Class Glutathione S-transferase Research Articles

Molecular and biochemical characterization of a plant-like iota-class glutathione S-transferase from the halotolerant cyanobacterium Halothece sp. PCC7418.

This study identifies a unique glutathione S-transferase (GST) in extremophile using genome, phylogeny, bioinformatics, functional characterization, and RNA sequencing analysis. Five putative GSTs (H0647, H0729, H1478, H3557, and H3594) were identified in Halothece sp. PCC7418. Phylogenetic analysis suggested that H0647, H1478, H0729, H3557, and H3594 are distinct GST classes. Of these, H0729 was classified as an iota-class GST, encoding a high molecular mass GST protein with remarkable features. The protein secondary structure of H0729 revealed the presence of a glutaredoxin (Grx) Cys-Pro-Tyr-Cys (C-P-Y-C) motif that overlaps with the N-terminal domain and harbors a topology similar to the thioredoxin (Trx) fold. Interestingly, recombinant H0729 exhibited a high catalytic efficiency for both glutathione (GSH) and 1-chloro-2, 4-dinitrobenzene (CDNB), with catalytic efficiencies that were 155- and 32-fold higher, respectively compared to recombinant H3557. Lastly, the Halothece gene expression profiles suggested that antioxidant and phase II detoxification encoding genes are crucial in response to salt stress. Iota-class GST was identified in cyanobacteria. This GST exhibited a high catalytic efficiency toward xenobiotic substrates. Our findings shed light a diversified evolution of GST in cyanobacteria and provide functional dynamics of the genes encoding the enzymatic antioxidant and detoxification systems under abiotic stresses.

Zeta class glutathione S-transferase is involved in phoxim tolerance and is potentially regulated by the transcription factor CncC in Agrotis ipsilon (Lepidoptera: Noctuidae)

The black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae), is an important agricultural pest. Phoxim is an organophosphate insecticide that has been widely used to control A. ipsilon. The extensive application of phoxim has resulted in a reduction in phoxim susceptibility in A. ipsilon. However, the molecular mechanisms underlying phoxim tolerance in A. ipsilon remain unclear. In this work, we report the involvement of AiGSTz1, a zeta class glutathione S-transferase, in phoxim tolerance in A. ipsilon. Exposure to a sublethal concentration (LC50) of phoxim dramatically upregulated the transcription level of the AiGSTz1 gene in A. ipsilon larvae, and this upregulation might be caused by phoxim-induced oxidative stress. The recombinant AiGSTz1 protein expressed in Escherichia coli was able to metabolize phoxim. Furthermore, AiGSTz1 displayed antioxidant activity to protect against oxidative stress. Knockdown of AiGSTz1 by RNA interference significantly increased the mortality rate of A. ipsilon larvae in response to phoxim. In addition, the transcription factor AiCncC can bind to the cap ‘n’ collar isoform C: muscle aponeurosis fibromatosis (CncC:Maf) binding site in the putative promoter of the AiGSTz1 gene. Silencing of AiCncC resulted in a dramatic downregulation of AiGSTz1. These results indicated that AiGSTz1 is involved in phoxim tolerance and is potentially regulated by AiCncC. These findings provide valuable insights into the defense mechanisms used by A. ipsilon against phoxim.

CIPK11 phosphorylates GSTU23 to promote cold tolerance in Camellia sinensis.

Cold stress negatively impacts the growth, development, and quality of Camellia sinensis (Cs, tea) plants. CBL-interacting protein kinases (CIPK) comprise a pivotal protein family involved in plant development and response to multiple environmental stimuli. However, their roles and regulatory mechanisms in tea plants (Camellia sinensis (L.) O. Kuntze) remain unknown. Here we show that CsCBL-interacting protein kinase 11 (CsCIPK11), whose transcript abundance was significantly induced at low temperatures, interacts and phosphorylates tau class glutathione S-transferase 23 (CsGSTU23). CsGSTU23 was also a cold-inducible gene and has significantly higher transcript abundance in cold-resistant accessions than in cold-susceptible accessions. CsCIPK11 phosphorylated CsGSTU23 at Ser37, enhancing its stability and enzymatic activity. Overexpression of CsCIPK11 in Arabidopsis thaliana resulted in enhanced cold tolerance under freezing conditions, while transient knockdown of CsCIPK11 expression in tea plants had the opposite effect, resulting in decreased cold tolerance and suppression of the C-repeat-binding transcription factor (CBF) transcriptional pathway under freezing stress. Furthermore, the transient overexpression of CsGSTU23 in tea plants increased cold tolerance. These findings demonstrate that CsCIPK11 plays a central role in the signaling pathway to cold signals and modulates antioxidant capacity by phosphorylating CsGSTU23, leading to improved cold tolerance in tea plants.

