpression of MaCYP82L1 increased coumarin content in transgenic hairy roots. This study not only identified MaCYP82L1 as an important regulator that adjusts drought and salt resistance, but also provided a link between coumarin metabolism and abiotic stresses.

The Glycine soja cytochrome P450 gene GsCYP82C4 confers alkaline tolerance by promoting reactive oxygen species scavenging.

Recent studies have demonstrated the crucial role of Cytochrome P450 enzymes (CYPs) in the production of secondary metabolites, phytohormones and antioxidants in plants. However, their functional characterization specifically under alkaline stress remains elusive. CYP82C4 was the key gene screened from a family of wild soybean CYPs in our previous studies. The aim of this present study was to clone the Glycine soja GsCYP82C4 gene and characterize its functions in Arabidopsis and Glycine max. The results showed that the GsCYP82C4 gene displayed a high expression in different plant tissues at mature stages compared to young stages. Further, higher temporal expression of the GsCYP82C4 gene was noted at 6, 12 and 24 h time points after alkali treatment in leaves compared to roots. In addition, overexpression of GsCYP82C4 improved alkaline stress tolerance in Arabidopsis via increased root lengths and fresh biomass and strengthened the antioxidant defense system via a reduction in superoxide radicals in transgenic lines compared to wild type (WT) and atcyp82c4 mutants. Further, the expression levels of stress-related marker genes were up-regulated in GsCYP82C4 OX lines under alkali stress. The functional analysis of GsCYP82C4 overexpression in soybean displayed better hairy root growth, increased fresh weight, higher antioxidant enzyme activities and reduced lipid peroxidation rates in OX lines compared to the soybean WT (K599) line. In total, our study displayed positive roles of GsCYP82C4 overexpression in both Arabidopsis and Glycine max to alleviate alkaline stress via altering expression abundance of stress responsive genes, stronger roots, higher antioxidant enzyme activities as well as reduced rates of lipid peroxidation and superoxide radicals.

Variability in Striga Resistance among a Collection of Diverse Rice Cultivars

Striga constitutes a major limitation to cereal crop production, and identifying cultivars that avoid or reduce the germination of the parasites’ seeds is crucial. This study evaluated a diverse collection of 31 rice cultivars for Striga resistance and the role of cytochrome P450 genes in resistance or susceptibility. The phenotype of the resistant was characterized by the ability of the variety to support no or few emerging Striga. The presence or absence of the cytochrome P450 gene was determined by Multiplex PCR analysis. Upon examination, it became clear that five cultivars showed good resistance to Striga, while twenty exhibited intermediate resistance and six were very susceptible. In contrast, the resistant genotypes had few or no emerged Striga. Striga emerged early and rapidly in susceptible genotypes, supporting a higher number of emerged and attached Striga and Striga dry weight per plant. Multiplexed PCR analysis showed that 87.1% of the cultivars possessed the 93-11/Bala alleles, and 12.9% had the Nipponbare/Azucena alleles for strigolactone biosynthesis. Evaluating the variability of the 3 000 rice genomic data in these genes revealed similar results. The outcome of this research identified genotypes that are resistant, tolerant, and susceptible. This finding may be useful in breeding program for Striga resistance. The next steps for this research could involve testing the resistant genotypes in the field or using them as a starting point for a genetic experiment.

Bimodal distribution of azole susceptibility in Sporothrix brasiliensis isolates in Brazil.

Sporothrix brasiliensis is an emerging zoonotic fungal pathogen that can be difficult to treat. Antifungal susceptibility testing was performed on the mold phase of a convenience sample of 61 Sporothrix spp. isolates from human and cat sporotrichosis cases in Brazil using the Clinical and Laboratory Standards Institute standard M38. A bimodal distribution of azole susceptibility was observed with 50% (28/56) of S. brasiliensis isolates showing elevated itraconazole minimum inhibitory concentrations ≥16 µg/mL. Phylogenetic analysis found the in vitro resistant isolates were not clonal and were distributed across three different S. brasiliensis clades. Single nucleotide polymorphism (SNP) analysis was performed to identify potential mechanisms of in vitro resistance. Two of the 28 resistant isolates (MIC ≥16 mg/L) had a polymorphism in the cytochrome P450 gene, cyp51, corresponding to the well-known G448S substitution inducing azole resistance in Aspergillus fumigatus. SNPs corresponding to other known mechanisms of azole resistance were not identified in the remaining 26 in vitro resistant isolates.

Transcriptomic Insights and Cytochrome P450 Gene Analysis in Kadsura coccinea for Lignan Biosynthesis.

Kadsura coccinea is a medicinal plant from the Schisandraceae family that is native to China and has great pharmacological potential due to its lignans. However, there are significant knowledge gaps regarding the genetic and molecular mechanisms of lignans. We used transcriptome sequencing technology to analyze root, stem, and leaf samples, focusing on the identification and phylogenetic analysis of Cytochrome P450 (CYP) genes. High-quality data containing 158,385 transcripts and 68,978 unigenes were obtained. In addition, 36,293 unigenes in at least one database, and 23,335 across five databases (Nr, KEGG, KOG, TrEMBL, and SwissProt) were successfully annotated. The KEGG pathway classification and annotation of these unigenes identified 10,825 categorized into major metabolic pathways, notably phenylpropanoid biosynthesis, which is essential for lignan synthesis. A key focus was the identification and phylogenetic analysis of 233 Cytochrome P450 (CYP) genes, revealing their distribution across 38 families in eight clans, with roots showing specific CYP gene expression patterns indicative of their role in lignan biosynthesis. Sequence alignment identified 22 homologous single genes of these CYPs, with 6 homologous genes of CYP719As and 1 of CYP81Qs highly expressed in roots. Our study significantly advances the understanding of the biosynthesis of dibenzocyclooctadiene lignans, offering valuable insights for future pharmacological research and development.

