OBJECTIVE: AP2/ERF (APETALA2/ethylene-responsive factor) superfamily is one of the largest gene families in plants and has been reported to participate in various biological processes, such as the regulation of biosynthesis of active lignan. However, few studies have investigated the genome-wide role of the AP2/ERF superfamily in Isatis indigotica. This study establishes a complete picture of the AP2/ERF superfamily in I. indigotica and contributes valuable information for further functional characterization of IiAP2/ERF genes and supports further metabolic engineering. METHODS: To identify the IiAP2/ERF superfamily genes, the AP2/ERF sequences from Arabidopsis thaliana and Brassica rapa were used as query sequences in the basic local alignment search tool. Bioinformatic analyses were conducted to investigate the protein structure, motif composition, chromosome location, phylogenetic relationship, and interaction network of the IiAP2/ERF superfamily genes. The accuracy of omics data was verified by quantitative polymerase chain reaction and heatmap analyses. RESULTS: One hundred and twenty-six putative IiAP2/ERF genes in total were identified from the I. indigotica genome database in this study. By sequence alignment and phylogenetic analysis, the IiAP2/ERF genes were classified into 5 groups including AP2, ERF, DREB (dehydration-responsive element-binding factor), Soloist and RAV (related to abscisic acid insensitive 3/viviparous 1) subfamilies. Among which, 122 members were unevenly distributed across seven chromosomes. Sequence alignment showed that I. indigotica and A. thaliana had 30 pairs of orthologous genes, and we constructed their interaction network. The comprehensive analysis of gene expression pattern in different tissues suggested that these genes may play a significant role in organ growth and development of I. indigotica. Members that may regulate lignan biosynthesis in roots were also preliminarily identified. Ribonucleic acid sequencing analysis revealed that the expression of 76 IiAP2/ERF genes were up- or down-regulated under salt or drought treatment, among which, 33 IiAP2/ERF genes were regulated by both stresses. CONCLUSION This study undertook a genome-wide characterization of the AP2/ERF superfamily in I. indigotica, providing valuable information for further functional characterization of IiAP2/ERF genes and discovery of genetic targets for metabolic engineering.
Abscisic Acid ; Isatis/genetics* ; Multigene Family ; Phylogeny ; Homeodomain Proteins/genetics* ; Genome, Plant

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.
Isatis/genetics* ; Plant Proteins/metabolism* ; Phylogeny ; Arabidopsis/genetics* ; Flavonoids ; Cloning, Molecular

The lignan glycosyltransferase UGT236(belonging to the UGT71 B family) from Isatis indigotica can catalyze the production of phloridzin from phloretin in vitro. UGT236 shares high identity with P2'GT from apple. In this study, the recombinant plasmid pET28 a-MBP-UGT236 was transferred into Escherichia coli Rosetta(DE3) cells and induced by isopropyl-β-D-thiogalactoside(IPTG). The purified UGT236 protein was used for enzymatic characterization with phloretin as substrate. The results showed that UGT236 had the optimal reaction temperature of 40 ℃ and the optimal pH 8(Na_2HPO_4-NaH_2PO_4 system). The UGT236 activity was inhibited by Ni~(2+) and Al~(3+), enhanced by Fe~(2+), Co~(2+), and Mn~(2+), and did not affected by Mg~(2+), Ca~(2+), Li~+, Na~+, or K~+. The K_m, K_(cat), and K_(cat)/K_m of phloretin were 61.03 μmol·L~(-1), 0.01 s~(-1), and 157.11 mol~(-1)·s~(-1)·L, and those of UDPG were 183.6 μmol·L~(-1), 0.01 s~(-1), and 51.91 mol~(-1)·s~(-1)·L, respectively. The possible active sites were predicted by homologous modeling and molecular docking. By mutagenisis and catalytic activity detection, three key active sites, Glu391, His15, and Thr141, were identified, while Phe146 was related to product diversity. In summary, we found that the lignan glycosyltransferase UGT236 from I.indigotica could catalyze the reaction of phloretin into phloridzin. Several key amino acid residues were identified by structure prediction, molecular docking, and site-mutagenesis, which provided a basis for studying the specificity and diversity of phloretin glycoside products. This study can provide a reference for artificially producing glycosyltransferase elements with high efficiency and specific catalysis.
Glucosyltransferases/genetics* ; Glycosyltransferases/metabolism* ; Isatis ; Lignans/metabolism* ; Molecular Docking Simulation ; Phloretin/metabolism* ; Phlorhizin/metabolism*

Isatidis Radix is the dried root of the Isatis indigotica, with pharmacological effects such as heat-clearing and detoxification, cooling blood and pharyngeal relief, antibacterial and anti-inflammatory effects. It is often used clinically to prevent and treat influenza and other diseases. In this paper, relevant domestic and foreign literatures in recent years were summarized, and it was found that Isatidis Radix lignans, indole alkaloids, polysaccharides, etc. were the main active components against influenza virus. Then its pharmacological effects and the mechanism of action were reviewed, providing a basis for in-depth research on the antiviral effect of Isatidis Radix.
Antiviral Agents/pharmacology* ; Drugs, Chinese Herbal ; Isatis ; Orthomyxoviridae ; Plant Roots ; Polysaccharides

