Cloning, Expression Characteristics of Farnesyl Pyrophosphate Synthase Gene from Platycodon grandiflorus and Functional Identification in Triterpenoid Synthesis.

Platycodon grandiflorus is a medicinal plant whose main component is platycodins, which have a variety of pharmacological effects and nutritional values. The farnesyl pyrophosphate synthase (FPS) is a key enzyme in the isoprenoid biosynthesis pathway, which catalyzes the synthesis of farnesyl diphosphate (FPP). In this study, we cloned the FPS gene from P. grandiflorus (PgFPS) with an ORF of 1260 bp, encoding 419 amino acids with a deduced molecular weight and theoretical pI of 46,200.98 Da and 6.52, respectively. The squalene content of overexpressed PgFPS in tobacco leaves and yeast cells extract was 1.88-fold and 1.21-fold higher than that of the control group, respectively, and the total saponin content was also increased by 1.15 times in yeast cells extract, which verified the biological function of PgFPS in terpenoid synthesis. After 48 h of MeJA treatment and 6 h of ethephon treatment, the expression of the PgFPS gene in roots and stems reached its peak, showing a 3.125-fold and 3.236-fold increase compared to the untreated group, respectively. Interestingly, the expression of the PgFPS gene in leaves showed a decreasing trend after exogenous elicitors treatment. The discovery of this enzyme will provide a novel perspective for enhancing the efficient synthesis of platycodins.

LC-MS and MALDI-MSI-based metabolomic approaches provide insights into the spatial-temporal metabolite profiles of Tartary buckwheat achene development.

Tartary buckwheat, celebrated as the "king of grains" for its flavonoid and phenolic acid richness, has health-promoting properties. Despite significant morphological and metabolic variations in mature achenes, research on their developmental process is limited. Utilizing Liquid chromatography-mass spectrometry and atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry imaging, we conducted spatial-temporal metabolomics on two cultivars during achene development. Metabolic profiles including 17 phenolic acids and 83 flavonoids are influenced by both varietal distinctions and developmental intricacies. Notably, flavonols, as major flavonoids, accumulated with achene ripening and showed a tissue-specific distribution. Specifically, flavonol glycosides and aglycones concentrated in the embryo, while methylated flavonols and procyanidins in the hull. Black achenes at the green achene stage have higher bioactive compounds and enhanced antioxidant capacity. These findings provide insights into spatial and temporal characteristics of metabolites in Tartary buckwheat achenes and serve as a theoretical guide for selecting optimal resources for food production.

Genome-wide identification and expression profiling analysis of the trihelix gene family and response of PgGT1 under abiotic stresses in Platycodon grandiflorus.

The trihelix gene family plays an important role in plant growth and abiotic stress responses. Through the analysis of genomic and transcriptome data, 35 trihelix family members were identified for the first time in Platycodon grandiflorus; they were classified into five subfamilies: GT-1, GT-2, SH4, GTγ, and SIP1. The gene structure, conserved motifs and evolutionary relationships were analyzed. Prediction of physicochemical properties of the 35 trihelix proteins founded, the number of amino acid molecules is between 93 and 960, theoretical isoelectric point is between 4.24 and 9.94, molecular weight is between 9829.77 and 107435.38, 4 proteins among them were stable, and all GRAVY is negative. The full-length cDNA sequence of the PgGT1 gene of the GT-1 subfamily was cloned by PCR. It is a 1165 bp ORF encoding a 387 amino acid protein, with a molecular weight of 43.54 kDa. The predicted subcellular localization of the protein in the nucleus was experimentally verified. After being treated with NaCl, PEG6000, MeJA, ABA, IAA, SA, and ethephon, the expression of PgGT1 gene showed an up-regulated trend except for the roots treated with NaCl and ABA. This study laid a bioinformatics foundation for the research of trihelix gene family and the cultivation of excellent germplasm of P. grandiflorus.

A transcriptional complex of FtMYB102 and FtbHLH4 coordinately regulates the accumulation of rutin in Fagopyrum tataricum.

Tartary buckwheat is rich in flavonoids, which not only play an important role in the plant-environment interaction, but are also beneficial to human health. Rutin is a therapeutic flavonol which is massively accumulated in Tartary buckwheat. It has been demonstrated that transcription factors control rutin biosynthesis. However, the transcriptional regulatory network of rutin is not fully clear. In this study, through transcriptome and target metabolomics, we validated the role of FtMYB102 and FtbHLH4 TFs at the different developmental stages of Tartary buckwheat. The elevated accumulation of rutin in the sprout appears to be closely associated with the expression of FtMYB102 and FtbHLH4. Yeast two-hybrid, transient luciferase activity and co-immunoprecipitation demonstrated that FtMYB102 and FtbHLH4 can interact and form a transcriptional complex. Moreover, yeast one-hybrid showed that both FtMYB102 and FtbHLH4 directly bind to the promoter of chalcone isomerase (CHI), and they can coordinately induce CHI expression as shown by transient luciferase activity assay. Finally, we transferred FtMYB102 and FtbHLH4 into the hairy roots of Tartary buckwheat and found that they both can promote the accumulation of rutin. Our results indicate that FtMYB102 and FtbHLH4 can form a transcriptional complex by inducing CHI expression to coordinately promote the accumulation of rutin.

