Total transcriptome response for tyrosol exposure in Aspergillus nidulans.

Although tyrosol is a quorum-sensing molecule of Candida species, it has antifungal activity at supraphysiological concentrations. Here, we studied the effect of tyrosol on the physiology and genome-wide transcription of Aspergillus nidulans to gain insight into the background of the antifungal activity of this compound. Tyrosol efficiently reduced germination of conidia and the growth on various carbon sources at a concentration of 35 mM. The growth inhibition was fungistatic rather than fungicide on glucose and was accompanied with downregulation of 2199 genes related to e.g. mitotic cell cycle, glycolysis, nitrate and sulphate assimilation, chitin biosynthesis, and upregulation of 2250 genes involved in e.g. lipid catabolism, amino acid degradation and lactose utilization. Tyrosol treatment also upregulated genes encoding glutathione-S-transferases (GSTs), increased specific GST activities and the glutathione (GSH) content of the cells, suggesting that A. nidulans can detoxify tyrosol in a GSH-dependent manner even though this process was weak. Tyrosol did not induce oxidative stress in this species, but upregulated "response to nutrient levels", "regulation of nitrogen utilization", "carbon catabolite activation of transcription" and "autophagy" genes. Tyrosol may have disturbed the regulation and orchestration of cellular metabolism, leading to impaired use of nutrients, which resulted in growth reduction.

Transcriptome sequencing and expression analysis in peanut reveal the potential mechanism response to Ralstonia solanacearum infection.

BACKGROUND: Bacterial wilt caused by Ralstonia solanacearum severely affects peanut (Arachis hypogaea L.) yields. The breeding of resistant cultivars is an efficient means of controlling plant diseases. Therefore, identification of resistance genes effective against bacterial wilt is a matter of urgency. The lack of a reference genome for a resistant genotype severely hinders the process of identification of resistance genes in peanut. In addition, limited information is available on disease resistance-related pathways in peanut. RESULTS: Full-length transcriptome data were used to generate wilt-resistant and -susceptible transcript pools. In total, 253,869 transcripts were retained to form a reference transcriptome for RNA-sequencing data analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of differentially expressed genes revealed the plant-pathogen interaction pathway to be the main resistance-related pathway for peanut to prevent bacterial invasion and calcium plays an important role in this pathway. Glutathione metabolism was enriched in wilt-susceptible genotypes, which would promote glutathione synthesis in the early stages of pathogen invasion. Based on our previous quantitative trait locus (QTL) mapping results, the genes arahy.V6I7WA and arahy.MXY2PU, which encode nucleotide-binding site-leucine-rich repeat receptor proteins, were indicated to be associated with resistance to bacterial wilt. CONCLUSIONS: This study identified several pathways associated with resistance to bacterial wilt and identified candidate genes for bacterial wilt resistance in a major QTL region. These findings lay a foundation for investigation of the mechanism of resistance to bacterial wilt in peanut.

Genome-wide analysis of LOG family genes in castor and RcLOG5 enhances drought, salt, and cold stress tolerance in Arabidopsis thaliana.

The gene encoding the specific phosphohydrolase LONELY GUY (LOG) plays an important role in the activation of cytokinin and the stress response in plant cells. However, the role of LOG genes in castor bean (Ricinus communis) has not been reported. In this study, we identified a total of nine members of the LOG gene family in the castor bean genome and investigated the upregulated expression of the RcLOG5 gene using transcriptome data analysis. We found that the RcLOG5 gene exhibited tissue-specific expression and was activated by polyethylene glycol, NaCl, low temperature, and abscisic acid stress. The subcellular localization results showed that the RcLOG5 gene is mainly located in the cytoplasm. Based on phenotypic and physiological indicators, namely root length, peroxidase activity, and malondialdehyde content, overexpression of the RcLOG5 gene not only improved the drought resistance, salt tolerance, and cold tolerance of transgenic Arabidopsis, but also shortened the dormancy period of the transgenic plants. Transcriptomic sequencing revealed that the overexpression of the RcLOG5 gene led to the enrichment of differentially expressed genes in the glutathione metabolism pathway in transgenic Arabidopsis. Moreover, the overexpression plants had higher levels of glutathione and a higher GSH/GSSG ratio under stress compared to the wild type. Therefore, we inferred that the RcLOG5 gene may be responsible for regulating cell membrane homeostasis by reducing the accumulation of reactive oxygen species through the glutathione pathway. Overall, the overexpression of the RcLOG5 gene positively regulated the stress resistance of transgenic Arabidopsis. This study provides valuable gene resources for breeding stress-tolerant castor bean varieties.

