Steroidal glycoalkaloids (SGAs), a class of specialized metabolites, are predominantly found in Solanum species. These compounds are recognized for their structural diversity and wide range of biological activities, including toxicity toward various plant pathogens and herbivores. The cultivated potato (Solanum tuberosum) primarily accumulates α-solanine and α-chaconine-bitter-tasting, toxic SGAs that together constitute over 90% of total SGAs. In contrast, the wild potato Solanum chacoense produces an array of rare SGAs, some reported to confer resistance to specific pests. However, the biosynthetic pathways of these uncommon SGAs remain poorly defined. In this study, we isolated and structurally characterized six SGAs from S. chacoense absent in cultivated potato, including two novel compounds: 12α-hydroxysolanine and 12α-hydroxychaconine. Recent evidence indicates that 2-oxoglutarate-dependent dioxygenases (DOXs) contribute to SGA structural diversification. Guided by this, we identified five candidate genes encoding DOX enzymes in S. chacoense. Biochemical assays revealed that one enzyme, designated Sc12DOX, catalyzes the C-12α hydroxylation of α-solanine and α-chaconine to yield 12α-hydroxysolanine and 12α-hydroxychaconine, respectively. These findings enhance our understanding of SGA structural and metabolic diversity within Solanum species.

Structural comparisons of bifunctional fatty acid dioxygenases with allene oxide, epoxy alcohol, or diol synthase activities.

Hydroxy fatty acids (HFAs) are multifunctional lipids exhibiting potent physiological activities via G protein-coupled receptors like GPR120, which modulates fat taste perception, metabolism, and immunity. Here, we explored the biotransformation of plant oil-derived fatty acids into HFAs using linoleate diol synthases (LDSs), fusion enzymes with dioxygenase (DOX) and hydroperoxide isomerase (HPI) domains. For instance, the natural 12-hydroxyoctadec-9Z-enoic acid (ricinoleic acid, 12-HOME) and 13-hydroxyoctadec-9Z-enoic acid prepared from linoleic acid were transformed into novel 8,12- and 8,13-dihydroxyoctadec-9Z-enoic acids (DiHOMEs) as well as their corresponding trihydroxy derivatives: 7,8,12-/8,11,12- and 7,8,13-/5,8,13-trihydroxyoctadec-9Z-enoic acids, respectively, by the LDS from Glomerella cingulata (Gc-LDS). The recombinant Escherichia coli expressing Gc-LDS efficiently produced 9.4 mM 8S,12R-DiHOME from 10 mM 12-HOME (187 U/g dry cells) under reducing conditions. Notably, 8S,12R-DiHOME elicited a potent GPR120-mediated Ca2+ response (EC50 = 0.43 μM), likely via enhanced hydrogen bonding with key receptor residues. This study contributes to the LDS-based biotransformation for developing functional HFAs.

