Efficient photocatalytic hydrogen peroxide production over S-scheme In2S3/molten salt modified C3N5 heterojunction.

Graphitic phase carbon nitride (g-C3N5), as a novel n-type metal-free material, is employed as a visible light-receptive catalyst because of its narrow band gap and abundant nitrogen. To overcome the low carrier mobility efficiency of g-C3N5, its modification by K ions was adopted. In addition, In2S3 was selected to couple with modified g-C3N5 to overcome the recombination of photogenerated e-/h+. As a novel photocatalytic material, it was proven to possess a high visible light absorption capacity and a strong H2O2 production ability (up to 3.89 mmol⋅L-1 in 2 h). Moreover, a S-scheme heterojunction structure was successfully constructed between the two materials, which was tested and confirmed to be successful in raising the photogenerated e-/h+ separation efficiency. Ultimately, the primary processes of photocatalytic H2O2 production were summarized by superoxide radical and rotating disc electron measurements. This research provides a fresh perspective for the synthesis of C3N5-based S-scheme heterojunction photocatalysts for producing H2O2.

Functional characterization of Fagopyrum tataricum ZIP gene family as a metal ion transporter.

The zinc/iron-regulated transporter-like proteins (ZIP) family acts as an important transporter for divalent metal cations such as Zn, Fe, Mn, Cu, and even Cd. However, their condition is unclear in Tartary buckwheat (Fagopyrum tataricum). Here, 13 ZIP proteins were identified and were predicted to be mostly plasma membrane-localized. The transient expressions of FtZIP2 and FtZIP6 in tobacco confirmed the prediction. Multiple sequence alignment analysis of FtZIP proteins revealed that most of them had 8 putative transmembrane (TM) domains and a variable region rich in histidine residues between TM3 and TM4, indicating the reliable affinity to metal ions. Gene expression analysis by qRT-PCR showed that FtZIP genes were markedly different in different organs, such as roots, stems, leaves, flowers, fruits and seeds. However, in seedlings, the relative expression of FtZIP10 was notably induced under the CdCl2 treatment, while excessive Zn2+, Fe2+, Mn2+ and Cd2+ increased the transcript of FtZIP5 or FtZIP13, in comparison to normal conditions. Complementation of yeast mutants with the FtZIP family genes demonstrate that FtZIP7/10/12 transport Zn, FtZIP5/6/7/9/10/11 transport Fe, FtZIP12 transports Mn and FtZIP2/3/4/7 transport Cd. Our data suggest that FtZIP proteins have conserved functions of transportation of metal ions but with distinct spatial expression levels.

Positive regulation of ABA signaling by MdCPK4 interacting with and phosphorylating MdPYL2/12 in Arabidopsis.

The phytohormone abscisic acid (ABA) regulates plant growth and development and stress resistance through the ABA receptor PYLs. To date, no interaction between CPK and PYL has been reported, even in Arabidopsis and rice. In this study, we found that MdCPK4 from Malus domestica (Md for short) interacts with two MdPYLs, MdPYL2/12, in the nucleus and the cytoplasm in vivo and phosphorylates the latter in vitro as well. Compared with the wild type (WT), the MdCPK4- or MdPYL2/12-overexpressing Arabidopsis lines showed more sensitivity to ABA, and therefore stronger drought resistance. The ABA-related genes (ABF1, ABF2, ABF4, RD29A and SnRK2.2) were significantly upregulated in the overexpressing (OE) lines after ABA treatment. These results indicate that MdCPK4 and MdPYL2/12 act as positive regulators in response to ABA-mediated drought resistance in apple. Our results reveal the relationship between MdCPK4 and MdPYL2/12 in ABA signaling, which will further enrich the molecular mechanism of drought resistance in plants.

FlbZIP12 gene enhances drought tolerance via modulating flavonoid biosynthesis in Fagopyrum leptopodum.

