Genome-wide identification and stress response analysis of BcaCPK gene family in amphidiploid Brassica carinata.

BACKGROUND: Calcium-dependent protein kinases (CPKs) are crucial for recognizing and transmitting Ca2+ signals in plant cells, playing a vital role in growth, development, and stress response. This study aimed to identify and detect the potential roles of the CPK gene family in the amphidiploid Brassica carinata (BBCC, 2n = 34) using bioinformatics methods. RESULTS: Based on the published genomic information of B. carinata, a total of 123 CPK genes were identified, comprising 70 CPK genes on the B subgenome and 53 on the C subgenome. To further investigate the homologous evolutionary relationship between B. carinata and other plants, the phylogenetic tree was constructed using CPKs in B. carinata and Arabidopsis thaliana. The phylogenetic analysis classified 123 family members into four subfamilies, where gene members within the same subfamily exhibited similar conserved motifs. Each BcaCPK member possesses a core protein kinase domain and four EF-hand domains. Most of the BcaCPK genes contain 5 to 8 introns, and these 123 BcaCPK genes are unevenly distributed across 17 chromosomes. Among these BcaCPK genes, 120 replicated gene pairs were found, whereas only 8 genes were tandem duplication, suggesting that dispersed duplication mainly drove the family amplification. The results of the Ka/Ks analysis indicated that the CPK gene family of B. carinata was primarily underwent purification selection in evolutionary selection. The promoter region of most BcaCPK genes contained various stress-related cis-acting elements. qRT-PCR analysis of 12 selected CPK genes conducted under cadmium and salt stress at various points revealed distinct expression patterns among different family members in response to different stresses. Specifically, the expression levels of BcaCPK2.B01a, BcaCPK16.B02b, and BcaCPK26.B02 were down-regulated under both stresses, whereas the expression levels of other members were significantly up-regulated under at least one stress. CONCLUSION: This study systematically identified the BcaCPK gene family in B. carinata, which contributes to a better understanding the CPK genes in this species. The findings also serve as a reference for analyzing stress responses, particularly in relation to cadmium and salt stress in B. carinata.

Native Approach to Controlled-Z Gates in Inductively Coupled Fluxonium Qubits.

The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit interactions are restricted to XX interactions. Consequently, effective ZZ or XZ interactions are only constructed either by temporarily populating higher-energy states, or by exploiting perturbative effects under microwave driving. Instead, we propose and demonstrate an inductive coupling scheme, which offers a wide selection of native qubit-qubit interactions for fluxonium. In particular, we leverage a built-in, flux-controlled ZZ interaction to perform qubit entanglement. To combat the increased flux-noise-induced dephasing away from the flux-insensitive position, we use a continuous version of the dynamical decoupling scheme to perform noise filtering. Combining these, we demonstrate a 20 ns controlled-z gate with a mean fidelity of 99.53%. More than confirming the efficacy of our gate scheme, this high-fidelity result also reveals a promising but rarely explored parameter space uniquely suitable for gate operations between fluxonium qubits.

ZmWRKY30 modulates drought tolerance in maize by influencing myo-inositol and reactive oxygen species homeostasis.

