Strigolactones affect the yield of Tartary buckwheat by regulating endogenous hormone levels.

BACKGROUND: As a newly class of endogenous phytohormones, strigolactones (SLs) regulate crop growth and yield formation by interacting with other hormones. However, the physiological mechanism of SLs affect the yield by regulating the balance of endogenous hormones of Tartary buckwheat is still unclear. RESULTS: In this study, a 2-year field experiment was conducted on Tartary buckwheat (Jinqiao 2) to study the effects of different concentrations (0, 10, and 20 µmol/L) of artificial synthetic analogs of SLs (rac-GR24) and inhibitor of SL synthesis (Tis-108) on the growth, endogenous-hormone content, and yield of Tartary buckwheat. The main-stem branch number, grain number per plant, grain weight per plant, and yield of Tartary buckwheat continuously decreased with increased rac-GR24 concentration, whereas the main-stem diameter and plant height initially increased and then decreased. Rac-GR24 treatment significantly increased the content of SLs and abscisic acid (ABA) in grains, and it decreased the content of Zeatin (Z) + Zeatin nucleoside (ZR). Conversely, Tis-108 treatment decreased the content of SLs and ABA but increased the content of Z + ZR. Results of correlation analysis showed that the content of ABA and SLs, the ratio of SLs/(Z + ZR), SLs/ABA, and ABA/(Z + ZR) were significantly negatively correlated with the yield of Tartary buckwheat, and that Z + ZR content was significantly positively correlated with the yield. Regression analysis further showed that ABA/ (Z + ZR) can explain 58.4% of the variation in yield. CONCLUSIONS: In summary, by adjusting the level of endogenous SLs in Tartary buckwheat, the balance of endogenous hormones in grains can be changed, thereby exerting the effect on yield. The results can provide a new agronomic method for the high-yield cultivation of Tartary buckwheat.

Genome-wide investigation of UDP-Glycosyltransferase family in Tartary buckwheat (Fagopyrum tataricum).

BACKGROUND: Tartary buckwheat (Fagopyrum tataricum) belongs to Polygonaceae family and has attracted increasing attention owing to its high nutritional value. UDP-glycosyltransferases (UGTs) glycosylate a variety of plant secondary metabolites to control many metabolic processes during plant growth and development. However, there have been no systematic reports of UGT superfamily in F. tataricum. RESULTS: We identified 173 FtUGTs in F. tataricum based on their conserved UDPGT domain. Phylogenetic analysis of FtUGTs with 73 Arabidopsis UGTs clustered them into 21 families. FtUGTs from the same family usually had similar gene structure and motif compositions. Most of FtUGTs did not contain introns or had only one intron. Tandem repeats contributed more to FtUGTs amplification than segmental duplications. Expression analysis indicates that FtUGTs are widely expressed in various tissues and likely play important roles in plant growth and development. The gene expression analysis response to different abiotic stresses showed that some FtUGTs were involved in response to drought and cadmium stress. Our study provides useful information on the UGTs in F. tataricum, and will facilitate their further study to better understand their function. CONCLUSIONS: Our results provide a theoretical basis for further exploration of the functional characteristics of FtUGTs and for understanding the growth, development, and metabolic model in F. tataricum.

Quantitative Analysis of Epigenetic Modifications in Fagopyrum Nuclei with Confocal Microscope, ImageJ, and R Studio.

Epigenetic programming plays a vital role in regulating pluripotency genes, which become activated or inactivated during the processes of dedifferentiation and differentiation during an organism's development. The analysis of epigenetic modifications has become possible through the technique of immunostaining, where specific antibodies allow the identification of a single target protein. This chapter describes a detailed protocol for the analysis of the epigenetic modifications with the use of confocal microscopy, subsequent image, and statistical analysis on the example of Fagopyrum calli with the use of nine antibodies raised against histone H3 and H4 methylation and acetylation on several lysines as well as DNA methylation.

