Small Hsps Research Articles

Heat Shock Proteins and Breast Cancer.

Heat shock proteins (Hsps) are a group of stress-induced proteins involved in protein folding and maturation. Based on their molecular weight, Hsps can be divided into six families: small Hsps, Hsp40, Hsp60, Hsp70, Hsp90, and large Hsps. In the process of breast cancer tumorigenesis, Hsps play a central role in regulating cell reactions and functions including proliferation, metastasis, and apoptosis. Moreover, some of the critical Hsps also regulate the fine balance between the protective and destructive immunological responses within the tumor microenvironment. In this review, we systematically summarize the roles of major Hsps in breast cancer biology and point out the potential uses of these proteins in breast cancer diagnosis and therapy. Understanding the roles of different families of Hsps in breast cancer pathogenesis will help in the development of more effective prevention and treatment measures for breast cancer.

Small heat shock proteins as modulators of cell death in Plasmodium falciparum parasites and its human host

Plasmodium falciparum, the predominant cause of severe malaria, thrives within both poikilotherm mosquitoes and homeotherm humans, navigating challenging temperature shifts during its life cycle. Survival in such varying environments necessitate the development of robust mechanisms, including a sophisticated protein folding system to mitigate proteopathy. The parasite needs to control the survival of its host cells which affects its chances of development and propagation. Central to this system are heat shock proteins (Hsps), among which small Hsps (sHsps) play pivotal roles in maintaining proteostasis (protein homeostasis). In both humans and P. falciparum, numerous sHsps have been identified, making them attractive candidates as biomarkers for diagnostic and drug development strategies. Evidence is accumulating suggesting that these sHsps participate in cell death processes, potentially influencing disease pathogenesis. Despite their significance, the precise functions of sHsps in P. falciparum’s adaptation to stress conditions remains largely unknown. Comparative structural analysis of sHsps between human and P. falciparum reveals species-specific variations. Despite conserved tertiary structures, unique motifs are found in parasite sHsps which may modulate specialised chaperone functions. This review discusses the conserved and distinctive motifs of sHsps from the human host and the parasite, offering insights into shared and unique attributes. These findings illuminate the potential for species-specific targeting of sHsps, as players in cell death processes that may foster innovative biomarker identification approaches. As malaria continues to ravage Sub-Saharan Africa, understanding the molecular intricacies guiding parasite survival are essential in the development of interventions with heightened efficacy against this global health crisis.

StHsfB5 Promotes Heat Resistance by Directly Regulating the Expression of Hsp Genes in Potato.

With global warming, high temperatures have become a major environmental stress that inhibits plant growth and development. Plants evolve several mechanisms to cope with heat stress accordingly. One of the important mechanisms is the Hsf (heat shock factor)-Hsp (heat shock protein) signaling pathway. Therefore, the plant transcription factor Hsf family plays important roles in response to heat stress. All Hsfs can be divided into three classes (A, B, and C). Usually, class-A Hsfs are transcriptional activators, while class-B Hsfs are transcriptional repressors. In potato, our previous work identified 27 Hsfs in the genome and analyzed HsfA3 and HsfA4C functions that promote potato heat resistance. However, the function of HsfB is still elusive. In this study, the unique B5 member StHsfB5 in potato was obtained, and its characterizations and functions were comprehensively analyzed. A quantitative real-time PCR (qRT-PCR) assay showed that StHsfB5 was highly expressed in root, and its expression was induced by heat treatment and different kinds of phytohormones. The subcellular localization of StHsfB5 was in the nucleus, which is consistent with the characterization of transcription factors. The transgenic lines overexpressing StHsfB5 showed higher heat resistance compared with that of the control nontransgenic lines and inhibitory lines. Experiments on the interaction between protein and DNA indicated that the StHsfB5 protein can directly bind to the promoters of target genes small Hsps (sHsp17.6, sHsp21, and sHsp22.7) and Hsp80, and then induce the expressions of these target genes. All these results showed that StHsfB5 may be a coactivator that promotes potato heat resistance ability by directly inducing the expression of its target genes sHsp17.6, sHsp21, sHsp22.7, and Hsp80.

