Search Results (346)

Global warming has resulted in an increase in the frequency of extreme high-temperature events. High temperatures can increase cell membrane permeability, elevate levels of osmotic adjustment substances, reduce photosynthetic capacity, impair plant growth and development, and even result in plant death. Under high-temperature stress, plants mitigate damage through physiological and biochemical adjustments, heat signal transduction, the regulation of transcription factors, and the synthesis of heat shock proteins. However, different plants exhibit varying regulatory abilities and temperature tolerances. Investigating the heat-resistance and regulatory mechanisms of plants can facilitate the development of heat-resistant varieties for plant genetic breeding and landscaping applications. This paper presents a systematic review of plant physiological and biochemical responses, regulatory substances, signal transduction pathways, molecular mechanisms—including the regulation of heat shock transcription factors and heat shock proteins—and the role of plant hormones under high-temperature stress. The study constructed a molecular regulatory network encompassing Ca²⁺ signaling, plant hormone pathways, and heat shock transcription factors, and it systematically elucidated the mechanisms underlying the enhancement of plant thermotolerance, thereby providing a scientific foundation for the development of heat-resistant plant varieties. Full article

Background/Objectives: Moso bamboo (Phyllostachys edulis), the most widely distributed bamboo species in China, is valued for both its shoots and timber. This species often faces challenges from high-temperature stress. To cope with this stress, Moso bamboo has evolved various adaptive mechanisms at the physiological and molecular levels. Although numerous studies have revealed that a large number of transcription factors (TFs) and genes play important roles in the regulatory network of plant heat stress responses, the regulatory network involved in heat responses remains incompletely understood. Methods: In this study, Moso bamboo was placed in a high-temperature environment of 42 °C for 1 h and 24 h, and transcriptome sequencing was carried out to accurately identify key molecules affected by high temperature and their related biological pathways. Results: Through a differential expression analysis, we successfully identified a series of key candidate genes and transcription factors involved in heat stress responses, including members of the ethylene response factor, HSF, WRKY, MYB, and bHLH families. Notably, in addition to traditional heat shock proteins/factors, multiple genes related to lipid metabolism, antioxidant enzymes, dehydration responses, and hormone signal transduction were found to play significant roles in heat stress responses. To further verify the changes in the expression of these genes, we used qRT-PCR technology for detection, and the results strongly supported their key roles in cellular physiological processes and heat stress responses. Conclusions: This study not only deepens our understanding of plant strategies for coping with and defending against extreme abiotic stresses but also provides valuable insights for future research on heat tolerance in Moso bamboo and other plants. Full article

Mystus guttatus, a second-class protected species in China, has undergone severe population decline due to anthropogenic and environmental pressures, yet conservation efforts are hindered by limited genomic resources and a lack of mechanistic insights into its stress response systems. Here, the first full-length transcriptome of M. guttatus was generated via SMRT sequencing. A total of 32,647 full-length transcripts were obtained, with an average length of 1783 bp. After structure and function annotation of full-length transcripts, 30,977 genes, 1670 transcription factors (TF), 918 alternative splicing (AS), and 11,830 simple sequence repeats (SSR) were identified. In order to further explore the stress resistance of M. guttatus, 93 genes belonging to the heat shock protein (HSP) family were identified and categorized into HSP70 and HSP90 subgroups. After phylogenetic analysis and selective stress analysis, it was discovered that the hsp family has suffered purifying selection and gene loss, potentially contributing to a decrease in the stress resilience and population of M. guttatus. Using protein interaction network and molecular docking tools, we observed the intricate interplay among HSPs and discovered HSP70-HOP-HSP90 interaction, which is an essential stress response mechanism. Our study sequenced the first full-length transcriptome of M. guttatus to enhance its genomic resources for its conservation and breeding and provide new insights into the future study of stress response mechanisms on M. guttatus. Full article

Background: Alpha-1 antitrypsin (AAT) is a multifunctional protease inhibitor that has been shown to have anti-inflammatory properties in various diseases. AAT has been reported to protect against renal injury via anti-apoptotic, anti-fibrotic, and anti-inflammatory effects. However, its role in mitigating renal inflammation and reducing high blood pressure induced by salt-loading has never been studied. Methods: In this study, we salt-loaded 129Sv mice to induce hypertension and then administered purified human AAT (hAAT) or the vehicle to investigate whether renal inflammation and associated inflammatory/signaling pathways are mitigated. Results: Western blotting and densitometric analysis showed administration of hAAT attenuated protein expression of kidney injury molecule-1 (KIM1), CD93, CD36, and the toll-like receptor 2 and 4 (TLR-2/4) in kidney lysates. Similarly, protein expression of two key inflammatory transcription factors, signal transducer and activator of transcription 3 (STAT3) and NF-Kappa B were shown to be attenuated in the kidneys of 129Sv mice that received hAAT. Conversely, hAAT treatment upregulated the expression of heat shock protein 70 (HSP70) and immunohistochemistry confirmed these findings. Conclusions: Purified hAAT administration may be efficacious in mitigating renal inflammation associated with the development of hypertension from salt-loading, potentially through a mechanism involving the reduction of pro-inflammatory and injury-associated proteins. Full article

