Search Results (420)

Isoliquiritigenin (ISL) is a type of chalcone that widely exists in medicinal plants of the Leguminosae family and exhibits a remarkable anti-ischemic stroke (IS) effect. However, the anti-IS mechanisms of ISL remain to be systematically elucidated. In this study, network pharmacology was used to predict potential targets related to the anti-IS effect of ISL. The binding ability of ISL to potential core targets was further analyzed by molecular docking and molecular dynamics (MD) simulations. By establishing an oxygen–glucose deprivation/reoxygenation (OGD/R)-induced HT22 cell model, the anti-IS mechanisms of ISL were investigated via RT-qPCR and Western Blot (WB). As a result, network pharmacology analysis revealed that APP, ESR1, MAO-A, PTGS2, and EGFR may be potential core targets of ISL for anti-IS treatment. Molecular docking and molecular dynamics simulation results revealed that ISL can stably bind to the five potential core targets and form stable complex systems with them. The results of the cell experiments revealed a significant anti-IS effect of ISL. Additionally, mRNA and protein expression levels of APP, MAO-A and PTGS2 or ESR1 in the ISL treatment group were significantly lower or higher than those in the OGD/R group In conclusion, ISL may improve IS by regulating the protein expression levels of APP, ESR1, MAO-A, and PTGS2. Full article

The RasGAP SH3 domain binding protein (G3BP) is a highly conserved family of proteins in eukaryotic organisms that coordinates signal transduction and post-transcriptional gene regulation and functions in the formation of stress granules. G3BPs have important roles in abiotic/biotic stresses in mammals, and recent research suggests that they have similar functions in higher plants. Brassica contains many important oilseeds, vegetables, and ornamental plants, but there are no reports on the G3BP family in Brassica species. In this study, we identified G3BP family genes from six species of the U’s triangle (B. rapa, B. oleracea, B. nigra, B. napus, B. juncea, and B. carinata) at the genome-wide level. We then analyzed their gene structure, protein motifs, gene duplication type, phylogeny, subcellular localization, SSR loci, and upstream miRNAs. Based on transcriptome data, we analyzed the expression patterns of B. napus G3BP (BnaG3BP) genes in various tissues/organs in response to Sclerotinia disease, blackleg disease, powdery mildew, dehydration, drought, heat, cold, and ABA treatments, and its involvement in seed traits including germination, α-linolenic acid content, oil content, and yellow seed. Several BnaG3BP DEGs might be regulated by BnaTT1. The qRT-PCR assay validated the inducibility of two cold-responsive BnaG3BP DEGs. This study will enrich the systematic understanding of Brassica G3BP family genes and lay a molecular basis for the application of BnaG3BP genes in stress tolerance, disease resistance, and quality improvement in rapeseed. Full article

Investigations of endogenous plant circular RNAs (circRNAs) in several plant species have revealed changes in their circular RNA profiles in response to biotic and abiotic stresses. Recently, circRNAs have emerged as critical regulators of gene expression. The destructive impacts on agriculture due to plant viral infections necessitate better discernment of the involvement of plant circRNAs during viral infection. However, few such studies have been conducted hitherto. Sobemoviruses cause great economic impacts on important crops such as rice, turnip, alfalfa, and wheat. Our current study investigates the dynamics of plant circRNA profiles in the host Arabidopsis thaliana (A. thaliana) during infections with the sobemoviruses Turnip rosette virus (TRoV) and Rice yellow mottle virus (RYMV), as well as the small circular satellite RNA of the Lucerne transient streak virus (scLTSV), focusing on circRNA dysregulation in the host plants and its potential implications in triggering plant cellular defense responses. Towards this, two rounds of deep sequencing were conducted on the RNA samples obtained from infected and uninfected plants followed by the analysis of circular RNA profiles using RNA-seq and extensive bioinformatic analyses. We identified 760 circRNAs, predominantly encoded in exonic regions and enriched in the chloroplast chromosome, suggesting them as key sites for circRNA generation during viral stress. Gene ontology (GO) analysis indicated that these circRNAs are mostly associated with plant development and protein binding, potentially influencing the expression of their host genes. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed photosynthesis as the most affected pathway. Interestingly, the non-coding exogenous scLTSV specifically induced several circRNAs, some of which contain open reading frames (ORFs) capable of encoding proteins. Our biochemical assays demonstrated that transgenic expression of scLTSV in A. thaliana enhanced resistance to TRoV, suggesting a novel strategy for improving plant viral resistance. Our results highlight the complexity of circRNA dynamics in plant–virus interactions and offer novel insights into potential circRNA-based strategies for enhancing plant disease resistance by modulating the differential expression of circRNAs. Full article