Co-chaperone BAG3 enters autophagic pathway via its interaction with microtubule associated protein 1 light chain 3 beta.

The co-chaperone BAG3 is a hub for a variety of cellular pathways via its multiple domains and its interaction with chaperones of the HSP70 family or small HSPs. During aging and under cellular stress conditions in particular, BAG3, together with molecular chaperones, ensures the sequestration of aggregated or aggregation-prone ubiquitinated proteins to the autophagic-lysosomal system via ubiquitin receptors. Accumulating evidence for BAG3-mediated selective autophagy independent of cargo ubiquitination led to analyses predicting a direct interaction of BAG3 with LC3 proteins. Phylogenetically, BAG3 comprises several highly conserved potential LIRs, LC3-interacting regions, which might allow for the direct targeting of BAG3 including its cargo to autophagosomes and drive their autophagic degradation. Based on pull-down experiments, peptide arrays and proximity ligation assays, our results provide evidence of an interaction of BAG3 with LC3B. In addition, we could demonstrate that disabling all predicted LIRs abolished the inducibility of a colocalization of BAG3 with LC3B-positive structures and resulted in a substantial decrease of BAG3 levels within purified native autophagic vesicles compared with wild-type BAG3. These results suggest an autophagic targeting of BAG3 via interaction with LC3B. Therefore, we conclude that, in addition to being a key co-chaperone to HSP70, BAG3 may also act as a cargo receptor for client proteins, which would significantly extend the role of BAG3 in selective macroautophagy and protein quality control.

HSP90 Antisense Oligonucleotide Enhances the Inhibitory Effect of Photothermal Therapy on Triple-Negative Breast Cancer Cells

Photothermal therapy is a potential strategy to treat triple-negative breast cancer. The expression of HSP90 in the tumor cells has been identified as a culprit for reducing the effectiveness of photothermal therapy, so using reagents with photothermal conversion to deliver HSP inhibitors can achieve good tumor suppression. However, the potential toxicity of small molecule HSPs inhibitors limits their further application development. Therefore, this study constructed a nanoplatform by graphene oxide (GO) to deliver antisense oligonucleotide (ASO) of HSP90 to improve the therapeutic effect. The photothermal performance of GO was confirmed by infrared thermal imager. MTT results showed that tumor cell viability was lower after the addition of ASO under irradiation. In addition, the result of western blot revealed that the expression of HSP90 decreased by 32% compared to the blank group under the action of ASO. All the above results indicated that our strategy enhances the inhibition of triple-negative breast cancer cells via suppressing the expression of HSP90 in photothermal therapy.

Heat shock proteins as diagnostic and prognostic markers in malignant tumors of the central nervous system

This review overview current epidemiology data of malignant tumors of the central nervous system, and determines the significance of molecular diagnostics and expression of heat shock proteins in tumorigenesis. Particular attention is paid to the description of molecular chaperones as diagnostic and prognostic markers, as well as the prospects for chaperones using in personalized therapy the central nervous system tumors. The search for literature was carried out on the database platforms Medline (via PubMed) and Scopus, Cochrane Library, The Lancet Public Health Journal published between 1988 and 2022. The material was searched for keywords and terms, including “heat shock proteins”, “tumors of the central nervous system”, “brain tumors”, “molecular diagnostics”, “expression of molecular chaperones”, Hsp110, Hsp90, Hsp70, Hsp60, Hsp40, small HSPs. Molecular chaperones, due to their important role in physiological processes in the cell, are highly expressed in brain tumors, and the expression level of HSPs strongly correlates with the degree of malignancy, invasive potential, and resistance to radiochemotherapy. For some HSPs (i.e. HSP10, HSPB1, DNAJC10, HSPA7, HSP90) a direct correlation has been found between the level of protein expression (based on IHC analysis) and a poor overall survival prognosis for patients with glial tumors. This indicates the prognostic value of these markers, which in the future may be included in the diagnostic panel when examining a tumor sample.

