Search Results (388)

Histone methylation plays important roles in plant development and adaptation to multiple stresses. SET domain group (SDG) proteins are identified as plant histone lysine methyltransferases in Arabidopsis and other crops. However, the SDG gene family and its functional roles in tomato remain unknown. In this research, 48 tomato SDG (SlSDG) gene family members were identified, and their chromosomal locations and conserved motifs were determined. According to phylogenetic analysis, the SlSDGs are divided into seven groups, which is consistent with Arabidopsis and rice. Promoter analysis indicated that the SlSDGs may be associated with biotic and abiotic stress responses. The expression pattern of SlSDGs illustrates that heat and cold stress significantly influence the transcript abundance of SDG14/19/21/23/48. The results of a VIGS assay showed that silencing SlSDG19 and SlSDG48 decreases tomato heat tolerance, while silencing SlSDG14 improves the heat tolerance of tomato plants. The analysis of downstream regulating genes indicated that heat shock proteins (HSPs), especially HSP70 and HSP90, act as critical effectors. Similarly, the experimental assay and expression analysis suggest that SDG21 and SDG23 positively and negatively regulate tomato cold tolerance through the CBF-COR pathway, respectively. These findings clarify the function of tomato SDG proteins and provide insight for the genetic improvement of tomato for temperature stress tolerance. Full article

Heat stress, intensified by global warming, is an increasing challenge for the growth and yield of the economically important crop Brassica rapa subsp. chinensis (NHCC). The Heat Shock Protein 70 (HSP70) family plays an important role in plant thermotolerance, but its molecular characteristics and regulatory mechanisms in this subspecies have not been investigated. Herein, we conducted a comprehensive genomic and transcriptional profiling of the BrcHSP70 gene lineage and revealed a total of 31 members. Our phylogenetic analysis revealed a closer evolutionary relationship to genes from B. rapa ssp. pekinensis (HCC) than to those found in Arabidopsis. Genomic analysis demonstrated that segmental duplication, with eight pairs identified, was the primary driving force for the family’s expansion, rather than tandem duplication. Additionally, the BrcHsp70 gene promoters are enriched with cis-acting elements responsive to phytohormones (particularly ABA) and abiotic stresses. Critically, under 38 °C high-temperature stress, the heat-resistant variety ‘SHI’ and heat-sensitive variety ‘Aijiaohuang’ exhibited distinct expression patterns, identifying key candidate genes implicated in thermotolerance. These results elucidate the evolutionary and regulatory features of the HSP70 family in NHCC, providing a new understanding of the molecular mechanisms of plant heat tolerance. Full article

Quinoa (Chenopodium quinoa), a stress-tolerant pseudocereal ideal for studying abiotic stress responses, was used to systematically identify optimal reference genes for qPCR normalization under gradient stresses: low temperatures (LT group: −2 °C to −10 °C), heat (HT group: 39° C to 45 °C), and drought (DR group: 7 to 13 days). Through multi-algorithm evaluation (GeNorm, NormFinder, BestKeeper, the ΔCt method, and RefFinder) of eleven candidates, condition-specific optimal genes were established as ACT16 (Actin), SAL92 (IT4 phosphatase-associated protein), SSU32 (Ssu72-like family protein), and TSB05 (Tryptophan synthase beta-subunit 2) for the LT group; ACT16 and NRP13 (Asparagine-rich protein) for the HT group; and ACT16, SKP27 (S-phase kinase), and NRP13 for the DR group, with ACT16, NRP13, WLIM96 (LIM domain-containing protein), SSU32, SKP27, SAL92, and UBC22 (ubiquitin-conjugating enzyme E2) demonstrating cross-stress stability (global group). DHDPS96 (dihydrodipicolinate synthase) and EF03 (translation elongation factor) showed minimal stability. Validation using stress-responsive markers—COR72 (LT), HSP44 (HT), COR413-PM (LT), and DREB12 (DR)—confirmed reliability; COR72 and COR413-PM exhibited oscillatory cold response patterns, HSP44 peaked at 43 °C before declining, and DREB12 showed progressive drought-induced upregulation. Crucially, normalization with unstable genes (DHDPS96 and EF03) distorted expression profiles. This work provides validated reference standards for quinoa transcriptomics under abiotic stresses. Full article