PEI functionalized cell membrane for tumor targeted and glutathione responsive gene delivery.

Polyethylenimine (PEI) is a broadly exploited cationic polymer due to its remarkable gene-loading capacity. However, the high cytotoxicity caused by its high surface charge density has been reported in many cell lines, limiting its application significantly. In this study, two different molecular weights of PEI (PEI10k and PEI25k) were crosslinked with red blood cell membranes (RBCm) via disulfide bonds to form PEI derivatives (RMPs) with lower charge density. Furthermore, the targeting molecule folic acid (FA) molecules were further grafted onto the polymers to obtain FA-modified PEI-RBCm copolymers (FA-RMP25k) with tumor cell targeting and glutathione response. In vitro experiments showed that the FA-RMP25k/DNA complex had satisfactory uptake efficiency in both HeLa and 293T cells, and did not cause significant cytotoxicity. Furthermore, the uptake and transfection efficiency of the FA-RMP25k/DNA complex was significantly higher than that of the PEI25k/DNA complex, indicating that FA grafting can increase transfection efficiency by 15 %. These results suggest that FA-RMP25k may be a promising non-viral gene vector with potential applications in gene therapy.

Pseudomonas mosselii improves cold tolerance of Asian rice (Oryza sativa L.) in a genotype-dependent manner by increasing proline in japonica and reduced glutathione in indica varieties.

Cold stress is an important factor limiting rice production and distribution. Identifying factors that contribute to cold tolerance in rice is of primary importance. While some plant specific genetic factors involved in cold tolerance have been identified, the role of the rice microbiome remains unexplored. In this study, we evaluated the influence of plant growth promoting bacteria (PGPB) with the ability of phosphate solubilization on rice cold tolerance and survival. To reach this goal, inoculated and uninoculated 2-week-old seedlings were cold stressed and evaluated for survival and other phenotypes such as electrolyte leakage (EL) and necessary elements for cold tolerance. The results of this study showed that of the five bacteria, Pseudomonas mosselii, improved both indica and japonica varietal plants' survival and decreased EL, indicating increased membrane integrity. We observed different possible cold tolerance mechanisms in japonica and indica plants such as increases in proline and reduced glutathione levels, respectively. This bacterium also improved the shoot growth of cold exposed indica plants during the recovery period. This study confirmed the host genotype dependent activity of P. mosselii and indicated that there is an interaction between specific plant genes and bacterial genes that causes different plant responses to cold stress.

Yeast Rim11 kinase responds to glutathione-induced stress by regulating the transcription of phospholipid biosynthetic genes.

Glutathione (GSH), a tripeptide composed of glycine, cysteine, and glutamic acid, is an abundant thiol found in a wide variety of cells, ranging from bacterial to mammalian cells. Adequate levels of GSH are essential for maintaining iron homeostasis. The ratio of oxidized/reduced GSH is strictly regulated in each organelle to maintain the cellular redox potential. Cellular redox imbalances cause defects in physiological activities, which can lead to various diseases. Although there are many reports regarding the cellular response to GSH depletion, studies on stress response to high levels of GSH are limited. Here, we performed genome-scale screening in the yeast Saccharomyces cerevisiae and identified RIM11, BMH1, and WHI2 as multicopy suppressors of the growth defect caused by GSH stress. The deletion strains of each gene were sensitive to GSH. We found that Rim11, a kinase important in the regulation of meiosis, was activated via autophosphorylation upon GSH stress in a glucose-rich medium. Furthermore, RNA-seq revealed that transcription of phospholipid biosynthetic genes was downregulated under GSH stress, and introduction of multiple copies of RIM11 counteracted this effect. These results demonstrate that S. cerevisiae copes with GSH stress via multiple stress-responsive pathways, including a part of the adaptive pathway to glucose limitation.

[Changes in the Activity of Antioxidant Systems of Escherichia coli under Phosphate Starvation].