Plant Responses to High-Temperature Stress

Temperature above optimal for the specie will reduce photosynthesis and increase dark respiration and photorespiration in part due to increased solubility of O2 compared to CO2 but also due to the decrease in CO2 mesophyll conductance to the chloroplast. In addition, night temperature has a great impact on carbohydrates balance because high night temperature reduces the efficiency of the generation of ATP from respiration consuming more sugars to maintain growth. Another effect on species that have their cycle sensitive to temperature, inducing the reproductive phase soon or later depending on air temperature. The majority of plants adapted to high temperatures above their optimum synthesize small HSPs, which will maintain the integrity and reactivity of bigger enzymes and membranes. Therefore, plant adaptation to high temperatures is a multigenic characteristic depending on biochemical, physiological, and morphological traits.

Relationships between the abundance of 29 proteins and several meat or carcass quality traits in two bovine muscles revealed by a combination of univariate and multivariate analyses

We aimed to evaluate the relationships between meat or carcass properties and the abundance of 29 proteins quantified in two muscles, Longissimus thoracis and Rectus abdominis, of Rouge des Prés cows. The relative abundance of the proteins was evaluated using a high throughput immunological method: the Reverse Phase Protein array. A combination of univariate and multivariate analyses has shown that small HSPs (CRYAB, HSPB6), fast glycolytic metabolic and structural proteins (MYH1, ENO3, ENO1, TPI1) when assayed both in RA and LT, were related to meat tenderness, marbling, ultimate pH, as well as carcass fat-to-lean ratio or conformation score. In addition to some small HSP, ALDH1A1 and TRIM72 contributed to the molecular signature of muscular and carcass adiposity. MYH1 and HSPA1A were among the top proteins related to carcass traits. We thus shortened the list to 10 putative biomarkers to be considered in future tools to manage both meat and carcass properties. SignificanceIn three aspects this manuscript is notable. First, this is the first proteomics study that aims to evaluate putative biomarkers of both meat and carcass qualities that are of economic importance for the beef industry. Second, the relationship between the abundance of proteins and the carcass or meat traits were evaluated by a combination of univariate and multivariate analyses on 48 cows that are representative of the biological variability of the traits. Third, we provide a short list of ten proteins to be tested in a larger population to feed the pipeline of biomarker discovery.

Growth-enhancing effect of bacterial and plant heat shock proteins in Escherichia coli

Heat shock proteins (Hsps) are frequent targets to be manipulated in Escherichia coli (E. coli) to improve the production of recombinant proteins and secondary metabolites for industrial applications. In this study, we examined if the heterologous expression of eukaryotic Hsps can effectively enhance bacterial growth, compared to overexpression of endogenous bacterial Hsps. Five transgenic E. coli cell lines (TCs), individually expressing recombinant bacterial Hsps (IbpA, IbpB, and DnaK) and plant Hsps [carrot (Daucus carota L.: Dc) Hsp17.7 and Hsp70], were generated to compare the growth-enhancing effect of each protein. Under normal and heat conditions, the TC expressing DcHsp17.7 showed the highest growth rate and maximum cell density. Under cold, acetate, and ethanol conditions, the TC overexpressing IbpA showed the highest growth rate. TCs expressing Hsps showed higher protein levels than the control. The amino acid sequence comparison shows that bacterial and plant small(s) Hsps are less conserved than larger Hsp70s. Conserved 13 a.a. sequences in the N-terminal domain of plant sHsps were not present in the bacterial IbpA and IbpB, suggesting possible differences in the functions of plant and bacterial sHsps. Results show that different Hsps could be employed to maximize bacterial cell growth for varied industrial applications.

