Molecular Mechanisms Of Resistance Research Articles

Molecular epidemiology of Acinetobacter baumannii during COVID-19 at a hospital in northern China

BackgroundThe wide spread of carbapenem-resistance clones of Acinetobacter baumannii has made it a global public problem. Some studies have shown that the prevalence of Acinetobacter baumannii clones can change over time. However, few studies with respect to the change of epidemiological clones in Acinetobacter baumannii during Corona Virus Disease 2019 (COVID-19) were reported. This study aims to investigate the molecular epidemiology and resistance mechanisms of Acinetobacter baumannii during COVID-19.ResultsA total of 95 non-replicated Acinetobacter baumannii isolates were enrolled in this study, of which 60.0% (n = 57) were identified as carbapenem-resistant Acinetobacter baumannii (CRAB). The positive rate of the blaOXA−23 gene in CRAB isolates was 100%. A total of 28 Oxford sequence types (STs) were identified, of which the most prevalent STs were ST540 (n = 13, 13.7%), ST469 (n = 13, 13.7%), ST373 (n = 8, 8.4%), ST938 (n = 7, 7.4%) and ST208 (n = 6, 6.3%). Differently, the most widespread clone of Acinetobacter baumannii in China during COVID-19 was ST208 (22.1%). Further study of multidrug-resistant ST540 showed that all of them were carrying blaOXA−23, blaOXA−66, blaADC−25 and blaTEM−1D, simultaneously, and first detected Tn2009 in ST540. The blaOXA−23 gene was located on transposons Tn2006 or Tn2009. In addition, the ST540 strain also contains a drug-resistant plasmid with msr(E), armA, sul1 and mph(E) genes.ConclusionThe prevalent clones of Acinetobacter baumannii in our organization have changed during COVID-19, which was different from that of China. ST540 strains which carried multiple drug-resistant mobile elements was spreading, indicating that it is essential to strengthen the molecular epidemiology of Acinetobacter baumannii.

Identification of cis-acting elements that regulate expression of the progesterone receptor gene PGR in the uterus.

The steroid hormone progesterone regulates a wide range of functions in the uterus, including menstruation, pregnancy establishment, pregnancy maintenance, and labor. The cellular effects of progesterone are mediated by the nuclear progesterone receptor (PGR). Progesterone resistance, a decreased cellular response to progesterone,is implicated in a wide range of pathologies including endometriosis, preterm birth, and endometrial cancer. Up to 10% of females within reproductive age are impacted by endometriosis, and no cure is available. This study hypothesizes that misregulation of PGR by upstream regulators is a potential cause of progesterone resistance. However, much remains unknown about the regulation of PGR expression, including the location of enhancers and the identity of transcriptional regulators that control PGR expression. In this study, candidate regulatory elements of PGR were identified by integrative analysis of genomic data, and their function was tested using the CRISPR activation system, with PGR mRNA levels as the readout. Using these methods, two PGR enhancers located at the PGR 3’ untranslated region and 200 kbs upstream of the PGR transcription start site were identified. These enhancers permitted the identification of candidate upstream regulators of PGR expression in the uterus, including GATA2, ARID1A, KLF9, and ESR1. Activation of ESR1 increased PGR mRNA levels in the presence of estradiol in cultured uterine cells. Through the discovery of PGR regulators, we can improve our understanding of molecular mechanisms of progesterone resistance. Ultimately, these regulators could be evaluated in cases of progesterone resistance and targeted in the development of therapies.

Molecular mechanism of TRIM32 in antiviral immunity in rainbow trout (Oncorhynchus mykiss)