Changes in the activity of antioxidant systems in Escherichia coli during phosphate starvation have been studied. It is shown that starvation was accompanied by a decrease in the intensity of respiration, an increase in the rate of superoxide production, and a decrease in the level of ATP. Simultaneously, there was a decrease in H2O2 in the medium and a significant increase in the expression of the katG and katE genes which encode the HPI and HPII catalases, respectively. At the same time, there was no drop in the membrane potential, which may indicate the retention of normal membrane activity in starving cells. It has been shown for the first time that the transition of E. coli to phosphate starvation is accompanied by significant changes in the status of glutathione. The most important of these are associated with a decrease in the level of reduced glutathione in the medium (GSHout) and with a simultaneous increase in its content in the cytoplasm (GSHin), as well as a shift in the GSHin to oxidized glutathione form (GSSGin) ratio towards reductive values, and GSHout/GSSGout towards oxidative values. Among the mutants used in the work, the gor trxB double mutant, which is deficient in the synthesis of glutathione reductase and thioredoxin reductase, showed the most pronounced distinctive features. Compared to the parental strain, this mutant showed a multiple higher expression of katG::lacZ, the highest level of oxidized intra- and extracellular glutathione, and, accordingly, the lowest GSH/GSSG ratio in both compartments. In general, the data we obtained indicate that during phosphate starvation the interaction of the glutathione redox-system and regulons that control protection against reactive oxygen species creates conditions that allow maintaining the concentration of ROS below the toxic level. As a result, phosphate-starved E. coli cells can maintain high viability for a long period of time, which allows them to quickly resume growth after the addition of phosphate.

THE ROLE OF HEREDITARY PREDISPOSITION (POLYMORPHIC MARKERS OF GLUTATHIONE-S-TRANSFERASE, CATALASE, ENDOTHELIAL NITROGEN OXIDE SYNTHASE GENES) AND SOME ADVERSE ENVIRONMENTAL FACTORS IN THE DEVELOPMENT OF BRONCHO-OBSTRUCTIVE PATHOLOGY IN CHILDREN LIVING IN RADIOACTIVELY CONTAMINATED AREAS. / РОЛЬ СПАДКОВОЇ СХИЛЬНОСТІ (ПОЛІМОРФНИХ МАРКЕРІВ ГЕНІВ ГЛУТАТІОН-S-ТРАНСФЕРАЗ, КАТАЛАЗИ, ЕНДОТЕЛІАЛЬНОЇ СИНТАЗИ ОКСИДУ АЗОТУ) ТА ДЕЯКИХ НЕСПРИЯТЛИВИХ ЧИННИКІВ ДОВКІЛЛЯ У ВИНИКНЕННІ БРОНХООБСТРУКТИВНОЇ ПАТОЛОГІЇ У ДІТЕЙ, МЕШКАНЦІВ РАДІОАКТИВНО ЗАБРУДНЕНИХ ТЕРИТОРІЙ.

OBJECTIVE: summarizing the results of many years of research by the authors on the influence of gene polymorphisms encoding xenobiotic biotransformation enzymes (GSTТ1, GSTM1, GSTР1), antioxidant protection (С^262Т of the catalase gene), endothelial nitric oxide synthase (4a/4b VNTR polymorphism of the eNOS gene), and some environmental factors on the occurrence of broncho-obstructive disorders and the development of bronchial asthma in children, residents of radioactively contaminated areas. MATERIALS AND METHODS: The examined school-aged children were residents of radioactively RCA who had no clinical signs of respiratory pathology. Deletion polymorphism of catalase gene (CAT C^262T), polymorphism of glutathione-S-transferase gene (GSTТ1, GSTM1, GSTР1) and the polymorphism in the 4th intron (4a/4b) of the eNOS gene were studied in the molecular genetics laboratory of the State Institution «Reference Center for Molecular Diagnostics of Public Health Ministry of Ukraine¼. Molecular genetic studies were performed by polymerase chain reaction. The study of the ventilation lung capacity was carried out by the method of computer spirometry based on the data of the «flow-volume¼ loop analysis. A pharmacological inhalation test with a bronchodilator drug which affects the ß2-adrenergic receptors of the lungs was used to detect early changes in the ventilatory lung capacity - bronchial hyperreactivity. RESULTS AND CONCLUSIONS: One of the leading mechanisms, due to which the implementation of hereditary predisposition to bronchial asthma in children living in radioactively contaminated areas is the polymorphism of certain genes of glutathione-S-transferase, catalase, endothelial nitric oxide synthase. With such polymorphic variants of the GST genes, isoforms of enzymes with reduced activity are produced, which limits their ability to effectively neutralize free radicals, which are formed in excess when free radical oxidation processes are activated due to the constant intake of radionuclides with a long half-life into the body of children. Unfavorable factors that increase the risk of developing broncho-obstructive disorders and the likelihood of their implementation in the form of bronchial asthma in children, residents of radioactively contaminated areas, have been identified. It has been established that among them the leading role is played by hereditary predisposition to this disease. On the part of the child, such negative factors were unfavorable conditions of intrauterine development, the presence of signs of exudative-catarrhal diathesis, manifestations of allergies and frequent respiratory diseases from the first months of life.