Binding of the HSF-1 DNA-binding domain to multimeric C. elegans consensus HSEs is guided by cooperative interactions

The protein HSF-1 is the controlling transcription factor of the heat-shock response (HSR). Its binding to the heat-shock elements (HSEs) induces the strong upregulation of conserved heat-shock proteins, including Hsp70s, Hsp40s and small HSPs. Next to these commonly known HSPs, more than 4000 other HSEs are found in the promoter regions of C. elegans genes. In microarray experiments, few of the HSE-containing genes are specifically upregulated during the heat-shock response. Most of the 4000 HSE-containing genes instead are unaffected by elevated temperatures and coexpress with genes unrelated to the HSR. This is also the case for several genes related to the HSP chaperone system, like dnj-12, dnj-13, and hsp-1. Interestingly, several promoters of the dedicated HSR-genes, like F44E5.4p, hsp-16.48p or hsp-16.2p, contain extended HSEs in their promoter region, composed of four or five HSE-elements instead of the common trimeric HSEs. We here aim at understanding how HSF-1 interacts with the different promoter regions. To this end we purify the nematode HSF-1 DBD and investigate the interaction with DNA sequences containing these regions. EMSA assays suggest that the HSF-1 DBD interacts with most of these HSE-containing dsDNAs, but with different characteristics. We employ sedimentation analytical ultracentrifugation (SV-AUC) to determine stoichiometry, affinity, and cooperativity of HSF-1 DBD binding to these HSEs. Interestingly, most HSEs show cooperative binding of the HSF-1 DBD with up to five DBDs being bound. In most cases binding to the HSEs of inducible promoters is stronger, even though the consensus scores are not always higher. The observed high affinity of HSF-1 DBD to the non-inducible HSEs of dnj-12, suggests that constitutive expression may be supported from some promoter regions, a fact that is evident for this transcription factor, that is essential also under non-stress conditions.

Small HSPs play an important role in crosstalk between HSF-HSP and ROS pathways in heat stress response through transcriptomic analysis in lilies (Lilium longiflorum)

BackgroundHigh temperature seriously limits the annual production of fresh cut lilies, which is one of the four major cut flowers in the global cut flower market. There were few transcriptomes focused on the gene expression of lilies under heat stress. In order to reveal the potential heat response patterns in bulbous plants and provide important genes for further genetic engineering techniques to improve thermotolerance of lily, RNA sequencing of lilies under heat treatments were conducted.ResultsIn this study, seedlings of Lilium longiflorum ‘White Heaven’ were heat-treated at 37 °C for different lengths of time (0 h, 0.5 h, 1 h, 3 h, 6 h, and 12 h with a 12 h-light/12 h-dark cycle). The leaves of these lily seedlings were immediately collected after heat treatments and quickly put into liquid nitrogen for RNA sequencing. 109,364,486–171,487,430 clean reads and 55,044 unigenes including 21,608 differentially expressed genes (DEGs) (fold change ≥2) were obtained after heat treatment. The number of DEGs increased sharply during the heat treatments of 0.5 h–1 h and 1 h–3 h compared to that of other periods. Genes of the heat stress transcription factor (HSF) family and the small heat shock proteins (small HSPs, also known as HSP20) family responded to heat stress early and quickly. Compared to that of the calcium signal and hormone pathways, DEGs of the HSF-HSP pathway and reactive oxygen species (ROS) pathway were significantly and highly induced. Moreover, they had the similar expression pattern in response to heat stress. Small HSPs family genes were the major components in the 50 most highly induced genes at each heat stress treatment and involved in ROS pathway in the rapid response to heat stress. Furthermore, the barley stripe mosaic virus induced gene silencing (BSMV-VIGS) of LlHsfA2 caused a significantly reduced thermotolerance phenotype in Lilium longiflorum ‘White Heaven’, meanwhile decreasing the expression of small HSPs family genes and increasing the ROS scavenging enzyme ascorbate peroxidase (APX) genes, indicating the potential interplay between these two pathways.ConclusionsBased on our transcriptomic analysis, we provide a new finding that small HSPs play important roles in crosstalk between HSF-HSP and ROS pathways in heat stress response of lily, which also supply the groundwork for understanding the mechanism of heat stress in bulbous plants.