Maize (Zea mays L.) is an important food crop with a wide range of uses in both industry and agriculture. Drought stress during its growth cycle can greatly reduce maize crop yield and quality. However, the molecular mechanisms underlying maize responses to drought stress remain unclear. In this work, a WRKY transcription factor-encoding gene, ZmWRKY30, from drought-treated maize leaves was screened out and characterized. ZmWRKY30 gene expression was induced by dehydration treatments. The ZmWRKY30 protein localized to the nucleus and displayed transactivation activity in yeast. Compared with wild-type (WT) plants, Arabidopsis lines overexpressing ZmWRKY30 exhibited a significantly enhanced drought stress tolerance, as evidenced by the improved survival rate, increased antioxidant enzyme activity by superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), elevated proline content, and reduced lipid peroxidation recorded after drought stress treatment. In contrast, the mutator (Mu)-interrupted ZmWRKY30 homozygous mutant (zmwrky30) was more sensitive to drought stress than its null segregant (NS), characterized by the decreased survival rate, reduced antioxidant enzyme activity (SOD, POD, and CAT) and proline content, as well as increased malondialdehyde accumulation. RNA-Seq analysis further revealed that, under drought conditions, the knockout of the ZmWRKY30 gene in maize affected the expression of genes involved in reactive oxygen species (ROS), proline, and myo-inositol metabolism. Meanwhile, the zmwrky30 mutant exhibited significant downregulation of myo-inositol content in leaves under drought stress. Combined, our results suggest that ZmWRKY30 positively regulates maize responses to water scarcity. This work provides potential target genes for the breeding of drought-tolerant maize.

Quantifying uncertainty: Air quality forecasting based on dynamic spatial-temporal denoising diffusion probabilistic model.

Air pollution constitutes a substantial peril to human health, thereby catalyzing the evolution of an array of air quality prediction models. These models span from mechanistic and statistical strategies to machine learning methodologies. The burgeoning field of deep learning has given rise to a plethora of advanced models, which have demonstrated commendable performance. However, previous investigations have overlooked the salience of quantifying prediction uncertainties and potential future interconnections among air monitoring stations. Moreover, prior research typically utilized static predetermined spatial relationships, neglecting dynamic dependencies. To address these limitations, we propose a model named Dynamic Spatial-Temporal Denoising Diffusion Probabilistic Model (DST-DDPM) for air quality prediction. Our model is underpinned by the renowned denoising diffusion model, aiding us in discerning indeterminacy. In order to encapsulate dynamic patterns, we design a dynamic context encoder to generate dynamic adjacency matrices, whilst maintaining static spatial information. Furthermore, we incorporate a spatial-temporal denoising model to concurrently learn both spatial and temporal dependencies. Authenticating our model's performance using a real-world dataset collected in Beijing, the outcomes indicate that our model eclipses other baseline models in terms of both short-term and long-term predictions by 1.36% and 11.62% respectively. Finally, we conduct a case study to exhibit our model's capacity to quantify uncertainties.

The maize WRKY transcription factor ZmWRKY64 confers cadmium tolerance in Arabidopsis and maize (Zea mays L.).

KEY MESSAGE: ZmWRKY64 positively regulates Arabidopsis and maize Cd stress through modulating Cd uptake, translocation, and ROS scavenging genes expression. Cadmium (Cd) is a highly toxic heavy metal with severe impacts on crops growth and development. The WRKY transcription factor is a significant regulator influencing plant stress response. Nevertheless, the function of the WRKY protein in maize Cd stress response remains unclear. Here, we identified a maize WRKY gene, ZmWRKY64, the expression of which was enhanced in maize roots and leaves under Cd stress. ZmWRKY64 was localized in the nucleus and displayed transcriptional activity in yeast. Heterologous expression of ZmWRKY64 in Arabidopsis diminished Cd accumulation in plants by negatively regulating the expression of AtIRT1, AtZIP1, AtHMA2, AtNRAMP3, and AtNRAMP4, which are involved in Cd uptake and transport, resulting in Cd stress tolerance. Knockdown of ZmWRKY64 in maize led to excessive Cd accumulation in leaf cells and in the cytosol of the root cells, resulting in a Cd hypersensitive phenotype. Further analysis confirmed that ZmWRKY64 positively regulated ZmABCC4, ZmHMA3, ZmNRAMP5, ZmPIN2, ZmABCG51, ZmABCB13/32, and ZmABCB10, which may influence Cd translocation and auxin transport, thus mitigating Cd toxicity in maize. Moreover, ZmWRKY64 could directly enhance the transcription of ZmSRG7, a reported key gene regulating reactive oxygen species homeostasis under abiotic stress. Our results indicate that ZmWRKY64 is important in maize Cd stress response. This work provides new insights into the WRKY transcription factor regulatory mechanism under a Cd-polluted environment and may lead to the genetic improvement of Cd tolerance in maize.