TRIM family proteins are widely found in multicellular organisms and are involved in a wide range of life activities, and also act as crucial regulators in the antiviral natural immune response. This study aimed to reveal the molecular mechanism of rainbow trout TRIM protein in the anti-IHNV process. The results demonstrated that 99.1 % homology between the rainbow trout and the chinook salmon (Oncorhynchus tshawytscha) TRIM32. When rainbow trout were infected with IHNV, the TRIM32 was highly expressed in the gill, spleen, kidney and blood. Meanwhile, rainbow trout TRIM32 has E3 ubiquitin ligase activity and undergoes K29-linked polyubiquitination modifications dependent on the RING structural domain was determined by immunoprecipitation. TRIM32 could interact with the NV protein of IHNV and degrade NV protein through the ubiquitin-proteasome pathway, and was also able to activate NF-κB transcription, thereby inhibiting the replication of IHNV. Moreover, the results of the animal studies showed that the survival rate of rainbow trout overexpressing TRIM32 was 70.2 % which was significantly higher than that of the control group, and stimulating the body to produce high levels of IgM when the host was infected with the virus. In addition, TRIM32 can activate the NF-κB signalling pathway and participate in the antiviral natural immune response. The results of this study will help us to understand the molecular mechanism of TRIM protein resistance in rainbow trout, and provide new ideas for disease resistance breeding, vaccine development and immune formulation development in rainbow trout.

Molecular Mechanisms of Resistance against PSII-Inhibiting Herbicides in Amaranthus retroflexus from the Czech Republic.

Amaranthus retroflexus L. (redroot pigweed) is one of the most problematic weeds in maize, sugar beet, vegetables, and soybean crop fields in Europe. Two pigweed amaranth biotypes (R1 and R2) from the Czech Republic resistant to photosystem II (PSII)-inhibiting herbicides were analyzed in this study. This study aimed to identify the genetic mechanisms that underlie the resistance observed in the biotypes. Additionally, we also intended to establish the use of chlorophyll fluorescence measurement as a rapid and reliable method for confirming herbicide resistance in this weed species. Both biotypes analyzed showed high resistance factors in a dose-response study and were thus confirmed to be resistant to PSII-inhibiting herbicides. A sequence analysis of the D1 protein revealed a well-known Ser-Gly substitution at amino acid position 264 in both biotypes. Molecular docking studies, along with the wild-type and mutant D1 protein's secondary structure analyses, revealed that the S264G mutation did not reduce herbicide affinity but instead indirectly affected the interaction between the target protein and the herbicides. The current study identified the S264G mutation as being responsible for conferring herbicide resistance in the pigweed amaranth biotypes. These findings can provide a strong basis for future studies that might use protein structure and mutation-based approaches to gain further insights into the detailed mechanisms of resistance in this weed species. In many individuals from both biotypes, resistance at a very early stage (BBCH10) of plants was demonstrated several hours after the application of the active ingredients by the chlorophyll fluorescence method. The effective PS II quantum yield parameter can be used as a rapid diagnostic tool for distinguishing between sensitive and resistant plants on an individual level. This method can be useful for identifying herbicide-resistant weed biotypes in the field, which can help farmers and weed management practitioners develop more effective weed control tactics.

Secondary Analysis of Human Bulk RNA-Seq Dataset Suggests Potential Mechanisms for Letrozole Resistance in Estrogen-Positive (ER+) Breast Cancer.

Estrogen receptor-positive (ER+) breast cancer is common among postmenopausal women and is frequently treated with Letrozole, which inhibits aromatase from synthesizing estrogen from androgens. Decreased estrogen slows the growth of tumors and can be an effective treatment. The increase in Letrozole resistance poses a unique problem for patients. To better understand the underlying molecular mechanism(s) of Letrozole resistance, we reanalyzed transcriptomic data by comparing individuals who responded to Letrozole therapy (responders) to those who were resistant to treatment (non-responders). We identified SOX11 and S100A9 as two significant differentially expressed genes (DEGs) between these patient cohorts, with "PLK1 signaling events" being the most significant signaling pathway. We also identified PRDX4 and E2F8 gene products as being the top mechanistic transcriptional markers for ER+ treatment resistance. Many of the significant DEGs that we identified play a known role in ER+ breast cancer or other types of cancer, which partially validate our results. Several of the gene products we identified are novel in the context of ER+ breast cancer. Many of the genes that we identified warrant further research to elucidate the more specific molecular mechanisms of Letrozole resistance in this patient population and could potentially be used as prognostic markers with further wet lab validation. We anticipate that these findings could contribute to improved detection and therapeutic outcomes in aromatase-resistant ER+ breast cancer patients.