Heat shock transcription factor (Hsf) plays a pivotal role in regulating plant growth, development, and stress responses. Hsf activates or represses target gene transcription by binding to the heat shock element (HSE) of downstream genes. However, the specific interaction sites between Hsf and the HSE in the promoter remain unclear. In this study, the critical amino acid residues of ZmHsf17 and the paralogous ZmHsf05 involved in DNA binding were identified using molecular docking models, site-directed mutagenesis, and the electrophoretic mobility shift assay (EMSA). The results reveal that both ZmHsf17 and ZmHsf05 bind to the HSE of the ZmPAH1 promoter via a conserved arginine residue located in the α3 helix of their DNA-binding domains. Sequence substitution experiments among distinct HSEs demonstrated that flanking sequences upstream and downstream of the HSE core synergistically contribute to the specificity of DNA-binding domain recognition. Comparative evolutionary analysis of DNA-binding domain sequences from 25 phylogenetically diverse species reveals that the α3 helix constitutes the most conserved structural element. This study elucidates the key interaction sites between maize HsfA2 and its target genes, providing theoretical insights into the binding specificity to the HSEs of the plant’s Hsf family and the functional divergence. Additionally, these findings offer new targets for the precise engineering of Hsf proteins and synthetic HSEs. Full article

Thermal manipulation (TM) during embryogenesis is a promising non-pharmacological strategy to enhance physiological resilience in broiler chickens. This study evaluated the impact of thermal conditioning of fertile eggs on growth performance, inflammatory responses, and molecular stress markers following a post-hatch lipopolysaccharide (LPS) challenge. Fertilized eggs (average weight 62 ± 3 g) were obtained from 35-week-old Indian River broiler breeder hens. A total of 720 eggs were randomly assigned to either the control group (n = 360) or the TM group (n = 360), with each group consisting of two replicates of 180 eggs. Control eggs were maintained under standard incubation conditions (37.8 °C, 56% RH), while TM eggs were subjected to elevated temperature (38.8 °C, 65% RH) for 18 h daily from embryonic day 10 to 18. On post-hatch day 15, control and TM groups were administered either saline or LPS via intraperitoneal (IP) injection. Body weight and temperature, internal organ weights, and splenic mRNA expression levels of inflammatory cytokines, toll-like receptors, transcription factors, and heat shock proteins were assessed. TM did not alter hatchability (p = 0.633), but significantly shortened hatch time (p < 0.05) and improved feed efficiency (p < 0.05). While LPS induced marked inflammatory responses in all birds, those subjected to TM exhibited attenuated proinflammatory cytokine expression, enhanced anti-inflammatory signaling, and differential regulation of stress-associated genes, including nuclear factor kappa B (NF-κB), heat shock protein 70 (HSP70), and heat shock factors (HSFs). These findings suggest that TM during incubation promotes a more regulated immune response and improved stress adaptation post-hatch. This approach offers a potential antibiotic-free intervention to enhance broiler health, performance, and resilience under immunological stress. Full article

Hybrid tea roses (Rosa hybrida) are economically important horticultural crops and highly susceptible to heat stress, which significantly impacts flower quality and yield. As a key member of the heat shock protein (HSP) family, HSP70 protein acts as a molecular chaperone and exhibits diverse abiotic stress response functions in plants. A total of 113 HSP70 transcription factors (TFs) with varying physical and chemical properties were identified in the genome of hybrid tea rose. Phylogenetic analysis showed that the identified TFs could classify into three (I, II, and III) subfamilies, with most members (51 TFs) falling in subfamily II. Wide gene structural variations were observed among the three subfamilies, with group I and II members lacking introns, while group III members only harbored 1~4 exons and introns. Numerous cis-acting elements associated with abiotic stress, hormone response, growth and development responses, as well as light response were detected in the HSP70 gene promoters. In addition, protein interaction networks predicted a wide range of interactions between different hybrid tea rose HSP70 subfamilies. Gene expression analysis revealed that 57 HSP70 genes had strong organ specificity and response to heat stress in the hybrid tea rose plants. Notably, the expression levels of two RhHSP70 genes, RhHSP70-69 and RhHSP70-88, were significantly increased after heat stress, indicating that these two genes might be crucial for plant heat stress response. Subcellular localization of RhHSP70-69 and RhHSP70-88 revealed that their proteins were located in the nucleus. Our results are not only useful for future evaluation of the regulatory roles of RhHSP70 genes in the hybrid tea rose growth and development, but also provides key genes for future molecular breeding of heat tolerant plants. Full article

