The cadmium hyperaccumulator
has remarkable abilities for cadmium (Cd) transport, accumulation and detoxification, but the transcriptional regulation mechanisms responsible for its Cd ...hyperaccumulation remain unknown. To address this knowledge gap, we conducted a comparative transcriptome study between
and the non-hyperaccumulating ecotype (NHE) of
with or without Cd treatment. Our results revealed many differentially expressed genes involved in heavy metal transport and detoxification that were abundantly expressed in
. Additionally, we identified a large number of differentially expressed transcription factor genes, highlighting the complexity of transcriptional regulatory networks. We further screened four transcription factor genes that were highly expressed in the roots of
as candidate genes for creating CRISPR/Cas9 knockout mutations. Among these, the
and
mutant lines exhibited decreased Cd accumulation in their aboveground parts, suggesting that these two transcription factors may play a role in the regulation of the Cd hyperaccumulation in
. Although further research will be required to determine the precise targeted genes of these transcription factors, combined transcriptome analysis and CRISPR/Cas9 technology provides unprecedented opportunities for identifying transcription factors related to Cd hyperaccumulation and contributes to the understanding of the transcriptional regulation mechanism of hyperaccumulation in
.
The cadmium hyperaccumulator Sedum plumbizincicola has remarkable abilities for cadmium (Cd) transport, accumulation and detoxification, but the transcriptional regulation mechanisms responsible for ...its Cd hyperaccumulation remain unknown. To address this knowledge gap, we conducted a comparative transcriptome study between S. plumbizincicola and the non-hyperaccumulating ecotype (NHE) of Sedum alfredii with or without Cd treatment. Our results revealed many differentially expressed genes involved in heavy metal transport and detoxification that were abundantly expressed in S. plumbizincicola. Additionally, we identified a large number of differentially expressed transcription factor genes, highlighting the complexity of transcriptional regulatory networks. We further screened four transcription factor genes that were highly expressed in the roots of S. plumbizincicola as candidate genes for creating CRISPR/Cas9 knockout mutations. Among these, the SpARR11 and SpMYB84 mutant lines exhibited decreased Cd accumulation in their aboveground parts, suggesting that these two transcription factors may play a role in the regulation of the Cd hyperaccumulation in S. plumbizincicola. Although further research will be required to determine the precise targeted genes of these transcription factors, combined transcriptome analysis and CRISPR/Cas9 technology provides unprecedented opportunities for identifying transcription factors related to Cd hyperaccumulation and contributes to the understanding of the transcriptional regulation mechanism of hyperaccumulation in S. plumbizincicola.
Main conclusion
S. plumbizincicola
genetic transformation was optimized using a self-excision molecular-assisted transformation system by integrating the
SpGRF4/SpGIF1
gene with XVE and Cre/loxP.
...Sedum plumbizincicola
, despite being an excellent hyperaccumulator of cadmium and zinc with significant potential for soil pollution phytoremediation on farmland, has nonetheless trailed behind other major model plants in genetic transformation technology. In this study, different explants and
SpGRF4
–
SpGIF1
genes were used to optimize the genetic transformation of
S. plumbizincicola
. We found that petiole and stem segments had higher genetic transformation efficiency than cluster buds. Overexpression of
SpGRF4
–
SpGIF1
could significantly improve the genetic transformation efficiency and shorten the period of obtaining regenerated buds. However, molecular assistance with overexpression of
SpGRF4–SpGIF1
leads to abnormal morphology, resulting in plant tissue enlargement and abnormal growth. Therefore, we combined
SpGRF4–SpGIF1
with XVE and Cre/loxP to obtain DNA autocleavage transgenic plants induced by estradiol, thereby ensuring normal growth in transgenic plants. This study optimized the
S. plumbizincicola
genetic transformation system, improved the efficiency of genetic transformation, and established a self-excision molecular-assisted transformation system. This work also established the basis for studying
S. plumbizincicola
gene function, and for
S. plumbizincicola
breeding and germplasm innovation.
Sedum plumbizincicola is a hyperaccumulating species with highly efficient uptake, translocation and distribution system for cadmium (Cd), a non-essential and toxic heavy metal. To understand the ...molecular regulation mechanisms of Cd transport and accumulation in this hyperaccumulator is still a challenge. In this study, we observed that exogenous gibberellin A3 (GA3) significantly reduced Cd loading efficiency from root to shoot and uploading efficiency from stem to leaves in S. plumbizincicola under Cd treatments, which provided us a remarkable opportunity to study the signaling mechanisms for regulation of highly efficient Cd transport and translocation in S. plumbizincicola. Here, we constructed a de novo full-length transcriptome database with the integration of full-length and next-generation transcriptome sequences for Cd-treated S. plumbizincicola with or without exogenous GA3 application. From this database, we identified 1461 differentially expressed genes (DEGs), which were related to solute transport, cell wall metabolism and signal transduction, and most of them were down-regulated by the exogenous application of gibberellin. In particularly, a substantial number of the downregulated genes belong to calmodulin-like (CML) proteins, calcium-dependent protein kinase, calcium-permeable channel, mitochondrial calcium uniporter (MCU) and Na+/Ca2+ exchanger-like proteins (NCL/EF-CAX). These results indicated that calcium homeostasis and signal transduction may play an important role in the regulation of highly efficient translocation of cadmium in hyperaccumulator S. pumbizincicola.