Heat shock proteins and the calcineurin-crz1 signaling regulate stress responses in fungi.

The heat shock proteins (Hsps) act as a molecular chaperone to stabilize client proteins involved in various cell functions in fungi. Hsps are classified into different families such as HSP90, HSP70, HSP60, HSP40, and small HSPs (sHsps). Hsp90, a well-studied member of the Hsp family proteins, plays a role in growth, cell survival, and pathogenicity in fungi. Hsp70 and sHsps are involved in the development, tolerance to stress conditions, and drug resistance in fungi. Hsp60 is a mitochondrial chaperone, and Hsp40 regulates fungal ATPase machinery. In this review, we describe the cell functions, regulation, and the molecular link of the Hsps with the calcineurin-crz1 calcium signaling pathway for their role in cell survival, growth, virulence, and drug resistance in fungi and related organisms.

MicroRNAs and Heat Shock Proteins in Breast Cancer Biology.

Breast cancer has five major immune types; luminal A, luminal B, HER2, Basal-like, and normal-like. Cells produce a family of protein called heat shock proteins (Hsps) in response to exposure to thermal and other proteotoxic stresses play essential roles in cancer metabolism and this large family shows a diverse set of Hsp involvement in different breast cancer immune types. Recently, Hsp members categorized according to their immune type roles. Hsp family consists of several subtypes formed by molecular weight; Hsp70, Hsp90, Hsp100, Hsp40, Hsp60, and small molecule Hsps. Cancer cells employ Hsps as survival factors since most of these proteins prevent apoptosis. Several studies monitored Hsp roles in breast cancer cells and reported Hsp27 involvement in drug resistance, Hsp70 in tumor cell transformation-progression, and interaction with p53. Furthermore, the association of Hsp90 with steroid receptors and signaling proteins in patients with breast cancer directed research to focus on Hsp-based treatments. miRNAs are known to play key roles in all types of cancer that are upregulated or downregulated in cancer which respectively referred to as oncogenes (oncomirs) or tumor suppressors. Expression profiles of miRNAs may be used to classify, diagnose, and predict different cancer types. It is clear that miRNAs play regulatory roles in gene expression and this work reveals miRNA correlation to Hsp depending on specific breast cancer immune types. Deregulation of specific Hsp genes in breast cancer subtypes allows for identification of new targets for drug design and cancer treatment. Here, we performed miRNA network analysis by recruiting Hsp genes detected in breast cancer subtypes and reviewed some of the miRNAs related to aforementioned Hsp genes.

The role of Bag3 in cell signaling.

Bag3 has been implicated in a wide variety of physiological processes from autophagy to aggresome formation and from cell transformation to survival. We argue that involvement of Bag3 in many of these processes is due to its distinct function in cell signaling. The structure of Bag3 suggests that it can serve as a scaffold that links molecular chaperones Hsp70 and small Hsps with components of a variety of signaling pathways. Major protein-protein interaction motifs of Bag3 that recruit components of signaling pathways are WW domain and PXXP motif that interacts with SH3-domain proteins. Furthermore, Hsp70-Bag3 appears to be a sensor of abnormal polypeptides during the proteotoxic stress. It also serves as a sensor of a mechanical force during mechanotransduction. Common feature of these and probably certain other sensory mechanisms is that they represent responses to specific kinds of abnormal proteins, i.e. unfolded filamin A in case of mechanotransduction or stalled translating polypeptides in case of sensing proteasome inhibition. Overall Hsp70-Bag3 module represents a novel signaling node that responds to multiple stimuli and controls multiple physiological processes.