Mechanism of azole resistance in Candida vulturna, an emerging multidrug resistant pathogen related with Candida haeumulonii and Candida auris.

Candida vulturna is an emerging pathogen belonging to the Metshnikowiaceae family together with Candida auris and Candida haemulonii species complex. Some strains of this species were reported to be resistant to several antifungal agents. This study aims to address identification difficulties, evaluate antiungal susceptibilities and explore the molecular mechanisms of azole resistance of Candida vulturna. We studied five C. vulturna clinical strains isolated in three Colombian cities. Identification was performed by phenotypical, proteomic and molecular methods. Antifungal susceptibility testing was performed following CLSI protocol. Its ERG11 genes were sequenced and a substitution was encountered in azole resistant isolates. To confirm the role of this substitution in the resistance phenotype, Saccharomyces cerevisiae strains with a chimeric ERG11 gene were created. Discrepancies in identification methods are highlighted. Sequencing confirmed the identification as C. vulturna. Antifungal susceptibility varied among strains, with four strains exhibiting reduced susceptibility to azoles and amphotericin B. ERG11 sequencing showed a point mutation (producing a P135S substitution) that was associated with the azole-resistant phenotype. This study contributes to the understanding of C. vulturna's identification challenges, its susceptibility patterns, and sheds light on its molecular mechanisms of azole resistance.

Transcriptome sequencing reveals non-coding RNAs respond to porcine reproductive and respiratory syndrome virus and Haemophilus parasuis co-infection in Kele piglets.

Co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and Haemophilus parasuis (HPS) has severely restricted the healthy development of pig breeding. Exploring disease resistance of non-coding RNAs in pigs co-infected with PRRSV and HPS is therefore critical to complement and elucidate the molecular mechanisms of disease resistance in Kele piglets and to innovate the use of local pig germplasm resources in China. RNA-seq of lungs from Kele piglets with single-infection of PRRSV or HPS and co-infection of both pathogens was performed. Two hundred and twenty-five differentially expressed long non-coding RNAs (DElncRNAs) and 30 DEmicroRNAs (DEmiRNAs) were identified and characterized in the PRRSV and HPS co-infection (PRRSV-HPS) group. Compared with the single-infection groups, 146 unique DElncRNAs, 17 unique DEmiRNAs, and 206 target differentially expressed genes (DEGs) were identified in the PRRSV-HPS group. The expression patterns of 20 DEmiRNAs and DElncRNAs confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) were consistent with those determined by high-throughput sequencing. In the PRRSV-HPS group, the target DEGs were enriched in eight immune Gene Ontology terms relating to two unique DEmiRNAs and 16 DElncRNAs, and the unique target DEGs participated the host immune response to pathogens infection by affecting 15 immune-related Kyoto Encyclopedia of Genes and Genomes enrichment pathways. Notably, competitive endogenous RNA (ceRNA) networks of different groups were constructed, and the ssc-miR-671-5p miRNA was validated as a potential regulatory factor to regulate DTX4 and AEBP1 genes to achieve innate antiviral effects and inhibit pulmonary fibrosis by dual-luciferase reporter assays. These results provided insight into further study on the molecular mechanisms of resistance to PRRSV and HPS co-infection in Kele piglets.

Quantitative phosphoproteomics reveals molecular pathway network in wheat resistance to stripe rust

