Excess manganese (Mn) and NH4+-N emissions from electrolytic manganese metal industrial tailwater may harm the environment. However, previous studies have not combined Mn-oxidizing microalgae to reclaim Mn with woodchip substrates for nitrogen removal from tailwater. Here, a two-stage bioreactor system was constructed to recover Mn by microalgal-mediated bio-oxidation in an algae reactor (AR) and remove nitrogen by denitrification in a woodchip reactor (WR). The results showed that up to 100 % of Mn2+ in the tailwater was removed after a 3-day incubation period. The maximum amount of biogenerated Mn oxide nanoparticles reached 13.34 mg/L with Mn4+ as the main Mn valence. Mn recovery reached 65.69 % through precipitate collection, and the NH4+-N removal efficiency reached 97 % in the AR. Mn oxidation by algae might promote oxidative removal of NH4+-N. NO3--N and total nitrogen removal efficiencies in the WR reached 82-90 % and 65-87 %, respectively, which was attributed to denitrification. The predominance of the denitrification gene narG in the WR may have driven the efficient nitrate removal. Flavobacterium, Acidovora, Massilia, Arcticibacter, and Acinetobacter were the most abundant genera in the WR and represented dominant denitrifying bacteria in the woodchip microbiome, indicating their important contribution to denitrification. Overall, the combined application of Mn-oxidizing algae and woodchip-denitrifying bioreactors may represent an efficient treatment technology for electrolytic manganese wastewater remediation.

Toxic Microcystis blooms are widespread in aquatic bodies, posing major threats to aquatic and human life. Recently, bioflocculants have attracted considerable attention as a promising biomaterial for Microcystis management. In search of a novel organism that can produce an efficient bioflocculant for controlling harmful algae sustainably, the native gastropod Cipangopaludina chinensis was co-cultured continuously with toxic Microcystis under different initial algal cell densities. The bioflocculation effect of snail mucus on toxic Microcystis, microcystin removal, and toxin accumulation in snails was investigated. In addition, the properties of the adhesive mucus were characterized using microscopic, X-ray diffraction, infrared spectroscopy, and polysaccharide and proteome analyses. Microcystis cells were captured and flocculated by the snail mucus; removal efficiencies of up to 89.9% and 84.8% were achieved for microalgae and microcystin-leucine arginine (MC-LR), respectively, when co-cultured with C. chinensis for only one day. After nine-day exposure, less than 5.49 µg/kg DW microcystins accumulated in the snails, indicating safety for human consumption. The snail mucus contained 104.3 µg/mg protein and 72.7 µg/mg carbohydrate, which provide several functional groups beneficial for Microcystis bioflocculation. The main monosaccharide subunits of polysaccharides are galactose, galactosamine, glucosamine, fucose, glucose, and mannose. Most of them are key components of polysaccharides in many bioflocculants. Gene Ontology analysis indicated the protein enrichment in binding processes and catalytic activity, which may account for Microcystis bioflocculation via protein binding or enzymatic reactions. The findings indicate that native C. chinensis secretes adhesive mucus that can act as bioflocculant for toxic Microcystis from ambient water and can be an effective and eco-friendly tool for Microcystis suppression.

Increasingly prevalent Microcystis blooms and the propagation of the associated resistance genes represent global environmental problems. Constructed wetlands (CWs) are a cost-effective technology used for wastewater treatment. In this study, the herb Alisma orientale and three industrial byproducts, namely, blast furnace slag, biochar, and sawdust, were selected to construct mini-CW units. Their potential to remediate toxic Microcystis and their influences on the behaviors of antibiotic-resistant genes (ARGs, sul1, sul2, and intl1) were analyzed. Approximately 98.46% of Microcystis cells were removed by the sawdust-based CW in just 2 d, wherein <0.37 μg/L residual microcystin (MC)-LR was detected, with a removal efficiency of >96.47%, which is potentially caused by the higher relative abundance of MC-degrading gene mlrA on the substrate. Lower target ARG accumulations in the sawdust-based CW may be attributed to the lower intl1 relative abundance and microbial function mobile element content, which could influence horizontal gene transfer. In three sequential batches for the treatment of eutrophic lake water, six sawdust-based CW units were assembled into CW microcosms. The efficiency of removal of Microcystis and MC-LR by planted CW microcosms ranged between 92.00% and 95.88% and between 86.48% and 94.82%, respectively; this was significantly (P < 0.05) higher than that by unplanted ones. Less accumulation of target ARGs was also observed in planted CWs. Planting considerably improved nitrogen removal, possibly owing to the enrichment of genes involved in the KEGG nitrogen metabolism pathway in the substrate through metagenomic analysis.