The whitefly Bemisia tabaci (Hemiptera: Aleyrodoidea) causes direct feeding damage to crop plants and transmits pathogenic plant viruses, thereby threatening global food security. Although whitefly-infecting RNA viruses are known and proposed as biocontrol agents, no insect DNA virus has been found in any member of Aleyrodoidea. Using rolling circle amplification (RCA) of viral DNA from whiteflies collected from crop fields in Morocco, followed by Illumina sequencing of the RCA products, we found a novel insect single-stranded (ss) DNA parvovirus (family Parvoviridae) in addition to plant ssDNA geminiviruses transmitted by whiteflies. Based on its genome organization with inverted terminal repeats and evolutionarily conserved proteins mediating viral DNA replication (NS1/Rep) and encapsidation (VP), encoded on the forward and reverse strands, respectively, we named this virus Bemisia tabaci ambidensovirus (BtaDV) and classified it as a founding member of a new genus within the subfamily Densovirinae. This subfamily also contains three distinct genera of ambisense densoviruses of other hemipteran insects (Aphidoidea, Coccoidea, and Psylloidea). Furthermore, we provide evidence for the genetic variants of BtaDV circulating in whitefly populations and for its partial sequences integrated into the B. tabaci genome, with one integrant locus potentially expressing a fusion protein composed of viral Rep endonuclease and host DNA-binding domains. This suggests a long-term virus-host interaction and neofunctionalization of BtaDV-derived endogenous viral elements. Full article

The large portion of the eukaryotic genomes was considered non-functional and called the “dark matter” of the genome, now appearing as regulatory hubs coding for RNAs without the potential for making proteins, known as non-coding RNA. Long non-coding RNA (lncRNA) is defined as functional RNA molecules having lengths larger than 200 nucleotides without the potential for coding for proteins. Thousands of lncRNAs are identified in different plants and animals. LncRNAs are characterized by a low abundance, fewer exons than mRNA, tissue-specific expression, and low sequence conservation compared to protein-coding genes (PCGs). LncRNAs, like PCGs, are regulated by promoters and enhancers with characteristic chromatin signatures, DNA methylation, multiple exons, introns, and alternate splicing. LncRNAs interact with DNA, mRNA, microRNA, and proteins, including chromatin/histone modifiers, transcription factors/repressors, epigenetic regulators, spliceosomal, and RNA-binding proteins. Recent observations indicate that lncRNAs code for small peptides, also called micropeptides (<100 amino acids), and are involved in the development and growth of plants, suggesting the bi-functional activities of lncRNAs. LncRNAs have emerged as the major regulators of diverse functions, principally by altering the transcription of target genes. LncRNAs are involved in plant growth, development, immune responses, and various physiological processes. Abiotic, biotic, nutrient, and other environmental stresses alter the expressions of numerous lncRNAs. Understanding the mechanisms of actions of lncRNAs opens up the possibility of improving agronomic traits by manipulating lncRNAs. However, further studies are required in order to find the interactions among the deregulated lncRNAs and validate the findings from high-throughput studies to harness their potential in crop improvement. Full article

The development of resistance to standard cytostatics, such as 5-fluorouracil (5-FU), significantly limits the efficacy of colon cancer therapy, prompting the search for novel anticancer agents, particularly among natural compounds. This study evaluated the anticancer effects of isorhamnetin, a plant-derived flavonol, and its ability to modulate the expression of drug-resistance-related biomarkers in SW-480 and HT-29 colon cancer cells, with a focus on ATP-binding cassette (ABC) transporters. Isorhamnetin demonstrated strong cytotoxic and proapoptotic activity on both cell lines, while showing lower toxicity toward normal HaCaT cells. In addition to suppressing the mRNA expression of drug-metabolizing enzymes (CYP1A1 and CYP1B1), isorhamnetin significantly reduced the mRNA levels of multidrug resistance-associated proteins 1 and 5 (MRP1 and MRP5), as well as the P-glycoprotein (P-gp) level in SW-480 and HT-29 cells. Molecular docking analysis revealed a high binding affinity of isorhamnetin to CYP1A1, CYP1B1, P-gp, MRP1, MRP5, and glutathione S-transferase (GST) proteins, with stronger interactions than those observed for 5-FU, suggesting potential interference with their function. These results provide a solid basis for future investigations to confirm the therapeutic potential of isorhamnetin as a modulator of drug resistance in colon cancer cells. Full article