Protein phosphorylation plays an important role in immune signaling transduction in plant resistance to pathogens. Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), severely devastates wheat production. Nonetheless, the molecular mechanism of wheat resistance to stripe rust remains limited. In this study, quantitative phosphoproteomics was employed to investigate the protein phosphorylation changes in wheat challenged by Pst. A total of 1537 and 2470 differentially accumulated phosphoproteins (DAPs) were identified from four early infection stage (6, 12, 18 and 24 h post-inoculation) in incompatible and compatible wheat-Pst interactions respectively. KEGG analysis revealed that Oxidative Phosphorylation, Phosphatidylinositol Signaling, and MAPK signaling processes are distinctively enriched in incompatible interaction, while Biosynthesis of secondary metabolites and RNA degradation process were significantly enriched in compatible interactions. In particular, abundant changes in phosphorylation levels of chloroplast proteins were identified, suggesting the regulatory role of photosynthesis in wheat-Pst interaction, which is further emphasized by protein-protein interaction (PPI) network analysis. Motif-x analysis identified [xxxxSPxxxx] motif, likely phosphorylation sites for defensive response-related kinases, and a new [xxxxSSxxxx] motif significantly enriched in incompatible interaction. The results shed light on the early phosphorylation events contributing to wheat resistance against Pst. Moreover, our study demonstrated that the phosphorylation levels of Nucleoside diphosphate kinase TaNAPK1 are upregulated at 12 hpi with CYR23 and at 24 hpi with CYR31. Transient silencing of TaNAPK1 was able to attenuate wheat resistance to CYR23 and CYR31. Our study provides new insights into the mechanisms underlying Pst-wheat interactions and may provide database to find potential targets for the development of new resistant varieties.

The role of adipose tissue dysfunction in hepatic insulin resistance and T2D.

The root cause of type 2 diabetes (T2D) is insulin resistance (IR), defined by the failure of cells to respond to circulating insulin to maintain lipid and glucose homeostasis. While the causes of whole-body insulin resistance are multifactorial, a major contributing factor is dysregulation of liver and adipose tissue function. Adipose dysfunction, particularly adipose tissue-IR (adipo-IR), plays a crucial role in the development of hepatic insulin resistance and the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) in the context of T2D. In this review, we will focus on molecular mechanisms of hepatic insulin resistance and its association with adipose tissue function. A deeper understanding of the pathophysiological mechanisms of the transition from a healthy state to insulin resistance, impaired glucose tolerance, and T2D may enable us to prevent and intervene in the progression to T2D.

PdPLR1 effectively enhances resistance of Populus deltoides ‘shalinyang’ to Anoplophora glabripennis by positive regulation of lignan synthesis

Anoplophora glabripennis (ALB) is one of the most devastating wood boring insects of poplars. Populus deltoides ‘Shalinyang (PdS), a new poplar variety, shows strong resistance to ALB infestation. However, the molecular mechanism of insect resistance in PdS is unclear. Here, we found that lignan content was much higher in PdS phloem after ALB infestation than in healthy trees, and that adding lignan to artificial diet significantly reduced: larval weight; digestive enzyme activity (cellulase [CL], polygalacturonase [PG]); detoxification enzyme activity (carboxylesterase [CarE], glutathione S-transferase [GSH-ST]); and defense enzyme activity (Catalase [CAT]). We further identified the lignan biosynthesis-related PdPLR1 gene (Pinoresinol-lariciresinol reductase, PLR) based on transcriptome analysis, and it was significantly up-regulated in the PdS phloem attacked by ALB. Overexpression of PdPLR1 in Arabidopsis increased th lignan content. In contrast, silencing PdPLR1 in PdS significantly decreased expression levels of PdPLR1 and lignan content by 82.45% and 56.85%. However, silencing PdPLR1 increased the number of adults ovipositions and eggs hatching. The activity of CL, PG, CarE, GSH-ST and CAT and the biomass of larvae fed on phloem of PdS with silenced PdPLR1 were significantly higher than in the control. Taken together, up regulation of PdPLR1 enhanced PdS resistance to ALB by regulating lignan synthesis. Our findings provide in-depth insights into the molecular mechanisms of PdS-ALB interactions, which lay the foundation for understanding of defense in poplars to pest infection.

Molecular Mechanisms of Bacterial Resistance to Antimicrobial Peptides in the Modern Era: An Updated Review.

