Expression Of Resistance Genes Research Articles

Circular RNA ath-circ032768, a competing endogenous RNA, response the drought stress by targeting miR472-RPS5 module.

CircRNAs (circular RNAs) reduce the abundance of miRNAs through ceRNA (competing endogenous RNA), to regulate many physiological processes and stress responses in plants. However, the role of circRNA in drought stress is poorly understood. Through ring identification and sequencing verification of ath-circ032768, bioinformatics analysis predicted the interaction of ath-circ032768-miR472-RPS5, and further obtained transgenic plants overexpressing ath-circ032768 and silencing STTM-miR472. The change in drought stress was analysed using biochemical and molecular biological methods. Sequencing and biological analysis confirmed that ath-circ032768, miR472 and RPS5 were responsive to drought stress, and changes in gene expression were consistent with the prediction of ceRNA. The silencing vectors ath-circ032768 and STTM-miR472 were constructed using molecular biology techniques, and stable transgenic plants with drought tolerance obtained. Further physiological and biochemical studies showed that ath-circ032768 could bind to miR472, and that miR472 could bind to the RPS5 gene, resulting in decreased expression of RPS5. Hence, ath-circ032768 can competitively inhibit degradation of RPS5 by miR472 through ceRNA. This process is accompanied by increased expression of DREB2A, RD29A and RD29B genes. Through the ath-circ032768-miR472-RPS5 pathway, the RPS5 stress resistance protein interacts with DREB2A protein to enhance expression of downstream drought resistance genes, RD29A and RD29B, and participate in the regulation mechanism of plant drought resistance, thereby improving drought tolerance of plants.

ABC transporter inhibition by beauvericin partially overcomes drug resistance in Leishmania tropica.

Leishmaniasis is a neglected tropical disease infecting the world's poorest populations. Miltefosine (ML) remains the primary oral drug against the cutaneous form of leishmaniasis. The ATP-binding cassette (ABC) transporters are key players in the xenobiotic efflux, and their inhibition could enhance the therapeutic index. In this study, the ability of beauvericin (BEA) to overcome ABC transporter-mediated resistance of Leishmania tropica to ML was assessed. In addition, the transcription profile of genes involved in resistance acquisition to ML was inspected. Finally, we explored the efflux mechanism of the drug and inhibitor. The efficacy of ML against all developmental stages of L. tropica in the presence or absence of BEA was evaluated using an absolute quantification assay. The expression of resistance genes was evaluated, comparing susceptible and resistant strains. Finally, the mechanisms governing the interaction between the ABC transporter and its ligands were elucidated using molecular docking and dynamic simulation. Relative quantification showed that the expression of the ABCG sub-family is mostly modulated by ML. In this study, we used BEA to impede resistance of Leishmania tropica. The IC50 values, following BEA treatment, were significantly reduced from 30.83, 48.17, and 16.83 µM using ML to 8.14, 11.1, and 7.18 µM when using a combinatorial treatment (ML + BEA) against promastigotes, axenic amastigotes, and intracellular amastigotes, respectively. We also demonstrated a favorable BEA-binding enthalpy to L. tropica ABC transporter compared to ML. Our study revealed that BEA partially reverses the resistance development of L. tropica to ML by blocking the alternate ATP hydrolysis cycle.

Dynamical model of antibiotic responses linking expression of resistance genes to metabolism explains emergence of heterogeneity during drug exposures

Antibiotic responses in bacteria are highly dynamic and heterogeneous, with sudden exposure of bacterial colonies to high drug doses resulting in the coexistence of recovered and arrested cells. The dynamics of the response is determined by regulatory circuits controlling the expression of resistance genes, which are in turn modulated by the drug’s action on cell growth and metabolism. Despite advances in understanding gene regulation at the molecular level, we still lack a framework to describe how feedback mechanisms resulting from the interdependence between expression of resistance and cell metabolism can amplify naturally occurring noise and create heterogeneity at the population level. To understand how this interplay affects cell survival upon exposure, we constructed a mathematical model of the dynamics of antibiotic responses that links metabolism and regulation of gene expression, based on the tetracycline resistance tet operon in E. coli. We use this model to interpret measurements of growth and expression of resistance in microfluidic experiments, both in single cells and in biofilms. We also implemented a stochastic model of the drug response, to show that exposure to high drug levels results in large variations of recovery times and heterogeneity at the population level. We show that stochasticity is important to determine how nutrient quality affects cell survival during exposure to high drug concentrations. A quantitative description of how microbes respond to antibiotics in dynamical environments is crucial to understand population-level behaviors such as biofilms and pathogenesis.

