Brusatol induces ferroptosis to inhibit hepatocellular carcinoma progression by targeting ATF3.

Ferroptosis is a novel form of programmed cell death that is triggered by iron-dependent lipid peroxidation. Brusatol (BRU), a natural nuclear factor erythroid 2-related factor 2 inhibitor, exhibits potent anticancer effects in various types of cancer. However, the exact mechanism of BRU in the treatment of hepatocellular carcinoma (HCC) remains unknown. The anticancer effects of BRU in HCC were detected using cell counting kit-8 and colony formation assays and a xenograft model. RNA sequencing (RNA-seq) and bioinformatics analyses of HCC cells were utilized to elucidate the mechanism underlying the effects of BRU in HCC. The levels of reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and Fe2+ were measured using assay kits. The expression of activating transcription factor 3 (ATF3) was tested using RT-qPCR, western blotting, and immunofluorescence staining. The role of ATF3 in BRU-induced ferroptosis was examined using siATF3. BRU significantly inhibited HCC cell proliferation, both in vitro and in vivo. BRU activated the ferroptosis signaling pathway and increased ATF3 expression. Furthermore, ATF3 knockdown impeded BRU-induced ferroptosis. BRU suppressed HCC growth through ATF3-mediated ferroptosis, supporting BRU as a promising therapeutic agent for HCC.

Simultaneous and sensitive detection of methylparaben and its metabolites by using molecularly imprinted solid-phase microextraction fiber array technique.

BACKGROUND: Methylparaben (MP), a commonly used antibacterial preservative, is widely used in personal care products, foods, and pharmaceuticals. MP and its metabolites are easy to enter the water environment, and their exposure and accumulation have negative effects on the ecological environment and human health, and have endocrine disrupting activity and potential physiological toxicity. It is still the primary issue of environmental analysis and ecological risk assessment to develop simple and reliable methods for simultaneous sensitive detection of these compounds in environmental water. RESULTS: In this paper, a flexible molecularly imprinted fiber array strategy is proposed for simultaneous enrichment and detection of trace MP and its four main metabolites. The experimental results showed that the three-fiber imprinted fiber array constructed by MP imprinted fiber had the best effect on the simultaneous enrichment of these five target analytes. The enrichment capacity of the imprinted fiber array was 214-456 times, 314-1201 times and 38-685 times that of commercial PA, PDMS and PDMS/DVB fiber arrays, respectively. The limit of detection (LOD) of this method was 0.033 µg L-1. The spiked recovery rate was 86.78-113.96 %, and RSD was less than 9.17 %. In addition, this molecularly imprinted SPME fiber array has good stability, long service life and can be used repeatedly at least 100 times. SIGNIFICANCE: This molecularly imprinted fiber array strategy can flexibly assemble different molecularly imprinted SPME fibers together, effectively improve the enrichment ability and detection sensitivity, and achieve simultaneous selective enrichment and detection of several analytes. This is an easy, efficient and reliable method for monitoring several trace analytes simultaneously in intricate environmental matrices.

Study on Shrinkage in Alkali-Activated Slag-Fly Ash Cementitious Materials.

Traditional silicate cement materials produce a large amount of CO2 during production, making it urgent to seek alternatives. Alkali-activated slag cement is a good substitute, as its production process has low carbon emissions and energy consumption, and it can comprehensively utilize various types of industrial waste residue while possessing superior physical and chemical properties. However, the shrinkage of alkali-activated concrete can be larger than that of traditional silicate concrete. To address this issue, the present study utilized slag powder as the raw material, sodium silicate (water glass) as the alkaline activator, and incorporated fly ash and fine sand to study the dry shrinkage and autogenous shrinkage values of alkali cementitious material under different content. Furthermore, combined with the change trend of pore structure, the impact of their content on the drying shrinkage and autogenous shrinkage of alkali-activated slag cement was discussed. Based on the author's previous research, it was found that by sacrificing a certain mechanical strength, adding fly ash and fine sand can effectively reduce the drying shrinkage and autogenous shrinkage values of alkali-activated slag cement. The higher the content, the greater the strength loss of the material and the lower the shrinkage value. When the fly ash content was 60%, the drying shrinkage and autogenous shrinkage of the alkali-activated slag cement mortar specimens decreased by about 30% and 24%, respectively. When the fine sand content was 40%, the drying shrinkage and autogenous shrinkage of the alkali-activated slag cement mortar specimens decreased by about 14% and 4%, respectively.