Immunostaining for Epigenetic Modifications in Fagopyrum Calli.

Immunostaining is a well-established technique for identifying specific proteins in tissue samples with specific antibodies to identify a single target protein. It is commonly used in research and provides information about cellular localization and protein expression levels. This chapter describes a detailed protocol for immunostaining fixed Fagopyrum calli embedded in Steedman's wax using nine antibodies raised against histone H3 and H4 methylation and acetylation on several lysines and DNA methylation.

Immunohistochemical Detection of the Wall Components on the Example of Shoot Apical Meristem of Fagopyrum esculentum and Fagopyrum tataricum.

Immunohistochemistry is a method that allows the detection of individual components of cell walls in an extremely precise way at the level of a single cell and wall domains. The cell wall antibodies detect specific epitopes of pectins, arabinogalactan proteins (AGP), hemicelluloses, and extensins. The presented method visualization of the selected pectic and AGP epitopes using antibodies directed to wall components is described. The method of the analysis of the chemical composition of the wall is present on the example of the shoot apical meristems of Fagopurum esculentum and Fagopyrum tataricum. Recommended protocols for immunostaining and examination on fluorescence microscopy level are presented.

Tartary buckwheat rutin: Accumulation, metabolic pathways, regulation mechanisms, and biofortification strategies.

Rutin is a significant flavonoid with strong antioxidant property and various therapeutic effects. It plays a crucial role in disease prevention and human health maintenance, especially in anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects. While many plants can synthesize and accumulate rutin, tartary buckwheat is the only food crop possessing high levels of rutin. At present, the rutin content (RC) is regarded as the key index for evaluating the nutritional quality of tartary buckwheat. Consequently, rutin has become the focus for tartary buckwheat breeders and has made considerable progress. Here, we summarize research on the rutin in tartary buckwheat in the past two decades, including its accumulation, biosynthesis and breakdown pathways, and regulatory mechanisms. Furthermore, we propose several strategies to increase the RC in tartary buckwheat seeds based on current knowledge. This review aims to provide valuable references for elevating the quality of tartary buckwheat in the future.

Accumulation of the bitter substance quercetin mediated by the overexpression of a novel seed-specific gene FtRDE2 in Tartary buckwheat.

Tartary buckwheat (Fagopyrum tataricum) is frequently employed as a resource to develop health foods, owing to its abundant flavonoids such as rutin. However, the consumption of Tartary buckwheat (TB) is limited in food products due to the strong bitterness induced by the hydrolysis of rutin into quercetin. This transformation is facilitated by the degrading enzyme (RDE). While multiple RDE isoenzymes exist in TB, the superior coding gene of FtRDEs has not been fully explored, which hinders the breeding of TB varieties with minimal bitterness. Here, we found that FtRDE2 is the most abundant enzyme in RDE crude extracts, and its corresponding gene is specifically expressed in TB seeds. Results showed that FtRDE2 has strong rutin hydrolysis activity. Overexpression of FtRDE2 not only significantly promoted rutin hydrolysis and quercetin accumulation but also dramatically upregulated genes involved in the early phase of flavonoid synthesis (FtPAL1、FtC4H1、Ft4CL1, FtCHI1) and anthocyanin metabolism (FtDFR1). These findings elucidate the role of FtRDE2, emphasizing it as an endogenous factor contributing to the bitterness in TB and its involvement in the metabolic regulatory network. Moreover, correlation analysis revealed a positive relationship between the catalytic activity of RDE extracts and the expression level of FtRDE2 during seed germination. In summary, our results suggest that FtRDE2 can serve as a promising candidate for the molecular breeding of a TB variety with minimal bitterness.

Water extract of Fagopyrum dibotrys (D. Don) Hara straw increases selenium accumulation in peach seedlings under selenium-contaminated soil.