Impact of the deletion glutathione S-transferase (class Mu) on lung cancer risk among smokers

BackgroundThe results of several studies assessing the effect of the glutathione S-transferase class Mu 1 (GSTM1) null variant on the genetic susceptibility of tobacco-related cancers have been conflicting. In this work, we aim to identify the impact of the deletion of GSTM1 on lung cancer risk among smokers.MethodsThis study was conducted on 20 patients diagnosed with primary lung cancer and 20 healthy individuals as a control group. They were subject to full medical history taking, complete clinical examination, and GSTM1 genotyping by PCR.ResultsBoth studied groups were matched for age, sex, and smoking status. No statistically significant difference was exhibited between the frequency of GSTM1 positive and GSTM1 null in the studied population. No risk of lung cancer associated with GSTM1 null genotype was demonstrated between the patients and control group (n = 14/20 cases) (p = 0.110, OR = 2.852, 95% CI 0.777–10.467). Additionally, there was no association between the risk of lung cancer and the presence of the gene either in smokers (p = 1, OR = 1.8 and 95% CI 0.124–26.196) or non-smokers; (p = 0.063, OR = 4.4 and 95% CI 0.889–21.78). No statistically significant risk was found between the frequencies of GSTM1 null and the various histopathological types of lung malignancy.ConclusionThe results of this work demonstrated no association between the occurrence of the GSTM1 null variant, even when stratified for smoking status, and the risk of lung cancer.

Cr(VI) behaves differently than Cr(III) in the uptake, translocation and detoxification in rice roots

Excessive accumulation of chromium (Cr) causes severe damage to both physiological and biochemical processes and consequently growth repression in plants. Hexavalent chromium [Cr(VI)]-elicited alterations in plants have been widely elucidated at either physiological or molecular level, whereas little is known about trivalent chromium [Cr(III)]. Here, we found that both Cr(III) and Cr(VI) significantly inhibited root growth in rice plants. However, rice plants under Cr(VI) showed significantly less inhibition in root growth than those under Cr(III) at low levels, which might be attributed to the different hormetic effects of Cr(III) and Cr(VI) on rice plants. It was unexpected that Cr(III) could be actively taken up by rice roots similarly to Cr(VI); whereas they exhibited different kinetic uptake patterns. Furthermore, root-to-shoot Cr translocation under Cr(VI) was much lower than that under Cr(III). These results indicate that the uptake, translocation, and toxicity of Cr(III) differed greatly from those of Cr(VI). Transcriptome profiling of rice roots revealed that a series of gene families involved in detoxification, including ATP-binding cassette (ABC) transporters, multidrug and toxic compound extrusion proteins (MATEs), and Tau class glutathione S-transferases (GSTUs), were significantly associated with Cr accumulation and detoxification in rice roots. In addition, much more members of these gene families were upregulated by Cr(VI) compared to Cr(III), suggesting their vital roles in Cr uptake, translocation, and detoxification, especially under Cr(VI) stress. Further comparison of gstu9 and gstu10/50 mutants with their wild type confirmed that GSTUs play complex roles in the intracellular Cr transport and redox homeostasis during Cr(III) or Cr(VI) stress. Taken together, our findings provides new insights into the differential behaviors of Cr(III) and Cr(VI) in rice roots, as well as new candidate genes such as OsABCs and OsGSTUs, to further elucidate the mechanisms of the uptake, translocation, and detoxification of Cr(III) and Cr(VI).

Downregulation of a Phi class glutathione S-transferase gene in transgenic torenia yielded pale flower color.