Glutathione dynamics is a potential predictive and therapeutic trait for neoadjuvant chemotherapy response in bladder cancer.

Radical cystectomy with preoperative cisplatin-based neoadjuvant chemotherapy (NAC) is the standard care for muscle-invasive bladder cancers (MIBCs). However, the complete response rate to this modality remains relatively low, and current clinicopathologic and molecular classifications are inadequate to predict NAC response in patients with MIBC. Here, we demonstrate that dysregulation of the glutathione (GSH) pathway is fundamental for MIBC NAC resistance. Comprehensive analysis of the multicohort transcriptomes reveals that GSH metabolism and immune-response genes are enriched in NAC-resistant and NAC-sensitive MIBCs, respectively. A machine-learning-based tumor/stroma classifier is applied for high-throughput digitalized immunohistochemistry analysis, finding that GSH dynamics proteins, including glutaminase-1, are associated with NAC resistance. GSH dynamics is activated in cisplatin-resistant MIBC cells, and combination treatment with a GSH dynamics modulator and cisplatin significantly suppresses tumor growth in an orthotopic xenograft animal model. Collectively, these findings demonstrate the predictive and therapeutic values of GSH dynamics in determining the NAC response in MIBCs.

Transcriptome analysis reveals the role of polysaccharide biosynthesis in the detoxification of Dendrobium nobile under zinc stress.

Plants can bind excessive heavy metals by synthesizing compounds to alleviate the harm caused by heavy metals. To reveal the mechanism by which Dendrobium nobile alleviates zinc stress, metabolome combined transcriptome analysis was used in this research. The results showed that zinc was mainly enriched in the roots and leaves and the biomass of the roots and leaves of D. nobile decreased significantly by 18.21 % and 49.22 % (P < 0.05) compared to the control (CK), respectively. Meanwhile, the contents of nonprotein thiol(NPT), glutathione(GSH), and phytochelatins (PCs) in the roots were significantly increased by 48.8 %, 78.3 %, and 45.4 % compared to CK, respectively. Through TEM testing, it was found that D. nobile exhibited toxic symptoms. Metabolome analysis showed that the metabolites of D. nobile under zinc stress were mainly enriched in biosynthesis of other secondary metabolites and carbohydrate metabolism. Nova-seq results identified 1202 differentially expressed genes(DEGs), of which 603 were upregulated and 599 were downregulated. Through GO and KEGG annotation analysis of these DEGs, it was found that PMR6 and PECS-2.1, SS1 and GLU3 genes were significantly upregulated, leading to an increase in the biosynthesis of xylan, pectin, starch and other polysaccharides in D. nobile. These polysaccharides can form a "Polysaccharide-Zn" with excess zinc. Meanwhile, the GSTs in glutathione metabolism were significantly upregulated, leading to a significant increase in the content of NPT, GSH, and PCs. These zinc complexes were transported to vacuoles through ABC transporters for compartmentalization, effectively alleviating the damage of zinc. The results can provide new insights for phytoremediation and quality assurance of medicinal D. nobile.

The glutathione import system satisfies the Staphylococcus aureus nutrient sulfur requirement and promotes interspecies competition.