Begonia semperflorens (B. semperflorens) is a popular ornamental plant widely used in landscapes such as plazas and flower beds, and it is also commonly grown as a potted plant indoors. It is known for its adaptability to high temperatures, drought, and shade. Under heat-tolerant conditions, heat shock transcription factors (HSFs) are key transcriptional regulatory proteins that play crucial roles in cellular processes. Despite extensive studies on the HSF family in various species, there has been no specific analysis targeting B. semperflorens. In this study, we identified 37 members of the BsHSF gene family in B. semperflorens based on its genome scaffold, which are unevenly distributed across the genome. Phylogenetic analysis reveals that these 37 members can be divided into three subfamilies. Analysis of their physicochemical properties shows significant diversity among these proteins. Except for the BsHSFB7 protein located in the cytoplasm, all other BsHSF proteins were found to be nuclear-localized. A comparison of the amino acid sequences indicates that all BsHSF proteins contain a conserved DNA-binding domain structure. Analysis of the promoter cis-acting elements also suggests that BsHSFs may be associated with heat stress and plant secondary metabolism. We further investigated the duplication events of BsHSF genes and their collinearity with genes from other Begonia species. Finally, through real-time quantitative PCR, we examined the expression patterns of the 37 BsHSFs in different plant tissues (roots, stems, leaves, and flowers) and their expression levels under heat stress treatment. The results show that, except for BsHSF29, all BsHSFs were expressed in various tissues, with varying expression levels across tissues. Except for BsHSF33 and BsHSF34, the expression levels of almost all BsHSF genes increased in response to heat treatment. In summary, these findings provide a better understanding of the role and regulatory mechanisms of HSFs in the heat stress response of B. semperflorens and lay the foundation for further exploration of the biological functions of BsHSFs in the stress responses of B. semperflorens. Full article

Spinach (Spinacia oleracea L.), a globally consumed, nutrient-dense vegetable, contains diverse vitamins and minerals. However, elevated temperatures can constrain yield by interrupting leaf development and photosynthetic efficiency. The mitochondrial transcription termination factor (mTERF) family, which regulates organellar gene expression, plays crucial roles in plant growth and photosynthetic regulation. Thus, characterization of the spinach mTERF (SomTERF) family is critical for elucidating thermotolerance mechanisms in this crop. In this study, we systematically identified 31 SomTERF genes from the spinach genome, which are distributed across five chromosomes and nine unassembled genomic scaffolds. Subcellular localization predictions indicated that these proteins predominantly target chloroplasts and mitochondria. Conserved domain analyses confirmed that all SomTERF proteins possess canonical mTERF domains and ten conserved motifs. Phylogenetic clustering segregated these proteins into nine distinct subgroups (I–IX), with significant divergence observed in gene copy numbers among subgroups. Cis-element screening identified an abundance of heat-, cold-, and hormone-responsive motifs within SomTERF promoter regions. Notably, seven members (including SomTERF5) exhibited pronounced enrichment of heat shock elements (HSEs). Organ-specific expression profiling revealed preferential leaf expression of these seven genes. Comparative RT-qPCR in heat-sensitive (Sp73) and heat-tolerant (Sp75) cultivars under thermal stress demonstrated genotype-dependent expression dynamics. Functional validation of SomTERF5 was achieved through cloning, and transgenic Arabidopsis overexpressing SomTERF5 showed significantly enhanced thermotolerance, as evidenced by improved survival rates following heat treatment. Yeast two-hybrid (Y2H) assays further revealed physical interaction between SomTERF5 and SopTAC2. This study provides a comprehensive foundation for understanding mTERF-mediated developmental regulation and advanced molecular breeding strategies for developing heat-resilient spinach varieties. Full article