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•GA greatly suppressed the highly efficient Cd translocation in hyperaccumulator.•A useful system to study the molecular regulation mechanism of Cd hyperaccumulation.•Integrated analysis of de novo full-length transcriptome in Sedum plumbizincicola.•Ca2+ homeostasis may involve in highly efficient Cd translocation.
A new generation of photothermal therapeutic agents based on biopolymer dopamine‐melanin colloidal nanospheres is described. Benefitting from their naturally wide distribution in humans, ...dopamine‐melanin colloidal nanospheres exhibit robust biocompatibility and biodegradability, and provide up to 40% photothermal conversion efficiency. After administration, they can efficiently damage tumors at low power density and short irradiation time without damaging healthy tissues.
In China, the implementation of 2-child policy since 2015 entitles increasing number of advanced maternal age. Recently, Chinese hypertensive disorders of pregnancy (HDP) in advanced-age women have ...attracted significant clinical and epidemiological research interest. Previous studies have shown an association between serum uric acid (SUA) levels and low birth weight (LBW) in children. Several studies have reported that advanced maternal age is a risk factor for many complications in pregnancy, including LBW. However, it remains unclear whether SUA affects LBW risk in advanced maternal age mothers with hypertensive diseases. The study was observational in nature. A total of 692 advanced maternal age with hypertension were enrolled in our study. A variety of demographic and vital sign data, laboratory test results, and pregnancy outcomes were collected. Children born with LBW served as the clinical endpoint. On admission, blood samples were taken, and women with advanced maternal ages were divided into 2 groups based on their SUA levels. In order to investigate the association between SUA and LBW, a logistic regression model was used. E-value analysis was used to determine the residual unmeasured confounding. The mean SUA level was increased in advanced maternal age patients with HDP. Of 692 newborns, 244 (35.26%) have LBW. With possible confounders adjusted, high SUA levels were independent risk factors for LBW (odds ratio OR2.88, 95% confidence intervals CI1.22–6.81), multivariate logistic regression analysis using SUA as a continuous variable recapitulated the pattern (OR 1.01, 95% CI 1.00–1.01). In addition, SUA levels in women with advanced maternal age and hypertension were linearly related to LBW incidence. According to this study, SUA levels in patients with advanced maternal age and HDP are associated with LBW incidence.
Peroxisome proliferator-activated receptor gamma (PPARƔ) contributes to human immunodeficiency virus (HIV)-1-induced dysfunction of brain endothelial cells. The aim of the present study was to ...evaluate the protection mechanism of PPARƔ against Tat-induced responses of adhesion molecules. We measured the protein expressions of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 in human brain microvascular endothelial cells (hCMEC/D3) and C57BL/6J mouse brain microvessels with Western blotting and immunofluorescent labeling. The mRNA levels of ICAM-1 and VCAM-1 were determined by real-time reverse-transcriptase polymerase chain reaction. HIV-1 Tat induced overexpression of ICAM-1 but not VCAM-1 in both hCMEC/D3 and brain microvessels, this response was attenuated by treatment with the PPARƔ agonist rosiglitazone. Tat-mediated upregulation of ICAM-1 and VCAM-1 levels were abolished by the addition of PPARƔ antagonist GW9662 and the Akt inhibitor KP3721, indicating that Akt signaling is involved in the PPARƔ-mediated protection of Tat-induced adhesion molecule upregulation. These results show that Akt signaling plays a key role in PPARƔ’s vascular inflammatory effects that contribute to blood–brain barrier damage.
The peroxide bleaching of high yield pulps from wood with Mg(OH)2 has been developing recently in the pulp and paper industry. However, there is still a lack of data on the application of Mg(OH)2 in ...peroxide bleaching of non-wood fibres. In this work, our purpose was to study the effect of Mg(OH)2 on peroxide bleaching of wheat straw soda-AQ pulp. The results showed that Mg(OH)2 significantly improved peroxide bleaching efficiency (expressed as the ratio between the brightness gain and the H2O2 consumption) and selectivity (expressed as the ratio between the brightness gain and the viscosity losses) of wheat straw soda-AQ pulp. The brightness, viscosity, and yield of bleached pulp can be significantly enhanced by increasing the replacement ratio of Mg(OH)2. However, at 100% replacement of NaOH with Mg(OH)2, the brightness of bleached pulp was much lower than that of the bleached pulp with NaOH as the sole alkaline source. When 24 to 73% of the NaOH was replaced with Mg(OH)2, the COD of the bleaching filtrate was 11 to 38% lower than that of the NaOH as the sole alkaline source. The lower solubility and alkalinity of Mg(OH)2, as well as the reduction of Cu ion content in bleached pulp were proposed as accounting for the favorable effect of Mg(OH)2 on peroxide bleaching of wheat straw soda-AQ pulp.