To promote the selenium (Se) uptakes in fruit trees under Se-contaminated soil, the effects of water extract of Fagopyrum dibotrys (D. Don) Hara straw on the Se accumulation in peach seedlings under selenium-contaminated soil were studied. The results showed that the root biomass, chlorophyll content, activities of antioxidant enzymes, and soluble protein content of peach seedlings were increased by the F. dibotrys straw extract. The different forms of Se (total Se, inorganic Se, and organic Se) were also increased in peach seedlings following treatment with the F. dibotrys straw extract. The highest total shoot Se content was treated by the 300-fold dilution of F. dibotrys straw, which was 30.87% higher than the control. The F. dibotrys straw extract also increased the activities of adenosine triphosphate sulfurase (ATPS), and adenosine 5'-phosphosulfate reductase (APR) in peach seedlings, but decreased the activity of serine acetyltransferase (SAT). Additionally, correlation and grey relational analyses revealed that chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se content. Overall, this study shows that the water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration.

The water extract of Fagopyrum dibotrys (D. Don) Hara straw promoted the selenium (Se) uptake in peach seedlings under selenium-contaminated soil. The concentration of F. dibotrys straw extract showed a quadratic polynomial regression relationship with the total root and shoot Se. Furthermore, chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se. This study shows that water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration.

Germplasm Resources and Metabolite Marker Screening of High-Flavonoid Tartary Buckwheat (Fagopyrum tataricum).

Tartary buckwheat is an annual minor cereal crop with a variety of secondary metabolites, endowing it with a high nutritional and medicinal value. Flavonoids constitute the primary compounds of Tartary buckwheat. Recently, metabolomics, as an adjunct breeding method, has been increasingly employed in crop research. This study explores the correlation between the total flavonoid content (TFC) and antioxidant capacity in 167 Tartary buckwheat varieties. Ten Tartary buckwheat varieties with significant differences in flavonoid content and antioxidant capacity were selected by cluster analysis. With the use of liquid chromatography-mass spectrometry, 58 flavonoid compounds were identified, namely, 42 flavonols, 10 flavanols, 3 flavanones, 1 isoflavone, 1 anthocyanidin, and 1 proanthocyanidin. Different samples were clearly separated by employing principal component analysis and partial least-squares discriminant analysis. Eight differential flavonoid compounds were further selected through volcano plots and variable importance in projection. Differential metabolites were highly correlated with TFC and antioxidant capacity. Finally, metabolic markers of kaempferol-3-O-hexoside, kaempferol-7-O-glucoside, and naringenin-O-hexoside were determined by the random forest model. The findings provide a basis for the selection and identification of Tartary buckwheat varieties with high flavonoid content and strong antioxidant activity.

Tartary Buckwheat (Fagopyrum tataricum) FtTT8 Inhibits Anthocyanin Biosynthesis and Promotes Proanthocyanidin Biosynthesis.

Tartary buckwheat (Fagopyrum tataricum) is an important plant, utilized for both medicine and food. It has become a current research hotspot due to its rich content of flavonoids, which are beneficial for human health. Anthocyanins (ATs) and proanthocyanidins (PAs) are the two main kinds of flavonoid compounds in Tartary buckwheat, which participate in the pigmentation of some tissue as well as rendering resistance to many biotic and abiotic stresses. Additionally, Tartary buckwheat anthocyanins and PAs have many health benefits for humans and the plant itself. However, little is known about the regulation mechanism of the biosynthesis of anthocyanin and PA in Tartary buckwheat. In the present study, a bHLH transcription factor (TF) FtTT8 was characterized to be homologous with AtTT8 and phylogenetically close to bHLH proteins from other plant species. Subcellular location and yeast two-hybrid assays suggested that FtTT8 locates in the nucleus and plays a role as a transcription factor. Complementation analysis in Arabidopsis tt8 mutant showed that FtTT8 could not recover anthocyanin deficiency but could promote PAs accumulation. Overexpression of FtTT8 in red-flowering tobacco showed that FtTT8 inhibits anthocyanin biosynthesis and accelerates proanthocyanidin biosynthesis. QRT-PCR and yeast one-hybrid assay revealed that FtTT8 might bind to the promoter of NtUFGT and suppress its expression, while binding to the promoter of NtLAR and upregulating its expression in K326 tobacco. This displayed the bidirectional regulating function of FtTT8 that negatively regulates anthocyanin biosynthesis and positively regulates proanthocyanidin biosynthesis. The results provide new insights on TT8 in Tartary buckwheat, which is inconsistent with TT8 from other plant species, and FtTT8 might be a high-quality gene resource for Tartary buckwheat breeding.