Effect of High-Intensity Interval Training on TCF7L2 Gene Expression in Hepatocytes of Obese Rats


 
 
 Objective: Hepatic glucose release is greatly increased in the presence of obesity and related diseases. The research objective was to explore the impact of high intensity interval training (HIIT) on TCF7L2 gene expression in hepatocytes of obese rats.
 Materials and Methods: Out of 21 male Wistar rats aged 10 weeks years (220±10 g), obesity was induced in 14 rats by 8-week high-fat diet. The rats were then divided into normal (n=7), obese control (n=7), and HIIT obese (n=7) groups. Rats in the HIIT group completed 8 weeks of HIIT/5 days weekly, whereas the other groups were inactive. After intervention, TCF7L2 gene expression in hepatocytes, insulin resistance and glucose compared using ANOVA /Tukey’s post hoc test between groups by SPSS-22.
 Results: Obesity induction led to a significant decrease in TCF7L2 gene expression (P: 0.011) and an increase in blood glucose (P: 0.009) and insulin resistance (P: 0.019) compared with the normal group (P< 0.001). On the other hand, interval training led to a significant increase in TCF7L2 gene expression (P: 0.029) and a decrease in blood glucose (P< 0.001) and insulin resistance (P< 0.001) in the obese group compared with the control group.
 Conclusion: The observed enhancement in fasting blood glucose levels among obese rats could be linked to increased TCF7L2 gene expression in liver cells, which appears to be a response to interval training intervention. Nevertheless, understanding the main mechanisms responsible for observed changes requires further studies in this field.
 
 

Abstract 4557: Overexpressed CPAP promotes cancer stemness and enhances chemo-resistance in HCC

Abstract Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is highly resistant to chemotherapy and targeted therapy. It was reported that HCC cancer stem cells (CSCs) are involved in chemo-drug resistance by regulating multidrug resistance (MDR) gene expression, such as ABC transporters. Our previous reports indicated that CPAP, a centrosomal protein, can promote HCC progression by up-regulating NF-κB and STAT3 transcriptional activities. Here, we demonstrated that overexpressed CPAP can increase cancer stemness features and CSCs-derived sorafenib resistance in HCC by up-regulating the transcriptional activities of NF-κB and β-catenin. Importantly, CPAP stably expressed HCC spheroids are significantly resistance to sorafenib in vitro and in vivo. Our results suggested that CD24 and ABCG2 are two potential downstream effectors in CPAP overexpressed HCC. CPAP can transcriptionally up-regulate CD24 and ABCG2 expression via Wnt/β-catenin and NF-κB signaling pathways, respectively; high CPAP/ABCG2/CD24 expression levels are negatively correlated with disease-specific survival rates in HCC patients. Combined treatment with sorafenib and Wnt/β-catenin pathway inhibitor PRI-724 significantly inhibited CPAP-overexpressing Hep3B spheroids-derived tumor growth in a xenograft mouse model. Our study highlights the oncogenic role of CPAP in promoting CSCs-induced sorafenib resistance in HCC and provides insights into potential therapeutic strategies. Citation Format: Liang-Yi Hung. Overexpressed CPAP promotes cancer stemness and enhances chemo-resistance in HCC [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 4557.

