The authors herein described a time-gated fluorescence resonance energy transfer (TGFRET) sensing strategy employing water-soluble long lifetime fluorescence quantum dots and gold nanoparticles to ...detect trace Hg2+ ions in aqueous solution. The water-soluble long lifetime fluorescence quantum dots and gold nanoparticles were functionalized by two complementary ssDNA, except for four deliberately designed T–T mismatches. The quantum dot acted as the energy-transfer donor, and the gold nanoparticle acted as the energy-transfer acceptor. When Hg2+ ions were present in the aqueous solution, DNA hybridization will occur because of the formation of T–Hg2+–T complexes. As a result, the quantum dots and gold nanoparticles are brought into close proximity, which made the energy transfer occur from quantum dots to gold nanoparticles, leading to the fluorescence intensity of quantum dots to decrease obviously. The decrement fluorescence intensity is proportional to the concentration of Hg2+ ions. Under the optimum conditions, the sensing system exhibits the same liner range from 1 × 10–9 to 1 × 10–8 M for Hg2+ ions, with the detection limits of 0.49 nM in buffer and 0.87 nM in tap water samples. This sensor was also used to detect Hg2+ ions from samples of tap water, river water, and lake water spiked with Hg2+ ions, and the results showed good agreement with the found values determined by an atomic fluorescence spectrometer. In comparison to some reported colorimetric and fluorescent sensors, the proposed method displays the advantage of higher sensitivity. The TGFRET sensor also exhibits excellent selectivity and can provide promising potential for Hg2+ ion detection.
Cannabis sativa, a dioecious plant that has been cultivated worldwide for thousands of years, is known for its secondary metabolites, especially cannabinoids, which possess several medicinal effects. ...In this study, we investigated the autopolyploidization effects on the biosynthesis and accumulation of these metabolites, transcriptomic and metabolomic analyses were performed to explore the gene expression and metabolic variations in industrial hemp autotetraploids and their diploid progenitors. Through these analyses, we obtained 1,663 differentially expressed metabolites and 1,103 differentially expressed genes. Integrative analysis revealed that phenylpropanoid and terpenoid biosynthesis were regulated by polyploidization. No substantial differences were found in the cannabidiol or tetrahydrocannabinol content between tetraploids and diploids. Following polyploidization, some transcription factors, including nine bHLH and eight MYB transcription factors, affected the metabolic biosynthesis as regulators. Additionally, several pivotal catalytic genes, such as flavonol synthase/flavanone 3-hydroxylase, related to the phenylpropanoid metabolic pathway, were identified as being modulated by polyploidization. This study enhances the overall understanding of the impact of autopolyploidization in C. sativa and the findings may encourage the application of polyploid breeding for increasing the content of important secondary metabolites in industrial hemp.
Jute (Corchorus spp.), belonging to the Malvaceae family, is an important natural fiber crop, second only to cotton, and a multipurpose economic crop. Corchorus capsularis L. is one of the only two ...commercially cultivated species of jute. Gene expression is spatiotemporal and is influenced by many factors. Therefore, to understand the molecular mechanisms of tissue development, it is necessary to study tissue-specific gene expression and regulation. We used weighted gene coexpression network analysis, to predict the functional roles of gene coexpression modules and individual genes, including those underlying the development of different tissue types. Although several transcriptome studies have been conducted on C. capsularis, there have not yet been any systematic and comprehensive transcriptome analyses for this species.
There was significant variation in gene expression between plant tissues. Comparative transcriptome analysis and weighted gene coexpression network analysis were performed for different C. capsularis tissues at different developmental stages. We identified numerous tissue-specific differentially expressed genes for each tissue, and 12 coexpression modules, comprising 126 to 4203 genes, associated with the development of various tissues. There was high consistency between the genes in modules related to tissues, and the candidate upregulated genes for each tissue. Further, a gene network including 21 genes directly regulated by transcription factor OMO55970.1 was discovered. Some of the genes, such as OMO55970.1, OMO51203.1, OMO50871.1, and OMO87663.1, directly involved in the development of stem bast tissue.
We identified genes that were differentially expressed between tissues of the same developmental stage. Some genes were consistently up- or downregulated, depending on the developmental stage of each tissue. Further, we identified numerous coexpression modules and genes associated with the development of various tissues. These findings elucidate the molecular mechanisms underlying the development of each tissue, and will promote multipurpose molecular breeding in jute and other fiber crops.