Members of the heat shock protein 20 (HSP20) family of proteins play an important role in responding to various forms of stress. Here, the expression of ClaHSP17.4 was induced by heat stress in watermelon. Then, a floral dipping approach was used to introduce the pCAMBIA1391b-GFP overexpression vector encoding the heat tolerance-related gene ClaHSP17.4 from watermelon into Arabidopsis thaliana, and we obtained ClaHSP17.4-overexpressing Arabidopsis plants. Under normal conditions, the phenotypes of transgenic and wild-type (WT) Arabidopsis plants were largely similar. Following exposure to heat stress, however, the germination rates (96%) of transgenic Arabidopsis plants at the germination stages were significantly higher than those of wild-type idopsis (17%). Specifically, the malondialdehyde (MDA) content of transgenic Arabidopsis was half that of the control group, while the activities of peroxidase (POD) and superoxide dismutase (SOD) were 1.25 times those of the control group after exposure to high temperatures for 12 h at the seedling stages. The proline content in ClaHSP17.4-overexpressing transgenic Arabidopsis increased by 17% compared to WT plants (* p < 0.05), while the soluble sugar content rose by 37% (* p < 0.05). These results suggest that ClaHSP17.4 overexpression indirectly improves the antioxidant capacity and osmotic regulatory capacity of Arabidopsis seedlings, leading to improved survival and greater heat tolerance. Meanwhile, the results of this study provide a reference for further research on the function of the ClHSP17.4 gene and lay a foundation for breeding heat-tolerant watermelon varieties and advancing our understanding of plant adaptation to environmental stress. Full article

Protein degradation plays a fundamental role in maintaining protein homeostasis and ensures proper cellular function by regulating protein quality and quantity. Heat shock protein 100 (Hsp100), found in bacteria, plants, and fungi, is a unique chaperone family responsible for rescuing misfolded proteins from aggregated states in an ATP-dependent manner. To date, they are primarily known to mediate heat stress adaptation and enhance cellular survival under extreme conditions in higher plants and algae. Resting cyst formation in dinoflagellates is widely recognized as a response to adverse conditions, which offers an adaptive advantage to endure harsh environmental extremes that are unsuitable for vegetative cell growth and survival. In this study, based on a full-length cDNA sequence, we characterized an Hsp100 gene (SaHsp100) from the cosmopolitan bloom-forming dinoflagellate Scrippsiella acuminata, aiming to examine its life stage-specific expression patterns and preliminarily explore its potential functions. The qPCR results revealed that Hsp100 transcript levels were significantly elevated in newly formed resting cysts compared to vegetative cells and continued to increase during storage under simulated marine sediment conditions (darkness, low temperature, and anoxia). Parallel reaction monitoring (PRM)-based quantification further confirmed that Hsp100 protein levels were significantly higher in resting cysts than in vegetative cells and increased after three months of storage. These findings collectively highlighted the fundamental role of Hsp100 in the alteration of the life cycle and dormancy maintenance of S. acuminata, likely by enhancing stress adaptation and promoting cell survival through participation in proteostasis maintenance, particularly under natural sediment-like conditions that trigger severe abiotic stress. Our work deepens the current understanding of Hsp family members in dinoflagellates, paving the way for future investigations into their ecological relevance within this ecologically significant group. Full article