MYB alternative promoter activity is increased in adenoid cystic carcinoma metastases and is associated with a specific gene expression signature

ObjectiveAdenoid cystic carcinoma (ACC) is a head and neck cancer with a poor long-term prognosis that shows frequent local recurrences and distant metastases. The tumors are characterized by MYB oncogene activation and are notoriously unresponsive to systemic therapies. The biological underpinnings behind therapy resistance of disseminated ACC are largely unknown. Here, we have studied the molecular and clinical significance of MYB alternative promoter (TSS2) usage in ACC metastases. Materials and methodsMYB TSS2 activity was investigated in primary tumors and metastases from 26 ACC patients using RNA-sequencing and quantitative real-time PCR analysis. Differences in global gene expression between MYB TSS2 high and low cases were studied, and pathway analyses were performed. ResultsMYB TSS2 activity was significantly higher in ACC metastases than in primary tumors (median activity 15.1 vs 3.0, P = 0.0003). MYB TSS2 high ACC metastases showed a specific gene expression signature, including increased expression of multi-drug resistance genes and canonical MYB target genes, and suppression of the p53 and NOTCH pathways. ConclusionsCollectively, our findings indicate that elevated MYB TSS2 activity is associated with metastases, potential drug resistance, and augmented MYB-driven gene expression in ACC. Our study advocates the need for new therapies that specifically target MYB and drug resistance mechanisms in disseminated ACC.

Acquired resistance or tolerance? – in search of mechanisms underlying changes in the resistance profile of Candida albicans and Candida parapsilosis as a result of exposure to methotrexate

The increasing prevalence of fungal strains showing acquired resistance and multidrug resistance is an increasing therapeutic problem, especially in patients with a severely weakened immune system and undergoing chemotherapy. What is also extremely disturbing is the similarity of the resistance mechanisms of fungal cells and other eukaryotic cells, including human cells, which may contribute to the development of cross-resistance in fungi in response to substances used in e.g. anticancer treatment. An example of such a drug is methotrexate, which is pumped out of eukaryotic cells by ABC transmembrane transporters - in fungi, used to remove azoles from fungal cells.For this reason, the aim of the study was to analyze the expression levels of genes: ERG11, MDR1 and CDR1, potentially responsible for the occurrence of cross-resistance in Candida albicans and Candida parapsilosis as a result of fungal exposure to methotrexate (MTX).In vitro exposure of C. albicans and C. parapsilosis strains to methotrexate showed a high increase in resistance to fluconazole and a partial increase in resistance to voriconazole. Analysis of the expression of resistance genes showed varied responses of the tested strains depending on the species. In the case of C. albicans, an increase in the expression of the MDR1 gene was observed, and a decrease in ERG11 and CDR1. However, for C. parapsilosis there was an increase in the expression of the CDR1 gene and a decrease in ERG11 and MDR1.We noted the relationship between the level of resistance to voriconazole and the level of ERG11 gene expression in C. albicans. This indicates that this type of relationship is different for each species. Our research confirms that the mechanisms by which fungi acquire resistance and develop cross-resistance are highly complex and most likely involve several pathways simultaneously. The emergence of multidrug resistance may be related to the possibility of developing tolerance to antimycotics by fungi.

Deep model predictive control of gene expression in thousands of single cells

Gene expression is inherently dynamic, due to complex regulation and stochastic biochemical events. However, the effects of these dynamics on cell phenotypes can be difficult to determine. Researchers have historically been limited to passive observations of natural dynamics, which can preclude studies of elusive and noisy cellular events where large amounts of data are required to reveal statistically significant effects. Here, using recent advances in the fields of machine learning and control theory, we train a deep neural network to accurately predict the response of an optogenetic system in Escherichia coli cells. We then use the network in a deep model predictive control framework to impose arbitrary and cell-specific gene expression dynamics on thousands of single cells in real time, applying the framework to generate complex time-varying patterns. We also showcase the framework’s ability to link expression patterns to dynamic functional outcomes by controlling expression of the tetA antibiotic resistance gene. This study highlights how deep learning-enabled feedback control can be used to tailor distributions of gene expression dynamics with high accuracy and throughput without expert knowledge of the biological system.