Mushrooms are part of the human diet since time immemorial, appreciated for their nutritional value and especially for their delicious flavors. Hundreds of volatile organic compounds (VOCs) have been identified in fungi contributing to the unique aroma of each species. Generally, studies on mushroom VOCs are carried out with chopped fruiting bodies of more or less one developmental stage. For determine fungal aromas for assessment of the food quality this procedure might be adequate. Nonetheless, for analysis of the biological role of fungal VOCs in context of inter alia VOC biosynthesis or fungal communication this approach can suffer from drawbacks. First of all, damaging fruiting bodies can lead to VOC artefacts due to cell disruption and the occurrence of unnatural enzymatic reactions. Furthermore, fungal VOC profiles are dynamic, changing with ongoing development. For better understanding of the biological function of fungal VOCs it is therefore helpful to know which volatile patterns are characteristic for a certain developmental stage.Against this background, an approach was developed enabling on one hand the cultivation of fungi during different developmental stages, including the growth of fruiting bodies, and on the other hand the non‐invasive analysis of VOCs in the headspace (HS) of fungal cultures. These requirements were complied with modified crystallizing dishes for culture purposes and a HS‐ SPME‐GC‐MS approach to analyze the VOCs. This method was applied to analyze the volatilomes of the dikaryotic strain C. aegerita AAE‐3 and four monokaryotic offspring siblings with different fruiting phenotypes throughout ten life stages. At early stages, in the HS of all tested strains alcohols and ketones, such as oct‐1‐en‐3‐ol, 2‐methylbutan‐1‐ol and cyclopentanone, were the most prominent VOCs. Particularly counting for the dikaryon, the volatilome altered with continued fruiting body development exhibiting remarkable changes during sporulation. Here, sesquiterpenes, especially Δ6‐protoilludene, α‐cubebene and δ‐cadinene, were the most abundant VOCs in the HS of C. aegerita AAE‐3. After sporulation, the amount of sesquiterpenes decreased along with the appearance of other VOCs including octan‐3‐one. In contrast, less VOCs were present in the HS of the monokaryotic strains of which all were as well detectable in the HS of the dikaryon. The changes of the volatilome were the fundament for a subsequent transcriptome analysis aiming to identify enzymes involved in fungal VOC biosynthesis, especially regarding C8 VOC formation, which is, despite the fact that these substances are ubiquitous found in fungi, still barely understood. The transcriptomic study was carried out with seven developmental stages of C. aegerita AAE‐3, which during the volatilome study exhibited interesting volatile patterns. Additionally, fruiting bodies (five stages) and mycelia (seven stages) samples were harvested separately to get further insights about the putative origin of the VOCs observed in the HS of C. aegerita. Combining transcriptome and volatilome data, enzymes putatively involved in the biosynthesis of C8 oxylipins in C. aegerita including lipoxygenases (LOXs), dioxygenases (DOXs), hydroperoxide lyases (HPLs), alcohol dehydrogenases (ADHs) and ene‐ reductases could be identified. Especially the putative DOX AAE3_13098, the putative HPLs AAE3_05330 and AAE3_09203, the putative ADHs AAE3_00054 and AAE3_06559 as well as the putative ene‐reductase AAE3_15349 exhibit remarkable transcriptomic patterns making these enzymes highly interesting for future characterization studies. Furthermore, the study showed that the mycelium is probably the main source for sesquiterpenes observed during sporulation in the HS of C. aegerita AAE‐3 cultures whereas changes in the Cs profile detected in late stages of development are probably due to the activity of enzymes located in the fruiting bodies.

The extreme adaptation potential of the generalist herbivore Tetranychus urticae (the two-spotted spider mite) to pesticides as well as diverse host plants has been associated with clade-specific gene expansions in known detoxifying enzyme families, and with extensive and rapid transcriptional responses. However, how this broad transcriptional potential is regulated remains largely unknown. Using a parental/F1 design in which four inbred strains were crossed to a common inbred strain, we assessed the genetic basis and inheritance of gene expression variation in T. urticae. Mirroring known phenotypic variation in the progenitor strains of the inbreds, we confirmed that the inbred strains we created were genetically distinct, varied markedly in pesticide resistance, and also captured variation in host plant fitness as is commonly observed in this species. By examining differences in gene expression between parents and allele-specific expression in F1s, we found that variation in RNA abundance was more often explained in trans as compared to cis, with the former associated with dominance in inheritance. Strikingly, in a gene ontology analysis, detoxification genes of the cytochrome P450 monooxygenase (CYP) family, as well as dioxygenases (DOGs) acquired from horizontal gene transfer from fungi, were specifically enriched at the extremes of trans-driven up- and downregulation. In particular, multiple CYPs and DOGs with broad substrate-specificities for pesticides or plant specialized compounds were exceptionally highly upregulated as a result of trans-regulatory variation, or in some cases synergism of cis and trans, in the most multi-pesticide resistant strains. Collectively, our findings highlight the potential importance of trans-driven expression variation in genes associated with xenobiotic metabolism and host plant use for rapid adaptation in T. urticae, and also suggests modular control of these genes, a regulatory architecture that might ameliorate negative pleiotropic effects.

Lipids are central at various stages of host–pathogen interactions in determining virulence and modulating plant defense. Free fatty acids may act as substrates for oxidizing enzymes [e.g., lipoxygenases (LOXs) and dioxygenases (DOXs)] that synthesize oxylipins. Fatty acids and oxylipins function as modulators of several pathways in cell-to-cell communication; their structural similarity among plant, fungal, and bacterial taxa suggests potential in cross-kingdom communication. We provide a prospect of the known role of fatty acids and oxylipins in fungi and bacteria during plant–pathogen interactions. In the pathogens, oxylipin-mediated signaling pathways are crucial both in development and host infection. Here, we report on case studies suggesting that oxylipins derived from oleic, linoleic, and linolenic acids are crucial in modulating the pathogenic lifestyle in the host plant. Intriguingly, overlapping (fungi-plant/bacteria-plant) results suggest that different inter-kingdom pathosystems use similar lipid signals to reshape the lifestyle of the contenders and occasionally determine the outcome of the challenge.