Cannabis sativa is highly cultivated owing to its secondary metabolites, especially cannabinoids, which possess several medicinal effects. This study aims to examine the effect of foliar application ...of kinetin (KT) on the growth, cannabinoid content, and transcriptome of C. sativa at the flowering stage. A pot experiment was conducted in a greenhouse under a 16h/8h light/dark cycle for growing, and the photoperiod was adjusted to 10h/14h to induce flowering. The plant was sprayed with 0, 20, 40, and 100 mg/L KT every 2 days for a total of six times. Phenotypic parameters (fresh weight, cannabinoid content, and enzyme activity) and metabolome were analyzed. Foliar application of 20 and 40 mg/L of KT increased the growth and cannabinoid content of C. sativa, particularly that of cannabidiol. Similarly, treatment with 20 mg/L of KT increased the Delta9-tetrahydrocannabinolcontent to 0.24%, which is below the legal value of 0.30% in North American countries. Plants treated with 20 and 40 mg/L of KT showed decreased activities of 3-hydroxy-3-methylglutaryl coenzyme A reductase and 1-deoxy-D-xylulose 5-phosphate synthase. KEGG pathway analysis showed that differentially expressed genes (DEGs) in the KT-treated cannabis were mainly enriched in 12 pathways, including sesquiterpenoid and triterpenoid biosynthesis, linoleic acid metabolism, flavonoid and phenylpropanoid biosynthesis, and other secondary metabolic pathways; 14DEGs (including eight upregulated and six downregulated genes) were enriched in sesquiterpene and triterpene biosynthesis pathways. Overall, these findings showed that KT plays a significant role in regulating terpenoid biosynthesis and the cannabinoid content of C. sativa.
Jute (Corchorus spp.) is the most important natural fiber crop after cotton in terms of cultivation area and production. Salt stress greatly restricts plant development and growth. A high-density ...genetic linkage map is the basis of quantitative trait locus (QTLs) mapping. Several high-density genetic maps and QTLs mapping related to salt tolerance have been developed through next-generation sequencing in many crop species. However, such studies are rare for jute. Only several low-density genetic maps have been constructed and no salt tolerance-related QTL has been mapped in jute to date.
We developed a high-density genetic map with 4839 single nucleotide polymorphism markers spanning 1375.41 cM and an average distance of 0.28 cM between adjacent markers on seven linkage groups (LGs) using an F2 jute population, LGs ranged from LG2 with 299 markers spanning 113.66 cM to LG7 with 1542 markers spanning 350.18 cM. In addition, 99.57% of gaps between adjacent markers were less than 5 cM. Three obvious and 13 minor QTLs involved in salt tolerance were identified on four LGs explaining 0.58-19.61% of the phenotypic variance. The interval length of QTL mapping varied from 1.3 to 20.2 cM. The major QTL, qJST-1, was detected under two salt stress conditions that explained 11.81 and 19.61% of the phenotypic variation, respectively, and peaked at 19.3 cM on LG4.
We developed the first high-density and the most complete genetic map of jute to date using a genotyping-by-sequencing approach. The first QTL mapping related to salt tolerance was also carried out in jute. These results should provide useful resources for marker-assisted selection and transgenic breeding for salt tolerance at the germination stage in jute.
Cannabis (Cannabis sativa L.) is a dioecious plant cultivated worldwide for thousands of years. Besides the narcotic and therapeutic effects, Cannabis can be used as raw materials in multiple fields, ...including bioenergy, textiles, food, and ecological restoration. It is also an efficient bioremediation agent for contaminated soil, as well as greenhouse gas absorption. With the expansion of the market, there has been an increased demand to develop Cannabis cultivars with enhanced traits. As a major science breakthrough, the advent of the CRISPR/Cas system will revolutionize the basic and applied research in Cannabis. This article provides an overview of the recent advances in the optimization of a transformation system and in the gene editing of Cannabis. To achieve the full potential of this environmentally friendly and sustainable crop, we highlight future directions of genetic modification as well as several bottlenecks to overcome.
Boehmeria tricuspis (Hance) Makino constitutes a hardy herbaceous or shrubby perennial native to East Asia that includes different ploidy levels and reproductive modes (diplosporous to sexual). ...Although several apomeiosis-associated genes have been described, the genetic control and molecular mechanisms underlying apomeiosis remain poorly understood. Moreover, the basis of the correlation between polyploidy and apomixis has not yet been clarified. We utilized long-read sequencing to produce a full-length reference floral transcriptome of B. tricuspis. Based on the generated database, gene expression of the female flowers of different ploidy levels and reproductive mode cytotypes was compared. Overall, 1,387 genes related to apomeiosis, 217 genes related to ploidy, and 9 genes associated with both apomixis and ploidy were identified. Gene Ontology analyses of this set of transcripts indicated reproductive genes, especially those related to “cell differentiation” and “cell cycle process,” as significant factors regulating apomeiosis. Furthermore, our results suggested that different expressions of stress response genes might be important in the preparation for apomeiosis transition. In addition, our observations indicated that the expression of apomeiosis may not depend on polyploidy but rather on deregulation of the sexual pathway in B. tricuspis.
