OBJECTIVE: miR-34c-3p is down-regulated in nasopharyngeal carcinoma (NPC). The biological role of miR-34c-3p in NPC and its underlying mechanisms are unknown and were explored in this study. METHODS: Flow cytometry and immunohistochemical staining were employed to detect cluster of differentiation 86 (CD86) and cluster of differentiation 206 (CD206) expression; quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were employed to examine mRNA expression and protein levels; cell counting kit-8 (CCK8) and transwell assays were employed to assess cell proliferation, migration, and invasion; and hematoxylin-eosin (HE) staining was employed to assess pathological changes in tumor tissues. RESULTS: Our results revealed that the miR-34c-3p mimic markedly inhibited M2 polarization of macrophages by targeting SLC7A11, and M2 macrophages transfected with the miR-34c-3p mimic inhibited the proliferation, migration, and invasion of NPC cells. The in vivo experiments further confirmed that miR-34c-3p mimics blocked tumor growth and reduced inflammatory infiltration in tumor tissues. CONCLUSION This study provides novel insights into the pathogenesis of NPC and a new treatment strategy.
MicroRNAs/metabolism* ; Nasopharyngeal Carcinoma/genetics* ; Humans ; Animals ; Nasopharyngeal Neoplasms/genetics* ; Macrophages/physiology* ; Cell Line, Tumor ; Mice ; Cell Proliferation ; Mice, Inbred BALB C ; Cell Movement ; Male ; Gene Expression Regulation, Neoplastic ; Mice, Nude ; Female

OBJECTIVE: Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection frequently develop central nervous system damage, yet the mechanisms driving this pathology remain unclear. This study investigated the primary pathways and key factors underlying brain tissue damage induced by the SARS-CoV-2 beta variant (lineage B.1.351). METHODS: K18-hACE2 and C57BL/6 mice were intranasally infected with the SARS-CoV-2 beta variant. Viral replication, pathological phenotypes, and brain transcriptomes were analyzed. Gene Ontology (GO) analysis was performed to identify altered pathways. Expression changes of host genes were verified using reverse transcription-quantitative polymerase chain reaction and Western blot. RESULTS: Pathological alterations were observed in the lungs of both mouse strains. However, only K18-hACE2 mice exhibited elevated viral RNA loads and infectious titers in the brain at 3 days post-infection, accompanied by neuropathological injury and weight loss. GO analysis of infected K18-hACE2 brain tissue revealed significant dysregulation of genes associated with innate immunity and antiviral defense responses, including type I interferons, pro-inflammatory cytokines, Toll-like receptor signaling components, and interferon-stimulated genes. Neuroinflammation was evident, alongside activation of apoptotic and pyroptotic pathways. Furthermore, altered neural cell marker expression suggested viral-induced neuroglial activation, resulting in caspase 4 and lipocalin 2 release and disruption of neuronal molecular networks. CONCLUSION These findings elucidate mechanisms of neuropathogenicity associated with the SARS-CoV-2 beta variant and highlight therapeutic targets to mitigate COVID-19-related neurological dysfunction.
Animals ; COVID-19/genetics* ; Mice ; Brain/metabolism* ; Apoptosis ; Mice, Inbred C57BL ; SARS-CoV-2/physiology* ; Pyroptosis ; Gene Expression Profiling ; Transcriptome ; Male ; Female

There is a large gap between production and demand of plant oil in China, which leads to the heavy reliance on imports. Diacylglycerol acyltransferase (DGAT) and phospholipid: diacylglycerol acyltransferase (PDAT) are two key enzymes responsible for the synthesis of triacylglycerol, thereby affecting the yield and quality of plant oil. This paper comprehensively reviews the research progress in DGAT and PDAT in terms of their biological functions in plant oil synthesis, the molecular mechanisms of regulating plant lipid metabolism, growth, and development under stress, and their roles in driving oil synthesis under the background of synthetic biology. Furthermore, future research and application of DGAT and PDAT are prospected. This review aims to provide a basis for deeply understanding the molecular mechanism of plant oil synthesis and improving the quality and productivity of oil crops by the utilization of DGAT and PDAT genes.
Diacylglycerol O-Acyltransferase/physiology* ; Plant Oils/metabolism* ; Acyltransferases/metabolism* ; Lipid Metabolism/genetics* ; Gene Expression Regulation, Plant ; Triglycerides/biosynthesis*