Genome-Wide Exploration of Long Non-Coding RNAs of Helicoverpa armigera in Response to Pyrethroid Insecticide Resistance.

Genome-wide long non-coding RNAs (lncRNAs) in low, moderate, and high pyrethroid insecticide-resistant and -susceptible strains of Helicoverpa armigera were identified in this study. Using 45 illumina-based RNA-sequencing datasets, 8394 lncRNAs were identified. In addition, a sublethal dose of deltamethrin was administered to a Korean-resistant strain (Kor-T). The average length of lncRNAs was approximately 531 bp, and the expression ratio of lncRNAs was 28% of the total RNA. The identified lncRNAs were divided into six categories-intronic, intergenic, sense, antisense, cis-RNA, and trans-RNA-based on their location and mechanism of action. Intergenic and intronic lncRNA transcripts were the most abundant (38% and 33%, respectively). Further, 828 detoxification-related lncRNAs were selected using the Gene Ontology analysis. The cytochrome P450-related lncRNA expression levels were significantly higher in susceptible strains than in resistant strains. In contrast, cuticle protein-related lncRNA expression levels were significantly higher in all resistant strains than in susceptible strains. Our findings suggest that certain lncRNAs contribute to the downregulation of insecticide resistance-related P450 genes in susceptible strains, whereas other lncRNAs may be involved in the overexpression of cuticle protein genes, potentially affecting the pyrethroid resistance mechanism.

Discovery of P450-Modified Sesquiterpenoids Levinoids A-D through Global Genome Mining.

Cytochrome P450-modified bacterial terpenoids remain in a vast chemical space to be explored. In the present study, we conducted global genome mining of 223,829 bacterial genomes and identified 2892 bacterial terpenoid biosynthetic gene clusters (BGCs) with cytochrome P450 genes. Among these, we selected 562 with multiple P450 enzymes, which were further clustered as 355 gene cluster families by sequence similarity analysis. We then chose lev, a BGC from Streptomyces levis MCCC1A01616, for heterologous expression and discovered four new α-amorphene-type sesquiterpenoids, levinoids A-D (1-4). The structures and absolute configurations of these four new compounds were determined by employing extensive NMR analysis, NMR chemical shift calculations with DP4+, and ECD calculations. Furthermore, levinoid C (3) exhibited a moderate level of neuroprotective activity (EC50 = 21 μM) in the glutamate-induced excitotoxicity cell model. Our findings highlight the untapped chemical diversity of P450-modified bacterial terpenoids, opening new avenues for further exploration and discovery.

Biomarker selection depends on gene function and organ: the case of the cytochrome P450 family genes in freshwater fish exposed to chronic pollution.

Pollution and its effects have been of major concern in recent decades. Many strategies and markers have been developed to assess their effects on biota. Cytochrome P450 (CYP) genes have received significant attention in this context because of their relationship with detoxification and activation of exogenous compounds. While their expression has been identified as a pollution exposure biomarker, in most cases, it has been tested only after acute exposures and for CYP genes associated with exogenous compounds. To elucidate CYP gene expression patterns under chronic pollution exposure, we have used the silverside Basilichthys microlepidotus as a model, which inhabits the Maipo River Basin, a freshwater system with different pollution levels. We performed next-generation RNA sequencing of liver and gill tissues from polluted and non-polluted populations. We found most CYP genes were not dysregulated by pollution, and the seven genes that were present and differentially expressed in liver and gill were mainly downregulated. Three CYP genes associated with exogenous compounds showed differential expression in the gill, while four CYP genes associated with endogenous compounds showed differential expression in the liver. The findings presented here highlight the importance of CYP genes, his family, tissues and his interaction in the context of pollution biomarkers use.

Grape seed extract prevents chlorpyrifos-induced toxicity in rat liver through the modulation of phase I detoxification pathway.

Chlorpyrifos (CPF) poisoning is a public health problem for which there is not currently any effective prophylaxis. In this study, we investigated the protective effect of grape seed extract (GSE) against CPF-induced hepatotoxicity. Rats were daily treated either with CPF (2mg/kg) or CPF and GSE (20mg/kg) for 1week, sacrificed, and their livers dissected for biochemical, molecular, and histopathological analyses. CPF generated liver dysfunction by altering carbohydrate, lipid, amino acid, ammonia and urea metabolism, and provoked mitochondrial impairment through disturbing tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OXPHOS), and mitochondrial viability. CPF also induced cholinergic excitotoxicity along with oxidative stress and histopathological alterations. Interestingly, treatment with GSE prevented all the detrimental effects of CPF through the regulation of cytochrome P450 (CYP450) gene expression. Molecular docking analysis indicated that GSE-containing polyphenols acted as epigenetic modulators through inhibiting DNA (cytosine-5)-methyltransferase 1 (DNMT1), thus favoring the CYP2C6 detoxification pathway. Thereby, GSE might be a promising strategy in the protection of the liver against CPF toxicity.