The members of glutathione S-transferase (GST) belonging to the Phi class of the GST family are known to play a role in anthocyanin transport to the vacuole. We isolated a GST orthologue from the torenia petal cDNA library. Transgenic plants transcribing GST double stranded RNA were generated from a torenia cultivar having blue flowers. These plants exhibited a range of flower colors, from blue to almost white. Quantitative RT-PCR confirmed the downregulation of the GST transcript, accompanied by a decrease in anthocyanin levels in the petals of the transgenic plants, whereas flavone levels remained unchanged. These results suggest that GST is involved in anthocyanin transport in torenia petals, and that anthocyanins and flavones are likely transported to the vacuole through different mechanisms.

An Epsilon Class Glutathione S-Transferase Gene Contributes to the Phytochemical Susceptibility of Tribolium castaneum (Coleoptera: Tenebrionidae)

Abstract Evidence is accumulating that insect epsilon class glutathione S-transferases (GSTs) play an important role in the resistance to xenobiotics such as insecticides. A Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) epsilon class GST gene, TcGSTe17, was previously found to be significantly induced following exposure to the plant derivative eucalyptol. However, whether TcGSTe17 is involved in resistance to eucalyptol remains unclear. In this study, TcGSTe17 was cloned from the T. castaneum. Development stage expression profiling revealed that TcGSTe17 was expressed at all development stages of T. castaneum but was highly expressed in late-stage larvae. Subsequent expression profiling of tissues showed that TcGSTe17 was highly expressed in the gut of larvae and the fat body of adults, and also revealed gender-specific expression patterns. In addition, the transcripts of TcGSTe17 were significantly increased following exposure to eucalyptol, and RNAi increased the susceptibility of the beetles to eucalyptol. Collectively, these results suggest that TcGSTe17 contributes to the susceptibility of T. castaneum to eucalyptol. These findings provide new data for the prevention of pest resistance.

Metabolism-Based Nontarget-Site Mechanism Is the Main Cause of a Four-Way Resistance in Shortawn Foxtail (Alopecurus aequalis Sobol.).

Alopecurus aequalis Sobol. is a predominant grass weed in Chinese winter wheat fields, posing a substantial threat to crop production owing to its escalating herbicide resistance. This study documented the initial instance of an A. aequalis population (AHFT-3) manifesting resistance to multiple herbicides targeting four distinct sites: acetyl-CoA carboxylase (ACCase), acetolactate synthase, photosystem II, and 1-deoxy-d-xylulose-5-phosphate synthase. AHFT-3 carried an Asp-to-Gly mutation at codon 2078 of ACCase, with no mutations in the remaining three herbicide target genes, and exhibited no overexpression of any target gene. Compared with the susceptible population AHFY-3, AHFT-3 metabolized mesosulfuron-methyl, isoproturon, and bixlozone faster. The inhibition and comparison of herbicide-detoxifying enzyme activities indicated the participation of cytochrome P450s in the resistance to all four herbicides, with glutathione S-transferases specifically linked to mesosulfuron-methyl. Three CYP72As and a Tau class glutathione S-transferase, markedly upregulated in resistant plants, potentially played pivotal roles in the multiple-herbicide-resistance phenotype.

Architecture and potential roles of a delta-class glutathione S-transferase in protecting honey bee from agrochemicals

The European honey bee, Apis mellifera, serves as the principle managed pollinator species globally. In recent decades, honey bee populations have been facing serious health threats from combined biotic and abiotic stressors, including diseases, limited nutrition, and agrochemical exposure. Understanding the molecular mechanisms underlying xenobiotic adaptation of A. mellifera is critical, considering its extensive exposure to phytochemicals and agrochemicals present in the environment. In this study, we conducted a comprehensive structural and functional characterization of AmGSTD1, a delta class glutathione S-transferase (GST), to unravel its roles in agrochemical detoxification and antioxidative stress responses. We determined the 3-dimensional (3D) structure of a honey bee GST using protein crystallography for the first time, providing new insights into its molecular structure. Our investigations revealed that AmGSTD1 metabolizes model substrates, including 1-chloro-2,4-dinitrobenzene (CDNB), p-nitrophenyl acetate (PNA), phenylethyl isothiocyanate (PEITC), propyl isothiocyanate (PITC), and the oxidation byproduct 4-hydroxynonenal (HNE). Moreover, we discovered that AmGSTD1 exhibits binding affinity with the fluorophore 8-Anilinonaphthalene-1-sulfonic acid (ANS), which can be inhibited with various herbicides, fungicides, insecticides, and their metabolites. These findings highlight the potential contribution of AmGSTD1 in safeguarding honey bee health against various agrochemicals, while also mitigating oxidative stress resulting from exposure to these substances.