Transcriptome Profiling, Physiological and Biochemical Analyses Reveal Comprehensive Insights in Cadmium Stress in Brassica carinata L.

With the constant progress of urbanization and industrialization, cadmium (Cd) has emerged as one of the heavy metals that pollute soil and water. The presence of Cd has a substantial negative impact on the growth and development of both animals and plants. The allotetraploid Brasscia. carinata, an oil crop in the biofuel industry, is known to produce seeds with a high percentage of erucic acid; it is also known for its disease resistance and widespread adaptability. However, there is limited knowledge regarding the tolerance of B. carinata to Cd and its physiological responses and gene expressions under exposure to Cd. Here, we observed that the tested B. carinata exhibited a strong tolerance to Cd (1 mmol/L CdCl2 solution) and exhibited a significant ability to accumulate Cd, particularly in its roots, with concentrations reaching up to 3000 mg/kg. Additionally, we found that the total oil content of B. carinata seeds harvested from the Cd-contaminated soil did not show a significant change, but there were noticeable alterations in certain constituents. The activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), were observed to significantly increase after treatment with different concentrations of CdCl2 solutions (0.25 mmol/L, 0.5 mmol/L, and 1 mmol/L CdCl2). This suggests that these antioxidant enzymes work together to enhance Cd tolerance. Comparative transcriptome analysis was conducted to identify differentially expressed genes (DEGs) in the shoots and roots of B. carinata when exposed to a 0.25 mmol/L CdCl2 solution for 7 days. A total of 631 DEGs were found in the shoots, while 271 DEGs were found in the roots. It was observed that these selected DEGs, which responded to Cd stress, also showed differential expression after exposure to PbCl2. This suggests that B. carinata may employ a similar molecular mechanism when tolerating these heavy metals. The functional annotation of the DEGs showed enrichment in the categories of 'inorganic ion transport and metabolism' and 'signal transduction mechanisms'. Additionally, the DEGs involved in 'tryptophan metabolism' and 'zeatin biosynthesis' pathways were found to be upregulated in both the shoots and roots of B. carinata, suggesting that the plant can enhance its tolerance to Cd by promoting the biosynthesis of plant hormones. These results highlight the strong Cd tolerance of B. carinata and its potential use as a Cd accumulator. Overall, our study provides valuable insights into the mechanisms underlying heavy metal tolerance in B. carinata.

The TabHLH35-TaWAK20-TaSPL5 pathway positively regulates Cd stress in wheat.

KEY MESSAGE: Cadmium-induced TaWAK20 regulates the cadmium stress response by phosphorylating TaSPL5 in wheat. Receptor-like kinases (RLKs) are thought to play important roles in responses to abiotic stresses in plants. In this study, we identified a cadmium (Cd)-induced RLK in wheat, TaWAK20, which is a positive regulator of the Cd stress response. TaWAK20 is specifically expressed in root tissue. Overexpression of TaWAK20 significantly improved the tolerance of Cd stress in wheat and decreased Cd accumulation in wheat plants by regulating reactive oxygen species production and scavenging. Yeast one-hybrid assays, electrophoretic mobility shift assays, and firefly luciferase activity analyses demonstrated that the TaWAK20 promoter was bound by the TabHLH35 transcription factor. TaWAK20 interacted with and phosphorylated squamosa promoter binding protein-like 5 (TaSPL5). Furthermore, phosphorylation of TaSPL5 increased its DNA-binding activity. In addition, Arabidopsis-expressing phosphorylated TaSPL5 exhibited greater Cd tolerance than Arabidopsis-expressing unphosphorylated TaSPL5. Taken together, these data identify a TabHLH35-TaWAK20-TaSPL5 module that regulates Cd stress.