From "resistance genes expression" to "horizontal migration" as well as over secretion of Extracellular Polymeric Substances: Sludge microorganism’s response to the increasing of long-term disinfectant stress

Glutaraldehyde-Didecyldimethylammonium bromides (GDs) has been frequently and widely employed in livestock and poultry breeding farms to avoid epidemics such as African swine fever, but its long-term effect on the active sludge microorganisms of the receiving wastewater treatment plant was keep unclear. Four simulation systems were built here to explore the performance of aerobic activated sludge with the long-term exposure of GDs and its mechanism by analyzing water qualities, resistance genes, extracellular polymeric substances and microbial community structure. The results showed that the removal rates of CODCr and ammonia nitrogen decreased with the exposure concentration of GDs increasing. It is worth noting that long-term exposure to GDs can induce the horizontal transfer and coordinated expression of a large number of resistance genes, such as qacE, sul1, tetx, and int1, in drug-resistant microorganisms. Additionally, it promotes the secretion of more extracellular proteins, including arginine, forming a "barrier-like" protection. Therefore, long-term exposure to disinfectants can alter the treatment capacity of activated sludge receiving systems, and the abundance of resistance genes generated through horizontal transfer and coordinated expression by drug-resistant microorganisms does pose a significant threat to ecosystems and health. It is recommended to develop effective pretreatment methods to eliminate disinfectants.

Abstract A028: Investigating the role of SOX2 in promoting anchorage-independent survival of ovarian cancer cells

Abstract Ovarian cancer (OVCA) is the most lethal gynecologic malignancy, often detected at an advanced stage. OVCA progression involves transcoelomic metastasis, where tumor cells disseminate into the peritoneal ascites. Malignant cells in the ascites adapt to survive under Anchorage-Independent (A-I) conditions by altering the expression of genes escalating anoikis (A-I cell death) resistance and metastasis. Our lab has shown that OVCA cells manipulate their transcriptomic profile to promote the expression of anoikis resistance genes in A-I. Expression profiling of genes upregulated in A-I revealed the transcription factor SRY-Box Transcription Factor 2 (SOX2) to be highly upregulated in response to OVCA cell detachment. While we have previously demonstrated that SOX2 is necessary for the A-I survival of OVCA cells, the specific mechanism underlying SOX2-dependent A-I survival remains unknown. RNA-sequencing studies performed in the high-grade serous ovarian cancer cell line, OVCAR3, revealed that the Leucine-rich repeat-containing G-protein coupled receptor 5, LGR5, is the most significantly upregulated gene in A-I compared to attached conditions. Importantly, amongst those genes that are upregulated in A-I, LGR5 is significantly downregulated following SOX2 knockdown in A-I. LGR5 is an ‘orphan’ G-protein coupled receptor known to modulate canonical Wnt signaling upon interacting with its ligand R-spondin1 (RSPO1). Time-course experiments in OVCAR3 cells revealed a striking increase in LGR5 expression that peaked after 24 hours in A-I. Furthermore, siRNA mediated knockdown of SOX2 downregulated LGR5 expression only in A-I, suggesting that LGR5 is a potential SOX2 target under A-I conditions. Interestingly, bioinformatics analysis of the existing OVCA datasets from the Cancer Genome Atlas showed increased expression of RSPO1, which correlated with a significant decrease in the overall survival of OVCA patients. Interaction of LGR5 with its ligand RSPO1 is crucial for the receptor to signal through the Wnt pathway to promote cell survival and cancer stemness. Although SOX2 and LGR5 are established markers of cancer stemness in various tumor types, their direct relationship in promoting tumor progression and regulation of OVCA A-I cell survival remains unknown. Our data suggests that increased SOX2 and LGR5 expression could drive OVCA cell survival under A-I conditions. Our current studies focus on understanding the molecular mechanisms behind SOX2-driven regulation of LGR5 and the role of LGR5 in driving OVCA A-I cell survival. Citation Format: Shriya Kamlapurkar, Coryn Stump, Mythreye Karthikeyan, Nadine Hempel. Investigating the role of SOX2 in promoting anchorage-independent survival of ovarian cancer cells [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A028.

IS26 and the IS26 family: versatile resistance gene movers and genome reorganizers.