Buckwheat (Fagopyrum esculentum) Hulls Are a Rich Source of Fermentable Dietary Fibre and Bioactive Phytochemicals.

Pseudo-cereals such as buckwheat (Fagopyrum esculentum) are valid candidates to promote diet biodiversity and nutrition security in an era of global climate change. Buckwheat hulls (BHs) are currently an unexplored source of dietary fibre and bioactive phytochemicals. This study assessed the effects of several bioprocessing treatments (using enzymes, yeast, and combinations of both) on BHs' nutrient and phytochemical content, their digestion and metabolism in vitro (using a gastrointestinal digestion model and mixed microbiota from human faeces). The metabolites were measured using targeted LC-MS/MS and GC analysis and 16S rRNA gene sequencing was used to detect the impact on microbiota composition. BHs are rich in insoluble fibre (31.09 ± 0.22% as non-starch polysaccharides), protocatechuic acid (390.71 ± 31.72 mg/kg), and syringaresinol (125.60 ± 6.76 mg/kg). The bioprocessing treatments significantly increased the extractability of gallic acid, vanillic acid, p-hydroxybenzoic acid, syringic acid, vanillin, syringaldehyde, p-coumaric acid, ferulic acid, caffeic acid, and syringaresinol in the alkaline-labile bound form, suggesting the bioaccessibility of these phytochemicals to the colon. Furthermore, one of the treatments, EC_2 treatment, increased significantly the in vitro upper gastrointestinal release of bioactive phytochemicals, especially for protocatechuic acid (p < 0.01). The BH fibre was fermentable, promoting the formation mainly of propionate and, to a lesser extent, butyrate formation. The EM_1 and EC_2 treatments effectively increased the content of insoluble fibre but had no effect on dietary fibre fermentation (p > 0.05). These findings promote the use of buckwheat hulls as a source of dietary fibre and phytochemicals to help meet dietary recommendations and needs.

Gene Cloning and Characterization of Transcription Factor FtNAC10 in Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn.).

NAC transcription factors play a significant role in plant stress responses. In this study, an NAC transcription factor, with a CDS of 792 bp encoding 263 amino acids, was cloned from Fagopyrum tataricum (L.) Gaertn. (F. tataricum), a minor cereal crop, which is rich in flavonoids and highly stress resistant. The transcription factor was named FtNAC10 (NCBI accession number: MK614506.1) and characterized as a member of the NAP subgroup of NAC transcriptions factors. The gene exhibited a highly conserved N-terminal, encoding about 150 amino acids, and a highly specific C-terminal. The resulting protein was revealed to be hydrophilic, with strong transcriptional activation activity. FtNAC10 expression occurred in various F. tataricum tissues, most noticeably in the root, and was regulated differently under various stress treatments. The over-expression of FtNAC10 in transgenic Arabidopsis thaliana (A. thaliana) seeds inhibited germination, and the presence of FtNAC10 enhanced root elongation under saline and drought stress. According to phylogenetic analysis and previous reports, our experiments indicate that FtNAC10 may regulate the stress response or development of F. tataricum through ABA-signaling pathway, although the mechanism is not yet known. This study provides a reference for further analysis of the regulatory function of FtNAC10 and the mechanism that underlies stress responses in Tartary buckwheat.