Study on the Film-Forming Mechanism of Polymer-Metal Oxide Composite Ink Systems Containing Different Polymer Molecules.

A printable, flexible display panel is an important trend in the field of information display, which requires better mechanical and electrical properties of device materials. Polymer-metal oxide composite materials are promising in the functional layer of a thin-film transistor (TFT) and can be sufficiently fabricated by polymer-metal salt solution systems through the sol-gel process. For the development of polymer-metal oxide composite ink, it is necessary to study the film-forming mechanism of the composite film during solidification, which is an important reference in ink component design. However, the evolution of the composite structure is quite complex, which brings a challenge to characterization and analyzation. We applied a series of characterization methods to study the film-forming process of composite ink from sol to gel and to solid, and an emerging testing technology, nano-infrared spectroscopy (nano-IR), was applied to characterize the gel film. The research conclusion showed that the type of functional group can significantly affect the morphology of the initial particle and can finally determine the microstructure of the composite film. The study provides references for the development of composite ink as well as the characterization method for ink and film with complex composition.

Highly Efficient Coremoval of Nitrate and Phosphate Driven by a Sulfur-Siderite Composite Reactive Filler toward Secondary Effluent Polishing.

Reactive fillers consisting of reduced sulfur and iron species (SFe-ReFs) have received increasing attention in tertiary wastewater treatment for nitrate and phosphate coremoval. However, the existing SFe-ReFs suffer from either low performance (e.g., pyrrhotite and pyrite) or unsatisfactory use in terms of combustible risk and residual nonreactive impurities (e.g., sulfur mixing with natural iron ores). Here, we developed a new type of sulfur-siderite composite ReF (SSCReF) with a structure of natural siderite powders eventually embedded into sulfur. SSCReFs exhibited many excellent properties, including higher mechanical strengths and hardness and especially much poorer ignitability compared to pure sulfur. By using SSCReF to construct packed-bed reactors, the highest denitrification and dephosphorization rates reached 829.70 gN/m3/d (25 wt % siderite) and 36.70 gP/m3/d (75 wt % siderite), respectively. Dephosphorization was demonstrated to be dependent on sulfur-driven denitrification, in which the acid produced from the later process promoted Fe(II) dissolution, which then directly combined with phosphate to form vivianite or further converted into phosphate adsorbents (ferrihydrite, a green rust-like compound). Water flush was an effective way to finally wash out these surface deposited Fe-P compounds, as well as those nonreactive impurities (Si and Al-bearing compounds) detached from SSCReF. Such a highly efficient and safe SSCReF holds considerable application potential in secondary effluent polishing.

The TabHLH094-TaMYC8 complex mediates the cadmium response in wheat.

In wheat, TaMYC8 is a negative regulator of cadmium (Cd)-responsive ethylene signaling. In this study, we functionally characterized TabHLH094, a basic helix-loop-helix (bHLH) transcription factor (TF) that inhibits the transcriptional activity of TaMYC8. The TabHLH094 protein was found in the nucleus of tobacco epidermal cells and exhibited transcriptional activation activity. Real-time quantitative PCR (RT-qPCR) indicated that TabHLH094 exhibited root-specific, Cd-responsive expression in wheat seedlings. Overexpression of TabHLH094 enhanced the tolerance of wheat seedlings to Cd exposure. The protein-protein interaction between TabHLH094 and TaMYC8 was verified by glutathione S-transferase (GST) pulldown, coimmunoprecipitation (Co-IP), yeast two-hybrid (Y2H), and bimolecular fluorescence complementation (BiFC) analyses. TabHLH094 was found to reduce the ability of TaMYC8 to bind to the TaERF6 promoter. Furthermore, TabHLH094 could also reduce aminocyclopropanecarboxylate oxidase (ACO) and ACC synthase (ACS) activities, both of which are necessary for ethylene biosynthesis. Taken together, these results indicate that TabHLH094 mediates Cd tolerance by regulating the transcriptional activity of TaMYC8 and decreasing ethylene production. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01404-1.