Effect of green finance reform and innovation pilot zone on improving environmental pollution: an empirical evidence from Chinese cities.

Under the strategic deployment of dual carbon goals, China has entered the stage of high-quality development of low-carbon economic transformation. Green finance is an important tool to provide financing support for the development of green low-carbon projects and prevent environmental and climate financial risks. Whether and how it can help the implementation of the dual carbon goals is worth pondering and studying. Based on this background, this study considers the green finance reform and innovation pilot policy zone jointly issued by the Central People's Bank of China, National Development, and Reform Commission in 2017 as a natural experiment. Based on the panel data of 288 cities nationwide from 2010 to 2019, the effect of emission reduction is estimated using the PSM-DID method. The following conclusions are drawn: (1) The green finance policy has effectively improved the city's environmental quality, and the pilot effect of green finance has a certain lag on SO2 emissions and industrial smoke (dust) emissions; (2) the mechanism inspection shows that the policy mechanism has promoted the technological innovation level, sewage treatment capacity, and garbage harmless treatment capacity of the pilot area to a certain extent; and (3) the impact of green finance policy on environmental quality has regional and industrial characteristics heterogeneity. The green finance pilot policy in eastern and central regions will inhibit SO2 emissions, but the emission reduction effect in western regions is not significant; The implementation of the pilot policy of the green financial reform and innovation pilot zone has significantly reduced the sulfur dioxide emissions of the old industrial base cities, but the effect of the policy on non-old industrial bases is not obvious. The research conclusion has important enlightenment significance for further improving the construction of financial system, promoting the green transformation of regional industry, and improving the quality of urban environment.

Fast Degradation of Rhodamine B by In Situ H2O2 Fenton System with Co and N Co-Doped Carbon Nanotubes.

In this study, an E-fenton oxidation system based on Co-N co-doped carbon nanotubes (Co-N-CNTs) was designed. The Co-N-CNTs system showed fast degradation efficiency and reusability for the degradation of rhodamine B (RhB). The XRD and SEM results showed that the Co-N co-doped carbon nanotubes with diameters ranging from 40 to 400 nm were successfully prepared. The E-Fenton degradation performance of Co-N-CNTs was investigated via CV, LSV and AC impedance spectroscopy. The yield of H2O2 could reach 80 mg/L/h within 60 min, and the optimal voltage and preparation temperature for H2O2 yield in this system was -0.7 V (vs. SCE) and 800 °C. For the target pollutant of RhB, the fast removal of RhB was obtained via the Co-N-CNTS/E-Fenton system (about 91% RhB degradation occurred during 60 min), and the •OH played a major role in the RhB degradation. When the Fe2+ concentrations increased from 0.3 to 0.4 mM, the RhB degradation efficiency decreased from 91% to about 87%. The valence state of Co in the Co-N-C catalyst drove a Co2+/Co3+ cycle, which ensured the catalyst had good E-Fenton degradation efficiency. This work provides new insight into the mechanism of an E-Fenton system with carbon-based catalysts for the efficient degradation of RhB.

Comparative transcriptome analysis identifies candidate genes related to seed coat color in rapeseed.

Yellow seed coat in rapeseed (Brassica napus) is a desirable trait that can be targeted to improve the quality of this oilseed crop. To better understand the inheritance mechanism of the yellow-seeded trait, we performed transcriptome profiling of developing seeds in yellow- and black-seeded rapeseed with different backgrounds. The differentially expressed genes (DEGs) during seed development showed significant characteristics, these genes were mainly enriched for the Gene Ontology (GO) terms carbohydrate metabolic process, lipid metabolic process, photosynthesis, and embryo development. Moreover, 1206 and 276 DEGs, which represent candidates to be involved in seed coat color, were identified between yellow- and black-seeded rapeseed during the middle and late stages of seed development, respectively. Based on gene annotation, GO enrichment analysis, and protein-protein interaction network analysis, the downregulated DEGs were primarily enriched for the phenylpropanoid and flavonoid biosynthesis pathways. Notably, 25 transcription factors (TFs) involved in regulating flavonoid biosynthesis pathway, including known (e.g., KNAT7, NAC2, TTG2 and STK) and predicted TFs (e.g., C2H2-like, bZIP44, SHP1, and GBF6), were identified using integrated gene regulatory network (iGRN) and weight gene co-expression networks analysis (WGCNA). These candidate TF genes had differential expression profiles between yellow- and black-seeded rapeseed, suggesting they might function in seed color formation by regulating genes in the flavonoid biosynthesis pathway. Thus, our results provide in-depth insights that facilitate the exploration of candidate gene function in seed development. In addition, our data lay the foundation for revealing the roles of genes involved in the yellow-seeded trait in rapeseed.