Effects of salt stress on root morphology, carbon and nitrogen metabolism, and yield of Tartary buckwheat.

This study aims to clarify the effects of different concentrations of sodium chloride on the carbon and nitrogen metabolism and yield of Tartary buckwheat. The salt-sensitive cultivar Yunqiao 2 was pot-grown and treated with four salt concentrations including 0, 2, 4, and 6 g kg-1. The root morphology index increased from seedling stage to maturate stage. The content of soluble protein in the leaves reached the maximum at the anthesis stage, and the other substances content and the enzymes activity related to carbon and nitrogen metabolism reached the maximum at the grain filling stage. The root morphology index, root activity; invertase, amylase, sucrose synthase, and sucrose phosphate synthase activities; nitrate-nitrogen, ammonium nitrogen, and soluble protein content; and nitrate reductase and glutamate synthase activities increased first and reached the maximum at 2 g kg-1 treatment and then decreased with increasing salt stress concentration. The content of soluble sugars and sucrose and the activity of glutamate dehydrogenase increased continuously with increasing salt concentration, and reached the maximum in the 6 g kg-1 treatment. The grain number per plant, 100-grain weight, and yield per plant increased first and reached the maximum at 2 g kg-1 treatment and then decreased with increasing salt stress concentration. In summary, moderate salt stress (2 g kg-1) can promote the root growth, increase the content of carbon and nitrogen metabolism-related substances and enzyme activity, and increase the yield per plant of Tartary buckwheat.

Tartary buckwheat protein-derived peptide AFYRW alleviates H2O2-induced vascular injury via the PI3K/AKT/NF-κB pathway.

Tartary buckwheat protein-derived peptide (Ala-Phe-Tyr-Arg-Trp, AFYRW) is a natural active peptide that hampers the atherosclerosis process, but the underlying role of AFYRW in angiogenesis remains unknown. Here, we present a system-based study to evaluate the effects of AFYRW on H2O2-induced vascular injury in human umbilical vein endothelial cells (HUVECs). HUVECs were co-incubated with H2O2 for 2 h in the vascular injury model, and AFYRW was added 24 h in advance to investigate the protective mechanism of vascular injury. We identified that AFYRW inhibits oxidative stress, cell migration, cell invasion, and angiogenesis in H2O2-treated HUVECs. In addition, we found H2O2-induced upregulation of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), phosphorylation of nuclear factor-κB (NF-κB) p65 and nuclear translocation of NF-κB decreased by AFYRW. Taken together, AFYRW attenuated H2O2-induced vascular injury through the PI3K/AKT/NF-κB pathway. Thereby, AFYRW may serve as a therapeutic option for vascular injuries.

Mechanism of action of buckwheat quercetin in regulating lipid metabolism and intestinal flora via Toll-like receptor 4 or nuclear factor κB pathway in rats on a high-fat diet.

OBJECTIVES: Buckwheat quercetin (QUE) was used as a dietary supplement to investigate the mechanism of QUE on the regulation of lipid metabolism and intestinal flora in hyperlipidemic rats. METHODS: Here, using a high-fat diet-induced hyperlipidemia model, the intervention was carried out by gavage of QUE at doses of 50, 100, and 200 mg/kg. Serum lipid levels, liver biochemical parameters, and histopathologic changes in the liver and intestinal microorganisms were measured in rats by enzyme-linked immunosorbent assay, hematoxylin-eosin, and high-throughput sequencing, respectively. RESULTS: Our results found that QUE, at a dose of 200 mg/kg, significantly reduced body weight, liver index, and lipid levels in rats (P < 0.05); improved hepatic oxidative stress; and repaired liver injury. In addition, the upregulation of beneficial bacteria, such as christensenellaceae and Bifidobacterium, in the organism increased the content of short-chain fatty acids, thus interfering with intestinal pH and improving the intestinal environment, while downregulating the relative abundance of Proteobacteria and Eubacterium_coprostanoligenes_group, and regulating the overproduction of butyrate. The real-time fluorescence quantitative polymerase chain reaction results found that QUE inhibited the expression of Toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) mRNA content and blocked the activation of the TLR4/NF-κB signaling pathway, thus affecting the downregulation of lipid levels and restoring intestinal homeostasis. CONCLUSIONS: A QUE dose of 200 mg/kg may improve lipid levels and the composition of intestinal flora through the TLR4/NF-κB pathway, suggesting that proteobacteria and christensenellaceae abundance changes may be biomarkers of potential diseases.