Background: Aluminum (Al) toxicity severely limits Medicago sativa (alfalfa) production on acidic soils, resulting in major yield losses worldwide. The highly conserved miRNA156 (miR156) functions by downregulating at least 11 SQUAMOSA promoter-binding protein-like (SPL) transcription factors in alfalfa, including SPL13, but its role in Al stress remains unclear. This study aimed to investigate the miR156/SPL regulatory network’s function in alfalfa under Al stress. Methods: Gene expression analyses, histochemical staining, nutrient profiling, phenotypic assays, transcriptome profiling, and ChIP-seq were conducted on alfalfa plants with altered miR156 and SPL13 expression to assess their roles in the Al stress response. Results: Al stress induced SPL13 expression while repressing miR156 in the roots. Elevated miR156 intensified Al accumulation, lipid peroxidation, and plasma membrane damage, accompanied by reduced leaf nitrogen, magnesium, sulfur, and phosphorus content. Phenotypically, increased SPL13 enhanced the root length and Al tolerance, whereas SPL13 silencing reduced tolerance. Transcriptome profiling of SPL13-silenced plants identified differentially expressed genes involved in the Al response, including aluminum-activated malate transporters and various transcription factors (GRAS, Myb-related, bHLH041, NAC, WRKY53, bZIP, and MADS-box). ChIP-seq revealed that SPL13 directly regulates genes encoding a protein kinase, cytochrome P450, and fasciclin-like arabinogalactan proteins. Conclusions: The MsmiR156/MsSPL13 network plays a crucial regulatory role in alfalfa’s response to Al toxicity. These findings provide novel genetic targets and foundational knowledge to advance molecular breeding for enhanced Al tolerance in alfalfa. Full article

Momordica balsamina, a plant traditionally used in African medicine, contains a 30 kDa protein, MoMo30, previously identified by our group as an anti-HIV agent that binds glycan residues on the gp120 envelope protein, thereby acting as an entry inhibitor. In this study, we investigated whether prolonged exposure to MoMo30 exerts selective pressure on HIV-1 and induces mutations in the viral envelope (env) gene. T-lymphocyte cells were infected with HIV-1_NL4-3 and continuously treated with MoMo30 over a 24-day period. Viral RNA was isolated at regular intervals, and env genes were sequenced using the Illumina platform. RNA sequence variant calling was performed using iVar, which uses a frequency-based binomial test with a default allele frequency threshold of 3% and a minimum base quality of 20 and applies Bonferroni correction for multiple testing. The infectivity of the MoMo30-exposed virus was assessed using MAGI-CXCR4 cells, visualized by β-galactosidase staining, and compared to untreated controls. Statistical significance was determined via two-way ANOVA. MoMo30-treated HIV-1 exhibited multiple detrimental mutations in gp120 and gp41, including missense, nonsense, and frameshift changes. Notably, 32% of N-linked glycosylation sites were deleted in the treated virus, while no such changes were observed in controls. Functionally, the MoMo30-treated virus demonstrated a sixfold reduction in infectivity compared to untreated HIV-1_NL4-3. These findings suggest that MoMo30 imposes genetic pressure on HIV-1_NL4-3, selecting for mutations that reduce viral fitness. Full article

The control of gene expression by cis-regulatory DNA sequences is a conserved genomic feature. The maize booster1 gene (b1) is a naturally occurring locus that serves as a mechanistic model for the control of gene expression from a distal cis element and a form of allelic interactions called paramutation. Two epi-alleles of b1 produce distinct pigmentation phenotypes correlated with transcriptional enhancement and the silencing of b1. These transcriptional dynamics depend on a hepta-tandem repeat sequence located 100 kb upstream of the b1 locus. In the heterozygous condition, the B′ epi-allele paramutates B-I, heritably converting the B-I epi-allele to the epigenetic state and expression level of B′, producing lightly pigmented plants. To identify b1TR-associated proteins, we used a targeted chromatin immunoprecipitation approach with a stably integrated transgenic b1TR locus. Applying a conservative filtering strategy, we detected several expected factors, including RNA Polymerase II, as well as the novel putative DNA-binding proteins ZAG4 and DDT4. ZAG4 and DDT4 activated GAL expression using b1TR as bait in yeast one-hybrid, supporting their potential interaction with this sequence. The identification of proteins uniquely associated with the UAS::b1TR chromatin provides insight into potential b1 regulatory factors and offers a foundation for future studies to investigate their roles in gene regulation. Full article