Insight into the physiological and molecular mechanisms of hot air treatment which reduce internal browning in winter-harvested pineapples

The columnar apple cultivar ‘McIntosh Wijcik’ was discovered as a spontaneous mutant from the top of a ‘McIntosh’ tree in the early 1960s. ‘McIntosh Wijcik’ exhibits the columnar growth phenotype: compact and sturdy growth, short internodes, and very few lateral shoots. Classical genetic analysis revealed that the columnar growth phenotype of ‘McIntosh Wijcik’ is controlled by a single dominant gene, Co. This review focuses on the advances made toward understanding the molecular mechanisms of columnar growth in the last decade. Molecular studies have shown that an 8.2 kb insertion in the intergenic region of the Co locus is responsible for the columnar growth phenotype of ‘McIntosh Wijcik’, implying that the insertion affects the expression patterns of adjacent genes. Among the candidate genes in the Co region, the expression pattern of MdDOX-Co, putatively encoding 2-oxoglutarate-dependent dioxygenase (DOX), was found to vary between columnar and non-columnar apples. Recent studies have found three functions of MdDOX-Co: facilitating bioactive gibberellin deficiency, increasing strigolactone levels, and positively regulating abscisic acid levels. Consequently, changes in these plant hormone levels caused by the ectopic expression of MdDOX-Co in the aerial organs of ‘McIntosh Wijcik’ can lead to dwarf trees with fewer lateral branches. These findings will contribute to the breeding and cultivation of new columnar apple cultivars with improved fruit quality.

BackgroundGeneralist herbivores such as the two-spotted spider mite Tetranychus urticae thrive on a wide variety of plants and can rapidly adapt to novel hosts. What traits enable polyphagous herbivores to cope with the diversity of secondary metabolites in their variable plant diet is unclear. Genome sequencing of T. urticae revealed the presence of 17 genes that code for secreted proteins with strong homology to “intradiol ring cleavage dioxygenases (DOGs)” from bacteria and fungi, and phylogenetic analyses show that they have been acquired by horizontal gene transfer from fungi. In bacteria and fungi, DOGs have been well characterized and cleave aromatic rings in catecholic compounds between adjacent hydroxyl groups. Such compounds are found in high amounts in solanaceous plants like tomato, where they protect against herbivory. To better understand the role of this gene family in spider mites, we used a multi-disciplinary approach to functionally characterize the various T. urticae DOG genes.ResultsWe confirmed that DOG genes were present in the T. urticae genome and performed a phylogenetic reconstruction using transcriptomic and genomic data to advance our understanding of the evolutionary history of spider mite DOG genes. We found that DOG expression differed between mites from different plant hosts and was induced in response to jasmonic acid defense signaling. In consonance with a presumed role in detoxification, expression was localized in the mite’s gut region. Silencing selected DOGs expression by dsRNA injection reduced the mites’ survival rate on tomato, further supporting a role in mitigating the plant defense response. Recombinant purified DOGs displayed a broad substrate promiscuity, cleaving a surprisingly wide array of aromatic plant metabolites, greatly exceeding the metabolic capacity of previously characterized microbial DOGs.ConclusionOur findings suggest that the laterally acquired spider mite DOGs function as detoxification enzymes in the gut, disarming plant metabolites before they reach toxic levels. We provide experimental evidence to support the hypothesis that this proliferated gene family in T. urticae is causally linked to its ability to feed on an extremely wide range of host plants.

Cultivated tomato (Solanum lycopersicum) contains α-tomatine, a steroidal glycoalkaloid (SGA), which functions as a defense compound to protect against pathogens and herbivores; interestingly, wild species in the tomato clade biosynthesize a variety of SGAs. In cultivated tomato, the metabolic detoxification of α-tomatine during tomato fruit ripening is an important trait that aided in its domestication, and two distinct 2-oxoglutarate-dependent dioxygenases (DOXs), a C-23 hydroxylase of α-tomatine (Sl23DOX) and a C-27 hydroxylase of lycoperoside C (Sl27DOX), are key to this process. There are tandemly duplicated DOX genes on tomato chromosome 1, with high levels of similarity to Sl23DOX. While these DOX genes are rarely expressed in cultivated tomato tissues, the recombinant enzymes of Solyc01g006580 and Solyc01g006610 metabolized α-tomatine to habrochaitoside A and (20R)-20-hydroxytomatine and were therefore named as habrochaitoside A synthase (HAS) and α-tomatine 20-hydroxylase (20DOX), respectively. Furthermore, 20DOX and HAS exist in the genome of wild tomato S. habrochaites accession LA1777, which accumulates habrochaitoside A in its fruits, and their expression patterns were in agreement with the SGA profiles in LA1777. These results indicate that the functional divergence of α-tomatine-metabolizing DOX enzymes results from gene duplication and the neofunctionalization of catalytic activity and gene expression, and this contributes to the structural diversity of SGAs in the tomato clade.