Transcriptomic analysis reveals key genes and pathways corresponding to Cd and Pb in the hyperaccumulator Arabis paniculata.

Soil and water are increasingly at risk of contamination from the toxic heavy metals lead (Pb) and cadmium (Cd). Arabis paniculata (Brassicaceae) is a hyperaccumulator of heavy metals (HMs) found widely distributed in areas impacts by mining activities. However, the mechanism by which A. paniculata tolerates HMs is still uncharacterized. For this experiment, we employed RNA sequencing (RNA-seq) in order to find Cd (0.25 mM)- and Pb (2.50 mM)-coresponsive genes A. paniculata. In total, 4490 and 1804 differentially expressed genes (DEGs) were identified in root tissue, and 955 and 2209 DEGs were identified in shoot tissue, after Cd and Pb exposure, respectively. Interestingly in root tissue, gene expression corresponded similarly to both Cd and Pd exposure, of which 27.48% were co-upregulated and 41.00% were co-downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that the co-regulated genes were predominantly involved in transcription factors (TFs), cell wall biosynthesis, metal transport, plant hormone signal transduction, and antioxidant enzyme activity. Many critical Pb/Cd-induced DEGs involved in phytohormone biosynthesis and signal transduction, HM transport, and transcription factors were also identified. Especially the gene ABCC9 was co-downregulated in root tissues but co-upregulated in shoot tissues. The co-downregulation of ABCC9 in the roots prevented Cd and Pb from entering the vacuole rather than the cytoplasm for transporting HMs to shoots. While in shoots, the ABCC9 co-upregulated results in vacuolar Cd and Pb accumulation, which may explain why A. paniculata is a hyperaccumulator. These results will help to reveal the molecular and physiological processes underlying tolerance to HM exposure in the hyperaccumulator A. paniculata, and aid in future efforts to utilize this plant in phytoremediation.

The SbbHLH041-SbEXPA11 Module Enhances Cadmium Accumulation and Rescues Biomass by Increasing Photosynthetic Efficiency in Sorghum.

In plants, expansin genes are responsive to heavy metal exposure. To study the bioremediary potential of this important gene family, we discovered a root-expressed expansin gene in sorghum, SbEXPA11, which is notably upregulated following cadmium (Cd) exposure. However, the mechanism underlying the Cd detoxification and accumulation mediated by SbEXPA11 in sorghum remains unclear. We overexpressed SbEXPA11 in sorghum and compared wild-type (WT) and SbEXPA11-overexpressing transgenic sorghum in terms of Cd accumulation and physiological indices following Cd. Compared with the WT, we found that SbEXPA11 mediates Cd tolerance by exerting reactive oxygen species (ROS)-scavenging effects through upregulating the expression of antioxidant enzymes. Moreover, the overexpression of SbEXPA11 rescued biomass production by increasing the photosynthetic efficiency of transgenic plants. In the pot experiment with a dosage of 10 mg/kg Cd, transgenic sorghum plants demonstrated higher efficacy in reducing the Cd content of the soil (8.62 mg/kg) compared to WT sorghum plants (9.51 mg/kg). Subsequent analysis revealed that the SbbHLH041 transcription factor has the ability to induce SbEXPA11 expression through interacting with the E-box located within the SbEXPA11 promoter. These findings suggest that the SbbHLH041-SbEXPA11 cascade module may be beneficial for the development of phytoremediary sorghum varieties.

The Genome-Wide Identification, Characterization, and Expression Analysis of the Strictosidine Synthase-like Family in Maize (Zea mays L.).