Autophagy is an evolutionarily conserved self-degradation process in eukaryotes. It not only plays a role in plant growth and development but also is involved in plant responses to biotic and abiotic stresses. Plants can initiate autophagy to degrade the surplus or damaged cytoplasmic materials and organelles, thus coping with abiotic and biotic stresses. The initiation of autophagy depends on autophagy-related genes (ATGs). The transcription factors can directly bind to the promoters of ATGs to activate autophagy and regulate their transcriptional levels and post-translational modifications. Furthermore, ATGs can directly or indirectly interact with plant hormones to regulate plant responses to stresses. When plants are exposed to salinity, drought, extreme temperatures, nutrient deficiencies, and pathogen stress, ATGs are significantly induced, which enhances the autophagy activity to facilitate the degradation of the denatured and misfolded proteins, thereby enhancing plant tolerance to adversity stresses. This article summarizes the discovery, structures, and classification of plant ATGs, reviews the research progress in the mechanisms of ATGs in plant responses to abiotic and biotic stresses, and prospects the future research directions. This review is expected to provide the genetic resources and a theoretical foundation for the genetic improvement of crops in responses to stress tolerance.
Autophagy/physiology* ; Stress, Physiological/genetics* ; Gene Expression Regulation, Plant ; Plants/metabolism* ; Transcription Factors/metabolism* ; Plant Proteins/genetics* ; Genes, Plant ; Plant Physiological Phenomena ; Droughts

Prunus mume is an ecologically and economically valuable plant with both medicinal and edible values. However, drought severely limits the promotion and cultivation of P. mume in the arid and semi-arid areas in northern China. In this study, we treated P. mume 'Meiren' with natural drought and then assessed photosynthetic and physiological indexes such as osmoregulatory substances, photosynthetic parameters, and antioxidant enzyme activities. Furthermore, we employed transcriptome sequencing to explore the internal regulatory mechanism of P. mume under drought stress. As the drought stress aggravated, the levels of chlorophyll a (Chla), chlorophyll b (Chlb), chlorophyll (a+b)[Chl(a+b)], and soluble protein (SP) in P. mume first elevated and then declined. The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum photochemical efficiency (Fv/Fm), effective photochemical quantum yield [Y(Ⅱ)], photochemical quenching (qP), and relative electron transport rate (ETR) all kept decreasing, while the levels of malondialdehyde, superoxide dismutase (SOD), peroxidase (POD), and osmoregulatory substances rose. Transcriptome sequencing revealed a total of 24 853 high-quality genes. Gene ontology (GO) enrichment showed that differentially expressed genes (DEGs) were the most under severe drought. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the DEGs during the four drought periods were mainly involved in the biosynthesis of secondary metabolites, plant-pathogen interaction, plant hormone signal transduction, starch and sucrose metabolism, and mitogen-activated protein kinase signaling pathways. Furthermore, we identified 16 key genes associated with the drought tolerance of P. mume 'Meiren'. This study discovered that P. mume might up-regulate or down-regulate the expression of drought tolerance-related genes such as SUS, P5CS, LEA, SOD, POD, SOD1, TPPD, and TPPA via transcription factors like MYB, ERF, bHLH, NAC, and WRKY to promote the accumulation of osmoregulatory substances like sucrose and enhance the activities of antioxidant enzymes such as SOD and POD, thus reducing the harm of reactive oxygen species and protecting the structure and function of the membrane system under drought stress. The findings provide theoretical references for further exploration of candidate genes of P. mume in response to drought stress and breeding of drought-tolerant varieties.
Droughts ; Photosynthesis/physiology* ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Prunus/genetics* ; Chlorophyll/metabolism* ; Plant Proteins/genetics*

