No abstract

Extraction of high-purity phosphate (P) from source-separated urine has attracted growing interest, given its potential economic and environmental benefits. In this study, we present an innovative strategy for selectively separating P from synthetic urine containing a high concentration of Cl − , simply by adjusting the charging and discharging processes of a flowelectrode capacitive deionization (FCDI) unit. During the charging process, both P and Cl − will be transported to the anode chamber and be adsorbed by the charged carbon particles. The inevitable Faradaic reactions induced the generation of H + and led to the conversion of charged P ions into uncharged H 3 PO 4 and spontaneous desorption into the electrolyte. When the electrode polarity is reversed, constantly charged species like Cl − would be mostly pushed back into the spacer chamber, whereas neutral H 3 PO 4 was expected to be selectively trapped in the anode chamber due to sluggish pH variations (particularly when using a higher carbon content), forming a P-rich solution. Under the optimal operating conditions (i.e., carbon content of 5 wt %, charging and discharging current densities of 10 and −15 A/m 2 , respectively, and charging and discharging current times of 120 and 30 min, respectively), a stable recovery efficiency (164 mg/L per cycle) and selectivity (ρ > 2, compared to Cl − ) of P were attained at a relatively low level of electric energy consumption. Results demonstrated that FCDI could be a promising technology for efficient P removal and recovery from source-separated urine without the consumption of additional chemicals.

Three amendments including limestone, MnO and natural zeolite were assessed for their stabilisation effects on Zn, Cu, Pb and Cd in sediment of east Dongting Lake, mid-south China. The metals were first subject to pollution status and potential ecological risk assessment to identify the current and potential hazards to ecology. Speciation of the metals in the sediment treated with amendments was then carried out by BCR sequential extraction procedure in order to evaluate metal contents and their potential mobility. The total concentrations of Zn, Cu, Pb and Cd in the east Dongting Lake were all above the means of national stream sediment and soil guidelines. The sediments were currently unpolluted to moderately pollute with Zn, Cu and Pb and strongly polluted with Cd. Zinc, Cu and Pb posed low risks to the lake ecosystem, and Cd had the highest potential risk that caused the overall risk of the sediment to be high or very high. Limestone stabilised Cu and Zn effectively, yet mobilisation of Cd and Pb by such amendment was also observed. MnO effectively reduced the extractable Cd and Pb. The effect of natural zeolite on metal stabilisation in the sediment was least notable. Limestone and MnO showed higher metal stabilisation efficiencies than zeolite. However, a single amendment is unable to achieve the goal of stabilisation for all metals. A combination use of the advantageous amendments or a search of a stronger stabiliser should be the interest of our future study.

No abstract

Many basic helix-loop-helix transcription factors (TFs) have been reported to promote anthocyanin biosynthesis in numerous plant species, but little is known about bHLH TFs that inhibit anthocyanin accumulation. In this study, SmbHLH1 from Solanum melongena was identified as a negative regulator of anthocyanin biosynthesis. However, SmbHLH1 showed high identity with SmTT8, which acts as a SmMYB113-dependent positive regulator of anthocyanin-biosynthesis in plants. Overexpression of SmbHLH1 in eggplant caused a dramatic decrease in anthocyanin accumulation. Only the amino acid sequences at the N and C termini of SmbHLH1 differed from the SmTT8 sequence. Expression analysis revealed that the expression pattern of SmbHLH1 was opposite to that of anthocyanin accumulation. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that SmbHLH1 could not interact with SmMYB113. Dual-luciferase assay demonstrated that SmbHLH1 directly repressed the expression of SmDFR and SmANS. Our results demonstrate that the biological function of bHLHs in anthocyanin biosynthesis may have evolved and provide new insight into the molecular functions of orthologous genes from different plant species.

No abstract

No abstract

The basic helix–loop–helix (bHLH) superfamily is considered the second largest transcription factor (TF) family. It plays regulatory roles in the developmental processes of plants and in their defense responses. In recent years, many bHLH superfamily genes have been identified and characterized in herbaceous and woody plants. However, the comprehensive genomic and functional analyses of these genes in eggplant (Solanum melongena L.) have not been reported. In this study, 121 bHLH TFs were identified in the recently released eggplant genome. The phylogeny, gene structure and conserved motifs of the SmbHLH gene were comprehensively studied. Subsequently, the phylogenetic relationship between the bHLH of eggplant and the bHLH of other species was analyzed, and the proteins were classified into 17 subfamilies. Among these protein sequences, 16 subgroups were clustered into the functional clades of Arabidopsis. Two candidate genes (SmbHLH1, SmbHLH117) that may be involved in anthocyanin biosynthesis were screened. The tissue specificity or differential expression of the bHLH genes in different tissues and under various light and temperature conditions suggested the differential regulation of tissue development and metabolism. This study not only provides a solid foundation for the functional dissection of the eggplant bHLH gene family but may also be useful for the future synthesis of anthocyanins in eggplant.