Colorful Image Colorization with Classification and Asymmetric Feature Fusion.

An automatic colorization algorithm can convert a grayscale image to a colorful image using regression loss functions or classification loss functions. However, the regression loss function leads to brown results, while the classification loss function leads to the problem of color overflow and the computation of the color categories and balance weights of the ground truth required for the weighted classification loss is too large. In this paper, we propose a new method to compute color categories and balance the weights of color images. In this paper, we propose a new method to compute color categories and balance weights of color images. Furthermore, we propose a U-Net-based colorization network. First, we propose a category conversion module and a category balance module to obtain the color categories and to balance weights, which dramatically reduces the training time. Second, we construct a classification subnetwork to constrain the colorization network with category loss, which improves the colorization accuracy and saturation. Finally, we introduce an asymmetric feature fusion (AFF) module to fuse the multiscale features, which effectively prevents color overflow and improves the colorization effect. The experiments show that our colorization network has peak signal-to-noise ratio (PSNR) and structure similarity index measure (SSIM) metrics of 25.8803 and 0.9368, respectively, for the ImageNet dataset. As compared with existing algorithms, our algorithm produces colorful images with vivid colors, no significant color overflow, and higher saturation.

Strength Characteristics and Microstructure Analysis of Alkali-Activated Slag-Fly Ash Cementitious Material.

Modifying the admixture of alkali-activated cementitious materials using components such as fly ash and fine sand may reduce CO2 emissions and conserve natural resources and energy. This study adopted strength testing, scanning electron microscopy, and mercury intrusion porosimetry to investigate the influence of different admixtures on the compressive strength and flexural strength of alkali slag cementing materials and the microstructure characteristics of hardened slurry under the action of load. The flexural strength of alkali slag cement slurry and mortar was reduced by replacing slag powder with fly ash. Content of fine sand less than 20% had little effect on the strength of alkali slag cement mortar; however, when the content of fine sand exceeded 30%, the strength decreased significantly. The hydration degree at 3 d was large, and the density of slurry increased with the extension of age. Increased fly ash or fine sand content decreased the density of the slurry, and increased fly ash resulted in a large number of unhydrated fly ash particles in the cementitious materials. Addition of fine sand resulted in a large number of microcracks in the slurry, which gradually decreased with the extension of hydration age.

Epithelioid Inflammatory Myofibroblastic Sarcoma with Leukemoid Reaction.

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare and aggressive inflammatory myofibroblastic tumour (IMT) variant. This report identifies the first case of EIMS with leukemoid reaction. This is also the first case in which pancreatic infiltration occurred from the disease onset. A 14-year male patient presented with an 18×18×10 cm mass at the retroperitoneal space and a white blood cell (WBC) count of 85×109/L. The mass and the invaded tissues were surgically removed with tumour-free margins. Histopathology and bone marrow aspiration confirmed the diagnosis of EIMS with leukemoid reaction. The tumour recurred with hepatic and pulmonary metastasis one month after the surgery. WBC count also increased progressively with the tumour recurrence. There is no consensus on the treatment of EIMS. Since ALK rearrangement presents in all the EIMS cases, surgical resection combined with crizotinib or other targeted drugs may improve the prognosis. Key Words: Sarcoma, Soft tissue neoplasms, Leukemoid reaction, Crizotinib.

Magnetoelectric Polymer Membrane-Based Electrical Microenvironment with Magnetically Controlled Antibacterial Activity.