BackgroundCyclocybe aegerita (syn. Agrocybe aegerita) is a commercially cultivated mushroom. Its archetypal agaric morphology and its ability to undergo its whole life cycle under laboratory conditions makes this fungus a well-suited model for studying fruiting body (basidiome, basidiocarp) development. To elucidate the so far barely understood biosynthesis of fungal volatiles, alterations in the transcriptome during different developmental stages of C. aegerita were analyzed and combined with changes in the volatile profile during its different fruiting stages.ResultsA transcriptomic study at seven points in time during fruiting body development of C. aegerita with seven mycelial and five fruiting body stages was conducted. Differential gene expression was observed for genes involved in fungal fruiting body formation showing interesting transcriptional patterns and correlations of these fruiting-related genes with the developmental stages. Combining transcriptome and volatilome data, enzymes putatively involved in the biosynthesis of C8 oxylipins in C. aegerita including lipoxygenases (LOXs), dioxygenases (DOXs), hydroperoxide lyases (HPLs), alcohol dehydrogenases (ADHs) and ene-reductases could be identified. Furthermore, we were able to localize the mycelium as the main source for sesquiterpenes predominant during sporulation in the headspace of C. aegerita cultures. In contrast, changes in the C8 profile detected in late stages of development are probably due to the activity of enzymes located in the fruiting bodies.ConclusionsIn this study, the combination of volatilome and transcriptome data of C. aegerita revealed interesting candidates both for functional genetics-based analysis of fruiting-related genes and for prospective enzyme characterization studies to further elucidate the so far barely understood biosynthesis of fungal C8 oxylipins.

In stark contrast to the reactivity of the bis-silylenyl dicarborane CB-Si2 (1) [CB = ortho-C,C'-C2B10H10, Si = PhC(tBuN)2Si] towards O2, N2O, and CO2, yielding the same dioxygenation product CB-Si2O2 (2) with a four-membered 1,3,2,4-disiladioxetane ring, the activation of the latter small molecules with the phosphanyl-silylenyl-functionalised CB-SiP (3) {P[double bond, length as m-dash]P[N(tBu)CH2]2} affords with O2 the CB-Si([double bond, length as m-dash]O)P([double bond, length as m-dash]O) silanone-phosphine oxide (4), with N2O the CB-Si([double bond, length as m-dash]O)P silanone-phosphine (5), and with CO2 the CB-Si(O2C[double bond, length as m-dash]O)P silicon carbonate-phosphine (6) and CB-C([double bond, length as m-dash]O)OSiOP ester (7), respectively.

Histoplasma capsulatum is an ascomyceteous fungus and a human lung pathogen, which is present in river valleys of the Americas and other continents. H. capsulatum and two related human pathogens, Blasmomyces dermatitidis and Paracoccidioides brasiliensis, belongs to the Ajellomycetaceae family. The genomes of all three species code for three homologous and tentative enzymes of the linoleate diol synthase (LDS) family of fusion enzymes with dioxygenase (DOX) and cytochrome P450 domains. One group aligned closely with 8R-DOX-5,8-LDS of Aspergilli, which oxidizes linoleic acid to 5S,8R-dihydroxylinoleic acid; this group was not further investigated. The second group aligned with 10R-DOX-epoxy alcohol synthase (EAS) of plant pathogens. Expression of this enzyme from B. dermatitidis revealed only 10R-DOX activities, i.e., oxidation of linoleic acid to 10R-hydroperoxy-8E,12Z-octadecadienoic acid. The third group aligned in a separate entity. Expression of these enzymes of H. capsulatum and B. dermatitidis revealed no DOX activities, but both enzymes transformed 13S-hydroperoxy-9Z,11E-octadecadienoic acid efficiently to 12(13S)epoxy-11-hydroperoxy-9Z-octadecenoic acid. Other 13-hydroperoxides of linoleic and α-linolenic acids were transformed with less efficiency and the 9-hydroperoxides of linoleic acid were not transformed. In conclusion, a novel EAS has been found in H. capsulatum and B. dermititidis with 13S-hydroperoxy-9Z,11E-octadecadienoic acid as the likely physiological substrate.