Antimicrobial resistance (AMR) poses a serious global health concern, resulting in a significant number of deaths annually due to infections that are resistant to treatment. Amidst this crisis, antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics (ATBs). These cationic peptides, naturally produced by all kingdoms of life, play a crucial role in the innate immune system of multicellular organisms and in bacterial interspecies competition by exhibiting broad-spectrum activity against bacteria, fungi, viruses, and parasites. AMPs target bacterial pathogens through multiple mechanisms, most importantly by disrupting their membranes, leading to cell lysis. However, bacterial resistance to host AMPs has emerged due to a slow co-evolutionary process between microorganisms and their hosts. Alarmingly, the development of resistance to last-resort AMPs in the treatment of MDR infections, such as colistin, is attributed to the misuse of this peptide and the high rate of horizontal genetic transfer of the corresponding resistance genes. AMP-resistant bacteria employ diverse mechanisms, including but not limited to proteolytic degradation, extracellular trapping and inactivation, active efflux, as well as complex modifications in bacterial cell wall and membrane structures. This review comprehensively examines all constitutive and inducible molecular resistance mechanisms to AMPs supported by experimental evidence described to date in bacterial pathogens. We also explore the specificity of these mechanisms toward structurally diverse AMPs to broaden and enhance their potential in developing and applying them as therapeutics for MDR bacteria. Additionally, we provide insights into the significance of AMP resistance within the context of host-pathogen interactions.

TGF-β: an active participant in the immune and metabolic microenvironment of multiple myeloma : TGF-β in the microenvironment of multiple myeloma.

Although substantial quantities of potent therapies for multiple myeloma (MM) have been established, MM remains an incurable disease. In recent years, our understanding of the initiation, development, and metastasis of cancers has made a qualitative leap. Cancers attain the abilities to maintain proliferation signals, escape growth inhibitors, resist cell death, induce angiogenesis, and more importantly, escape anti-tumor immunity and reprogram metabolism, which are the hallmarks of cancers. Besides, different cancers have different tumor microenvironments (TME), thus, we pay more attention to the TME in the pathogenesis of MM. Many researchers have identified that myeloma cells interact with the components of TME, which is beneficial for their survival, ultimately causing the formation of immunosuppressive and high-metabolism TME. In the process, transforming growth factor-β (TGF-β), as a pivotal cytokine in the TME, controls various cells' fates and influences numerous metabolic pathways, including inhibiting immune cells to infiltrate the tumors, suppressing the activation of anti-tumor immune cells, facilitating more immunosuppressive cells, enhancing glucose and glutamine metabolism, dysregulating bone metabolism and so on. Thus, we consider TGF-β as the tumor promoter. However, in healthy cells and the early stage of tumors, it functions as a tumor suppressor. Due to the effect of context dependence, TGF-β has dual roles in TME, which attracts us to further explore whether targeting it can overcome obstacles in the treatment of MM by regulating the progression of myeloma, molecular mechanisms of drug resistance, and various signaling pathways in the immune and metabolic microenvironment. In this review, we predominantly discuss that TGF-β promotes the development of MM by influencing immunity and metabolism.

The Rhododendron Chrysanthum Pall.s' Acetylation Modification of Rubisco Enzymes Controls Carbon Cycling to Withstand UV-B Stress.

Lysine acetylation of proteins plays a critical regulatory function in plants. A few advances have been made in the study of plant acetylproteome. However, until now, there have been few data on Rhododendron chrysanthum Pall. (R. chrysanthum). We analyzed the molecular mechanisms of photosynthesis and stress resistance in R. chrysanthum under UV-B stress. We measured chlorophyll fluorescence parameters of R. chrysanthum under UV-B stress and performed a multi-omics analysis. Based on the determination of chlorophyll fluorescence parameters, R. chrysanthum Y(NO) (Quantum yield of non-photochemical quenching) increased under UV-B stress, indicating that the plant was damaged and photosynthesis decreased. In the analysis of acetylated proteomics data, acetylated proteins were found to be involved in a variety of biological processes. Notably, acetylated proteins were significantly enriched in the pathways of photosynthesis and carbon fixation, suggesting that lysine acetylation modifications have an important role in these activities. Our findings suggest that R. chrysanthum has decreased photosynthesis and impaired photosystems under UV-B stress, but NPQ shows that plants are resistant to UV-B. Acetylation proteomics revealed that up- or down-regulation of acetylation modification levels alters protein expression. Acetylation modification of key enzymes of the Calvin cycle (Rubisco, GAPDH) regulates protein expression, making Rubisco and GAPDH proteins expressed as significantly different proteins, which in turn affects the carbon fixation capacity of R. chrysanthum. Thus, Rubisco and GAPDH are significantly differentially expressed after acetylation modification, which affects the carbon fixation capacity and thus makes the plant resistant to UV-B stress. Lysine acetylation modification affects biological processes by regulating the expression of key enzymes in photosynthesis and carbon fixation, making plants resistant to UV-B stress.