Karst lands provide a poor substrate to support plant growth, as they are low in nutrients and water content. Common buckwheat (Fagopyrum esculentum) is becoming a popular crop for its gluten-free grains and their high levels of phenolic compounds, but buckwheat yields are affected by high water requirements during grain filling. Here, we describe a wild population of drought-tolerant Fagopyrum leptopodum and its potential for enhancing drought tolerance in cultivated buckwheat. We determined that the expression of a gene encoding a Basic leucine zipper (bZIP) transcription factor, FlbZIP12, from F. leptopodum is induced by abiotic stresses, including treatment with the phytohormone abscisic acid, salt, and polyethylene glycol. In addition, we show that overexpressing FlbZIP12 in Tartary buckwheat (Fagopyrum tataricum) root hairs promoted drought tolerance by increasing the activities of the enzymes superoxide dismutase and catalase, decreasing malondialdehyde content, and upregulating the expression of stress-related genes. Notably, FlbZIP12 overexpression induced the expression of key genes involved in flavonoid biosynthesis. We also determined that FlbZIP12 interacts with protein kinases from the FlSnRK2 family in vitro and in vivo. Taken together, our results provide a theoretical basis for improving drought tolerance in buckwheat via modulating the expression of FlbZIP12 and flavonoid contents.

Cloning and functional characterization of FtWRKY29, a low phosphorus stress-inducible transcription factor in Tartary buckwheat.

The regulation of the expression of genes related to abiotic stress in plants is significantly influenced by the binding of the transcription factor (TF) WRKY to the W-box elements in their promoters. The findings of this study have confirmed that the ability of Tartary buckwheat (Fagopyrum tataricum Gaertn.) to tolerate phosphorus (P) deficiency is regulated by FtWRKY29, which is classified as a member of group II of the WRKY family. The roots predominantly exhibited an enhanced expression of FtWRKY29, which was significantly upregulated in response to low-P-induced stress. The W-box motif was bound to by FtWRKY29 which enhanced the transcription of genes and was localized to the nucleus. The overexpression of FtWRKY29 in Arabidopsis thaliana produced transgenic lines that exhibited phenotypes typical of diminished sensitivity to low-P-induced stress by promoting root growth, increasing P-uptake, and regulating the accumulation of anthocyanin. The low-P-responsive genes, PHT1;1, PHT1;4, and PHO1 were significantly up-regulated in these lines. In addition, the overexpression of FtWRKY29 restored the P-absorption ability of the wrky75 mutant to a certain extent. Moreover, the binding of FtWRKY29 to the promoter of PHT1;1 activated its expression in tobacco. It was also observed that FtWRKY29 interacts with AtMPK3, AtMPK6, FtMPK3, and FtMPK7. This study provides preliminary evidence that FtWRKY29 improved the tolerance of transgenic A. thaliana plants to low-P-induced stress and deepened the understanding of the regulatory mechanism behind the same in Tartary buckwheat.

Efficient Photocatalytic H2 O2 Production Ability of a Novel Graphitic Carbon Nitride/Carbon Composites under Visible Light.

In the present work, using one-step calcination of a mixture made of potassium hydroxide (KOH), melamine, and microplastics, this work prepares a novel graphitic carbon nitride/carbon (g-C3 N4 /C) composite, which can be employed to photo-catalytically produce hydrogen peroxide (H2 O2 ) at a high rate up to 6.146 mmol g-1 h-1 under visible light irradiation. By analyzing the energy band structure of the catalyst, the production of H2 O2 in this system consists of two single-electron reactions. The modification of KOH makes abundant N-vacancies caused by cyano-groups in g-C3 N4 , enhancing the electron absorption ability. Moreover, the introduction of graphitic carbon increases its specific surface area and porosity and improves the adsorption ability of O2 . Simultaneously, their synergism reduces the g-C3 N4 band gap, making both the conduction-band and valence-band positions more negative, showing enhanced reduction ability, lowering the energy barrier for oxygen reduction, and greatly improving the photogeneration performance of H2 O2 .

An R2R3-MYB FtMYB11 from Tartary buckwheat has contrasting effects on abiotic tolerance in Arabidopsis.