Beta-amylases (BAMs), key enzymes in starch hydrolysis, play an important role in plant growth, development, and resistance to abiotic stress. To mine the saline-alkali tolerance-related BAM genes in alfalfa (Medicago sativa L.), we identified MsBAM genes in the whole genome. The physicochemical properties, phylogeny, gene structures, conserved motifs, secondary structures, promoter cis-acting elements, chromosome localization, and gene replication relationships of BAM gene family members were analyzed. RNA-seq and quantitative real-time PCR (qRT-PCR) were employed to analyze the expression patterns of BAM family members under saline-alkali stress. The results showed that 54 BAM genes were identified in the genome, which were classified into 8 subgroups according to the phylogenetic tree. The members of the same subgroup had similar gene structures except that those of subgroups 1 and 7 had large differences. Conserved motif analysis showed that all MsBAM proteins had a typical glycohydrolysis domain. The chromosome localization analysis showed that MsBAM gene family members were unevenly distributed on 27 chromosomes. The duplication of gene segments led to the increase in BAM gene number in alfalfa. The promoters of BAM genes contained a large number of elements in response to plant hormones and stress. Transcriptome data and qRT-PCR results showed that the expression levels of most MsBAM genes were up-regulated in response to saline-alkali stress. Under the saline-alkali stress, the expression levels of 28 genes, including MsBAM6, were up-regulated on days 1 and 7, and those of 5 genes, including MsBAM9, were up-regulated by over 2 folds. In addition, under salt-alkali stress, BAM activity and soluble sugar content were significantly increased. These results indicate that BAM genes play a key role in alfalfa in response to saline-alkali stress, laying a foundation for further research in this field.
Medicago sativa/physiology* ; beta-Amylase/metabolism* ; Phylogeny ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Multigene Family ; Alkalies ; Plant Proteins/genetics*

Picea mongolica, known for its remarkable tolerance to cold, drought, and salinity, is a key species for ecological restoration and urban greening in the "Three Norths" region of China. MYB transcription factors are involved in plant responses to abiotic stress and synthesis of secondary metabolites. However, studies are limited regarding the MYB transcription factors in P. mongolica and their roles in salt stress tolerance. In this study, 196 MYBs were identified based on the genome of Picea abies and the transcriptome of P. mongolica. Phylogenetic analysis classified the MYB transcription factors into seven subclasses. The R2R3-MYB subclass contained the maximum number of genes (84.77%), while the R-R and R1R2R3 subclasses each represented the smallest proportion, at about 0.51%. The MYB transcription factors within the same subclass were highly conserved, exhibiting similar motifs and gene structures. Experiments with varying salt stress gradients revealed that P. mongolica could tolerate the salt concentration up to 1 000 mmol/L. From the transcriptome data of P. mongolica exposed to salt stress (1 000 mmol/L) for 0, 3, 6, 12, and 24 h, a total of 34 differentially expressed MYBs were identified, which suggested that these MYBs played a key role in regulating the response to salt stress. The proteins encoded by these differentially expressed genes varied in length from 89 aa to 731 aa, with molecular weights ranging from 10.19 kDa to 79.73 kDa, isoelectric points between 4.80 and 9.91, and instability coefficients from 41.20 to 70.99. Subcellular localization analysis indicated that most proteins were localized in the nucleus, while three were found in the chloroplasts. Twelve MYBs were selected for quantitative real-time PCR (qRT-PCR), which showed that their expression patterns were consistent with the RNA-seq data. This study provides valuable data for further investigation into the functions and mechanisms of MYB family members in response to salt stress in P. mongolica.
Picea/physiology* ; Transcription Factors/classification* ; Salt Stress/genetics* ; Phylogeny ; Plant Proteins/genetics* ; Salt Tolerance/genetics* ; Gene Expression Regulation, Plant