Integrated Transcriptome and Metabolome Analysis Reveals Molecular Mechanisms Underlying Resistance to Phytophthora Root Rot.

Soybean production is significantly impacted by Phytophthora root rot (PRR), which is caused by Phytophthora sojae. The nucleotide-binding leucine-rich repeat (NLR) gene family plays a crucial role in plant disease resistance. However, current understanding of the function of soybean NLR genes in resistance to PRR is limited. To address this knowledge gap, transgenic soybean plants overexpressing the NLR gene (Glyma.18g283200) were generated to elucidate the molecular mechanism of resistance. Here, transcript changes and metabolic differences were investigated at three time points (12, 24, and 36 h) after P. sojae infection in hypocotyls of two soybean lines, Dongnong 50 (susceptible line, WT) and Glyma.18g283200 overexpression line (resistant line, OE). Based on the changes in differentially expressed genes (DEGs) in response to P. sojae infection in different lines and at different time points, it was speculated that HOPZ-ACTIVATED RESISTANCE 1 (ZAR1), valine, leucine, and isoleucine degradation, and phytohormone signaling may be involved in the defense response of soybean to P. sojae at the transcriptome level by GO term and KEGG pathway enrichment analysis. Differentially accumulated metabolites (DAMs) analysis revealed that a total of 223 and 210 differential metabolites were identified in the positive ion (POS) and negative ion (NEG) modes, respectively. An integrated pathway-level analysis of transcriptomics (obtained by RNA-seq) and metabolomics data revealed that isoflavone biosynthesis was associated with disease resistance. This work provides valuable insights that can be used in breeding programs aiming to enhance soybean resistance against PRR.

Whole-genome resequencing of grass carp (Ctenopharyngodon idella) for genome-wide association study on GCRV resistance

Grass carp (Ctenopharyngodon idella) is a highly productive freshwater fish species that annually contributes significant economic value to the aquaculture industry. However, its production is frequently affected by grass carp haemorrhagic disease (GCHD), which is caused by grass carp reovirus (GCRV). To elucidate the molecular mechanism of GCRV resistance in C. idella, whole-genome resequencing of both susceptible and resistant C. idella was conducted, yielding a total of 3,941,776 high quality single nucleotide polymorphisms (SNPs). A genome-wide association study (GWAS) then identified five significant SNPs, located on chromosomes 2, 3, 5, 6 and 10, associated with the trait of GCRV resistance. An integrative analysis of the GWAS and a previous transcriptome study was performed, and five common genes were identified, including b4galt2 (β-1,4-galactosyltransferase 2), kif2c (Kinesin family member 2C), jmjd8 (JmjC domain containing 8), selenom (Selenoprotein M), and znfx1 (Zinc finger NFX1-type containing 1). This study serves as a valuable basis for implementing marker-assisted selection (MAS) to improve GCRV resistance in C. idella breeding programs, and provides insight into developing methods to control the spread of GCHD.

Ewingella americana Infections in Humans-A Narrative Review.

Ewingella americana is a Gram-negative rod that belongs to the order Enterobacterales and the family Yersiniaceae and was first identified in 1983 from 10 clinical strains in the United States of America. The present study aimed to identify all the published cases of E. americana in the literature, describe the epidemiological, clinical, and microbiological characteristics, and provide data regarding its antimicrobial resistance, treatment, and outcomes. A narrative review was performed based on a PubMed and Scopus databases search. In total, 16 studies provided data on 19 patients with infections by E. americana. The median age of the patients was 55 years, and 47.4% were male. The most common infections were those of the bloodstream, the respiratory tract, and the peritoneal cavity. Antimicrobial resistance to cephalosporins, aminoglycosides, and the combination of trimethoprim with sulfamethoxazole was minimal, and these were the most commonly used antimicrobials for treating these infections. No included study provided information on the genetic or molecular mechanism of this pathogen's antimicrobial resistance. The overall mortality was minimal, with only one patient with bacteremia succumbing to the infection. Further studies are needed to better understand this microorganism, its pathogenic potential in humans, and the genetic and molecular mechanisms underlying its antimicrobial resistance, for which very little evidence exists to date.