Profiling of polyphenols for in-depth understanding of Tartary buckwheat sprouts: Correlation between cultivars and active components, dynamic changes and the effects of ultraviolet B stress.

Tartary buckwheat sprouts have a high nutritional value and are gluten-free, and polyphenols are their main active constituents. However, information regarding the active constituents' difference of Tartary buckwheat sprouts grown from seeds with different morphology, at different developmental stages and environments is limited. Here, we developed a LC-MS-based targeted metabolomics approach to analyze polyphenols (46 flavonoids and 6 anthraquinones) in 40 Tartary buckwheat sprouts varieties. Both flavonoids and anthraquinones contributed to significant differences in sprouts grown from seed with different color or shape. Twenty-seven differential compounds were all at a higher level in 3-day-old sprouts, and the fold change from 3-day-old to 8-day-old sprouts was 1.42-6.64. A total of 25 differential compounds were all significantly upregulated upon UV-B radiation, especially for epicatechin. This study is valuable not only for better breeding cultivars of Tartary buckwheat sprouts, but also assessing their metabolic quality.

Promoting direct interspecies electron transfer and acetoclastic methanogenesis for enhancing anaerobic digestion of butanol octanol wastewater by coupling granular activated carbon and exogenous hydrogen.

Butanol octanol wastewater (BOW) generated from syngas conversion of coal contained abundant toxic organic pollutants. Anaerobic digestion is a promising technology for BOW, but abundant toxic substances would inhibit the activity of anaerobic microorganisms. Granular activated carbon (GAC) and exogenous hydrogen (EH2) were employed to enhance anaerobic digestion of BOW. The results indicated that methane production increased to 289.55 ± 17.43 mL CH4/g COD in EH2/GAC group, which was 1.07, 2.04, and 1.98 times of that in GAC, EH2, and control groups, respectively. In EH2/GAC group. The relative abundance of Geobacter and Methanosaeta increased rapidly to 25.36% and 52.81%, respectively, and the relative abundance of Clostridium was 9.78%. The underlying mechanism might be that GAC promoted the enrichment of Geobacter, and EH2 changed metabolic mechanism of Clostridium, stimulating the enrichment of Methanosaeta. Direct interspecies electron transfer was promoted by EH2/GAC, thus improving the methane production rate of BOW.

Coupling granular activated carbon and exogenous hydrogen to enhance anaerobic digestion of phenol via predominant syntrophic acetate oxidation and hydrogenotrophic methanogenesis pathway.

Anaerobic digestion is a promising biological method for treating phenol-containing wastewater. However, the low methane yield of phenol due to the biological toxicity limits its potential application. This study presents a novel method to enhance the conversion rate of phenol to methane by coupling of granular activated carbon and exogenous hydrogen (GAC/H2). The cumulative methane production in the GAC/H2, H2, GAC, and control groups were 408.2 ± 16.2, 336.5 ± 5.7, 287.2 ± 26. 2, and 258.1 ± 8.6 mL‬ CH4/g COD, respectively. Compared with the control group, the hydrogenotrophic methanogenic activity and electron transfer activity of GAC/H2 group were increased by 403.9 and 367.4%, respectively. The results of the 16SrRNA analysis indicated GAC enhanced the relative abundances of Syntrophus and Syntrophorhabdus, and hydrogen promoted the relative abundances of Cryptanaerobacter, Aminicenantes, and Methanobacterium. Therefore, the coupling of GAC and exogenous hydrogen promoted a dominate SAO-HM pathway to convert phenol to methane.

A POCS super resolution restoration algorithm based on BM3D.

The inherent shortcoming of POCS (Projection Onto Convex Sets) is its sensitiveness to noise. The restoration quality of POCS based super resolution will severely decline when the noise is larger. In practical applications, the low resolution images generally include some kinds of noise, such as camera internal noise, transmission system noise and coherent noise. Therefore POCS cannot be used directly in super-resolution restoration for observed low resolution images. In order to solve the noise sensitive problem of the traditional POCS restoration algorithm, we firstly propose to optimize the BM3D (Block-Matching 3D) filtering by mean pre-screening of image blocks and limiting the number of image blocks. Then we combine the optimized BM3D filtering with POCS restoration in this paper. Experimental results show that the proposed POCS super resolution restoration algorithm based on BM3D can achieve better restoration effect when the low resolution images contain noise. Furthermore no noise can be perceived in the restored high resolution image basically.