Water temperature significantly affects the physiological balance of aquatic organisms like crustaceans, and heat shock proteins (HSPs) are crucial for stress resistance and pathogen defense. This study conducted a genome-wide analysis to explore the functional characteristics of the Hsp70 gene family in Procambarus clarkii. Fifteen Hsp70 family members were identified, with several genes showing upregulation under non-lethal heat shock (NLHS) and pathogen challenges. RNA-Seq and qPCR analyses confirmed increased expression of certain PcHsp70s during NLHS, indicating NLHS activation of the Hsp70 family to enhance immune regulation. dsRNA-mediated silencing of Hsp70 led to downregulation of TLR pathway genes (e.g., TLR1, TLR6), suggesting Hsp70 regulates the TLR signaling pathway for immune responses. These findings reveal that NLHS-induced Hsp70 upregulation improves pathogen resistance, offering insights for addressing temperature fluctuations and disease outbreaks in aquaculture to optimize management practices. 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: The peony (Paeonia suffruticosa Andr.), a globally valued woody ornamental species, suffers severe heat-induced floral damage that compromises its horticultural value. While the HSP20 proteins are critical for plant thermotolerance, their genomic organization and regulatory dynamics remain uncharacterized in the peony. This study aims to systematically identify the PsHSP20 genes, resolve their molecular features, and elucidate their heat-responsive expression patterns to enable targeted thermotolerance breeding. Methods: The genome-wide identification employed HMMER and BLASTP searches against the peony genome. The physicochemical properties and protein structures of the gene family were analyzed using online websites, such as Expasy, Plant-mPLoc, and SOPMA. The cis-regulatory elements were predicted using PlantCARE. Expression profiles under different times of 40 °C heat stress were validated by qRT-PCR (p < 0.05). Results: We identified 58 PsHSP20 genes, classified into 11 subfamilies. All members retain the conserved α-crystallin domain, and exhibit predominant nuclear/cytoplasmic localization. Chromosomal mapping revealed uneven distribution without lineage-specific duplications. The promoters were enriched in stress-responsive elements (e.g., HSE, ABRE) and in 24 TF families. The protein networks linked 13 PsHSP20s to co-expressed partners in heat response (GO:0009408) and ER protein processing (KEGG:04141). Transcriptomics demonstrated rapid upregulation of 48 PsHSP20s within 2 h of heat exposure, with PsHSP20-12, -34, and -51 showing the highest induction (>15-fold) at 6 h/24 h. Conclusions: This first genome-wide study resolves the architecture and heat-responsive dynamics of the PsHSP20 family. The discovery of early-induced genes (PsHSP20-12/-34/-51) provides candidates for thermotolerance enhancement. These findings establish a foundation for molecular breeding in the peony. Full article

Heat shock proteins belong to a highly conserved family of chaperone proteins, and in addition to their participation in the regulation of cellular proteostasis (folding of polypeptides and proteins, disaggregation of incorrectly folded peptides, and participation in autophagy processes), also play a significant immunomodulatory role in both innate and adaptive immunity. Changes in the HSP level, both downwards (e.g., in neurodegenerative diseases) and upwards (e.g., autoimmune, oncological diseases), underlie the pathogenesis of many somatic and oncological pathologies. In this review, we consider the main physiological mechanisms of HSP level regulation and also analyze pharmacological, genetically engineered methods of modulating the chaperone level, citing the advantages and disadvantages of a particular method of influence. In conclusion, modulation of the HSP level, according to numerous preclinical studies, can have a significant impact on the course of various pathological conditions, which, in turn, can be used to develop new therapeutic approaches, when the effect on the level of chaperones can be used as monotherapy or as an adjuvant method of action. Full article

Marine heatwaves (MHWs) have recently become more frequent, intense, and prolonged, posing significant threats to marine life and fisheries. In this study, transcriptomic analysis was employed to investigate the genes and pathways in Seriola dumerili that respond to MHW-induced stress at 28 °C (T28) and 32 °C (T32), using 24 °C (T24) as the control. Transcriptome sequencing revealed that 17 differentially expressed genes (DEGs) belonging to the heat shock protein (HSP) families—HSP30, HSP40, HSP70, and HSP90—were significantly upregulated under short-lasting MHW stress in the T24-4d vs. T32-4d comparison. Additionally, genes related to oxidative stress (e.g., protein disulfide isomerase family A member 6 [pdia6]), immune responses (e.g., interferon regulatory factor 5 [irf5]), and energy metabolism (e.g., hexokinase-1 [hk1]) were also identified. Enrichment analysis of DEGs in the T24-4d vs. T32-4d group revealed that S. dumerili exhibited adaptive responses to MHWs through the upregulation of HSPs and the activation of antioxidant, energy metabolism, and immune response pathways. However, in the T24-13d vs. T32-13d group, DEGs associated with these pathways were either not significantly expressed or were downregulated. These findings indicate that S. dumerili is unable to sustain its adaptive responses under repeated, intense MHW exposure, resulting in the disorder of its antioxidant defense system, immune suppression, and metabolic dysfunction. This study provides valuable insights into the molecular responses of S. dumerili to MHWs and supports the selection for thermal resistance in this species. 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