The "hard to clean" parts of food processing devices (e.g., the corners of pipes) are difficult to disinfect. This challenge might be overcome through the application of a positive electrical environment. However, the chemical modification of a material surface is complex and difficult. In this work, we developed a smart electroactive TbxDy1-xFe alloy/poly(vinylidene fluoride-trifluoroethylene) (TD/P(VDF-TrFE)) magnetoelectric coating to endow stainless steel with the function of a smart adjustable electrical environment, which was realized by the introduction of a magnetic field of various intensities (0-1800 Oe). An antibacterial assay showed that the polarized coating@stainless steel (P-CS) exhibited antibacterial effects, with the highest antibacterial effect observed at 1800 Oe. Furthermore, in this study, we have, for the first time, explored the antibacterial mechanism of TD/P(VDF-TrFE)-assisted electrical stimulation based on the bacterial intracellular reactive oxygen species (ROS) level, cell respiratory chain, and membrane potential. The results showed that a microelectric field was formed on the P-CS sample in an aqueous solution, which not only generated ROS on the cathode surface but also caused H+ consumption in the electrochemical gradient of the bacterial membrane, leading to OH- production and inhibition of adenosine triphosphate (ATP) synthesis. In addition, the electric field also induced hyperpolarization of the membrane potential in Escherichia coli cells via a K+ efflux, thus inducing rearrangement of the outer membrane. In conclusion, an adjustable surface potential was established through the introduction of magnetoelectric polymer coatings, which endowed stainless steel with magnetically controlled antibacterial effects.

Genome-Wide Identification of the TIFY Gene Family in Brassiceae and Its Potential Association with Heavy Metal Stress in Rapeseed.

The TIFY gene family plays important roles in various plant biological processes and responses to stress and hormones. The chromosome-level genome of the Brassiceae species has been released, but knowledge concerning the TIFY family is lacking in the Brassiceae species. The current study performed a bioinformatics analysis on the TIFY family comparing three diploid (B. rapa, B. nigra, and B. oleracea) and two derived allotetraploid species (B. juncea, and B. napus). A total of 237 putative TIFY proteins were identified from five Brassiceae species, and classified into ten subfamilies (six JAZ types, one PPD type, two TIFY types, and one ZML type) based on their phylogenetic relationships with TIFY proteins in A. thaliana and Brassiceae species. Duplication and synteny analysis revealed that segmental and tandem duplications led to the expansion of the TIFY family genes during the process of polyploidization, and most of these TIFY family genes (TIFYs) were subjected to purifying selection after duplication based on Ka/Ks values. The spatial and temporal expression patterns indicated that different groups of BnaTIFYs have distinct spatiotemporal expression patterns under normal conditions and heavy metal stresses. Most of the JAZIII subfamily members were highest in all tissues, but JAZ subfamily members were strongly induced by heavy metal stresses. BnaTIFY34, BnaTIFY59, BnaTIFY21 and BnaTIFY68 were significantly upregulated mostly under As3+ and Cd2+ treatment, indicating that they could be actively induced by heavy metal stress. Our results may contribute to further exploration of TIFYs, and provided valuable information for further studies of TIFYs in plant tolerance to heavy metal stress.

Clarifying the relationship among green investment, clean energy consumption, carbon emissions, and economic growth: a provincial panel analysis of China.

As a financial activity with the main purpose of ecological protection and environmental governance, green investment has important practical significance for promoting sustainable economic development. Previous studies have not addressed the relationship between green investment, clean energy consumption, carbon emissions, and economic growth. We use panel data from 30 provinces and cities in China from 2003 to 2017 to build a simultaneous equation model, which can evaluate the nonlinear relationship and avoid the endogeneity of the model. The research results show that, firstly, green investment has a significant positive impact on clean energy consumption and economic growth. However, it has no significant effect on carbon dioxide emissions. Second, the curve of clean energy consumption and per capita GDP conforms to the positive U-shaped characteristic, while the curve of carbon emissions and per capita GDP conforms to the EKC curve, meeting the inverted U-shaped characteristic. And the inflection point of clean energy use occurred earlier than the inflection point of CO2 emissions. When per capita GDP is greater than 105,735.93 (RMB), the use of clean energy will increase, and carbon dioxide emissions will decrease, thereby achieving a win-win situation for the environment and the economy. Finally, according to the survey results, it is suggested that green investment is an effective means to encourage clean energy consumption and economic growth.

Burden of cancer and changing cancer spectrum among older adults in China: Trends and projections to 2030.