Integrated transcriptomic and pathway analyses of sorghum plants revealed the molecular mechanisms of host defense against aphids.

Sugarcane aphid has emerged as a major pest of sorghum recently, and a few sorghum accessions were identified for resistance to this aphid so far. However, the molecular and genetic mechanisms underlying this resistance are still unclear. To understand these mechanisms, transcriptomics was conducted in resistant Tx2783 and susceptible BTx623 sorghum genotypes infested with sugarcane aphids. A principal component analysis revealed differences in the transcriptomic profiles of the two genotypes. The pathway analysis of the differentially expressed genes (DEGs) indicated the upregulation of a set of genes related to signal perception (nucleotide-binding, leucine-rich repeat proteins), signal transduction [mitogen-activated protein kinases signaling, salicylic acid (SA), and jasmonic acid (JA)], and plant defense (transcription factors, flavonoids, and terpenoids). The upregulation of the selected DEGs was verified by real-time quantitative PCR data analysis, performed on the resistant and susceptible genotypes. A phytohormone bioassay experiment showed a decrease in aphid population, plant mortality, and damage in the susceptible genotype when treated with JA and SA. Together, the results indicate that the set of genes, pathways, and defense compounds is involved in host plant resistance to aphids. These findings shed light on the specific role of each DEG, thus advancing our understanding of the genetic and molecular mechanisms of host plant resistance to aphids.

Use of Viscous medium to study anthelmintic drug action in Caenorhabditis elegans

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity.

Comprehensive Overview of Broadly Neutralizing Antibodies against SARS-CoV-2 Variants.

Currently, SARS-CoV-2 has evolved into various variants, including the numerous highly mutated Omicron sub-lineages, significantly increasing immune evasion ability. The development raises concerns about the possibly diminished effectiveness of available vaccines and antibody-based therapeutics. Here, we describe those representative categories of broadly neutralizing antibodies (bnAbs) that retain prominent effectiveness against emerging variants including Omicron sub-lineages. The molecular characteristics, epitope conservation, and resistance mechanisms of these antibodies are further detailed, aiming to offer suggestion or direction for the development of therapeutic antibodies, and facilitate the design of vaccines with broad-spectrum potential.

Transcriptome responses of Arabidopsis to necrotrophic fungus Alternaria brassicae reveal pathways and candidate genes associated with resistance.

Alternaria leaf blight (ALB), caused by a necrotrophic fungus Alternaria brassicae is a serious disease of oleiferous Brassicas resulting in significant yield losses worldwide. No robust resistance against A. brassicae has been identified in the Brassicas. Natural accessions of Arabidopsis show a spectrum of responses to A. brassicae ranging from high susceptibility to complete resistance. To understand the molecular mechanisms of resistance/ susceptibility, we analysed the comparative changes in the transcriptome profile of Arabidopsis accessions with contrasting responses- at different time points post-infection. Differential gene expression, GO enrichment, pathway enrichment, and weighted gene co-expression network analysis (WGCNA) revealed reprogramming of phenylpropanoid biosynthetic pathway involving lignin, hydroxycinnamic acids, scopoletin, anthocyanin genes to be highly associated with resistance against A. brassicae. T-DNA insertion mutants deficient in the biosynthesis of coumarin scopoletin exhibited enhanced susceptibility to A. brassicae. The supplementation of scopoletin to medium or exogenous application resulted in a significant reduction in the A. brassicae growth. Our study provides new insights into the transcriptome dynamics in A. brassicae-challenged Arabidopsis and demonstrates the involvement of coumarins in plant immunity against the Brassica pathogen A. brassicae.