Metabolic-GWAS provides insights into genetic architecture of seed metabolome in buckwheat.

BACKGROUND: Buckwheat (Fagopyrum spp.), belonging to the Polygonaceae family, is an ancient pseudo-cereal with high nutritional and nutraceutical properties. Buckwheat proteins are gluten-free and show balanced amino acid and micronutrient profiles, with higher content of health-promoting bioactive flavonoids that make it a golden crop of the future. Plant metabolome is increasingly gaining importance as a crucial component to understand the connection between plant physiology and environment and as a potential link between the genome and phenome. However, the genetic architecture governing the metabolome and thus, the phenome is not well understood. Here, we aim to obtain a deeper insight into the genetic architecture of seed metabolome in buckwheat by integrating high throughput metabolomics and genotyping-by-sequencing applying an array of bioinformatics tools for data analysis. RESULTS: High throughput metabolomic analysis identified 24 metabolites in seed endosperm of 130 diverse buckwheat genotypes. The genotyping-by-sequencing (GBS) of these genotypes revealed 3,728,028 SNPs. The Genome Association and Prediction Integrated Tool (GAPIT) assisted in the identification of 27 SNPs/QTLs linked to 18 metabolites. Candidate genes were identified near 100 Kb of QTLs, providing insights into several metabolic and biosynthetic pathways. CONCLUSIONS: We established the metabolome inventory of 130 germplasm lines of buckwheat, identified QTLs through marker trait association and positions of potential candidate genes. This will pave the way for future dissection of complex economic traits in buckwheat.

Genome-Wide Identification and Functional Analysis of the TIFY Family Genes in Response to Abiotic Stresses and Hormone Treatments in Tartary Buckwheat (Fagopyrum tataricum).

TIFY is a plant-specific gene family with four subfamilies: ZML, TIFY, PPD, and JAZ. Recently, this family was found to have regulatory functions in hormone stimulation, environmental response, and development. However, little is known about the roles of the TIFY family in Tartary buckwheat (Fagopyrum tataricum), a significant crop for both food and medicine. In this study, 18 TIFY family genes (FtTIFYs) in Tartary buckwheat were identified. The characteristics, motif compositions, and evolutionary relationships of the TIFY proteins, as well as the gene structures, cis-acting elements, and synteny of the TIFY genes, are discussed in detail. Moreover, we found that most FtTIFYs responded to various abiotic stresses (cold, heat, salt, or drought) and hormone treatments (ABA, MeJA, or SA). Through yeast two-hybrid assays, we revealed that two FtTIFYs, FtTIFY1 and FtJAZ7, interacted with FtABI5, a homolog protein of AtABI5 involved in ABA-mediated germination and stress responses, implying crosstalk between ABA and JA signaling in Tartary buckwheat. Furthermore, the overexpression of FtJAZ10 and FtJAZ12 enhanced the heat stress tolerance of tobacco. Consequently, our study suggests that the FtTIFY family plays important roles in responses to abiotic stress and provides two candidate genes (FtJAZ10 and FtJAZ12) for the cultivation of stress-resistant crops.

In vitro gastrointestinal digestion of buckwheat (Fagopyrum esculentum Moench) protein: release and structural characteristics of novel bioactive peptides stimulating gut cholecystokinin secretion.