Aquatic plants can be used for in situ remediation of water-borne pharmaceutical compounds; however, such information and that of the potential risks of metabolites released into the environment are limited. This study determined the capacity of Canna indica and Acorus calamus used in the remediation of water-borne sulfonamides (SA). The tolerance, removal, accumulation, and biotransformation of various water-borne SAs were investigated in vivo by exposing plants to SA solutions (50 µg/L and 500 µg/L). After 28 days, C. indica removed more SAs (89.3–97.8%) than A. calamus (12.8–84.6%) and non-planted systems (8.0–69.3%). The SA removal results, except from the A. calamus system with 500 µg/L SA, fit the first-order kinetics model. The estimated half-lives of all SAs were 3–40 h and 2–60 h in the C. indica and A. calamus systems, respectively. In vivo biotransformation and rhizosphere degradation were the major phyto-removal mechanisms, constituting 24.9–81.1% and 0.0–37.1% of all SAs in the C. indica and A. calamus systems, respectively. SA acetyl metabolites were detected only in plant tissues supporting evidence for plant metabolic processes without risk into the environment. SA metabolism including oxidation, methylation, and conjugation via acetylation was potentially beneficial to accumulation and tolerate stress of antibiotic. Canna indica was more suitable for cleaning SA. Our findings better clarify the potential and low risks of phytoremediation in antibiotic-contaminated waters.

Frost-free areas have suitable climate for wetland plant growth and constructed wetlands (CW) technology. Information on the quantification of plant biomass and uptake efficiency in field-scale CWs is limited in these climates. The removal efficiency of total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), and total suspended solids (TSS) in wastewater from sewage plants, domestic sewage, and an industrial park in 15 rural and urban CWs in Guangdong Province, China, with an average temperature of 30 °C was evaluated. The effects of influent concentration, hydraulic load, the wastewater's physicochemical properties, operating conditions, and plant uptake were analysed. The mean removal rates were 40.0%, 45.2%, 41.1%, and 71.7% for TN, TP, COD, and TSS, respectively, which were higher than the removal load of the field-scale CWs in temperate regions. Removal loads of TN, TP, COD, and TSS were highest in CWs that have been operating for 5-6 years, treating wastewater volumes of over 1 m3/m2·d. The removal efficiency was mainly related to the inflow concentration and less affected by the type of CWs. Nutrient accumulation trends were primarily linked to influent concentrations (TN: r2 = 0.89, P = 0.007; TP: r2 = 0.96, P = 0.001) and plant biomass (TN: r2 = 0.96, P = 0.001; TP: r2 = 0.92, P = 0.004). Plant biomass contributed 2%-29% and 2%-70%, respectively, to removing N and P in CWs. The average uptake concentration of N and P in aboveground plant organs (15.66 ± 4.44 mg N/g, 2.15 ± 1.18 mg P/g) was generally higher than that of other temperate plants. A strong relationship between TN and TP in the biomass was also observed; however, the relationship is only restricted by the influent TP concentration. Arundo donax is well-adapted for nutrient accumulation and adaptation and is an ideal wetland plant to purify wastewater in frost-free climates.

To study the functions of bHLH TFs in Brassica napus, five fulllength cDNA sequences of BnbHLH92 genes are cloned from Brassica napus by the homologous cloning method and named as BnbHLH92-1, BnbHLH92-2, BnbHLH92-3, BnbHLH92-4, BnbHLH92-5, respectively. And the length of the coding region for each gene is 738, 657, 684, 741, 717 bp, respectively. The qRTPCR result shows that BnbHLH92-1 gene is expressed in the root of the bolting stage and flowering stage as well as the two leaves stage, but the other BnbHLH92 genes mainly expressed in the roots of the bolting stage and the flowering stage. The expression of BnbHLH92 genes is significantly affected by abiotic stress, which increases the amount of genes expression. The expression level of five BnbHLH92 genes reach its highest under a low temperature stress for 4, 6, 6, 6 and 6 h, under a high temperature stress for 2, 6, 6, 8 and 4 h, under a salt stress for 6, 6, 24, 24 and 24 h, respectively. The expression of each BnbHLH92 gene is also increased in different degrees under ABA induction. It is found that there is an ABA response element (ABRE) on the promoter sequence of each BnbHLH92 gene.