Sulfur is an indispensable element for bacterial proliferation. Prior studies demonstrated that the human pathogen Staphylococcus aureus utilizes glutathione (GSH) as a source of nutrient sulfur; however, mechanisms of GSH acquisition are not defined. Here, we identify a five-gene locus comprising a putative ABC-transporter and predicted γ-glutamyl transpeptidase (ggt) that promotes S. aureus proliferation in medium supplemented with either reduced or oxidized GSH (GSSG) as the sole source of nutrient sulfur. Based on these phenotypes, we name this transporter operon the glutathione import system (gisABCD). Ggt is encoded within the gisBCD operon, and we show that the enzyme is capable of liberating glutamate using either GSH or GSSG as substrates, demonstrating it is a bona fide γ-glutamyl transpeptidase. We also determine that Ggt is expressed in the cytoplasm, representing only the second example of cytoplasmic Ggt localization, the other being Neisseria meningitidis. Bioinformatic analyses revealed that Staphylococcus species closely related to S. aureus encode GisABCD-Ggt homologs. However, homologous systems were not detected in Staphylococcus epidermidis. Consequently, we establish that GisABCD-Ggt provides a competitive advantage for S. aureus over S. epidermidis in a GSH- and GSSG-dependent manner. Overall, this study describes the discovery of a nutrient sulfur acquisition system in S. aureus that targets GSSG in addition to GSH and promotes competition against other staphylococci commonly associated with the human microbiota.

DMT1 differentially regulates mitochondrial complex activities to reduce glutathione loss and mitigate ferroptosis.

Mitochondria are vital for energy production and redox homeostasis, yet knowledge of relevant mechanisms remains limited. Here, through a genome-wide CRISPR-Cas9 knockout screening, we have identified DMT1 as a major regulator of mitochondria membrane potential. Our findings demonstrate that DMT1 deficiency increases the activity of mitochondrial complex I and reduces that of complex III. Enhanced complex I activity leads to increased NAD+ production, which activates IDH2 by promoting its deacetylation via SIRT3. This results in higher levels of NADPH and GSH, which improve antioxidant capacity during Erastin-induced ferroptosis. Meanwhile, loss of complex III activity impairs mitochondrial biogenesis and promotes mitophagy, contributing to suppression of ferroptosis. Thus, DMT1 differentially regulates activities of mitochondrial complex I and III to cooperatly suppress Erastin-induced ferroptosis. Furthermore, NMN, an alternative method of increasing mitochondrial NAD+, exhibits similar protective effects against ferroptosis by boosting GSH in a manner similar to DMT1 deficiency, shedding a light on potential therapeutic strategy for ferroptosis-related pathologies.

Genome-wide identification and characterization of Glutathione S-Transferases (GSTs) and their expression profile under abiotic stresses in tobacco (Nicotiana tabacum L.).

BACKGROUND: Glutathione S-transferases (GSTs) are large and multifunctional proteases that play an important role in detoxification, protection against biotic and abiotic stresses, and secondary metabolite transportation which is essential for plant growth and development. However, there is limited research on the identification and function of NtGSTs. RESULTS: This study uses K326 and other six tobacco varieties (Hongda, HG, GDH11, Va116, VG, and GDH88) as materials to conduct comprehensive genome-wide identification and functional characterization of the GST gene in tobacco. A total of 59 NtGSTs were identified and classified into seven subfamilies via the whole-genome sequence analysis, with the Tau type serving as the major subfamily. The NtGSTs in the same branch of the evolutionary tree had similar exon/intron structure and motif constitution. There were more than 42 collinear blocks between tobacco and pepper, tomato, and potato, indicating high homology conservation between them. Twelve segmental duplicated gene pairs and one tandem duplication may have had a substantial impact on the evolution and expansion of the tobacco GST gene family. The RT-qPCR results showed that the expression patterns of NtGSTs varied significantly among tissues, varieties, and multiple abiotic stresses, suggesting that NtGST genes may widely respond to various abiotic stresses and hormones in tobacco, including NtGSTF4, NtGSTL1, NtGSTZ1, and NtGSTU40. CONCLUSIONS: This study provides a comprehensive analysis of the NtGST gene family, including structures and functions. Many NtGSTs play a critical regulatory role in tobacco growth and development, and responses to abiotic stresses. These findings offer novel and valuable insights for understanding the biological function of NtGSTs and the reference materials for cultivating highly resistant varieties and enhancing the yield and quality of crops.

Characterization of glutathione-specific gamma glutamyl cyclotransferase (ChaC) in Bombyx mori.