Chinese tongue sole (Cynoglossus semilaevis) is an important marine fish in China. It has sexual dimorphism. The weight and growth rate of female fish are much greater than those of male fish. However, high temperatures can induce sex reversal in genetic female fish (ZW) to phenotypic male fish; thus, identifying the genetic elements involved in temperature perception will provide the molecular basis for sex control. The heat shock transcription factor (hsf) is known as an important component of temperature sensing and mediates the heat shock response in fish such as Danio rerio; however, its function in C. semilaevis is unclear. In this study, five hsf genes (hsf1, hsf2, hsf4, hsf5a, and hsf5b) were identified in tongue sole and found to be expressed in the gonads at different developmental stages, peaking from 7M to 1Y. Gonadal in situ hybridization revealed that hsf gene signals were mainly localized in germ cells, e.g., sperm in the testis and all-stage oocytes in the ovary. Upon high-temperature stimulation, the expression of the hsf gene in the gonads increased gradually with increasing stimulation time, but different hsf genes presented different response patterns. After the RNA interference of hsf in the testis and ovarian cell lines, a series of sex-related genes, such as foxl2 and dmrt1, significantly changed. In vivo RNA interference had an effect on the female gonads and mainly affected neurl3 expression. On the basis of these data, we speculate that hsf responds to temperature stimulation and plays an important role in sex differentiation. This study helps elucidate the relationship between temperature sensing and sex differentiation in C. semilaevis. Full article

Panax ginseng plants are susceptible to high temperatures and intense sunlight, necessitating cultivation under artificially shaded structures. Identifying the genes associated with heat resistance is critical for advancing molecular breeding strategies to develop heat-tolerant ginseng varieties. Heat-shock transcription factors (HSFs) are widely recognized as key regulators of plant responses to abiotic stresses, primarily by controlling heat-shock proteins (HSPs). To identify HSF genes in P. ginseng, transcriptome analysis was conducted on ginseng plants subjected to heat-shock treatment (1 h at 40 °C). Among the 26 HSF unigenes annotated from the ginseng transcriptome, a unigene related to the HSFA2 family exhibited the highest transcriptional activity following heat-shock treatment. The expression of PgHSFA2, a gene identified from this unigene, was analyzed under temperature and salt-stress conditions in ginseng plants using qPCR. The results showed that PgHSFA2 was highly responsive to various abiotic stresses, including heat, cold, salt, and intense sunlight. To assess the functional role of PgHSFA2, transgenic tobacco plants overexpressing this gene were analyzed. The overexpression of PgHSFA2 led to an elevated expression of heat-shock proteins (HSPs) in tobacco, resulting in enhanced resistance to high temperature and salt stress. Transgenic tobacco plants exhibited significantly less reduction in chlorophyll fluorescence compared to nontransgenic controls when exposed to salt stress (200 and 400 mM NaCl) and high-temperature stress (42 °C), indicating improved stress tolerance. In conclusion, PgHSFA2 is a crucial HSF that regulates the transcriptional control of HSPs in ginseng plants. The constitutive expression of PgHSFA2 in transgenic ginseng could potentially confer improved tolerance to high temperatures, making it a valuable target for molecular breeding. Full article

Heat shock transcription factor (Hsf) plays a crucial role in the signal transduction pathways of plants in response to drought stress. However, studies exploring the specific functions and mechanisms of action of the Hsf family in tea plants (Camellia sinensis L.) remain limited. In this study, we identified 31 members of the CsHsf family from the C. sinensis genome. CsHsf10 was determined to be a potential drought-resistant candidate gene by screening 10 highly expressed genes in mature leaves and confirming results through RT-qPCR. Correlation analysis indicates that CsHsf10 may enhance the drought resistance of tea plants by participating in the tea polyphenol synthesis pathway and regulating the expression of antioxidant enzyme genes. Furthermore, overexpression experiments in Arabidopsis and antisense oligonucleotide experiments in tea plants corroborated that CsHsf10 exerts a significant positive regulatory effect on drought resistance in tea plants. Yeast one-hybrid assays and dual luciferase reporter gene experiments demonstrated that CsHsf10 can directly target CsPOD17, significantly promoting its transcriptional expression. Additionally, we found that the expression of CsHsf10 contributes to the increased accumulation of catechin components in tea plants under drought stress. These findings suggest that, during the response of tea plants to drought stress, CsHsf10 not only enhances antioxidant capacity by regulating the activity of antioxidant enzymes but also optimizes the physiological state of tea plants by influencing the accumulation of secondary metabolites, thereby significantly improving their drought resistance. Full article