Cucumber (Cucumis sativus L.) is one of the most widely cultivated vegetables in the world. High temperature and other stress conditions can affect the growth and development of this plant, even leading to the decreases in yield and quality. The mitogen-activated protein kinase (MAPK) family plays a crucial role in plant stress responses. However, the role of MPK4 in the stress response of cucumber remains to be reported. In this study, we cloned CsMPK4, which encoded 383 amino acid residues. The qRT-PCR results showed that the expression level of CsMPK4 was the highest in leaves and flowers, moderate in roots, and the lowest in stems and tendrils. CsMPK4 was located in the nucleus and cytoplasm, and it had a close relationship with CmMPK4 in muskmelon. The cucumber plants overexpressing CsMPK4 became stronger and shorter, with reduced length and quantity of tendrils. Moreover, the transgenic seedlings were more resistant to high temperatures, with decreased malondialdehyde (MDA) content and increased activities of peroxidase (POD) and superoxide dismutase (SOD) in young leaves. Furthermore, the protein-protein interaction between CsMPK4 and CsVQ10, a member of the valine-glutamine family, was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. The results suggested that CsVQ10 cooperated with CsMPK4 in response to the high temperature stress in cucumber. This study laid a foundation for the further study on the stress response mechanism of CsMPK4 and the breeding of stress-resistant cucumber varieties.
Cucumis sativus/metabolism* ; Mitogen-Activated Protein Kinases/physiology* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Cloning, Molecular

Sucrose non-fermenting 1-related protein kinase 1 (SnRK1) is one of the highly conserved Ca²⁺ non-dependent serine/threonine protein kinases, playing a crucial role in regulating the stress responses, growth, and development of plants. SnRK1 is a three-subunit complex, and it is involved in responding to the signaling transduction induced by low-energy/low-sugar conditions. SnRK1 responds biotic and abiotic stress conditions (such as salt, drought, low/high temperatures, and diseases) through phosphorylation of key metabolic enzymes and regulatory proteins, regulation of transcription, and interactions with other proteins. Furthermore, SnRK1 is not only involved in hormone signaling pathways mediated by abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA), but also regulates plant autophagy by inhibiting the activity of target of rapamycin (TOR). In this review, we summarized the current results of research on the discovery, structure, and classification of plant SnRK1 and its roles in the stress responses, growth, and development of plants. Furthermore, this article proposes the directions of future research. This review provides good genetic resources and a theoretical basis for the genetic improvement and biological breeding for enhancing the stress tolerance of crops.
Stress, Physiological/physiology* ; Protein Serine-Threonine Kinases/metabolism* ; Plant Development/genetics* ; Signal Transduction ; Gene Expression Regulation, Plant ; Plant Proteins/physiology* ; Plants/metabolism* ; Arabidopsis Proteins/physiology* ; Plant Growth Regulators/metabolism*

Small nuclear RNAs (snRNAs) refer to a class of highly abundant and functionally important non-coding small RNAs that are localized in the eukaryotic nucleus. These snRNAs are highly conserved in different eukaryotes during evolution and form complexes with specific chaperones to fulfill critical biological functions, including precursor messenger RNA (pre-mRNA) splicing and ribosomal RNA (rRNA) modification. Consequently, the regulation of snRNA gene expression is a crucial biological process for plants. In plants, the transcription and processing of snRNAs are regulated by RNA polymerase (Pol), snRNA-activating protein complex (SNAPc), defective in snRNA processing (DSP), and specific cis-elements in the snRNA promoter regions. Proper regulation of snRNA expression is essential for normal plant growth, development, and stress responses. This review summarizes the classification, structures, transcriptional regulation, and biological functions of plant snRNA genes, while outlining future research directions for snRNAs.
RNA, Small Nuclear/physiology* ; Gene Expression Regulation, Plant ; Transcription, Genetic ; Plants/metabolism* ; RNA, Plant/genetics*