Objective To investigate the expression of fractional exhaled nitric oxide (FeNO) and indoleamine 2, 3 dioxygenase (IDO) in children with allergic asthma and their diagnostic values for the disease. Methods Sixty children with allergic asthma hospitalized and treated in Luoyang Maternal and Child Health Hospital from 2016 to 2019 were selected as observation group, and 60 healthy children who underwent physical examination during the same time period in the hospital were selected as control group. The levels of FeNO, IDO, eosinophils and lung function of the two groups were observed, and the correlation among them was also analyzed. Then the diagnostic values of FeNO and IDO levels for allergic asthma were analyzed by receiver operating characteristics (ROC) curve. Results The observation group has higher FeNO level and lower IDO activity than the control group (P<0.05). The forced expiratory volume in 1 second (FEV1)/ forced vital capicity (FVC) levels in the observation group were significantly lower than those in the control group (P<0.05), and the eosinophil count was significantly higher than that in the control group (P<0.05). FeNO levels were negatively correlated with FEV1/FVC in children with allergic asthma (r=-0.667, P<0.05), and positively correlated with eosinophil count (r=0.813, P<0.05). The level of IDO was positively correlated with FEV1/FVC (r=0.725, P<0.05), and negatively correlated with eosinophil count (r=-0.583, P<0.05). ROC curve analysis showed that single FeNO, single IDO and FeNO combined with IDO had certain diagnostic value for allergic asthma in children. However, FeNO combined with IDO has the highest diagnostic value for allergic asthma in children, with area under curve, sensitivity and specificity as 0.937, 83.3%, and 100%, respectively. Conclusions Children with allergic asthma have increased FeNO level and decreased IDO activity, and the combined detection of FeNO and IDO has high diagnostic value for allergic asthma in children. Key words: Fractional exhaled nitric oxide; Indoleamine 2, 3 Dioxygenase; Allergic asthma; Expression level; Diagnostic value

Objective To investigate the effects of miR-27b targeting ten-eleven translocation methylcytosine dioxygenase 2 (TET2) on oxidized low-density lipoprotein (ox-LDL) induced inflammatory responses and apoptosis in endothelial cells. Methods Double luciferase reporter gene analysis verified the targeting effect of miR-27b on TET2. Human umbilical vein endothelial cells (HUVECs) were induced by ox-LDL in vitro. Eight groups were set up including control group, ox-LDL group, ox-LDL+ anti-miR-con group, ox-LDL+ anti-miR-27b group, ox-LDL+ pcDNA group, ox-LDL+ pcDNA-TET2 group, anti-miR-27b+ si-con group and anti-miR-27b+ si-TET2 group. qRT-PCR was used to detect the expression of miR-27b and TET2 at mRNA level. Cell viability was detected by MTT assay. Cell apoptosis rate was detected by flow cytometry. Western blot was used to detect the expression of TET2, Cyclin D1 and caspase-3 at protein level. Results TET2 was the target gene of miR-27b. TET2 expression could be negatively regulated by miR-27b. ox-LDL increased the expression of miR-27b and reduced the expression of TET2 in HUVECs. The secretion of inflammatory factors and apoptosis rates of HUVECs in the control, ox-LDL+ anti-miR-27b, ox-LDL+ pcDNA-TET2 and anti-miR-27b+ si-con groups were significantly lower than those in the ox-LDL, ox-LDL+ anti-miR-con, ox-LDL+ pcDNA and anti-miR-27b+ si-TET2 groups, respectively (P<0.05). Conclusions miR-27b promoted ox-LDL-induced inflammatory responses and apoptosis in endothelial cells through down-regulating the expression of TET2. Key words: miR-27b; ox-LDL; TET2; HUVEC; Inflammatory response; Apoptosis

A summary of the most recent applications of malonyl peroxides as reagents in organic synthesis is discussed. The microreview covers the latest selected examples on the usage of malonyl peroxides: dioxygenation and oxyamination of alkenes; oxidative C–O coupling with arenes, enol ethers, 1,3-dicarbonyl and N-heterocyclic compounds; sulfoxide synthesis.