Heat Shock Proteins: Potential Modulators and Candidate Biomarkers of Peripartum Cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is a potentially life-threatening condition in which heart failure and systolic dysfunction occur late in pregnancy or within months following delivery. To date, no reliable biomarkers or therapeutic interventions for the condition exist, thus necessitating an urgent need for identification of novel PPCM drug targets and candidate biomarkers. Leads for novel treatments and biomarkers are therefore being investigated worldwide. Pregnancy is generally accompanied by dramatic hemodynamic changes, including a reduced afterload and a 50% increase in cardiac output. These increased cardiac stresses during pregnancy potentially impair protein folding processes within the cardiac tissue. The accumulation of misfolded proteins results in increased toxicity and cardiac insults that trigger heart failure. Under stress conditions, molecular chaperones such as heat shock proteins (Hsps) play crucial roles in maintaining cellular proteostasis. Here, we critically assess the potential role of Hsps in PPCM. We further predict specific associations between the Hsp types Hsp70, Hsp90 and small Hsps with several proteins implicated in PPCM pathophysiology. Furthermore, we explore the possibility of select Hsps as novel candidate PPCM biomarkers and drug targets. A better understanding of how these Hsps modulate PPCM pathogenesis holds promise in improving treatment, prognosis and management of the condition, and possibly other forms of acute heart failure.

Comparative transcriptome analysis of cells from different areas reveals ROS responsive mechanism at sclerotial initiation stage in Morchella importuna

Morels are some of the most highly prized edible and medicinal mushrooms, with great economic and scientific value. Outdoor cultivation has been achieved and expanded on a large scale in China in recent years. Sclerotial formation is one of the most important phases during the morel life cycle, and previous reports indicated that reactive oxygen species (ROS) play an important role. However, ROS response mechanisms at sclerotial initiation (SI) stage are poorly understood. In this study, comparative transcriptome analyses were performed with sclerotial and hyphal cells at different areas in the same plate at SI stage. Gene expression was significantly different at SI stage between sclerotial formation and mycelia growth areas. GO and KEGG analyses indicated more vigorous metabolic characteristics in the hyphae area, while transcription process, DNA repair, and protein processing were enriched in sclerotial cells. Gene expression related to H2O2 production was high in the hyphae area, while expression of H2O2-scavenging genes was high in sclerotial cells, leading to a higher H2O2 concentration in the hyphal region than in the sclerotium. Minor differences were observed in gene expression of H2O2-induced signaling pathway in sclerotial and hyphal cells; however, expression levels of the target genes of transcription factor MSN2, important in the H2O2-induced signaling pathways, were significantly different. MSN2 enhanced stress response regulation in sclerotia by regulating these target genes. Small molecular HSPs were also found upregulated in sclerotial cells. This study indicated that sclerotial cells are more resistant to ROS stress than hyphal cells through transcriptional regulation of related genes.

Small Hsps as Therapeutic Targets of Cystic Fibrosis Transmembrane Conductance Regulator Protein.

Human small heat shock proteins are molecular chaperones that regulate fundamental cellular processes in normal and pathological cells. Here, we have reviewed the role played by HspB1, HspB4 and HspB5 in the context of Cystic Fibrosis (CF), a severe monogenic autosomal recessive disease linked to mutations in Cystic Fibrosis Transmembrane conductance Regulator protein (CFTR) some of which trigger its misfolding and rapid degradation, particularly the most frequent one, F508del-CFTR. While HspB1 and HspB4 favor the degradation of CFTR mutants, HspB5 and particularly one of its phosphorylated forms positively enhance the transport at the plasma membrane, stability and function of the CFTR mutant. Moreover, HspB5 molecules stimulate the cellular efficiency of currently used CF therapeutic molecules. Different strategies are suggested to modulate the level of expression or the activity of these small heat shock proteins in view of potential in vivo therapeutic approaches. We then conclude with other small heat shock proteins that should be tested or further studied to improve our knowledge of CFTR processing.

General Structural and Functional Features of Molecular Chaperones.