SUMMARYIn Gram-negative bacteria, the insertion sequence IS26 is highly active in disseminating antibiotic resistance genes. IS26 can recruit a gene or group of genes into the mobile gene pool and support their continued dissemination to new locations by creating pseudo-compound transposons (PCTs) that can be further mobilized by the insertion sequence (IS). IS26 can also enhance expression of adjacent potential resistance genes. IS26 encodes a DDE transposase but has unique properties. It forms cointegrates between two separate DNA molecules using two mechanisms. The well-known copy-in (replicative) route generates an additional IS copy and duplicates the target site. The recently discovered and more efficient and targeted conservative mechanism requires an IS in both participating molecules and does not generate any new sequence. The unit of movement for PCTs, known as a translocatable unit or TU, includes only one IS26. TU formed by homologous recombination between the bounding IS26s can be reincorporated via either cointegration route. However, the targeted conservative reaction is key to generation of arrays of overlapping PCTs seen in resistant pathogens. Using the copy-in route, IS26 can also act on a site in the same DNA molecule, either inverting adjacent DNA or generating an adjacent deletion plus a circular molecule carrying the DNA segment lost and an IS copy. If reincorporated, these circular molecules create a new PCT. IS26 is the best characterized IS in the IS26 family, which includes IS257/IS431, ISSau10, IS1216, IS1006, and IS1008 that are also implicated in spreading resistance genes in Gram-positive and Gram-negative pathogens.

Establishment of an efficient genetic transformation system for Tanacetum cinerariifolium

The Dalmatian Daisy Tanacetum cinerariifolium is an Asteraceae plant species that produces the natural insecticide “pyrethrum”, which is effective against mosquito disease vectors and household pests. To enhance the content of pyrethrum in flowers, a more detailed understanding of the mechanisms underlying pyrethrum biosynthesis is needed. Even though gene transformation and genome editing techniques are vital for investigating pyrethrin biosynthesis, limited information is available on the transformation of T. cinerariifolium. Furthermore, each seedling possesses a distinct genotype with large variations by self-incompatibility. We herein employed T. cinerariifolium line #14 with weak self-incompatibility to establish a protocol of efficient regeneration from leaf segments and transformation. Leaf segments formed calli on 1/2 Murashige and Skoog’s basal medium (MS) with naphthalene acetic acid 1 mg L−1 and 6-benzylaminopurine (BAP) 2 mg L−1, regenerated shoots from calli on 1/2 MS with BAP 0.5 mg L−1 and GA3 0.2 mg L−1, and elongated shoot stems on 1/2 MS with indole-3-butyric acid 0.5 mg L−1 and BAP 0.5 mg L−1. To establish genetic transformation, Rhizobium radiobacter strain EHA105 with the highest infectivity and the mas1'-2' bidirectional promoter with the highest expression of the nptII resistance gene were used, and the antibiotic G418 was added to medium at a concentration of 10 to 20 mg L−1 to select transformed cells. Using established regeneration techniques, we successfully obtained transformants that highly expressed the transgene gusA. This technique will be useful for creating genetically modified T. cinerariifolium, particularly for elucidating the mechanism of pyrethrin biosynthesis toward the creation of pyrethrin-rich traits.

Vitis vinifera L. seed standardized extract; a promising therapeutic against metabolic syndrome induced by high-fat/high-carbohydrate diet and streptozotocin in rats