R2R3-MYB transcription factors play important roles in response to abiotic stresses in planta, such as salt, drought, and osmotic stress. However, the role of FtMYB11 in Tartary buckwheat (Fagopyrum tataricum) in drought and osmotic tolerance has not yet been elucidated. In this study, we found that FtMYB11 was markedly induced by exogenous abscisic acid (ABA), salinity, and mannitol. Further, FtMYB11-overexpressing Arabidopsis showed hypersensitivity to ABA-mediated seed germination and seedling establishment through regulating transcripts of AtCBF1, AtDREB2A, and AtRD20, compared with wild type, indicating that FtMYB11 plays a positive role in ABA signaling. In contrast, transgenic lines overexpressing FtMYB11 were sensitive to mannitol and NaCl treatments, suggesting that FtMYB11 plays a negative role in osmotic tolerance. Intriguingly, the transcripts of ABA biosynthetic enzyme genes were significantly elevated in plants overexpressing FtMYB11 after exposure to osmotic stresses, such as AtABA3 and AtNCED3. In addition, flavonoid biosynthesis genes were also upregulated in transgenic Arabidopsis under ABA, salt, and drought treatments, including AtC4H, AtF3H, AtANS, AtFLS, and At4CL. The drought tolerance assay showed that plants overexpressing FtMYB11 displayed greater tolerance to water deficit through regulating MDA and proline content. Taken together, FtMYB11 has opposite roles in response to abiotic stresses, but it may mediate flavonoid biosynthesis through regulation of related enzyme genes.

Facile synthesis of NiAl2O4/g-C3N4 composite for efficient photocatalytic degradation of tetracycline.

Designing high-efficiency photocatalysts responsive to visible light is important for the degradation of antibiotics in water. Heterojunction engineering is undoubtedly an effective strategy to improve the photocatalytic performance. In this work, spinel-type metal oxides (NiAl2O4, NAO) are synthesized by a simple sol-gel and calcination process. After compounding graphitic carbon nitride (g-C3N4), NAO/g-C3N4 heterojunction is obtained, which then is used as the photocatalyst for tetracycline hydrochloride (TC). The effects of photocatalyst dosage, the initial concentration of TC, and solution pH on photodegradation performance are systematically studied. The removal rate of TC on NAO/g-C3N4 reach up to ∼90% after visible light irradiation for 2 hr and the degradation rate constant is ∼7 times, and ∼32 times higher than that of pure NAO and g-C3N4. The significantly improved photocatalytic activity can be attributed to the synergistic effect between well matched energy levels in NAO/g-C3N4 heterojunctions, improvement of interfacial charge transfer, and enhancement of visible light absorption. This study provides a way for the synthesis of efficient photocatalysts and an economic strategy for removing antibiotics contamination in water.

FtNAC31, a Tartary buckwheat NAC transcription factor, enhances salt and drought tolerance in transgenic Arabidopsis.

Tartary buckwheat [Fagopyrum tataricum (L.) Gaertn.] is a pseudocereal with strongly abiotic resistance. NACs, one of the largest plant-specific transcription factors (TFs), are involved in various stress responses. However, the characteristics and regulatory mechanisms of NAC TFs remain unclarified clearly in Tartary buckwheat (TB). In this study, it validated that salt, drought, and abscisic acid (ABA) stress significantly up-regulated the expression of NAC TF gene FtNAC31. Its coding protein has a C-terminal transactivated domain and localized in the nucleus, suggesting that FtNAC31 might play a transcriptional activation role in TB. Notably, overexpression of FtNAC31 lowered the seed germination rate upon ABA treatment and enhanced the tolerance to salt and drought stress in transgenetic Arabidopsis. Furthermore, under various stresses, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in FtNAC31 overexpressed lines exhibited a sharp increase trend. Meanwhile, the expression levels of several stress-associated genes including RD29A, RD29B, RD22, DREB2B, NCED3, and POD1, were dramatically upregulated in lines overexpressing FtNAC31. Altogether, overproduction of FtNAC31 could enhance the resistance to salt and drought stresses in transgenic Arabidopsis, which most likely functioned in an ABA-dependent way.