Identification of putative promoter elements for epsilon glutathione s-transferases genes associated with resistance to DDT in the malaria vector mosquito anopheles arabiensis

The purpose of this study was to identify the putative regulatory elements in the promoter region of An. arabiensis strains which differed in susceptibility to DDT and compare with those identified in its sibling An. gambaie. Basal expression level of Epsilon class GSTs (Glutathione S – transferases) GSTe1 gene was 0.512 – 0.658 (95% CI) and GSTe2 0.672 – 1.204 (95% CI) in adults of DDT resistant KGB compared to 0.031 – 0.04 (95% CI) and 0.148 – 0.199 (95% CI) respectively in susceptible MAT strains of An. arabiensis. Induced mean expression of GSTe2 in larvae exposed to DDT for one hour was 0.901 – 1.172 (95% CI) in KGB and 0.475 – 0.724 (95% CI) in MAT strain. In present work, strain specific primers were used to amplify and sequenced the promoter regions of GSTe1 and GSTe2 in the KGB, MAT and field specimens. Computational analysis revealed presence of classical arthropod initiator sequence TCAGT and putative core promoter elements, GC, CAAT, TATA boxes. A typical TATA box was identified at 35 bp upstream Transcription Start Site (TSS) in GSTe1 but was absent in GSTe2. Several binding sites for regulatory elements downstream and multiple polymorphic sites were identified between strains. The role of these regulatory elements in transcription of these genes has not been determined. However, on comparison the 2 bp adenosine indel (insertion/deletion) which was essential in driving the promoter activity in An. gambiae was identified only DDT resistant KGB strain.

Epsilon Class Glutathione S-Transferase Confers Phoxim Tolerance in the Black Cutworm Agrotis ipsilon (Lepidoptera: Noctuidae).

The black cutworm Agrotis ipsilon is a serious crop pest. Phoxim, an organophosphorus insecticide, has been widely used to control A. ipsilon. When phoxim is extensively applied, the susceptibility of A. ipsilon to insecticide is reduced. However, the mechanisms of tolerance of A. ipsilon to phoxim remain unclear. Herein, we report that an epsilon class glutathione S-transferase, AiGSTE1, confers phoxim tolerance in A. ipsilon. Exposure to a sublethal concentration (LC50) of phoxim caused oxidative stress and activated the transcription of AiGSTe1 genes in A. ipsilon larvae. Recombinant AiGSTE1 expressed in Escherichia coli could metabolize phoxim. Furthermore, E. coli cells overexpressing AiGSTE1 displayed significant tolerance to oxidative stress. Knockdown of AiGSTe1 by RNA interference significantly increased the mortality of A. ipsilon larvae to phoxim. These results demonstrate that AiGSTE1 confers phoxim tolerance in A. ipsilon by metabolizing the insecticide and preventing phoxim-induced oxidative stress.

Identification and Functional Analysis of an Epsilon Class Glutathione S-Transferase Gene Associated with α-Pinene Adaptation in Monochamus alternatus.

Alpha-pinene is one of the main defensive components in conifers. Monochamus alternatus (Coleoptera: Cerambycidae), a wood borer feeding on Pinaceae plants, relies on its detoxifying enzymes to resist the defensive terpenoids. Here, we assayed the peroxide level and GST activity of M. alternatus larvae treated with different concentrations of α-pinene. Meanwhile, a gst gene (MaGSTe3) was isolated and analyzed. We determined its expression level and verified its function. The results showed that α-pinene treatment led to membrane lipid peroxidation and thus increased the GST activity. Expression of MaGSTe3 was significantly upregulated in guts following exposure to α-pinene, which has a similar pattern with the malonaldehyde level. In vitro expression and disk diffusion assay showed that the MaGSTe3 protein had high antioxidant capacity. However, RNAi treatment of MaGSTe3 did not reduce the hydrogen peroxide and malonaldehyde levels, while GST activity was significantly reduced. These results suggested MaGSTe3 takes part in α-pinene adaptation, but it does not play a great role in the resistance of M. alternatus larvae to α-pinene.