Metabolic syndrome (MetS) is a group of abnormal disorders; hypertension, glucose intolerance, dyslipidemia, proinflammatory, and prothrombotic states, affecting approximately 14 % of the world's population. The potential of grape seeds extract (GSE) supplementation to improve the metabolic disturbances and their related conditions like obesity, type 2 diabetes, and nonalcoholic fatty liver disease was investigated in this study. In-vitro metabolic syndrome assays were investigated through α-amylase, α-glucosidase, lipase, lipoxygenase (LOX), cyclooxygenases (COX-1 and COX-2), renin and angiotensin converting enzyme (ACE) inhibition assays. Additionally, in-vivo rat model of high-fat-high-carbohydrate diet (HFD)-induced MetS was established, where metformin (MT) (200 mg/kg) was used as a reference drug and GSE was given at 100 and 200 mg/kg by oral gavage. GSE was standardized using HPLC analysis for the major reported compound; catechin which should be ≥ 160.76 ± 5.52 μg/mL. Total phenolic content of GSE was 21.12±0.61 µg gallic acid equivalent/1 mg extract and total flavonoid content was 23.81±0.64 µg rutin equivalent/1 mg extract. In-vitro assays revealed the potential of GSE to manage the metabolic syndrome, besides its strong antioxidant capacity. Treatment with GSE (100 mg/kg and 200 mg/kg) markedly (P < 0.05) controlled the weight gain, improved the metabolic pathways (total glucose, cholesterol, triglycerides, AST, and ALT), oxidative stress parameters (MDA, GSH, and catalase) and inflammatory biomarkers in HFD fed rats. GSE downregulated the expression of insulin resistance gene (IR) and some inflammatory related genes (TNF-α and NF-κB), additionally it improved the pathological features of metabolic conditions and upgraded the expression of Nrf2 compared to HFD group. The superior effects were owned to the high dose of GSE, 200 mg/kg b.wt. (P < 0.05, P < 0.001). All results sustenance the beneficial effects of the standardized GSE in the management of metabolic syndrome.

Brain-Decellularized ECM-Based 3D Myeloid Sarcoma Platform: Mimicking Adaptive Phenotypic Alterations in the Brain.

Leukemia circulates in the bloodstream and induces various symptoms and complications. Occasionally, these cells accumulate in non-marrow tissues, forming a tumor-like myeloid sarcoma (MS). When the blast-stage leukemia cells invade the brain parenchyma, intracranial MS occurs, leading to a challenging prognosis owing to the limited penetration of cytostatic drugs into the brain and the development of drug resistance. The scarcity of tissue samples from MS makes understanding the phenotypic changes occurring in leukemia cells within the brain environment challenging, thereby hindering development of effective treatment strategies for intracranial MS. This study presents a novel 3D in vitro model mimicking intracranial MS, employing a hydrogel scaffold derived from the brain-decellularized extracellular matrix in which suspended leukemia cells are embedded, simulating the formation of tumor masses in the brain parenchyma. This model reveals marked phenotypic changes in leukemia cells, including altered survival, proliferation, differentiation, and cell cycle regulation. Notably, proportion of dormant leukemia stem cells increases and expression of multidrug resistance genes is upregulated, leading to imatinib resistance, mirroring the pathological features of in vivo MS tissue. Furthermore, suppression of ferroptosis is identified as an important characteristic of intracranial MS, providing valuable insights for the development of targeted therapeutic strategies.

Genome-Wide Analysis of Pentatricopeptide Repeat Gene Family in Peanut and Identification of AhPPR598 Resistance to Ralstonia solanacearum

Pentatricopeptide repeat (PPR) proteins, with tandem 30–40 amino acids, were characterized as one kind of nucleus coding protein. They have been demonstrated to play important roles in RNA editing, plant growth and development, and plant immunity. Although the PPR gene family has been characterized in some plant species, less is known about this family in peanut, especially their functions in response to Ralstonia solanacearum. In this study, we performed a genome-wide analysis to identify PPR genes and their functions in resistance to R. solanacearum. Here, 389, 481, and 1079 PPR genes were identified from Arachis duranensis, Arachis ipaensis, and Arachis hypogaea, respectively. Allopolyploidization was the main reason for the increased number of the AhPPR members. Gene duplication brought about 367 pairs of homologous genes of PPRs in A. hypogaea. Whole-genome replication, tandem repeats, scattered repeats, and unconnected repeats constituted the replication types. The substitution rates of nonsynonymous (Ka) versus synonymous (Ks) of all homologous pairs were less than 1.0, suggesting that the homologous AhPPRs underwent intense purifying selection pressure and remained conserved in both structure and function. RNA-seq and RT-qPCR analyses showed that AhPPR598 gene was highly expressed in the aerial part of peanut and involved in response to R. solanacearum. The transient expression of AhPPR598 in Nicotiana benthamiana induced the HR-mediated cell death, up-regulated expression of resistant marker genes, and enhanced the resistance to R. solanacearum, suggesting AhPPR598 was a positive regulator of immunity by regulating the JA and SA pathways. These results provide a new understanding of the origin, distribution, and evolution of the AhPPR gene family and potential gene resources for peanut-resistant breeding.