Plastome comparison and phylogenomics of Fagopyrum (Polygonaceae): insights into sequence differences between Fagopyrum and its related taxa.

BACKGROUND: Fagopyrum (Polygonaceae) is a small plant lineage comprised of more than fifteen economically and medicinally important species. However, the phylogenetic relationships of the genus are not well explored, and the characteristics of Fagopyrum chloroplast genomes (plastomes) remain poorly understood so far. It restricts the comprehension of species diversity in Fagopyrum. Therefore, a comparative plastome analysis and comprehensive phylogenomic analyses are required to reveal the taxonomic relationship among species of Fagopyrum. RESULTS: In the current study, 12 plastomes were sequenced and assembled from eight species and two varieties of Fagopyrum. In the comparative analysis and phylogenetic analysis, eight previously published plastomes of Fagopyrum were also included. A total of 49 plastomes of other genera in Polygonaceae were retrieved from GenBank and used for comparative analysis with Fagopyrum. The variation of the Fagopyrum plastomes is mainly reflected in the size and boundaries of inverted repeat/single copy (IR/SC) regions. Fagopyrum is a relatively basal taxon in the phylogenomic framework of Polygonaceae comprising a relatively smaller plastome size (158,768-159,985 bp) than another genus of Polygonaceae (158,851-170,232 bp). A few genera of Polygonaceae have nested distribution of the IR/SC boundary variations. Although most species of Fagopyrum show the same IRb/SC boundary with species of Polygonaceae, only a few species show different IRa/SC boundaries. The phylogenomic analyses of Fagopyrum supported the cymosum and urophyllum groups and resolved the systematic position of subclades within the urophyllum group. Moreover, the repeat sequence types and numbers were found different between groups of Fagopyrum. The plastome sequence identity showed significant differences between intra-group and inter-group. CONCLUSIONS: The deletions of intergenic regions cause a short length of Fagopyrum plastomes, which may be the main reason for plastome size diversity in Polygonaceae species. The phylogenomic reconstruction combined with the characteristics comparison of plastomes supports grouping within Fagopyrum. The outcome of these genome resources may facilitate the taxonomy, germplasm resources identification as well as plant breeding of Fagopyrum.

Preparation and characterization of novel Niln2S4/UiO-66 photocatalysts for the efficient degradation of antibiotics in water.

Photocatalysis is considered an economical, environmentally friendly, and effective technology for removing pollutants. The construction of Z-Scheme heterojunctions has been identified as one of the feasible solutions capable of enhancing the photocatalytic activity. Herein, a series of visible light responsive photocatalysts (NiIn2S4/UiO-66 composites) with excellent activity and stability were prepared by using a solvothermal process. It is found that 20 mg L-1 of tetracycline (TC) could be almost completely degraded under visible light irradiation within 1 h, when the mass ratio of NiIn2S4 to UiO-66 is 0.5:1 (NISU-0.5) and the solution pH = 11. In addition, after six cycles, the degradation rate of tetracycline photocatalyzed by NISU-0.5 still reach up to 90%. Ultraviolet photoelectron spectra (UPS), X-ray photoelectron spectra (XPS) and electron spin resonance measurements (ESR) confirm the formation of the Z-Scheme heterostructure between NiIn2S4 and UiO-66. The synergistic effect between built-in electric field, energy band bending and coulomb interactions in interface of Z-Scheme heterojunction is conducive to restrain the recombination of photogenerated electrons and holes, which greatly improve the photocatalytic activity. In conclusion, this study offers a new thought for design and synthesis of Z-Scheme heterojunctions and provides a cost-effective strategy for solving environmental pollution and energy problems in the future.

The response of tartary buckwheat and 19 bZIP genes to abscisic acid (ABA).