Ginger (Zingiber officinale Roscoe), valued both for its medicinal and culinary uses, can be adversely affected by abiotic stresses such as high temperature and drought, which can impact its growth and development. The HSP90 gene family has been recognized as a crucial element for enhancing heat and drought resistance in plants. Nevertheless, no studies have yet reported on the HSP90 gene family in ginger. This study investigates the HSP90 gene family in ginger and its crucial role in the plant’s responses to abiotic stresses. A total of 11 ZoHSP90 members were identified in the ginger genome, and these genes were unevenly distributed across five chromosomes. Bioinformatics analyses revealed that the HSP90 proteins in ginger vary in size, ranging from 306 to 886 amino acids. These proteins are predominantly located in the cytoplasm, endoplasmic reticulum, and mitochondria. Notably, ten conserved motifs were identified, with variations in motif distribution correlating with phylogenetic relationships among the genes. Furthermore, the gene structure analysis indicated differences in exon numbers, which may reflect specialized regulatory mechanisms and functional differentiation among the ZoHSP90 genes. Cis-acting elements within the promoter regions of the ZoHSP90 genes were identified, and their involvement in stress responses and hormonal signaling pathways was revealed. These elements are critical for regulating gene expression patterns in response to environmental stimuli, such as methyl jasmonate, salicylic acid, and abscisic acid. The presence of these elements indicates that ZoHSP90 genes play significant regulatory roles in plant adaptation to environmental changes. Expression profiling of the ZoHSP90 genes under various abiotic stress conditions demonstrated tissue specificity and dynamic regulation. Different ZoHSP90 genes exhibited distinct expression patterns in response to low-temperature, drought, high-temperature, and salt stresses. This suggests that the HSP90 gene family in ginger possesses both conserved functions and species-specific adaptations to optimize stress responses. Overall, this research provides valuable insights into the molecular functions of the HSP90 gene family in ginger and lays the groundwork for future studies aimed at enhancing crop resilience through genetic engineering. The findings contribute to a deeper understanding of plant adaptability to environmental stressors, which is crucial for improving agricultural productivity in the face of climate change. Full article

Phoebe bournei, a rare tree species native to China, holds considerable economic importance. The heat shock protein 70 (Hsp70) family is a group of molecular chaperones that is broadly distributed across living organisms and play a critical role in processes like growth, development, and stress response. While Hsp70 genes have been identified and studied in various plant species, their specific functions in the growth and development of P. bournei remain unexplored. We performed a comprehensive analysis of the Hsp70 gene family in P. bournei, identifying a total of 45 Hsp70 genes, which were classified into four groups (I–IV) through phylogenetic analysis. All Hsp70 proteins possessed conserved structural domains, including motif 7, and introns were present in 77.8% of the genes. Chromosomal localization and collinearity analyses of the Hsp70 genes revealed their evolutionary relationships and potential gene duplication events. Examination of the cis-acting elements within the Hsp70 promoter regions revealed that the predominant elements were associated with growth and development, followed by those responsive to hormones, and then elements linked to abiotic stress. Nine genes with high expression were selected for RT-qPCR analysis. Under high-temperature stress, all nine genes were differentially upregulated, and most of these genes belonged to subfamilies II and III, indicating that these two subfamilies have strong potential for heat resistance. In this study, we have elucidated the molecular characteristics and heat response properties of the Hsp70 gene family in P. bournei, revealing the mechanisms behind its heat stress response. Our work provides a reference for stress breeding in P. bournei and a theoretical basis for the exploration of heat tolerance in woody plants. Full article