Glutathione (GSH) contributes to redox maintenance and detoxification of various xenobiotic and endogenous substances. γ-glutamyl cyclotransferase (ChaC) is involved in GSH degradation. However, the molecular mechanism underlying GSH degradation in silkworms (Bombyx mori) remains unknown. Silkworms are lepidopteran insects that are considered to be an agricultural pest model. We aimed to examine the metabolic mechanism underlying GSH degradation mediated by B. mori ChaC and successfully identified a novel ChaC gene in silkworms (herein, bmChaC). The amino acid sequence and phylogenetic tree revealed that bmChaC was closely related to mammalian ChaC2. We overexpressed recombinant bmChaC in Escherichia coli, and the purified bmChaC showed specific activity toward GSH. Additionally, we examined the degradation of GSH to 5-oxoproline and cysteinyl glycine via liquid chromatography-tandem mass spectrometry. Quantitative real-time polymerase chain reaction revealed that bmChaC mRNA expression was observed in various tissues. Our results suggest that bmChaC participates in tissue protection via GSH homeostasis. This study provides new insights into the activities of ChaC and the underlying molecular mechanisms that can aid the development of insecticides to control agricultural pests.

Exploring the molecular basis of resistance to Botrytis cinerea in chickpea genotypes through biochemical and morphological markers.

Chickpea (Cicer arietinum L.) is an important pulse crop around the globe and a valuable source of protein in the human diet. However, it is highly susceptible to various plant pathogens such as fungi, bacteria, and viruses, which can cause significant damage from the seedling phase until harvest, leading to reduced yields and affecting its production. Botrytis cinerea can cause significant damage to chickpea crops, especially under high humidity and moisture conditions. This fungus can cause grey mould disease, which can lead to wilting, stem and pod rot, and reduced yields. Chickpea plants have developed specific barriers to counteract the harmful effects of this fungus. These barriers include biochemical and structural defences. In this study, the defence responses against B. cinerea were measured by the quantification of biochemical metabolites such as antioxidant enzymes, malondialdehyde (MDA), proline, glutathione (GSH), H2O2, ascorbic acid (AA) and total phenol in the leaf samples of chickpea genotypes (one accession of wild Cicer species, viz. Cicer pinnatifidum188 identified with high level of resistance to Botrytis grey mould (BGM) and a cultivar, Cicer arietinumPBG5 susceptible to BGM grown in the greenhouse). Seedlings of both the genotypes were inoculated with (1 × 104 spore mL-1) inoculum of isolate 24, race 510 of B. cinerea and samples were collected after 1, 3, 5, and 7 days post-inoculation (dpi). The enhanced enzymatic activity was observed in the pathogen-inoculated leaf samples as compared to uninoculated (healthy control). Among inoculated genotypes, the resistant one exhibited a significant change in enzymatic activity, total phenolic content, MDA, proline, GSH, H2O2, and AA, compared to the susceptible genotype. The study also examined the isozyme pattern of antioxidant enzymes at various stages of B. cinerea inoculation. Results from scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy revealed that BGM had a more significant impact on susceptible genotypes compared to resistant ones when compared to the control (un-inoculated). In addition, SEM and FTIR spectroscopy analyses confirmed the greater severity of BGM on susceptible genotypes compared to their resistant counterparts. Our results suggest the role of antioxidant enzymes and other metabolites as defence tools and biochemical markers to understand compatible and non-compatible plant-pathogen interactions better. The present investigation will assist future plant breeding programs aimed at developing resistant varieties.

Redox perturbations in yeast cells lacking glutathione reductase.

Cellular redox homeostasis has a major effect on cell functions and its maintenance is supported by glutathione and protein thiols which serve as redox buffers in cells. The regulation of the glutathione biosynthetic pathway is a focus of a lot of scientific research. However, still little is known about how complex cellular networks influence glutathione homeostasis. In this work was used an experimental system based on an S. cerevisiae yeast mutant with a lack of the glutathione reductase enzyme and allyl alcohol as a precursor of acrolein inside the cell to determine the cellular processes influencing glutathione homeostasis. The absence of Glr1p slows down the growth rate of the cell population, especially in the presence of allyl alcohol, but does not lead to complete inhibition of the cell's reproductive capacity. It also amends the GSH/GSSG ratio and the share of NADPH and NADP+ in the total NADP(H) pool. The obtained results show that potential pathways involved in the maintenance of redox homeostasis are based from one side on de novo synthesis of GSH as indicated by increased activity of γ-GCS and increased expression of GSH1 gene in the Δglr1 mutant, from the other hand, on increased the level of NADPH. This is because the lower ratio of GSH/GSSG can be counterbalanced with the NADPH/NADP+ alternative system. The higher level of NADPH can be used by the thioredoxin system and other enzymes requiring NADPH to reduce cytosolic GSSG and maintain glutathione redox potential.