Grain size and grain weight are critical factors influencing crop yield. In rice (Oryza sativa L.), the auxin response factor (OsARF) family proteins, key components of the auxin signaling pathway, function as transcription factors and play essential roles in regulating various plant growth and development processes, including seed development. Here, we identified that Oryza sativa AUXIN RESPONSE FACTOR 25 (OsARF25) plays an essential role in regulating grain size and grain weight by activating the expression of SHORT GRAIN 1 (SG1) and Oryza sativa OVATE FAMILY PROTEIN 04 (OsOFP04). The osarf25 mutants showed larger grains with increased grain length, grain width, and 1000-grain weight. Furthermore, molecular evidence demonstrated that OsARF25 functions as a transcriptional activator. RNA-seq analysis further identified its target genes SG1 and OsOFP04. In addition, OsARF25 directly binds to the promoters of SG1 and OsOFP04 and activates their expression. Further, the osarf25 mutant exhibited enhanced sensitivity to brassinolide treatment, confirming that the targeting of SG1 and OsOFP04 by OsARF25 mediates BR signaling. Taken together, our study revealed that OsARF25 functions as a regulator of grain length, grain width, and grain weight by participating in the BR signaling pathway, and it has potential value for molecular breeding in rice. Full article

(1) RNA-binding proteins (RBPs) play a crucial role in regulating gene expression in plants, affecting growth, development, and stress responses. Accurate prediction of plant-specific RBPs is vital for understanding gene regulation and enhancing genetic improvement. (2) Methods: We propose an ensemble learning method that integrates shallow and deep learning. It integrates prediction results from SVM, LR, LDA, and LightGBM into an enhanced TextCNN, using K-Peptide Composition (KPC) encoding (k = 1, 2) to form a 420-dimensional feature vector, extended to 424 dimensions by including those four prediction outputs. Redundancy is minimized using a Pearson correlation threshold of 0.80. (3) Results: On the benchmark dataset of 4992 sequences, our method achieved an ACC of 97.20% and 97.06% under 5-fold and 10-fold cross-validation, respectively. On an independent dataset of 1086 sequences, our method attained an ACC of 99.72%, an ${\mathrm{F}1}_{\mathrm{s}\mathrm{c}\mathrm{o}\mathrm{r}\mathrm{e}}$ of 99.72%, an MCC of 99.45%, an SN of 99.63%, and an SP of 99.82%, outperforming RBPLight by 12.98 percentage points in ACC and the original TextCNN by 25.23 percentage points. (4) Conclusions: These results highlight our method’s superior accuracy and efficiency over PSSM-based approaches, enabling large-scale plant RBP prediction. Full article

Tomato spotted wilt virus (TSWV) is a highly destructive plant pathogen and transmitted by several thrips including the western flower thrips, Frankliniella occidentalis. A structural N protein encoded in the viral genome represents the nucleocapsid protein by binding to the viral RNA genome. However, it remains unknown how the RNA-binding protein specifically interacts with the viral RNA from host RNAs in the target cells. To study the molecular basis of N function, we produced the protein in Escherichia coli and the resulting purified recombinant protein was used to investigate the protein–RNA interactions. The recombinant N protein migrated on agarose gel to the anode in the electric field due to its high basic isoelectric point. This electrostatic property led N protein to bind to DNA as well as RNA. It also bound to both single-stranded (ssRNA) and double-stranded RNA (dsRNA). However, when the total RNA was extracted from plant tissues collected from TSWV-infected host, the RNA extract using the recombinant N protein was much richer in the TSWV genome compared to that without the protein. To investigate the specificity of N protein to ssRNA, the three-dimensional structure was predicted using the AlphaFold program and showed its trimeric oligomerization with the binding pocket for ssRNA. This was supported by the differential susceptibility of N protein with ssRNA and dsRNA against RNase attack. Furthermore, a thermal shift assay to analyze the RNA and protein interaction showed that ssRNA strongly interacted with N protein compared to dsRNA. In addition, the N gene was expressed along with the multiplication of the viral RNA genome segments from the segment-specific fluorescence in situ hybridization analysis in different tissues during different developmental stages of the virus-infected F. occidentalis. These results suggest that the functional trimeric N proteins bind to the viral RNA to form a basic nucleocapsid structure at a specific virus-replicating compartment within the host cells. Full article