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and is associated with several gastric diseases, including gastritis, peptic ulcer disease, and gastric cancer. The bacterium’s ability to thrive in the harsh gastric environment is due, to some extent, to its stress response mechanisms, with its heat shock proteins (HSPs) playing a putative, yet not fully understood, role in these adaptive processes. HSPs are a family of molecules, highly conserved throughout phylogenesis, that assist in protein folding, prevent aggregation, and ensure cellular homeostasis under stressful conditions. In H. pylori, HSPs contribute to survival in the stomach’s acidic environment and oxidative stress. Furthermore, they aid in the bacterium’s ability to adhere to gastric epithelial cells, modulate the host immune response, and form biofilms, all contributing to chronic infection and pathogenicity. The role of microbial HSPs in antibiotic resistance has also emerged as a critical area of research, as these proteins help stabilize efflux pumps, protect essential proteins targeted by antibiotics, and promote biofilm formation, thereby reducing the efficacy of antimicrobial treatments. Among bacterial HSPs, GroEL and DnaK are probably the major proteins that control most of the H. pylori’s functioning. Indeed, both proteins possess remarkable acid resistance, high substrate affinity, and dual roles in protein homeostasis and host interaction. These features make them critical for H. pylori’s adaptation, persistence, and pathogenicity in the gastric niche. In addition, recent findings have also highlighted the involvement of HSPs in the crosstalk between H. pylori and gastric epithelial cells mediated by the release of bacterial outer membrane vesicles and host-derived exosomes, both of these extracellular vesicles being part of the muco-microbiotic layer of the stomach and influencing cellular signalling and immune modulation. Considering their critical role in the survival and persistence of bacteria, microbial HSPs also represent potential therapeutic targets. Strategies aimed at inhibiting microbial HSP function, combined with conventional antibiotics or developing vaccines targeting microbial HSPs, could provide new avenues for the treatment of H. pylori infections and combat antibiotic resistance. This review explores the multifaceted roles of microbial HSPs in the pathogenesis of H. pylori, highlighting their contributions to bacterial adhesion, immune evasion, stress response, and antibiotic resistance. Full article

Background/Objectives: Desiccation profoundly influences the distribution and abundance of intertidal seaweeds, necessitating robust molecular adaptations. Sargassum muticum is a brown seaweed inhabiting intertidal rocky substrates. During low tides, this species undergoes periodic aerial exposure. Such environmental conditions necessitate robust physiological mechanisms to mitigate desiccation stress. Yet, the molecular basis of this adaptation remains poorly understood. Methods: To investigate desiccation-responsive genes and elucidate the underlying mechanisms of adaptation, we exposed S. muticum to 6 h of controlled desiccation stress in sterilized ceramic trays, simulating natural tidal conditions, and performed comparative transcriptome analysis using RNA-seq on the Illumina NovaSeq 6000 platform. Results: High-quality sequencing identified 66,192 unigenes, with 1990 differentially expressed genes (1399 upregulated and 591 downregulated). These differentially expressed genes (DEGs) were categorized into regulatory genes—including mitogen-activated protein kinase (MAPK), calmodulin, elongation factor, and serine/threonine-protein kinase—and functional genes, such as heat shock protein family members (HSP20, HSP40, and HSP70), tubulin (TUBA and TUBB), and endoplasmic reticulum homeostasis-related genes (protein disulfide-isomerase A6, calreticulin, and calnexin). Gene Ontology (GO) enrichment highlighted upregulated DEGs in metabolic processes like glutathione metabolism, critical for oxidative stress mitigation, while downregulated genes were linked to transport functions, such as ammonium transport, suggesting reduced nutrient uptake during dehydration. KEGG pathway analysis revealed significant enrichment in “protein processing in endoplasmic reticulum” and “MAPK signaling pathway-plant”, implicating endoplasmic reticulum stress response and conserved signaling cascades in desiccation adaptation. Validation via qRT-PCR confirmed consistent expression trends for key genes, reinforcing the reliability of transcriptomic data. Conclusions: These findings suggest that S. muticum undergoes extensive biological adjustments to mitigate desiccation stress, highlighting candidate pathways for future investigations into recovery and tolerance mechanisms. Full article