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Xie F.,Jiangxi Academy of Agricultural science | Xie F.,Huazhong Agricultural University | Fan R.,Huazhong Agricultural University | Yi Q.,Huazhong Agricultural University | And 5 more authors.

A low cost bio-sorbent, named "PPF resin", was prepared by immobilizing persimmon residual with formaldehyde and it was characterized before and after adsorption of Pd(II). The adsorption behavior of PPF resin towards Pd(II) from aqueous solutions was studied by batch and column adsorption methods. The adsorption equilibrium of Pd(II) on PPF resin was achieved within 840min, and the experimental data were well fitted with the pseudo-second-order rate model. Higher initial concentration and adsorption temperature led to higher equilibrium adsorption amount, and the adsorption isotherms could be well described by Langmuir model. The column studies suggested that the resin was effective for the adsorption of Pd(II) from aqueous solutions, and the loaded Pd(II) could be easily desorbed by acidic thiourea solution. The adsorption process of Pd(II) on PPF resin might be the multiple reactions of electrostatic interaction and reductive adsorption, in which Pd(II) was reduced to Pd(0) as confirmed by the XRD pattern of PPF resin after adsorption of Pd(II). The resin exhibited outstanding selective adsorption towards Pd(II) from actual leach liquor of waste PCBs at a high concentration of HNO3. The results suggested that the PPF resin can be used as an active bio-sorbent for the recovery of Pd(II) from aqueous environment. © 2016 Elsevier B.V. Source

Guan C.,Huazhong Agricultural University | Chen W.,Huazhong Agricultural University | Mo R.,Huazhong Agricultural University | Du X.,Jiangxi Academy of Agricultural science | And 4 more authors.
Frontiers in Plant Science

Chinese pollination-constant non-astringent (C-PCNA) persimmon (Diospyros kaki Thunb.) is considered to be an important germplasm resource for the breeding of PCNA cultivars, though its molecular mechanisms of astringency removal remain to be elucidated. Previously, we showed that the abundance of pyruvate kinase gene transcripts increased rapidly during astringency removal in C-PCNA persimmon fruit. Here, we report the full-length coding sequences of six novel DkPK genes from C-PCNA persimmon fruit isolated based on a complementary DNA (cDNA) library and transcriptome data. The expression patterns of these six DkPK genes and correlations with the soluble proanthocyanidin (PA) content were analyzed during various fruit development stages in different types of persimmon, with DkPK1 showing an expression pattern during the last stage in C-PCNA persimmon that was positively correlated with a decrease in soluble PAs. Phylogenetic analysis revealed that DkPK1 belongs to cytosolic-1 subgroup, and subcellular localization analysis confirmed that DkPK1 is located in the cytosol. Notably, tissue expression profiling revealed ubiquitous DkPK1 expression in different persimmon organs, with the highest expression in seeds. Furthermore, transient over-expression of DkPK1 in persimmon leaves resulted in a significant decrease in the content of soluble PAs but a significant increase in the transcript levels of pyruvate decarboxylase genes (DkPDC1, -3, -4, -5), which catalyze the conversion of pyruvate to acetaldehyde. Thus, we propose that an acetaldehyde-based coagulation effect reduces the content of soluble PAs. Taken together, our results suggest that DkPK1 might be involved in the natural removal of astringency at the last developmental stage in C-PCNA persimmon. This is the first report to identify several novel full-length DkPK genes as well as their potential roles in the natural loss of astringency in C-PCNA persimmon. © 2016, Guan, Chen, Mo, Du, Zhang and Luo. Source

Yang S.,Huazhong Agricultural University | Jiang Y.,Huazhong Agricultural University | Xu L.,Huazhong Agricultural University | Shiratake K.,Nagoya University | And 4 more authors.
Plant Physiology and Biochemistry