A tau class glutathione S-transferase in tea plant, CsGSTU45, facilitates tea plant susceptibility to Colletotrichum camelliae infection mediated by jasmonate signaling pathway.

Tea plant [Camellia sinensis (L.) O. Kuntze], as one of the most important commercial crops, frequently suffers from anthracnose caused by Colletotrichum camelliae. The plant-specific tau (U) class of glutathione S-transferases (GSTU) participates in ROS homeostasis. Here, we identified a plant-specific GST tau class gene from tea plant, CsGSTU45, which is induced by various stresses, including C. camelliae infection, by analyzing multiple transcriptomes. CsGSTU45 plays a negative role in disease resistance against C. camelliae by accumulating H2 O2 . JA negatively regulates the resistance of tea plants against C. camelliae, which depends on CsGSTU45. CsMYC2.2, which is the key regulator in the JA signaling pathway, directly binds to and activates the promoter of CsGSTU45. Furthermore, silencing CsMYC2.2 increased disease resistance associated with reduced transcript and protein levels of CsGSTU45, and decreased contents of H2 O2 . Therefore, CsMYC2.2 suppresses disease resistance against C. camelliae by binding to the promoter of the CsGSTU45 gene and activating CsGSTU45. CsJAZ1 interacts with CsMYC2.2. Silencing CsJAZ1 attenuates disease resistance, upregulates the expression of CsMYC2.2 elevates the level of the CsGSTU45 protein, and promotes the accumulation of H2 O2 . As a result, CsJAZ1 interacts with CsMYC2.2 and acts as its repressor to suppress the level of CsGSTU45 protein, eventually enhancing disease resistance in tea plants. Taken together, the results show that the JA signaling pathway mediated by CsJAZ1-CsMYC2.2 modulates tea plant susceptibility to C. camelliae by regulating CsGSTU45 to accumulate H2 O2 .

OsGSTU17, a Tau Class Glutathione S-Transferase Gene, Positively Regulates Drought Stress Tolerance in Oryza sativa.

As a great threat to the normal growth of rice, drought not only restricts the growth of rice, but also affects its yield. Glutathione S-transferases (GSTs) have antioxidant and detoxification functions. In rice, GSTs can not only effectively cope with biological stress, but also play a defense role against abiotic stress. In this study, we selected OsGSTU17, a member gene that was induced by drought, to explore the role of GSTs and analyze their physiological mechanisms that are involved in rice drought tolerance. With the CRISPR/Cas9 knockout system techniques, we obtained two independent mutant lines of osgstu17. After 14 days of drought stress treatment, and then re-supply of the water for 10 days, the survival rate of the osgstu17 mutant lines was significantly reduced compared to the wild-type (WT). Similarly, with the 10% (w/v) PEG6000 hydroponics experiment at the seedling stage, we also found that compared with the WT, the shoot and root biomass of osgstu17 mutant lines decreased significantly. In addition, both the content of the MDA and H2O2, which are toxic to plants, increased in the osgtu17 mutant lines. On the other hand, chlorophyll and proline decreased by about 20%. The activity of catalase and superoxide dismutase, which react with peroxides, also decreased by about 20%. Under drought conditions, compared with the WT, the expressions of the drought stress-related genes OsNAC10, OsDREB2A, OsAP37, OsP5CS1, OsRAB16C, OsPOX1, OsCATA, and OsCATB in the osgtu17 mutant lines were significantly decreased. Finally, we concluded that knocking out OsGSTU17 significantly reduced the drought tolerance of rice; OsGSTU17 could be used as a candidate gene for rice drought-tolerant cultivation. However, the molecular mechanism of OsGSTU17 involved in rice drought resistance needs to be further studied.