Tartary buckwheat is a kind of plant which can be used as medicine as well as edible. Abscisic acid (ABA) signaling plays an important role in the response of plants such as tartary buckwheat to drought and other stress. However, there are not many studies on tartary buckwheat by ABA treatment. In this study, the germination, root length, stoma, and anthocyanin accumulation of tartary buckwheat were all significantly affected by ABA. ABA signaling is important for plants to respond to drought and other stresses, the bZIP gene family is an important member of the ABA signaling pathway. Through the analysis of the origin relationship between tartary buckwheat bZIP family and its related species, 19 bZIP genes in tartary buckwheat were found to be relatively conserved, which laid a foundation for further study of bZIP family. The qRT-PCR results showed that most of the group members were induced by ABA treatment, including 0, 15, 30, 50, 70 µM ABA and 0, 0.5, 2, 4, 8, 16, 24 h ABA treatment. These results suggested that ABA could affect the growth and development of tartary buckwheat, and FtbZIPs might have different functions in the response of tartary buckwheat to drought. This study will be helpful to further analyze the genetic breeding and economic value of tartary buckwheat resistance.

Characterization of abscisic acid (ABA) receptors and analysis of genes that regulate rutin biosynthesis in response to ABA in Fagopyrum tataricum.

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) is a nutritional crop, which has high rutin, and is good for health. Until now, plant genetic engineering is insufficient for Tartary buckwheat. Abscisic acid (ABA), as one of phytohormones, is involved in the regulation of plant growth and development, and responses to diverse environmental challenges. Although ABA receptors have been well characterized in Arabidopsis, it is little understood in Tartary buckwheat. In this study, we identified 12 ABA receptors, designated as FtRCAR1 through FtRCAR12 in Tartary buckwheat. FtRCARs are divided into three subfamily. Based on the similarity, we could predict that FtRCARs comprise of the monomeric (FtRCAR1, 3, 4, 5, 9, 10, 11 and 12) and the dimeric (FtRCAR2, 7 and 8) state in solution. The analysis of the transcript pattern indicated that most of FtRCARs were significantly variable among the root, stem, leaf, flower and seed, while FtRCAR4 transcript was undetectable under in all tissues. The transcript levels of FtRCARs under ABA treatment indicated that most FtRCARs transcripts were depressed, indicating a possible feedback regulation of ABA signaling. The analysis of rutin biosynthesis related-genes indicated that ABA up-graduated CHS, CHI, F3'H, F3H and FLS transcript levels, while transcripts of 4CL and PAL were down-regulated. In addition, the transcription factors that mediated the rutin biosynthesis related-genes were also regulated by exogenous ABA. Thus, the identification and the characterization of FtRCARs would enable us to further understand the role of ABA signal in Tartary buckwheat.

FtMYB6, a Light-Induced SG7 R2R3-MYB Transcription Factor, Promotes Flavonol Biosynthesis in Tartary Buckwheat (Fagopyrum tataricum).

Tartary buckwheat (Fagopyrum tataricum) is rich in flavonols, which are thought to be highly beneficial for human health. However, little is known about the regulatory mechanism of flavonol biosynthesis in Tartary buckwheat. In this study, we identified and characterized a novel SG7 R2R3-MYB transcription factor in Tartary buckwheat, FtMYB6. We showed that FtMYB6 is located in the nucleus and acts as a transcriptional activator. The FtMYB6 promoter showed strong spatiotemporal specificity and was induced by light. The expression of FtMYB6 showed a significant correlation with rutin accumulation in the roots, stems, leaves, and flowers. Overexpression of FtMYB6 in transgenic Tartary buckwheat hairy roots and tobacco (Nicotiana tabacum) plants significantly increased the accumulation of flavonols. In transient luciferase (LUC) activity assay, FtMYB6 promoted the activity of FtF3H and FtFLS1 promoters and inhibited the activity of the Ft4CL promoter. Collectively, our results suggest that FtMYB6 promotes flavonol biosynthesis by activating FtF3H and FtFLS1 expression.

A WRKY transcription factor, FtWRKY46, from Tartary buckwheat improves salt tolerance in transgenic Arabidopsis thaliana.