Dinoflagellates are unicellular organisms that are crucial components of aquatic ecosystems, known as important primary producers and causes of harmful blooms. They have complex life cycles, including immotile stages, which contribute to their distribution and survival in unfavorable conditions. Temperature changes, primarily cold stress, significantly impact dinoflagellate physiology, influencing metabolic processes, growth rates, and encystment/excystment cycles. This study investigates the transcriptome of temporary cold-induced cysts in the marine planktonic dinoflagellate Prorocentrum cordatum. We compared gene expression in cysts subjected to a 7-h cold incubation with those returned to standard cultivation conditions and motile vegetative cells. Our results showed a marked predominance of downregulated genes in cold-induced cysts. Encystment affected signaling pathways, including calcium and protein kinase signaling, as well as RNA and protein metabolism. Upon returning to standard conditions, RNA metabolism was reactivated; upregulation of genes encoding some calcium-binding proteins and kinases was observed. Additionally, we analyzed RNA-binding pentatricopeptide repeat-containing proteins, the genes encoding which changed their expression in P. cordatum cysts, for similarities to plant MRL1 proteins. Finally, we focused on MEI2-like proteins to confirm their role in non-sexual cyst formation and position them within the diversity of MEI2 homologs in dinoflagellates. Full article

Rice blast disease is a major threat to rice yields. Sustainable control relies on resistant varieties, where plant immunity is triggered by pattern recognition receptors like receptor-like proteins (RLPs). The rice RLP chitin-elicitor binding protin (CEBiP) recognizes fungal chitin and confers blast resistance to pathogen Magnaporthe oryzae. However, understanding of the broader signaling and metabolomic pathways associated with CEBiP activation remains limited. Here, we performed an integrated transcriptomic and metabolomic analysis of the rice Zhonghua 11 genotype and CEBiP knockout plants. Both plants were infected with M. oryzae, and infected leaves were harvested at 24, 48, and 72 hpi for RNA sequencing and Liquid Chromatography-Tandem Mass Spectrometry analysis. Transcriptomics identified a total of 655 genes that were differentially regulated upon knockout of CEBiP; they were mainly related to diterpenoid/phenylpropanoid biosynthesis, nitrogen metabolism, the mitogen-activated protein kinasesignaling pathway, plant–pathogen interaction, and plant hormone signal transduction. The presence of a large number of pathogenesis-related protein 1 family genes indicates the key role of salicylic acid (SA) in CEBiP immunity. Metabolomics detected a total of 962 differentially accumulated metabolites and highlights the roles of caffeine and glutathione metabolism in CEBiP-mediated immunity. Since caffeine and glutathione metabolism can regulate SA signaling, we propose that SA signaling plays a central role in the CEBiP immune function. Full article

SPLs (SQUAMOSA promoter binding protein-like) are pivotal in regulating plant development and stress responses. Although SPL genes have been characterized in a series of plant species, no systematic analysis has been performed on bananas, one of the most consumed tropical fruits with immense economic importance worldwide. Here, 55 putative MaSPL genes were identified in Musa acuminata ssp. malaccensis var. Pahang and classified into seven groups based on phylogenetic analysis. The RNA-seq analysis revealed that the expression of MaSPLs presented distinct spatiotemporal patterns in different tissues at different developmental stages, indicating a potential role in banana growth and development. Furthermore, MaSPL1 was found to be predominantly expressed in banana fruits during the fruit development and the early postharvest stages. Notably, the transient overexpression of MaSPL1 accelerated the fruit ripening in bananas. In conclusion, this study provides comprehensive information for further investigation of the specific roles of SPL genes in banana developmental processes, particularly during fruit development and post-harvest stages, and may implement molecular strategies to regulate maturation and enhance fruit quality in bananas. Full article