Spermatogenesis is a complex and highly regulated process involving the proliferation, differentiation, and apoptosis of germ cells. This process is controlled by various hormonal, genetic, and environmental factors, including temperature. In hormonal regulation, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) are essential for correct spermatogenesis development from the early stages and spermatogonia proliferation to germ cell maturation. Other hormones, like inhibin and activin, finely participate tuning the process of spermatogenesis. Genetic regulation involves various transcription factors, such as SOX9, SRY, and DMRT1, which are crucial for the development and maintenance of the testis and germ cells. MicroRNAs (miRNAs) play a significant role by regulating gene expression post-transcriptionally. Epigenetic modifications, including DNA methylation, histone modifications, and chromatin remodelling, are also vital. Temperature regulation is another critical aspect, with the testicular temperature maintained around 2–4 °C below body temperature, essential for efficient spermatogenesis. Heat shock proteins (HSPs) protect germ cells from heat-induced damage by acting as molecular chaperones, ensuring proper protein folding and preventing the aggregation of misfolded proteins during thermal stress. Elevated testicular temperature can impair spermatogenesis, increasing germ cell apoptosis and inducing oxidative stress, DNA damage, and the disruption of the blood–testis barrier, leading to germ cell death and impaired differentiation. The cellular mechanisms of germ cell proliferation, differentiation, and death include the mitotic divisions of spermatogonia to maintain the germ cell pool and produce spermatocytes. Spermatocytes undergo meiosis to produce haploid spermatids, which then differentiate into mature spermatozoa. Apoptosis, or programmed cell death, ensures the removal of defective germ cells and regulates the germ cell population. Hormonal imbalance, genetic defects, and environmental stress can trigger apoptosis during spermatogenesis. Understanding these mechanisms is crucial for addressing male infertility and developing therapeutic interventions. Advances in molecular biology and genetics continue to uncover the intricate details of how spermatogenesis is regulated at multiple levels, providing new insights and potential targets for treatment. Full article

Neuropilin-1 is henceforth a relevant target in cancer treatment; however, its way of action remains partly elusive, and the development of small inhibitory molecules is therefore required for its study. Here, we report that two small-sized neuropilin antagonists (NRPa-47 and NRPa-48), VEGF-A₁₆₅/NRP-1 binding inhibitors, are able to decrease VEGF-Rs phosphorylation and to modulate their downstream cascades in the triple-negative breast cancer cell line (MDA-MB-231). Nevertheless, NRPas exert a divergent pathway regulation of MAPK phosphorylation, such as JNK-1/-2/-3, ERK-1/-2, and p38β/γ/δ-kinases, as well as their respective downstream targets. However, NRPa-47 and NRPa-48 apply a common down-regulation of the p38α-kinase phosphorylation and their downstream targets, emphasising its central regulating role. More importantly, none of the 40 selected kinases, including SAPK2a/p38α, are affected in vitro by NRPas, strengthening their specificity. Taken together, NRPas induced cell death by the down-modulation of pro-apoptotic and anti-apoptotic proteins, cell death receptors and adaptors, heat shock proteins (HSP-27/-60/-70), cell cycle proteins (p21, p27, phospho-RAD17), and transcription factors (p53, HIF-1α). In conclusion, we showed for the first time how NRPas may alter tumour cell signalling and contribute to the down-modulation of the cancer therapeutic key factor p38α-kinase phosphorylation. Thus, the efficient association of NRPas and p38α-kinase inhibitor strengthened this hypothesis. Full article

High temperatures can severely affect plant development and cause a notable decrease in crop yields. Currently, most studies use whole plants that are exposed to steady, high temperatures. This does not reflect the conditions encountered in natural fields, and it overlooks possible differences and coordination between the shoots and roots under heat stress (HS). Here, we analyzed the transcriptome changes in whole plants, shoots, and roots exposed separately to HS. In total, 3346 differentially expressed genes (DEGs) were obtained. Plants in which only the shoots were HS-treated showed minor transcriptional changes compared with whole plants exposed to HS. 62 genes were specifically expressed in HS treatment on shoots, and most of these genes have not been reported to function in HS. We found NAC1 may enhance plant heat tolerance. Utilizing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, HS-treated shoots showed enhanced gene transcription, protein folding, and MAPK signaling but decreased auxin signaling, while HS-treated roots showed an increase in oxidative stress and suppression of starch and sucrose metabolism. The binding of cis-regulatory elements by transcription factors that act downstream in reactive oxygen species (ROS), abscisic acid (ABA), and brassinosteroid (BR) signaling was significantly enriched at the putative promoters of co-expressed genes in shoots and roots under HS treatments on aboveground tissues or roots. Moreover, 194 core HS-responsive genes were identified from all HS treatments, of which 125 have not been reported to function in HS responses. Among them, we found that REV1 and MYC67 may positively regulate the response of plants to heat shock. This work uncovers many new HS-responsive genes and distinct response strategies employed by shoots and roots following HS exposure. Additionally, ROS, ABA, and BR or their downstream signaling factors may be important components for transmitting heat shock signals between shoots and roots. Full article