Two full-length cDNAs of the cyclin-D3-1-like gene, named as BnCYCD3-1-like-1 and BnCYCD3-1-like-2 respectively were obtained from Brassica napus, both of which encoded a cell cycle protein CYCD3. Alternative splicing (AS) events of the two genes' transcripts were identified, assigned as BnCYCD3-1-like-1-1, BnCYCD3-1-like-1-2, BnCYCD3-1-like-2-1 and BnCYCD3-1-like-2-2 respectively. BnCYCD3-1-like-1-1 and BnCYCD3-1-like-2-1 were both fully-spliced transcripts which encoded a complete protein containing a LXCXE motif, two cyclin boxes and a PEST domain, while other two alternative splicing transcripts both resulted in the early termination of the protein translation. BnCYCD3-1-like-2-2 retained the third intron, lacking a PEST domain, while BnCYCD3-1-like-1-2 retained all the introns, lacking the C-terminal cyclin domain and a PEST domain. The expression pattern for tissue and development specification of the AS transcripts were investigated. The results showed that the standard splicing transcripts (BnCYCD3-1-like-1-1 and BnCYCD3-1-like-2-1) with complete structural domains were found with the most abundant expression in seeds, followed by leaves, and the least expression in stems. Both of BnCYCD3-1-like-2-1 and BnCYCD3-1-like-2-2 had the highest abundance in leaves, followed by roots. In addition, by applying various biotic and abiotic stresses on Brassica napus, the variations in the expression of each transcript under stress treatment were studied. Also, it was found that AS of the cyclin-D3-1-like gene may play an important role in helping Brassica napus respond to environmental stresses by coordinating the levels of transcripts of standard splicing and alternative splicing.

The test combined the concentration in 0.5mg⋅L−1, 1.0mg⋅L−1, 1.5mg⋅L−1 of 1-naphthaleneacetic acid (NAA) and a concentration of 2.0mg⋅L−1, 2.5mg⋅L−1, 3.0mg⋅L−1 of 6-benzylaminopurine (6-BA), from which we got a comprehensive evaluation of shoots survival ratio, growing point proliferated rate and shoots growth status together. From all the treatment we selected MS + 1.0mg⋅L−1 NAA + 3.0mg⋅L−1 6-BA for the optimum combination, for its live ratio of budding leaves on 92.59%, growing point proliferation rate on 629.60%. In this experiment, each treatment adventitious buds were over 300.00%, that all the treatments are able to use as the media formulations for proliferation of adventitious buds.

As one of the model medicinal plants for exploration of biochemical pathways and molecular biological questions on complex metabolic pathways, Catharanthus roseus synthesizes more than 100 terpenoid indole alkaloids (TIAs) used for clinical treatment of various diseases and for new drug discovery. Given that extensive studies have revealed the major metabolic pathways and the spatial-temporal biosynthesis of TIA in C. roseus plant, little is known about subcellular and inter-cellular trafficking or long-distance transport of TIA end products or intermediates, as well as their regulation. While these transport processes are indispensable for multi-organelle, -tissue and -cell biosynthesis, storage and their functions, great efforts have been made to explore these dynamic cellular processes. Progress has been made in past decades on transcriptional regulation of TIA biosynthesis by transcription factors as either activators or repressors; recent studies also revealed several transporters involved in subcellular and inter-cellular TIA trafficking. However, many details and the regulatory network for controlling the tissue-or cell-specific biosynthesis, transport and storage of serpentine and ajmalicine in root, catharanthine in leaf and root, vindoline specifically in leaf and vinblastine and vincristine only in green leaf and their biosynthetic intermediates remain to be determined. This review is to summarize the progress made in biosynthesis, transcriptional regulation and transport of TIAs. Based on analysis of organelle, tissue and cell-type specific biosynthesis and progresses in transport and trafficking of similar natural products, the transporters that might be involved in transport of TIAs and their synthetic intermediates are discussed; according to transcriptome analysis and bioinformatic approaches, the transcription factors that might be involved in TIA biosynthesis are analyzed. Further discussion is made on a broad context of transcriptional and transport regulation in order to guide our future research.

As one type of the most important alkaloids in the world, terpenoid indole alkaloids (TIAs) show a wide range of pharmaceutical activities that are beneficial for clinical treatments. Catharanthus roseus produces approximately 130 identified TIAs and is considered to be a model plant to study TIA biosynthesis. In order to increase the production of high medical value metabolites whose yields are extremely low in C. roseus, genetic engineering combined with transcriptional regulation has been applied in recent years. By using bioinformatics which is based on RNA sequencing (RNA-seq) data from methyl jasmonate (MeJA)-treated C. roseus as well as phylogenetic analysis, the present work aims to screen candidate genes that may be involved in the regulation of TIA biosynthesis, resulting in a novel AP2/ERF transcription factor, CR1 (Catharanthus roseus 1). Subsequently, virus-induced gene silencing (VIGS) of CR1 was carried out to identify the involvement of CR1 in the accumulations of several TIAs and quantitative real-time PCR (qRT-PCR) was then applied to detect the expression levels of 7 genes in the related biosynthetic pathway in silenced plants. The results show that all the 7 genes were upregulated in CR1-silenced plants. Furthermore, metabolite analyses indicate that silencing CR1 could increase the accumulations of vindoline and serpentine in C. roseus. These results suggest a novel negative regulator which may be involved in the TIAs biosynthetic pathway.