The WRKY transcription factor family includes plant-specific transcription factors that are widely involved in plant biotic and abiotic stress responses, growth and development. Tartary buckwheat is a type of small grain with strong resistance to adverse growing conditions. No systematic exploration of the WRKY family in Tartary buckwheat has yet been reported. In this paper, we report the FtWRKY46 gene from Tartary buckwheat and study its role in salt tolerance. FtWRKY46 has transcriptional activation activity in yeast, and FtWRKY46 fused to yellow fluorescent protein localizes to the nucleus. Further studies have found that its transcriptional activation region is located at the N-terminus. A yeast one-hybrid assay indicated that FtWRKY46 could bind to a W-box and activate reporter gene expression. Similarly, transient cotransfection showed that FtWRKY46 could specifically bind to W-box regions and activate reporter gene expression in plants. Furthermore, ectopic expression of FtWRKY46 could enhance Arabidopsis tolerance to salt stress. More specifically, the seed germination rate, root length, chlorophyll content and proline content were significantly higher in transgenic plants ectopically expressing FtWRKY46 than in WT plants after salt stress (P < 0.05), while MDA levels were significantly lower than in WT plants (P < 0.05). Additionally, salt treatment increased the expression of stress-related genes. To summarize, our results suggest that ectopic expression of FtWRKY46 enhance the stress tolerance of transgenic plants by modulating ROS clearance and stress-related gene expression.

Tartary buckwheat transcription factor FtbZIP83 improves the drought/salt tolerance of Arabidopsis via an ABA-mediated pathway.

Plants are subjected to a variety of abiotic stresses during their lifetime, and drought and salt stress are some of the main causes of reduced crop yields. Previous studies have shown that AREB/ABFs within bZIP transcription factors are involved in plant drought and salt stress responses in an ABA-dependent manner. However, the properties and functions of AREB/ABFs in Fagopyrum tataricum, a cereal with good resistance to abiotic stresses, are poorly understood. In this study, a gene encoding an AREB/ABF, designated FtbZIP83, was first isolated from Tartary buckwheat. Expression analysis in Tartary buckwheat indicated that FtbZIP83 was significantly induced by abscisic acid (ABA), NaCl and polyethylene glycol (PEG). The overexpression of FtbZIP83 in Arabidopsis resulted in increased drought/salt tolerance, which was attributed not only to higher proline (Pro) contents and antioxidant enzyme activity in transgenic lines compared with controls but also to the lower reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content. In addition, we found that FtbZIP83 was able to respond to drought and salt stress by upregulating the transcript abundance of downstream ABA-inducible gene. Furthermore, promoter sequence analysis showed that ABREs were present, and the activity of the FtbZIP83 promoter in transgenic Arabidopsis after drought stress was significantly higher than that under normal conditions. Based on the potential signalling pathways involved in AREB/ABFs, we also screened for the interaction protein FtSnRK2.6/2.3, which may phosphorylate FtbZIP83. Collectively, these results provide evidence that FtbZIP83, as a positive regulator, responds to drought/salt stress via an ABA-dependent signalling pathway composed of SnRK2-AREB/ABF.

Investigation of coal and gas outburst risk by microseismic monitoring.

In order to improve the monitoring and prediction of coal and gas outburst, this paper proposes a new method for dynamic regional prediction of coal and gas outburst using microseismic (MS) monitoring. The theoretical basis of this method is presented. An index evaluation system was established and applied, based on which field tests were carried out in a coal mine. The results show that seismic monitoring with frequency and energy indexes can obtain good results for mining disturbance intensity monitoring and geological structure detection; the regional stress distribution detected by seismic wave tomography is consistent with the theoretical stress field, making its use of great significance for optimizing coal and gas outburst drilling parameters and improving overall tunneling efficiency. This approach overcomes the limitations of traditional methods in the temporal and spatial dimensions and realizes dynamic and continuous monitoring of coal and gas outburst-prone areas.