Maize is often subjected to various environmental stresses. The strictosidine synthase-like (SSL) family is thought to catalyze the key step in the monoterpene alkaloids synthesis pathway in response to environmental stresses. However, the role of ZmSSL genes in maize growth and development and its response to stresses is unknown. Herein, we undertook the systematic identification and analysis of maize SSL genes. Twenty SSL genes were identified in the maize genome. Except for chromosomes 3, 5, 6, and 10, they were unevenly distributed on the remaining 6 chromosomes. A total of 105 SSL genes from maize, sorghum, rice, Aegilops tauschii, and Arabidopsis were divided into five evolutionary groups, and ZmSSL gene structures and conserved protein motifs in the same group were similar. A collinearity analysis showed that tandem duplication plays an important role in the evolution of the SSL family in maize, and ZmSSL genes share more collinear genes in crops (maize, sorghum, rice, and Ae. tauschii) than in Arabidopsis. Cis-element analysis in the ZmSSL gene promoter region revealed that most genes contained many development and stress response elements. We evaluated the expression levels of ZmSSL genes under normal conditions and stress treatments. ZmSSL4-9 were widely expressed in different tissues and were positively or negatively regulated by heat, cold, and infection stress from Colletotrichum graminicola and Cercospora zeina. Moreover, ZmSSL4 and ZmSSL5 were localized in the chloroplast. Taken together, we provide insight into the evolutionary relationships of the ZmSSL genes, which would be useful to further identify the potential functions of ZmSSLs in maize.

Co-Expression Network Analysis of the Transcriptome Identified Hub Genes and Pathways Responding to Saline-Alkaline Stress in Sorghum bicolor L.

Soil salinization, an intractable problem, is becoming increasingly serious and threatening fragile natural ecosystems and even the security of human food supplies. Sorghum (Sorghum bicolor L.) is one of the main crops growing in salinized soil. However, the tolerance mechanisms of sorghum to saline-alkaline soil are still ambiguous. In this study, RNA sequencing was carried out to explore the gene expression profiles of sorghum treated with sodium bicarbonate (150 mM, pH = 8.0, treated for 0, 6, 12 and 24 h). The results show that 6045, 5122, 6804, 7978, 8080 and 12,899 differentially expressed genes (DEGs) were detected in shoots and roots after 6, 12 and 24 h treatments, respectively. GO, KEGG and weighted gene co-expression analyses indicate that the DEGs generated by saline-alkaline stress were primarily enriched in plant hormone signal transduction, the MAPK signaling pathway, starch and sucrose metabolism, glutathione metabolism and phenylpropanoid biosynthesis. Key pathway and hub genes (TPP1, WRKY61, YSL1 and NHX7) are mainly related to intracellular ion transport and lignin synthesis. The molecular and physiological regulation processes of saline-alkali-tolerant sorghum are shown by these results, which also provide useful knowledge for improving sorghum yield and quality under saline-alkaline conditions.

Overexpression of ApHIPP26 from the Hyperaccumulator Arabis paniculata Confers Enhanced Cadmium Tolerance and Accumulation to Arabidopsis thaliana.

Cadmium (Cd) is a toxic heavy metal that seriously affects metabolism after accumulation in plants, and it also causes adverse effects on humans through the food chain. The HIPP gene family has been shown to be highly tolerant to Cd stress due to its special domain and molecular structure. This study described the Cd-induced gene ApHIPP26 from the hyperaccumulator Arabis paniculata. Its subcellular localization showed that ApHIPP26 was located in the nucleus. Transgenic Arabidopsis overexpressing ApHIPP26 exhibited a significant increase in main root length and fresh weight under Cd stress. Compared with wild-type lines, Cd accumulated much more in transgenic Arabidopsis both aboveground and underground. Under Cd stress, the expression of genes related to the absorption and transport of heavy metals underwent different changes in parallel, which were involved in the accumulation and distribution of Cd in plants, such as AtNRAMP6 and AtNRAMP3. Under Cd stress, the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase) in the transgenic lines were higher than those in the wild type. The physiological and biochemical indices showed that the proline and chlorophyll contents in the transgenic lines increased significantly after Cd treatment, while the malondialdehyde (MDA) content decreased. In addition, the gene expression profile analysis showed that ApHIPP26 improved the tolerance of Arabidopsis to Cd by regulating the changes of related genes in plant hormone signal transduction pathway. In conclusion, ApHIPP26 plays an important role in cadmium tolerance by alleviating oxidative stress and regulating plant hormones, which provides a basis for understanding the molecular mechanism of cadmium tolerance in plants and provides new insights for phytoremediation in Cd-contaminated areas.