In this paper, through the collection and collation of ancient herbs, medical books and prescriptions, combined with modern literature, the historical changes of the name, origin, position, medicinal parts, collection, processing and processing of bluegrass were systematically combed and verified.It can be seen from the research that bluegrass was first used as medicine by the fruit, namely blueberry, which was originally Polygonum tinctorium. Since the Ming and Qing Dynasties, blueberry was rarely used, and it has been no longer used medicinally. In the Wei and Jin Dynasties, the medicinal parts extended to the stems and leaves, and most of them used juice as medicine.Since the Tang Dynasty, origin has been extended to Isatis indigotica, Baphicacanthus cusia, Indigofera tinctoria, Compositae plant Wulan, etc. In the Song Dynasty, the medicinal parts extended to the roots, and the "Banlangen" began to appear, and gradually became the main medicinal parts of blue medicinal materials, the main base of which was B. cusia. Since the Qing Dynasty, I. indigotica, a Cruciferae, has gradually become a genuine indigo root, while B. cusia has become a southern indigo root. It was the first mineral dye imported from abroad for thrush, and then used as medicine, also known as clam powder. Because it was found that it had the same effect with the extract of bluegrass, it was also named indigo naturalis in China, which has lasted till now. The main stream of Isatidis Folium in the past dynasties is the dry stem and leaf of Clerodendrum cyrtophylum. Since the Qing Dynasty, the stem and leaf of Isatis indigotica, P. tinctorium and other blue grasses have been gradually mixed as substitutes and gradually become the mainstream.
China ; Clerodendrum ; Isatis ; Medicine, Chinese Traditional ; Plants, Medicinal

OBJECTIVE: To investigate anti-inflammatory and immunomodulation effects of different ecotype from Isatidis Radix growing in Gansu province. METHODS: Mice were randomly divided into 6 groups (=11)and used the auricular swelling and paw edema to observe the anti-inflammatory effects of Isatidis Radix; Mice were randomly divided into 7 groups (=11) and through the gasbag synovitis model to observe the anti-inflammatory effects of Isatidis Radix; Mice were randomly divided into 6 groups (=11), the immunosuppressed model were established by injection of cyclophosphamide (CTX) to study the effects of Isatidis Radix on index of thymus, blood routine and cytokines. RESULTS: Gansu different ecotype from Isatidis Radix could reduce the swelling of the mice auricle, paw edema and total protein, leukotriene B(LTB)and malonaldehyde(MDA) in airbag synovitis exudates, and upgrade serum levels of superoxide dismutase (SOD); Degrade the tumor necrosis factor-α (TNF-α) and upgrade the index of thymus, the number of red and white corpuscles, the level of interferon-γ (IFN-γ), interleukin-4 (IL-4) (<0.05, 0.01) of mice immunosuppressed model; Above the research of anti-inflammatory and immunomodulation, there were no significant differences between Isatidis Radix of Gansu different ecotype and tetraploid. CONCLUSIONS Different ecotype of Isatidis Radix has obvious functions in anti-inflammatory and immunomodulation, but there are no significant differences between Gansu different ecotype and tetraploid.
Animals ; Anti-Inflammatory Agents ; pharmacology ; China ; Cytokines ; immunology ; Drugs, Chinese Herbal ; pharmacology ; Ecotype ; Immunomodulation ; drug effects ; Isatis ; chemistry ; Mice ; Plant Extracts ; pharmacology ; Random Allocation

Isatis indigotica Fort., belonging to Cruciferae, is one of the most commonly used plants in traditional Chinese medicine. The accumulation of the effective components of I. indigotica is related with its growth conditions. The GRAS genes are members of a multigene family of transcriptional regulators that play a crucial role in plant growth. Although the activities of many GRAS genes have long been recognized, only in recent years were some of them identified and functionally characterized in detail. In the present study, 41 GRAS genes were identified from I. indigotica through bioinformatics methods for the first time. They were classified into ten groups according to the classification of Arabidopsis and rice. The characterization, gene structure, conserved motifs, disordered N-terminal domains, and phylogenetic reconstruction of these GRASs were analyzed. Forty-three orthologous gene pairs were shared by I. indigotica and Arabidopsis, and interaction networks of these orthologous genes were constructed. Furthermore, gene expression patterns were investigated by analysis in methyl jasmonate (MeJA)-treated I. indigotica hairy roots based on RNA-seq data. In conclusion, this comprehensive analysis would provide rich resources for further studies of GRAS protein functions in this plant.
Computational Biology ; Gene Expression Profiling ; Genes, Plant ; Isatis ; genetics ; Medicine, Chinese Traditional ; Transcription Factors ; genetics