Functional characterization of SlGSTD3 and SlGSTD4 associated with phoxim and chlorpyrifos resistance in Spodoptera litura

Glutathione S-transferases (GSTs) is one of the main detoxification enzyme systems in insects and play important roles in insecticide resistance by direct metabolism, sequestration and antioxidant activity. Several GSTs genes in Spodoptera litura, a polyphagous agricultural pest, have been demonstrated to be overexpressed and involved in organophosphates and pyrethroids resistance. Previous studies have indicated the significant overexpression of two delta class GSTs genes (SlGSTd3 and SlGSTd4) in organophosphates and pyrethroids resistant populations. Here, they were heterologous expressed, and their metabolism activity and antioxidant activity were determined. Results indicated that the recombinant protein SlGSTD3 and SlGSTD4 both showed metabolism activity to phoxim and chlorpyrifos, but not to fenvalerate, cyhalothrin or beta cypermethrin. The metabolism activity of SlGSTD3 to phoxim and chlorpyrifos is higher than that of SlGSTD4. The recombinant vector of SlGSTD3 and SlGSTD4 both showed antioxidant activity after exposure to cumene hydroperoxide. Further modeling and docking analysis indicated that the 3D structure of SlGSTD3 and SlGSTD4 were well shaped for phoxim and chlorpyrifos, and the binding affinity for phoxim was stronger than that of chlorpyrifos. Our work provides evidence that SlGSTd3 and SlGSTd4 both play roles in phoxim and chlorpyrifos resistance in S. litura.

Sublethal effects of halofenozide on larval development and detoxification in Phaedon brassicae (Coleoptera: Chrysomelidae).

The brassica leaf beetle, Phaedon brassicae, is a serious defoliator of cruciferous crops. Halofenozide (Hal), an ecdysone agonist, is a new class of insect growth-regulating insecticide. Our preliminary experiment revealed the outstanding larval toxicity of Hal against P. brassicae. However, the metabolic degradation of this compound in insects remains unclear. In this study, oral administration of Hal at LC10 and LC25 caused severe separation of the cuticle and epidermis, leading to larval molting failure. Sublethal dose exposure also significantly reduced the larval respiration rate as well as their pupation rates and pupal weights. Conversely, the activities of the multifunctional oxidase, carboxylesterase (CarE), and glutathione S-transferase (GST) were significantly enhanced in Hal-treated larvae. Further analysis using RNA sequencing identified 64 differentially expressed detoxifying enzyme genes, including 31 P450s, 13 GSTs, and 20 CarEs. Among the 25 upregulated P450s, 22 genes were clustered into the CYP3 clan, and the other 3 genes belonged to the CYP4 clan. Meanwhile, 3 sigma class GSTs and 7 epsilon class GSTs were dramatically increased, accounting for the majority of the upregulated GSTs. Moreover, 16 of the 18 overexpressed CarEs were clustered into the coleopteran xenobiotic-metabolizing group. These results showed the augmented expression of detoxification genes in P. brassicae after exposed to sublethal dose of Hal, and helped to better understand the potential metabolic pathways that could contribute to the reduced sensitivity to Hal in this pest. Overall, a deep insight into the detoxification mechanisms would provide practical guidance for the field management of P. brassicae.

Functional analysis of an overexpressed glutathione S-transferase BdGSTd5 involved in malathion and malaoxon detoxification in Bactrocera dorsalis

Glutathione S-transferases (GSTs) are one of the three detoxification enzyme families. The constitutive and inducible overexpression of GSTs genes plays an important role in insecticide resistance. Previous study showed that malathion resistance was polygenic, and elevated GSTs activity was one of the important factor participating in malathion resistance of Bactrocera dorsalis (Hendel), a serious economic pest worldwide. BdGSTd5 overexpression was inducible upon exposure to malathion. However, the involvement of BdGSTd5 in malathion resistance has not been clarified. In this study, we found that BdGSTd5 sequence harbored the conserved region of delta class GSTs, which were overexpressed in malathion resistant strain of B. dorsalis compared to malathion susceptible strain. The highest mRNA expression level of BdGSTd5 was found in 1-day-old adult, and the levels decreased with aging. The dsBdGSTd5 injection effectively silenced (73.4% reduction) the expression of BdGSTd5 and caused significant increase in susceptibility to malathion with a cumulative mortality increasing of 13.5% at 72 h post malathion treatment (p < 0.05). Cytotoxicity assay demonstrated that BdGSTd5 was capable of malathion detoxification. Molecular docking analysis further indicated the interactive potential of BdGSTd5 with malathion and its toxic oxide malaoxon. The recombinant BdGSTd5 exhibited glutathione-conjugating activity toward 1-chloro-2, 4-dinitrobenzene and malathion and malaoxon metabolic capacity with significant reduction (p < 0.05) of the peak areas by 90.0% and 73.1%, respectively. Taken together, the overexpressed BdGSTd5 contributes to malathion metabolism and resistance, which detoxify the malathion in B. dorsalis via directly depleting malathion and malaoxon.