Validation of reference genes for gene expression studies in tartary buckwheat (Fagopyrum tataricum Gaertn.) using quantitative real-time PCR.

Quantitative real-time reverse transcriptase polymerase chain reaction is a sensitive technique for quantifying gene expression levels. By implementing three distinct algorithms (geNorm, normFinder and BestKeeper), we have validated the stability of the expression of seven candidate reference genes in tartary buckwheat, including FtSAND, FtCACS, FtExpressed1, FtGAPDH, FtActin, FtEF-1a and FtH3. In this study, the results indicated that FtCACS and FtSAND were the best reference genes for 'abiotic cotyledons', FtExpressed1 and FtEF-1α were the best reference genes for aluminium treatment, FtCACS and FtExpressed1 performed the best for the immature seed stage, FtCACS was best for the abiotic treatment, and FtH3 appeared to be the most suitable reference gene for the abiotic treatment in hypocotyls and all samples in this study. In contrast, FtActin and FtGAPDH are unsuitable genes. Our findings offer additional stable reference genes for gene expression research on tartary buckwheat at the immature seed stage and under abiotic treatment.

Genome-Wide Investigation of the Auxin Response Factor Gene Family in Tartary Buckwheat (Fagopyrum tataricum).

Auxin signaling plays an important role in plant growth and development. It responds to various developmental and environmental events, such as embryogenesis, organogenesis, shoot elongation, tropical growth, lateral root formation, flower and fruit development, tissue and organ architecture, and vascular differentiation. However, there has been little research on the Auxin Response Factor (ARF) genes of tartary buckwheat (Fagopyrum tataricum), an important edible and medicinal crop. The recent publication of the whole-genome sequence of tartary buckwheat enables us to study the tissue and expression profile of the FtARF gene on a genome-wide basis. In this study, 20 ARF (FtARF) genes were identified and renamed according to the chromosomal distribution of the FtARF genes. The results showed that the FtARF genes belonged to the related sister pair, and the chromosomal map showed that the duplication of FtARFs was related to the duplication of the chromosome blocks. The duplication of some FtARF genes shows conserved intron/exon structure, which is different from other genes, suggesting that the function of these genes may be diverse. Real-time quantitative PCR analysis exhibited distinct expression patterns of FtARF genes in various tissues and in response to exogenous auxin during fruit development. In this study, 20 FtARF genes were identified, and the structure, evolution, and expression patterns of the proteins were studied. This systematic analysis laid a foundation for the further study of the functional characteristics of the ARF genes and for the improvement of tartary buckwheat crops.

Characterization of Three Glucosyltransferase Genes in Tartary Buckwheat and Their Expression after Cold Stress.

Anthocyanins confer the red color in the hypocotyl of tartary buckwheat sprouts. Uridine diphosphate (UDP)-glucose:flavonoid 3-O-glycosyltransferase (UFGT) stabilizes anthocyanin by attaching the glucosyl moiety from UDP-glucose to the C3 hydroxyl of anthocyanin. In this study, we characterized three UFGT-like genes, designated FtUFGT1, 2, and 3 from tartary buckwheat. The results revealed that FtUFGT1, FtUFGT2, and FtUFGT3 can convert cyanidin to cyanidin 3-O-glucoside, with specific activities of 20.01 × 10(-3), 8.93 × 10(-3), and 20.24 × 10(-3) IU/mg, respectively. The active-site residues of the C-terminal domains and the N-terminal domains are important for the donor and acceptor recognition of these proteins. The expression of the three FtUFGTs paralleled the tissue-specific anthocyanin accumulation. After cold treatment, the increased content of anthocyanin was accompanied by the up-regulated expression of the three FtUFGTs. Among these three UGFT gene members, FtUFGT3 showed the highest expression level and the highest specific activity, suggesting that FtUFGT3 might be the major gene involved in anthocyanin biosynthesis. These results suggested that the FtUFGT genes, FtUFGT3 in particular, might be important candidates for anthocyanin formation in tartary buckwheat sprouts.