Phenolic compounds, metabolites of the phenylpropanoid pathway, play an important role in the growth and environmental adaptation of many plants. Phenylalanine ammonia-lyase (PAL) is the first key enzyme of the phenylpropanoid pathway. The present study was designed to investigate whether there is a multi-gene family in I. Indigotic and, if so, to characterize their properties. We conducted a comprehensive survey on the transcription profiling database by using tBLASTn analysis. Several bioinformatics methods were employed to perform the prediction of composition and physicochemical characters. The expression levels of IiPAL genes in various tissues of I. indigotica with stress treatment were examined by quantitative real-time PCR. Protoplast transient transformation was used to observe the locations of IiPALs. IiPALs were functionally characterized by expression with pET-32a vector in Escherichia colis strain BL21 (DE3). Integration of transcripts and metabolite accumulations was used to reveal the relation between IiPALs and target compounds. An new gene (IiPAL2) was identified and both IiPALs had the conserved enzymatic active site Ala-Ser-Gly and were classified as members of dicotyledon. IiPAL1 and IiPAL2 were expressed in roots, stems, leaves, and flowers, with the highest expression levels of IiPAL1 and IiPAL2 being observed in stems and roots, respectively. The two genes responded to the exogenous elicitor in different manners. Subcellular localization experiment showed that both IiPALs were localized in the cytosol. The recombinant proteins were shown to catalyze the conversion of L-Phe to trans-cinnamic acid. Correlation analysis indicated that IiPAL1 was more close to the biosynthesis of secondary metabolites than IiPAL2. In conclusion, the present study provides a basis for the elucidation of the role of IiPALs genes in the biosynthesis of phenolic compounds, which will help further metabolic engineering to improve the accumulation of bioactive components in I. indigotica.
Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Isatis ; enzymology ; genetics ; Molecular Sequence Data ; Multigene Family ; Phenylalanine Ammonia-Lyase ; chemistry ; genetics ; metabolism ; Phylogeny ; Plant Proteins ; chemistry ; genetics ; metabolism ; Sequence Alignment

Based on the transcriptome data, we cloned the open reading frame of IiHCT gene from Isatis indigotica, and then performed bioinformatic analysis of the sequence. Further, we detected expression pattern in specific organs and hairy roots treated methyl jasmonate( MeJA) by RT-PCR. The IiHCT gene contains a 1 290 bp open reading frame( ORF) encoding a polypeptide of 430 amino acids. The predicted isoelectric point( pI) was 5.7, a calculated molecular weight was about 47.68 kDa. IiHCT was mainly expressed in stem and undetectable in young root, leaf and flower bud. After the treatment of MeJA, the relative expression level of IiHCT increased rapidly. The expression level of IiHCT was the highest at 4 h and maintained two fold to control during 24 h. In this study, cloning of IiHCT laid the foundation for illustrating the biosynthesis mechanism of phenylpropanoids in I. indigotica.
Acyltransferases ; chemistry ; genetics ; metabolism ; Amino Acid Sequence ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Isatis ; chemistry ; classification ; enzymology ; genetics ; Models, Molecular ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Plant Proteins ; chemistry ; genetics ; metabolism ; Quinic Acid ; metabolism ; Sequence Alignment ; Shikimic Acid ; metabolism

The experiment included three potassium levels (K0 0 g x kg(-1), K1 0.33 g x kg(-1), K2 0.67 g x kg(-1)) and two water gradients (well watered and drought stress), then measured growth indicators, SOD, POD, CAT activities and concents of osmotic regulation substances. To explore the effects of K fertilizer and water on growth and physiological characteristics of Isatis indigotica, providing reference for improving drought resistance of I. indigotica. The result showed drought stress inhibited the growth and decreased the biomass of I. indigotica but K fertilizer can alleviate the drought stress. Compared with K0 treatment, K1, K2 treatment increased the biomass of overground part of by 89. 13% ,60. 87% under drought stress. The corresponding increase in soluble sugar content was 16.67%, 5.00%, and in proline content was 42.41%, 65.62%, respectively. SOD,POD and CAT activities was significantly improved in K1, K2 treatment in comparison with K0 treatment under drought stress, but soluble protein content significantly reduced. The conclusion is that appropriate amount of K fertilizer can increase the activities of antioxidase and the content of osmoregulation substance under drought stress, and improve drought resistance of I. indigotica.
Fertilizers ; analysis ; Isatis ; chemistry ; enzymology ; growth & development ; metabolism ; Peroxidase ; metabolism ; Plant Proteins ; metabolism ; Potassium ; analysis ; metabolism ; Seedlings ; chemistry ; enzymology ; growth & development ; metabolism ; Superoxide Dismutase ; metabolism ; Water ; analysis ; metabolism