Comparative physiological and proteomic response to phosphate deficiency between two wheat genotypes differing in phosphorus utilization efficiency.

Genetic variation in phosphorus utilization efficiency (PUE) widely exists among wheat genotypes. However, the underlying mechanisms are still unclear. Two contrasting wheat genotypes, Heng4399 (H4399) and Tanmai98 (TM98), were screened out from 17 bread wheat genotypes based on shoot soluble phosphate (Pi) concentrations. The TM98 had a significantly higher PUE than the H4399, especially under Pi deficiency. The induction of genes in the PHR1-centered Pi signaling pathway was significantly higher in TM98 than in H4399. Collectively, through a label-free quantitative proteomic analysis, 2110 high-confidence proteins were identified in shoots of the two wheat genotypes. Among them, 244 and 133 proteins were differentially accumulated under Pi deficiency in H4399 and TM98, respectively. The abundance of proteins related to nitrogen and phosphorus metabolic processes, small molecule metabolic process, and carboxylic acid metabolic process weas significantly affected by Pi deficiency in the shoots of the two genotypes. The abundance of proteins in energy metabolism, especially photosynthesis, was decreased by Pi deficiency in the shoots of H4399. Inversely, the PUE-efficient genotype TM98 could maintain protein abundance in energy metabolism. Moreover, the proteins involved in pyruvate metabolism, glutathione metabolism, and sulfolipid biosynthesis were significantly accumulated in TM98, which probably contributed to its high PUE. SIGNIFICANCE: Improving the PUE of wheat is urgent and crucial for sustainable agriculture. Genetic variation among wheat genotypes provides materials for exploring the underlying mechanisms for high PUE. This study selected two wheat genotypes with contrasting PUE to reveal the differences in the physiological and proteomic responses to phosphate deficiency. The PUE-efficiency genotype TM98 greatly induced the expression of genes in the PHR1-centered Pi signaling pathway. Subsequently, the TM98 could maintain the abundance of proteins related to energy metabolism and enhance the abundance of proteins involved in pyruvate metabolism, glutathione metabolism, and sulfolipid biosynthesis to increase PUE under Pi deficiency. The differentially expressed genes or proteins between the genotypes with contrasting PUE would provide potential and basis for breeding wheat varieties with improved phosphorus use efficiency.

Comprehensive Transcriptome Analysis of Responses during Cold Stress in Wheat (Triticum aestivum L.).

Wheat production is often impacted by pre-winter freezing damage and cold spells in later spring. To study the influences of cold stress on wheat seedlings, unstressed Jing 841 was sampled once at the seedling stage, followed by 4 °C stress treatment for 30 days and once every 10 days. A total of 12,926 differentially expressed genes (DEGs) were identified from the transcriptome. K-means cluster analysis found a group of genes related to the glutamate metabolism pathway, and many genes belonging to the bHLH, MYB, NAC, WRKY, and ERF transcription factor families were highly expressed. Starch and sucrose metabolism, glutathione metabolism, and plant hormone signal transduction pathways were found. Weighted Gene Co-Expression Network Analysis (WGCNA) identified several key genes involved in the development of seedlings under cold stress. The cluster tree diagram showed seven different modules marked with different colors. The blue module had the highest correlation coefficient for the samples treated with cold stress for 30 days, and most genes in this module were rich in glutathione metabolism (ko00480). A total of eight DEGs were validated using quantitative real-time PCR. Overall, this study provides new insights into the physiological metabolic pathways and gene changes in a cold stress transcriptome, and it has a potential significance for improving freezing tolerance in wheat.

Metabolomic, DNA Methylomic, and Transcriptomic Profiling of Suberoylanilide Hydroxamic Acid Effects on LPS-Exposed Lung Epithelial Cells.