Integrative physiological and transcriptome analyses provide insights into the Cadmium (Cd) tolerance of a Cd accumulator: Erigeron canadensis.

Cadmium (Cd) is a highly toxic pollutant in soil and water that severely hampers the growth and reproduction of plants. Phytoremediation has been presented as a cost-effective and eco-friendly method for addressing heavy metal pollution. However, phytoremediation is restricted by the limited number of accumulators and the unknown mechanisms underlying heavy metal tolerance. In this study, we demonstrated that Erigeron canadensis (Asteraceae), with its strong adaptability, is tolerant to intense Cd stress (2 mmol/L CdCl2 solution). Moreover, E. canadensis exhibited a strong ability to accumulate Cd2+ when treated with CdCl2 solution. The activity of some antioxidant enzymes, as well as the malondialdehyde (MDA) level, was significantly increased when E. canadensis was treated with different CdCl2 solutions (0.5, 1, 2 mmol/L CdCl2). We found high levels of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities under 1 mmol/L CdCl2 treatment. Comparative transcriptomic analysis identified 5,284 differentially expressed genes (DEGs) in the roots and 3,815 DEGs in the shoots after E. canadensis plants were exposed to 0.5 mM Cd. Functional annotation of key DEGs indicated that signal transduction, hormone response, and reactive oxygen species (ROS) metabolism responded significantly to Cd. In particular, the DEGs involved in auxin (IAA) and ethylene (ETH) signal transduction were overrepresented in shoots, indicating that these genes are mainly involved in regulating plant growth and thus likely responsible for the Cd tolerance. Overall, these results not only determined that E. canadensis can be used as a potential accumulator of Cd but also provided some clues regarding the mechanisms underlying heavy metal tolerance.

Highly sensitive SERS detection in a non-volatile liquid-phase system with nanocluster-patterned optical fiber SERS probes.

The use of surface-enhanced Raman scattering (SERS) spectroscopy for the detection of substances in non-volatile systems, such as edible oil and biological cells, is an important issue in the fields of food safety and biomedicine. However, traditional dry-state SERS detection with planar SERS substrates is not suitable for highly sensitive and rapid SERS detection in non-volatile liquid-phase systems. In this paper, we take contaminant in edible oil as an example and propose an in situ SERS detection method for non-volatile complex liquid-phase systems with high-performance optical fiber SERS probes. Au-nanorod clusters are successfully prepared on optical fiber facet by a laboratory-developed laser-induced dynamic dip-coating method, and relatively high detection sensitivity (LOD of 2.4 × 10-6 mol/L for Sudan red and 3.6 × 10-7 mol/L for thiram in sunflower oil) and good reproducibility (RSD less than 10%) are achieved with a portable Raman spectrometer and short spectral integration time of 10 s even in complex edible oil systems. Additionally, the recovery rate experiment indicates the reliability and capability of this method for quantitative detection applications. This work provides a new insight for highly sensitive and rapid SERS detection in non-volatile liquid-phase systems with optical fiber SERS probes and may find important practical applications in food safety and biomedicine.

Low estrogen level in aged mice leads to abnormal oogenesis affecting the quality of surrounded nucleolus-type immature oocytes.