Molecular identification and biochemical characteristics of a delta class glutathione S-transferase gene (FcδGST) from Chinese shrimp Fenneropenaeus chinensis

Molecular identification and biochemical characteristics of a delta class glutathione S-transferase gene (FcδGST) from Chinese shrimp Fenneropenaeus chinensis

Genome-wide identification and characterization of glutathione S-transferase gene family in quinoa (Chenopodium quinoa Willd.).

The present investigation was envisaged for large scale in-silico genome wide identification and characterization of glutathione S-transferases (GSTs) in Chenopodium quinoa. In this study, a total of 120 GST genes (CqGSTs) were identified and divided into 11 classes of which tau and phi were highest in numbers. The average protein length of protein was found to be 279.06 with their corresponding average molecular weight of 31,819.4kDa. The subcellular localization analysis results showed that proteins were centrally localized in the cytoplasm followed by chloroplast, mitochondria and plastids. Structural analysis revealed the presence of 2 -14 exons in CqGST genes. Most of the proteins possessed two exon one intron organization. MEME analysis identified 15 significantly conserved motifs with a width of 6-50 amino acids. Motifs 1, 3, 2, 5, 6, 8, 9 and 13 were found specifically in tau class family; motifs 3, 4, 5, 6, 7 and 9 were found in phi class gene family, while motifs 3, 4, 13 and 14 were found in metaxin class. Multiple sequence alignment revealed highly conserved N-terminus with active site serine (Ser; S) or cysteine (Cys; C) residue for the activation of GSH binding and GST catalytic activity. The gene loci were found to be unevenly distributed across 18 different chromosomes with a maximum of 17 genes located on chromosome number 7. Dominance of alpha helix was followed by coil, extended strand and beta turns. Gene duplication analysis revealed that segmental duplication and purifying type selection were highest in number and found to be main source of expansion of GST gene family. Cis acting regulatory elements analysis showed the presence of 21 different elements involved in stress, hormone and light response and cellular development. The evolutionary relationship of CqGST proteins carried out using maximum likelihood method revealed that all the tau and phi class GSTs were closely associated with those of G. max, O. sativa and A. thaliana. Molecular docking of GST molecules with the fungicide metalaxyl showed that the CqGSTF1 had the lowest binding energy. The comprehensive study of CqGST gene family in quinoa provides groundwork for further functional analysis of CqGST genes in the species at molecular level and has potential applications in plant breeding.

PeGSTU58, a Glutathione S-Transferase from Populus euphratica, Enhances Salt and Drought Stress Tolerance in Transgenic Arabidopsis.

Glutathione S-transferases (GSTs) play a crucial role in responding to abiotic stress and are an important target for research on plant stress tolerance mechanisms. Populus euphratica is a promising candidate species for investigating the abiotic tolerance mechanisms in woody plants. In our previous study, PeGSTU58 was identified as being associated with seed salinity tolerance. In the present study, PeGSTU58 was cloned from P. euphratica and functionally characterized. PeGSTU58 encodes a Tau class GST and is located in both the cytoplasm and nucleus. Transgenic Arabidopsis overexpressing PeGSTU58 displayed enhanced tolerance to salt and drought stress. Under salt and drought stress, the transgenic plants exhibited significantly higher activities of antioxidant enzymes, including SOD, POD, CAT, and GST, compared to the wild-type (WT) plants. Additionally, the expression levels of several stress-responsive genes, including DREB2A, COR47, RD22, CYP8D11, and SOD1 were upregulated in PeGSTU58 overexpression lines compared to those in WT Arabidopsis under salt and drought stress conditions. Furthermore, yeast one-hybrid assays and luciferase analysis showed that PebHLH35 can directly bind to the promoter region of PeGSTU58 and activate its expression. These results indicated that PeGSTU58 was involved in salt and drought stress tolerances by maintaining ROS homeostasis, and its expression was positively regulated by PebHLH35.