Satiety hormone cholecystokinin (CCK) plays a vital role in appetite inhibition. Its secretion is regulated by dietary components. The search for bioactive compounds that stimulate CCK secretion is currently an active area of research. The objective of this study was to evaluate the ability of buckwheat (Fagopyrum esculentum Moench) protein digest (BPD) to stimulate CCK secretion in vitro and in vivo and clarify the structural characteristics of peptides stimulating CCK secretion. BPD was prepared by an in vitro gastrointestinal digestion model. The relative molecular weight of BPD was <10 000 Da, and peptides with <3000 Da accounted for 70%. BPD was rich in essential amino acids Lys, Leu, and Val but lacked sulfur amino acids Met and Cys. It had a stimulatory effect on CCK secretion in vitro and in vivo. Chromatographic separation was performed to isolate peptide fractions involved in CCK secretion, and five novel CCK-releasing peptides including QFDLDD, PAFKEEHL, SFHFPI, IPPLFP, and RVTVQPDS were successfully identified. A sequence length range of 6-8 and marked hydrophobicity (18-28) were observed among the most CCK-releasing peptides. The present study demonstrated for the first time that BPD could stimulate CCK secretion and clarify the structural characteristics of bioactive peptides having CCK secretagogue activity in BPD.

Biochemical and transcriptomic responses of buckwheat to polyethylene microplastics.

The ubiquity of microplastic is widely recognized as pollution. Microplastic can affect the growth performances of plants. Buckwheat is a potential model crop to investigate plant responses to hazardous materials. Still, little is known about the response of buckwheat to microplastics. Thus, this study investigated the effect and uptake of polyethylene (PE) in buckwheat plant growth by monitoring the morphological and photosynthetic merits, antioxidant systems and transcriptome analysis of gene expression. Results confirmed that the impacts of PE on buckwheat growth were dose-dependent, while the highest concentration (80 mg/L) exposure elicited significantly negative responses of buckwheat. PE can invade buckwheat roots and locate in the vascular tissues. PE exposure disturbed the processes of carbon fixation and the synthesis of ATP from ADP + Pi in buckwheat leaves. The promotion of photosynthesis under PE exposure could generate extra energy for buckwheat leaves to activate antioxidant systems by increasing the antioxidant enzyme activities at an expense of morphological merits under microplastic stresses. Further in-depth study is warranted about figuring out the interactions between microplastics and biochemical responses (i.e., photosynthesis and antioxidant systems), which have great implications for deciphering the defense mechanism of buckwheat to microplastic stresses.

Antidiabetic activity of Tartary buckwheat protein-derived peptide AFYRW and its effects on protein glycosylation of pancreas in mice.

Diabetes Mellitus (DM) is one of the most important public health problems, and new antidiabetic drugs with fewer side effects are urgently needed. Here, we measured the antidiabetic effects of an antioxidant peptide (Ala-Phe-Tyr-Arg-Trp, AFYRW) from Tartary Buckwheat Albumin (TBA) in a high-fat diet/streptozotocin (HFD/STZ)-induced diabetic mouse model. The data showed that AFYRW suppressed hepatocyte steatosis and triglycerides while ameliorating insulin resistance in mice. Successively, the influence of AFYRW on aberrant protein glycosylation in diabetic mice was further investigated by lectin microarrays. The results suggested AFYRW could restore the expression of GalNAc, GalNAcα1-3Gal and GalNAcα1-3Galß1-3/4Glc recognized by PTL-I, Siaα2-3Galß1-4Glc(NAc)/Glc, Siaα2-3Gal, Siaα2-3 and Siaα2-3GalNAc recognized by MAL-II, terminating in GalNAcα/ß1-3/6Gal recognized by WFA and αGalNAc, αGal, anti-A and B recognized by GSI-I to normal levels in the pancreas of HFD-STZ-induced diabetic mice. This work may provide new targets for the future discovery of potential biomarkers to evaluate the efficacy of food-derived antidiabetic drugs based on precise alterations of glycopatterns in DM.