CONTEXT: With aging, various problems in the reproductive system emerge, especially in females. However, our understanding of reproductive aging in livestock and humans is limited. AIMS: We aimed to investigate reproductive changes between young and aged mice. METHODS: Eight- to ten-week-old female mice were used as the young group, and 10-month-old mice were studied as the aged group. Reproductive changes were investigated from physiological, histological, cytological, and epigenetic perspectives. KEY RESULTS: The estrus cycle was shortened (P <0.0001), and the estradiol (E2) concentration was lower in aged mice (P <0.01), whereas the progesterone (P4) concentration did not differ between young and aged mice (P >0.05). The histological results revealed a lower number of antral follicles in the ovary and disordered epithelial tissue structures in the oviducts in aged mice. During oogenesis, the surrounded nucleolus (SN)-type oocytes in aged mice exhibited increased mitochondrial agglutination (P <0.05) and cellular apoptosis (P <0.01) as well as decreased H3K36 triple-methylation (P <0.001). Although many defects existed, the oocytes from aged mice could normally support cellular reprogramming after somatic cell nuclear transfer. CONCLUSIONS: Our results indicate that the reduced levels of reproductive hormones in aged females lead to shorter estrus cycles and reduced follicular development, leading to abnormal oogenesis, particularly in SN-type immature oocytes. IMPLICATIONS: These results provide new insight that enhance our understanding and improve the reproductive ability of aged females.

The TaWRKY22-TaCOPT3D Pathway Governs Cadmium Uptake in Wheat.

Cadmium (Cd) is a heavy metal nonessential for plants; this toxic metal accumulation in crops has significant adverse effects on human health. The crosstalk between copper (Cu) and Cd has been reported; however, the molecular mechanisms remain unknown. The present study investigated the function of wheat Cu transporter 3D (TaCOPT3D) in Cd tolerance. The TaCOPT3D transcripts significantly accumulated in wheat roots under Cd stress. Furthermore, TaCOPT3D-overexpressing lines were compared to wildtype (WT) plants to test the role of TaCOPT3D in Cd stress response. Under 20 mM Cd treatment, TaCOPT3D-overexpressing lines exhibited more biomass and lower root, shoot, and grain Cd accumulation than the WT plants. In addition, overexpression of TaCOPT3D decreased the reactive oxygen species (ROS) levels and increased the active antioxidant enzymes under Cd conditions. Moreover, the transcription factor (TF) TaWRKY22, which targeted the TaCOPT3D promoter, was identified in the regulatory pathway of TaCOPT3D under Cd stress. Taken together, these results show that TaCOPT3D plays an important role in regulating plant adaptation to cadmium stress through bound by TaWRKY22. These findings suggest that TaCOPT3D is a potential candidate for decreasing Cd accumulation in wheat through genetic engineering.

Complete chloroplast genome features of the model heavy metal hyperaccumulator Arabis paniculata Franch and its phylogenetic relationships with other Brassicaceae species.

Arabis paniculata Franch (Brassicaceae) has been widely used for the phytoremediation of heavy mental, owing to its hyper tolerance of extreme Pb, Zn, and Cd concentrations. However, studies on its genome or plastid genome are scarce. In the present study, we obtained the complete chloroplast (cp) genome of A. paniculata via de novo assembly through the integration of Illumina reads and PacBio subreads. The cp genome presents a typical quadripartite cycle with a length of 153,541 bp, and contains 111 unigenes, with 79 protein-coding genes, 28 tRNAs and 4 rRNAs. Codon usage analysis showed that the codons for leucine were the most frequent codons and preferentially ended with A/U. Synonymous (Ks) and non-synonymous (Ka) substitution rate analysis indicated that the unigenes, ndhF and rpoC2, related to "NADH-dehydrogenase" and "RNA polymerase" respectively, underwent the lowest purifying selection pressure. Phylogenetic analysis demonstrated that Arabis flagellosa and A. hirsuta are more similar to each other than to A. paniculata, and Arabis is the closest relative of Draba among all Brassicaceae genera. These findings provide valuable information for the optimal exploitation of this model species as a heavy-metal hyperaccumulator. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01151-1.