Molybdenum inhibited the growth of Phytophthora nicotiana and improved the resistance of Nicotiana tabacum L. against tobacco black shank

Tobacco black shank (TBS) is a soil-borne fungal disease caused by Phytophthora nicotiana (P. nicotianae), significantly impeding the production of high-quality tobacco. Molybdenum (Mo), a crucial trace element for both plants and animals, plays a vital role in promoting plant growth, enhancing photosynthesis, bolstering antioxidant capacity, and maintaining ultrastructural integrity. However, the positive effect of Mo on plant biotic stress is little understood. This study delves into the inhibitory effects of Mo on P. nicotianae and seeks to unravel the underlying mechanisms. The results showed that 16.32 mg/L of Mo significantly inhibited mycelial growth, altered mycelial morphological structure, damaged mycelial cell membrane, and ultimately led to the leakage of cell inclusions. In addition, 0.6 mg/kg Mo applied in soil significantly reduced the severity of TBS. Mo increased photosynthetic parameters and photosynthetic pigment contents of tobacco leaves, upregulated expression of NtPAL and NtPPO resistance genes, as well as improved activities of SOD, POD, CAT, PPO, and PAL in tobacco plants. Furthermore, Mo could regulate nitrogen metabolism and amino acids metabolism to protect tobacco plants against P. nicotianae infection. These findings not only present an ecologically sound approach to control TBS but also contribute valuable insights to the broader exploration of the role of microelements in plant disease management.

Evaluation of screening methods for anthracnose fruit rot resistance in chilli (Capsicum spp.)

Anthracnose fruit rot caused by Colletotrichum spp. is a serious production constraint causing severe marketable yield loss in chilli. Field evaluation of chilli accessions for resistance to Colletotrichum spp. depends on various factors affecting disease expression such as edaphic conditions, temperature, rainfall, humidity and other variables that are difficult to control, therefore considered less accurate. Also, high chances of cross contamination with different Colletotrichum species leads to inconclusive assays for specific pathogen species and isolate. To identify a stable and reliable screening method, various chilli accessions were subjected to in vitro pin-prick and non-wounding spray methods using a specific pathogen isolates. When chilli accessions were screened against C. gloeosporioides isolate ‘IHRCg-1’, the in vitro pin- prick method showed positive correlation with the non- wounding spray method, except in the accession PBC80. The change in bioassay influenced the disease reaction pattern in the accession PBC 80, probably the pin pricks break the basal cuticle defense mechanism that was retained in spray inoculation method indicating varied resistance pattern. However, in the accession PBC 81 stable resistance pattern was observed against isolates of both species viz., C. truncatum ‘IIHR Ct-1’ and C. gloeosporioides ‘IIHR Cg-1’ and in the accession PBC 80 against C. truncatum ‘IIHR Ct-1’ in both the inoculation methods that depicted the expression of resistance genes during both methods of inoculation. Based on disease development pattern, the red ripe chilli expressed a variant reaction to infection by C. truncatum and C. gloeosporioides. The peak anthracnose infection at 10 DAI and 14 DAI is an accurate duration to record ‘IIHR Cg-1’ and ‘IIHR Ct-1’ infection, respectively on chilli ripe fruit for assaying the resistance.