Molecular chaperones are a group of structurally diverse and highly conserved ubiquitous proteins. They play crucial roles in facilitating the correct folding of proteins in vivo by preventing protein aggregation or facilitating the appropriate folding and assembly of proteins. Heat shock proteins form the major class of molecular chaperones that are responsible for protein folding events in the cell. This is achieved by ATP-dependent (folding machines) or ATP-independent mechanisms (holders). Heat shock proteins are induced by a variety of stresses, besides heat shock. The large and varied heat shock protein class is categorised into several subfamilies based on their sizes in kDa namely, small Hsps (HSPB), J domain proteins (Hsp40/DNAJ), Hsp60 (HSPD/E; Chaperonins), Hsp70 (HSPA), Hsp90 (HSPC), and Hsp100. Heat shock proteins are localised to different compartments in the cell to carry out tasks specific to their environment. Most heat shock proteins form large oligomeric structures, and their functions are usually regulated by a variety of cochaperones and cofactors. Heat shock proteins do not function in isolation but are rather part of the chaperone network in the cell. The general structural and functional features of the major heat shock protein families are discussed, including their roles in human disease. Their function is particularly important in disease due to increased stress in the cell. Vector-borne parasites affecting human health encounter stress during transmission between invertebrate vectors and mammalian hosts. Members of the main classes of heat shock proteins are all represented in Plasmodium falciparum, the causative agent of cerebral malaria, and they play specific functions in differentiation, cytoprotection, signal transduction, and virulence.

Isolation and Characterization of a Rice Mitochondrial Small Heat Shock Protein Gene

To understand the role of small heat shock protein (sHSPs) in rice plant response to various stresses such as the heat and oxidative stresses, a cDNA encoding a 24.1 kDa mitochondrial small HSP (Oshsp24.1) was isolated from rice by rapid amplification of cDNA ends (RACE) PCR. The deduced amino acid sequence shows very high similarity with other plant small HSPs. DNA gel blot analysis suggests that the rice genome contains more than one copy of Oshsp24.1. High level of expression of Oshsp24.1 transcript was observed in rice seedlings in response to heat, methyl viologen, hydrogen peroxide, ozone, salt and heavy metal stresses. Recombinant OsHSP24.1 protein was produced in E. coli cells for biochemical assay. The protein formed oligomeric complex when incubated with Sulfo-EGS (ethylene glycol bis (succinimidyl succinate)). Our results shows that Oshsp24.1 has an important role in abiotic stress response and have potential for developing stress-tolerant plants.

High‐temperature resilience in Bacillus safensis primed wheat plants: A study of dynamic response associated with modulation of antioxidant machinery, differential expression of HSPs and osmolyte biosynthesis

Changing climate scenario is posing a major threat to agricultural sector worldwide. Wheat, a weather sensitive crop, is envisaged to face significant yield loss in coming decades due to accelerating global average temperature. In recent years Plant Growth Promoting Bacteria (PGPR) have been successfully used in sustainable crop improvement programme and abiotic stress alleviation. However, PGPR mediated thermal adaptation and underlying crosstalk of diverse signalling networks have mostly remained obscure. Hence, this study aims to investigate the adaptive modifications of PGPR primed wheat plants at biochemical and gene expression levels which make them more resilient to high temperature. Our findings suggested that B. safenisis priming mostly dealt with shielding the cellular functions and particularly chloroplast organization from heat induced oxidative injury. B. safensis priming positively modulated expressions of HSPs and small HSPs before and during heat stress. Better performance of various redox enxymes and antioxidants associated with ascorbate - glutathione cycle together with low proline profusion due to high PDH expression provided efficient heat adaptive path without generation of excessive ROS. Bacterial priming elicited expression of ADC1 and ADC2 linked to putrescine synthesis and also significantly enhanced accumulation GB, TSS and phenols in response to heat stress. B. safensis priming induced multilevel systematic modulation minimizes heat injury, chloroplast damage and improved heat endurance.