Persimmon fruits accumulate a large amount of proanthocyanidins (PAs) in “tannin cells” during development that cause the sensation of astringency due to coagulation of oral proteins. Pollination-constant non-astringent (PCNA) is a spontaneous mutant persimmon phenotype that loses its astringency naturally on the tree at maturity; while the more common non-PCNA fruits remain rich in PAs until they are fully ripened. Here, we isolated a DkMATE1 gene encoding a Multidrug And Toxic Compound Extrusion (MATE) family protein from the Chinese PCNA (C-PCNA) ‘Eshi 1’. Expression patterns of DkMATE1 were positively correlated with the accumulation of PAs in different types of persimmons fruits during fruit development. An analysis of the inferred amino acid sequences and phylogenetic relationships indicated that DkMATE1 is a putative PA precursor transporter, and subcellular localization assays revealed that DkMATE1 is localized in the vacuolar membrane. Ectopic expression of the DkMATE1 in Arabidopsis tt12 mutant supported that DkMATE1 could complement its biological function in transporting epicatechin 3′-O-glucoside as a PAs precursor from the cytoplasm to vacuole. Furthermore, the transient over-expression and silencing of DkMATE1 in ‘Mopanshi’ persimmon leaves resulted in a significant increase and a decrease in PA content, respectively. The analysis of cis-elements in DkMATE1 promoter regions indicated that DkMATE1 might be regulated by DkMYB4, another well-known structural gene in persimmon. Overall, our results show that DkMATE1 may be an essential PA precursor membrane transporter that plays an important role in PA biosynthesis in persimmon. © 2016 Elsevier Masson SAS Source

Yi Q.,Huazhong Agricultural University | Yi Q.,Jingchu University of Technology | Fan R.,Huazhong Agricultural University | Xie F.,Jiangxi Academy of Agricultural science | And 4 more authors.
Journal of the Taiwan Institute of Chemical Engineers

A natural resin, named "PPF resin", was prepared by cross-linking persimmon tannin with formaldehyde and employed as adsorbents for selective recovery of Pd(II) from nitric acid medium. Parameters such as acidic media, HNO3 concentration, contact time, initial metal concentration and temperature were investigated in detail. The adsorption behavior followed the typical monolayer type of Langmuir model and the maximum adsorption capacity reached 259.7mgg-1 at 323K. The obtained thermodynamic parameters (δG, δH and δS) revealed that this adsorption process was feasible, spontaneous and endothermic process. After adequately characterizing the samples by FT-IR, XRD, XPS and SEM-EDS, the adsorption mechanism was proposed to be complex formation and redox reaction. The Pd(II) recovery from industrial nitric acid extract of printed circuit boards was effective and highly selective, and the loaded Pd(II) can be easily desorbed using acidic thiourea solutions. Therefore, the present results provide a new, low cost and effective approach for palladium recovery from e-wastes in nitric acid medium. © 2016 Taiwan Institute of Chemical Engineers. Source

Mo R.,Huazhong Agricultural University | Yang S.,Huazhong Agricultural University | Huang Y.,Huazhong Agricultural University | Chen W.,Huazhong Agricultural University | And 4 more authors.
Tree Genetics and Genomes

Pollination constant non-astringency (PCNA)-type persimmons are the most desirable cultivar because the fruit loses astringency naturally and does not require any treatments for edibility. The mechanism of natural astringency loss in Chinese PCNA (C-PCNA)-type persimmon is probably related to the coagulation of soluble tannins into insoluble tannins, which is quite different from that in the Japanese PCNA (J-PCNA) type. In this work, three types of persimmon cultivars were sampled: ‘Luotian-tianshi’ (C-PCNA), ‘Maekawa-jirou’ (J-PCNA), and ‘Mopanshi’ (pollination constant astringent (PCA)) were sampled. Three DkADH and four DkPDC genes were isolated from C-PCNA plants. Three candidate genes for soluble tannins coagulation identified in C-PCNA fruit (DkADH1, DkPDC1, and DkPDC2) were characterized through combined analysis of spatiotemporal expression patterns and tannin and acetaldehyde contents during fruit development. Transient over-expression in persimmon leaves showed that DkADH1 and DkPDC2 led to a significant decrease in the levels of soluble tannins in infiltrated leaves. These results indicated that DkADH and DkPDC genes should be considered key genes for natural astringency loss in C-PCNA types. © 2016, Springer-Verlag Berlin Heidelberg. Source

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