Suberoylanilide hydroxamic acid (SAHA) is a histone deacetylase (HDAC) inhibitor with anticancer effects via epigenetic and non-epigenetic mechanisms. The role of SAHA in metabolic rewiring and epigenomic reprogramming to inhibit pro-tumorigenic cascades in lung cancer remains unknown. In this study, we aimed to investigate the regulation of mitochondrial metabolism, DNA methylome reprogramming, and transcriptomic gene expression by SAHA in lipopolysaccharide (LPS)-induced inflammatory model of lung epithelial BEAS-2B cells. LC/MS was used for metabolomic analysis, while next-generation sequencing was done to study epigenetic changes. The metabolomic study reveals that SAHA treatment significantly regulated methionine, glutathione, and nicotinamide metabolism with alteration of the metabolite levels of methionine, S-adenosylmethionine, S-adenosylhomocysteine, glutathione, nicotinamide, 1-methylnicotinamide, and nicotinamide adenine dinucleotide in BEAS-2B cells. Epigenomic CpG methyl-seq shows SAHA revoked a list of differentially methylated regions in the promoter region of the genes, such as HDAC11, miR4509-1, and miR3191. Transcriptomic RNA sequencing (RNA-seq) reveals SAHA abrogated LPS-induced differentially expressed genes encoding proinflammatory cytokines, including interleukin 1α (IL1α), IL1ß, IL2, IL6, IL24, and IL32. Integrative analysis of DNA methylome-RNA transcriptome displays a list of genes, of which CpG methylation correlated with changes in gene expression. qPCR validation of transcriptomic RNA-seq data shows that SAHA treatment significantly reduced the LPS-induced mRNA levels of IL1ß, IL6, DNA methyltransferase 1 (DNMT1), and DNMT3A in BEAS-2B cells. Altogether, SAHA treatment alters the mitochondrial metabolism, epigenetic CpG methylation, and transcriptomic gene expression to inhibit LPS-induced inflammatory responses in lung epithelial cells, which may provide novel molecular targets to inhibit the inflammation component of lung carcinogenesis. PREVENTION RELEVANCE: Inflammation increases the risk of lung cancer and blocking inflammation could reduce the incidence of lung cancer. Herein, we demonstrate that histone deacetylase inhibitor suberoylanilide hydroxamic acid regulates metabolic rewiring and epigenetic reprogramming to attenuate lipopolysaccharide-driven inflammation in lung epithelial cells.

Genes encoding cytochrome P450 monooxygenases and glutathione S-transferases associated with herbicide resistance evolved before the origin of land plants.

Cytochrome P450 (CYP) monooxygenases and glutathione S-transferases (GST) are enzymes that catalyse chemical modifications of a range of organic compounds. Herbicide resistance has been associated with higher levels of CYP and GST gene expression in some herbicide-resistant weed populations compared to sensitive populations of the same species. By comparing the protein sequences of 9 representative species of the Archaeplastida-the lineage which includes red algae, glaucophyte algae, chlorophyte algae, and streptophytes-and generating phylogenetic trees, we identified the CYP and GST proteins that existed in the common ancestor of the Archaeplastida. All CYP clans and all but one land plant GST classes present in land plants evolved before the divergence of streptophyte algae and land plants from their last common ancestor. We also demonstrate that there are more genes encoding CYP and GST proteins in land plants than in algae. The larger numbers of genes among land plants largely results from gene duplications in CYP clans 71, 72, and 85 and in the GST phi and tau classes [1,2]. Enzymes that either metabolise herbicides or confer herbicide resistance belong to CYP clans 71 and 72 and the GST phi and tau classes. Most CYP proteins that have been shown to confer herbicide resistance are members of the CYP81 family from clan 71. These results demonstrate that the clan and class diversity in extant plant CYP and GST proteins had evolved before the divergence of land plants and streptophyte algae from a last common ancestor estimated to be between 515 and 474 million years ago. Then, early in embryophyte evolution during the Palaeozoic, gene duplication in four of the twelve CYP clans, and in two of the fourteen GST classes, led to the large numbers of CYP and GST proteins found in extant land plants. It is among the genes of CYP clans 71 and 72 and GST classes phi and tau that alleles conferring herbicide resistance evolved in the last fifty years.