Summary
Hemp (Cannabis sativa L.) is an annual and typically dioecious crop. Due to the therapeutic potential for human diseases, phytocannabinoids as a medical therapy is getting more attention ...recently. Several candidate genes involved in cannabinoid biosynthesis have been elucidated using omics analysis. However, the gene function was not fully validated due to few reports of stable transformation for Cannabis tissues. In this study, we firstly report the successful generation of gene‐edited plants using an Agrobacterium‐mediated transformation method in C. sativa. DMG278 achieved the highest shoot induction rate, which was selected as the model strain for transformation. By overexpressing the cannabis developmental regulator chimera in the embryo hypocotyls of immature grains, the shoot regeneration efficiency was substantially increased. We used CRISPR/Cas9 technology to edit the phytoene desaturase gene and finally generated four edited cannabis seedlings with albino phenotype. Moreover, we propagated the transgenic plants and validated the stable integration of T‐DNA in cannabis genome.
To implement effective control and abatement programs for contaminants accumulating in sediments, strategies are needed for evaluating the quality of amended sediments. In this study, phytotoxicity ...of the sediments contaminated by cadmium and phenanthrene was evaluated after in situ remediation with multi-walled carbon nanotubes (MWCNTs) as adsorbents. Adsorption experiments and measurement of aqueous concentrations of the contaminants in overlying water were used to investigate the remediation effectiveness from physical and chemical aspects. The results indicated that MWCNTs showed a much better adsorption performance towards phenanthrene and Cd(II) compared with the sediments. The in situ remediation with MWCNTs could distinctly decrease the aqueous concentrations of phenanthrene and Cd(II) released from the sediments, reducing environmental risk towards overlying water. Influences of MWCNTs dose, MWCNTs diameter, and contact time on phtotoxicity of the contaminated sediments were studied. No significant inhibition of the amended sediments on germination of the test species was observed in the experiments, while the root growth was more sensitive than biomass production to the changes of contaminant concentrations. The analysis of Pearson correlation coefficients between evaluation indicators and associated remediation parameters suggested that phytotoxicity of sediments might inaccurately indicate the changes of pollutant content, but it was significant in reflecting the ecotoxicity of sediments after remediation.
•Use of MWCNTs for in situ remediation of contaminated sediments was explored.•Phytotoxicity of contaminated sediments before and after remediation was evaluated.•Root growth was more sensitive to the changes of pollutant concentration.•Phytotoxicity might inaccurately indicate the changes of pollutant content.
•A combination of GWAS and RNA-seq analyses identified candidate genes related to flax fatty acids.•The temporal expression of candidate genes related to fatty acid synthesis during the development ...of flax seeds was studied.•In addition, the correlation between candidate genes and fatty acid components at different developmental stages was analyzed to explore the effects of candidate genes in the process of fatty acid metabolism and accumulation.
Flax seeds have a high oil content and are rich in unsaturated fatty acids, which have advantageous effects in preventing chronic diseases, such as cardiovascular diseases. At present, flax seeds are mainly developed for oil. Therefore, it is of practical significance to identify the candidate genes of fatty acid metabolism in flax seeds for breeding flax seeds with high oil content. In the present study, a natural population of flax containing 224 samples planted in 3 different environments was studied. The genome-wide association analysis (GWAS) of seed fatty acid content was conducted based on specific length amplified fragment sequencing (SLAF-seq) data. Transcriptome sequencing (RNA-seq) of samples from 3 different periods (14 d, 21 d and 28 d after anthesis) during seed development of the low oil variety Shuangya 4 and the high oil variety NEW was performed. The candidate genes for seed fatty acid metabolism were identified by combined analysis of these 2 methods. GWAS detected 16 SNP loci significantly associated with seed fatty acid content, and RNA-seq analysis identified 11,802 differentially expressed genes between high and low oil samples. Pathway enrichment analysis revealed that some differentially expressed genes were classified into fatty acid-related pathways. After comparison of these differentially expressed genes with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, 20 genes homologous to other species were obtained. After analysis, 10 candidate genes were screened by GWAS and RNA-seq screening. Of these 10 genes, qRT-PCR assays using flax seeds in 5 different developmental stages showed that the expression levels of 6 candidate genes were significantly correlated with 5 fatty acid contents in seeds of the high oil variety NEW. Through metabolic pathway analysis found that 6 genes were involved in important fatty acid metabolic pathways, and some of them also have upstream and downstream regulation relations. The present study combined GWAS and RNA-seq methods to identify candidate genes for fatty acid metabolism in flax seeds, which provided reference for screening of candidate genes with complex traits.
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