Спін-каталіз окиснення ненасичених субстратів моно- і ди-оксигеназами, вільними від кофактору. Як триплетний кисень може подолати спінову заборону

Objective To explore potential therapeutic targets for neonatal hypoxic brain injury, we analyzed the effects of hypoxia on the gene expression profiles and signaling pathway in 3D cultured cerebral cortex cells. Methods R studio software was used to analyze the differentially expressed genes of hypoxia treated cerebral cortex cell data (GSE112137) which was downloaded from GEO database. Gene Oncology and KEGG software were used to enrich the molecular function, biological process and signaling pathways of differentially expressed genes. Then String and Cytoscape software were adapted to analyzed gene interaction network between these genes. Results There were 395 increasing genes and 185 decreasing genes (Change Fold≥2) were identified in hypoxic cerebral cells compared with the control groups. Most elevated genes were mainly related with molecular function including dioxygenase activity, isomerase activity and misfolded protein binding, while the decreasing genes were enriched in RNA polymerase Ⅱ proximal promoter sequence-specific DNA binding. Biological process enrichment analysis revealed that hypoxia up-regulated genes were associated with endoplasmic reticulum stress, oxidation-reduction process and glycolysis, while down-regulated genes were involved in the progress of neural development and cell differentiation. KEGG pathway enrichment results indicated hypoxia increasing genes were mainly related with endoplasmic reticulum protein processing, glycolysis, amino acid biosynthesis, and decreasing genes were mainly enriched in Parkinson′s disease signaling pathway. Conclusions Hypoxia in human cerebral cortex cells could cause endoplasmic reticulum stress, protein misfolding and metabolic abnormalities, inhibited the development of neuron cells. Drugs targeting these process may be beneficial to alleviate cerebral hypoxia injury. Key words: Hypoxia-ischemia, brain; Organ culture techniques; Gene expression profiling; Signal transduction; Computational biology

Molecular biological and cultivation-based approaches were used to investigate the microbial community of tehnogenic soil contaminated with poorly degradable toxic (chlorinated) aromatic compounds. Diversity of the bphA1 genes, the key genes for the degradation of biphenyl/polychlorinated biphenyls (PCB) was assessed, and new bacterial degraders of biphemyl/PCB were isolated. Cloning of the PCR product obtained using the DNA isolated from soil as a template and the primers to the biphenyl 2,3-dioxygenase α-subunit gene (bphA1) revealed two types of the genes of aromatic dioxygenases (DO) with the highest similarity (97.8‒99.5%) to the genes encoding the Rieske cluster of DO α-subunits (bphA1) from uncultured bacteria. Two biphenyl-degrading isolates obtained from an enrichment culture of a soil sample incubated with biphenyl were identified as Pseudomonas (VRP2-6 and VRP2-2). According to their 16S rRNA gene sequences, they exhibited the highest similarity to the type strain of P. taiwanensis (99%) and P. alcaligenes (100%), respectively. Analysis of the bphA1 sequences of strains VRP2-6 and VRP2-2 revealed the similarity to those of the known biphenyl-degrading pseudomonads not exceeding 97.3%. The isolate VRP2-6 efficiently utilized ortho- and para-monochlorinated biphenyls and degraded dichlorinated biphenyl oxidizing both the ortho- and para-chlorinated rings of the biphenyl molecule. New pseudomonad strains may be of interest for development of biotechnologies aimed at monitoring and remediation of biphenyl/PCB-contaminated soils.

Tuberculosis still threatens public health.Despitemany methods of diagnosis and treatment, there are still no satisfactory diagnostic methods, and there are still challenges in treatment, especially multidrug-resistant tuberculosis.Therefore, it is urgent to seek sensitive and specific diagnostic markers for tuberculosis, to improve the anti-tuberculosis treatment effect and improve the prognosis of tuberculosis.Indoleamine 2, 3-dioxygenase (IDO) is a key rate-limiting enzyme in the catabolism of tryptophan (Trp) into kynurenine (Kyn), which is involved in regulation of cellular immune function, especially T cells.This article reviews the role of IDO in immunomodulation, especially in the occurrence and development of tuberculosis, and is expected to become a diagnostic marker and immunotherapy target for tuberculosis. Key words: Tuberculosis; Dioxygenases; Immunomodulation; Immunotherapy