Method for plasmid-based antibiotic-free fermentation

BackgroundAntibiotic-based plasmid selection and maintenance is a core tool in molecular biology; however, while convenient, this strategy has numerous drawbacks for biological manufacturing. Overuse of antibiotics and antibiotic resistance genes (ARG) contributes to the development of antimicrobial resistance, which is a growing threat to modern medicine. Antibiotics themselves are costly and therefore often omitted in fermentations, leading to plasmid loss and a corresponding loss in product yield. Furthermore, constitutive expression of a plasmid-encoded antibiotic resistance gene imposes a significant metabolic burden on the cells. For many fermentation products (e.g., in nutrition and medicine), the use of antibiotic resistance genes is subject to strict regulations and should be avoided. We present a method for plasmid selection and maintenance with stringent selection pressure that is independent of antibiotics and ARG. Furthermore, it can be used without any restrictions regarding culture medium and temperature.ResultsThe developed method involves modification of a bacterial strain such that an essential gene is expressed genomically under the control of an inducible promoter. A copy of the same essential gene with the endogenous promoter is supplied on a plasmid for selection. In the absence of the inducer for the genomic copy of the essential gene, cells rely on expression of the plasmid-encoded gene copy, leading to tight selection for plasmid maintenance. Induction of the genomic copy of the essential gene enables the engineered strain to be propagated in the absence of a plasmid. Here, we describe the genetic setup and demonstrate long-term, tight selection for plasmid maintenance with a variety of different plasmids and E. coli strains.ConclusionsThis method facilitates plasmid-based fermentations by eliminating the need for antibiotic selection and improving plasmid maintenance.

Response of Rice Somatic Embryogenesis to Exogenous Melatonin About Its Role in Scavenging Reactive Oxygen Species

&lt;p&gt;The success rate of explant morphogenesis in plant breeding using tissue culture techniques is frequently plagued by browning due to the oxidation of phenolic compounds. The cumulated amount of reactive oxygen species (ROS) drives the oxidation of phenolic compounds. Melatonin is reported to take a part in modulating the regulation of antioxidant gene expression, reducing the accumulation of reactive oxygen species, and enhancing the efficacy of tissue culture. This study aims to determine the optimal melatonin concentration on the efficiency of plantlet regeneration and expression of the antioxidant resistance gene in rice callus. This study utilizes rice TN1, Gogo Niti II, Ketan Hitam, and Cigeulis cultivars. Melatonin at 0, 10, and 15 µM concentrations is supplemented in plantlet regeneration media. Rice antioxidant-related genes, Mn-SOD, Cu/ZnSOD, Cytosolic APX, CAT, GPOD, OsAPX, and OsCATA, expressed after melatonin supplementation. Melatonin concentration at 10 µM generates the highest expression of all tested genes in TN1 compared to other varieties. The cumulated amount of hydrogen peroxide (H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;) shows that Melatonin has the potential to increase the proportion of plant regeneration in Cigeulis (90.48%) and Ketan Hitam (91.67%) varieties with a concentration of 10 µM and in TN1 (94.44%) and Gogo Niti II (80%) at a concentration of 15 µM.&lt;/p&gt;

The role of basic leucine zipper transcription factor E4BP4 in cancer: a review and update.

Mutations in the genes of tumor cells and the disorder of immune microenvironment are the main factors of tumor development. The sensitivity of tumor cells to chemotherapy drugs affect the treatment of tumor. Nuclear transcription factor E4BP4 is dysregulated in a variety of malignant tumors. It can suppress the transcription of NFKBIA, RASSF8, SOSTDC1, FOXO-induced genes (TRAIL, FAS, GADD45a and GADD45b) and Hepcidin, up-regulate RCAN1-1 and PRNP, activate mTOR and p38 in cancer cells. Also, E4BP4 can regulate tumor immune microenvironment. TGFb1/Smad3/E4BP4/ IFNγ axis in NK cells plays an important role in antitumor immunotherapy. Over expression of E4BP4 inhibited the development of Th17 cells by directly binding to the RORγt promoter. Moreover, recent studies have shown that E4BP4 inhibited the expression of multidrug resistance genes. In this review, we summarize the molecular mechanism of E4BP4 in cancer cellular process, the effects of E4BP4 in cancer immunotherapy and antitumor drug resistance, to provide theoretical basis for tumor treatment strategies targeting E4BP4.