BACKGROUND: Cancer creates considerable challenges for China with its aging population. This analysis aimed to estimate the burden of cancer and transition in cancer spectrum among older adults in China by 2030. METHODS: Using data from the National Central Cancer Registry of China, we estimated annual percent change (APC) in cancer incidence and mortality rates among adults aged 60 years and above between 2006 and 2015 using joinpoint regression. We further estimated the number of new cancer cases and deaths from 2020 to 2030 based on the APC and population projections. RESULTS: Although cancer incidence and mortality rates have been decreasing among older adults in China between 2006 and 2015, there were marked increases in the incidence and mortality rates of cervical (incidence: APC = 9.2%, mortality: APC = 7.6% all p < 0.05) and thyroid cancers (incidence: APC = 9.3%, p < 0.05) in older women. Between 2015 and 2030, the number of new cancer cases is projected to increase by 46% from 2.2 million to 3.2 million; cancer deaths will increase by 31% from 1.6 million to 2.1 million among older Chinese adults. In 2015, the 3 most common cancers were lung, colorectal and breast cancer in women, and lung, colorectal and stomach cancer in men. By 2030, cervical cancer is projected to be the most common cancer in women, followed by lung and thyroid cancer; prostate cancer will surpass stomach cancer to become the third most common cancer in men. In both sexes, lung, liver and stomach cancer were the top 3 leading causes of cancer deaths in 2015. In women, cervical cancer will surpass lung cancer as the leading cause of cancer deaths by 2030. CONCLUSION: The growing burden of cervical, thyroid and prostate cancer among older Chinese adults represents a major shift in cancer spectrum in this population.

Weight loss in children undergoing allogeneic hematopoietic stem cell transplantation within the first 100 days: Its influencing factors and impact on clinical outcomes.

Purpose/Objective: This study aimed to evaluate the nutritional status of children subjected to allogeneic hematopoietic stem cell transplantation (alloHSCT) in the first 100 days. Objectives were to clarify the effect of weight loss on clinical outcomes, and to analyze factors influencing weight loss. Methods: Eighty pediatric patients receiving alloHSCT were enrolled in the study. Body mass index (BMI) z-scores and weight for age (WFA) z-scores were collected. A multivariate regression model was set up to investigate factors affecting weight loss. Post-transplant clinical outcomes relative to weight loss on 100 days after transplantation were analyzed. Results: At admission, eight patients (10%) were underweight, the number had increased to 23 (30.67%) by 100 days post-HSCT. On day + 100, only nutrition screening tool for childhood cancer (SCAN) scores ≥ 3 (OR: 4.474, 95% CI: 1.215, 16.472; P = 0.024) and acute graft versus host disease (aGVHD) (OR: 9.915, 95% CI: 3.302, 29.771; P < 0.001) were regarded as significant influencing factors of weight loss. The Weight loss ≥ 5% group was associated with longer hospital stays (P = 0.001), greater cost of inpatient treatment (P = 0.001), and a higher incidence of 100-day re-admission and intensive care unit (ICU) transfer (P = 0.03 and P = 0.033, respectively). Cumulative number of fever days (P = 0.023) and antibiotic use (P = 0.007) also increased significantly. The Weight loss ≥ 5% group had a significantly lower one-year overall survival rate compared with the Weight loss < 5% group (P = 0.015). Conclusion: Pediatric patients' nutritional status declined significantly after HSCT. Weight loss within the first 100 days influenced short-term clinical outcomes and one-year overall survival.

Healthcare-Seeking Behavior among Chinese Older Adults: Patterns and Predictive Factors.

This study aimed to investigate the patterns and predictive factors of healthcare-seeking behavior among older Chinese adults. A sample of 10,914 participants aged ≥60 years from the 2011, 2013 and 2015 China Health and Retirement Longitudinal Study (CHARLS) was included. The bivariate analyses and Heckman selection model was used to identify predictors of healthcare-seeking behavior. Results shows that the utilization rate of outpatient services increased from 21.61% in 2011 to 32.41% in 2015, and that of inpatient services increased from 12.44% to 17.68%. In 2015, 71.93% and 92.18% chose public medical institutions for outpatient and inpatient services, 57.63% and 17.00% chose primary medical institutions. The individuals who were female, were younger, lived in urban, central or western regions, had medical insurance, had poor self-rated health and exhibited activity of daily living (ADL) impairment were more inclined to outpatient and inpatient services. Transportation, medical expenses, the out-of-pocket ratio and the urgency of the disease were associated with provider selection. The universal medical insurance schemes improved health service utilization for the elderly population but had little impact on the choice of medical institutions. The older adults preferred public institutions to private institutions, preferred primary institutions for outpatient care, and higher-level hospitals for hospitalization.

Effects of an individualized analgesia protocol on the need for medical interventions after adenotonsillectomy in children: a randomized controlled trial.

BACKGROUND: It has been proposed that the dose of rescue opioids should be individually titrated to the severity of obstructive sleep apnea after adenotonsillectomy. However, a sleep study is not always available before adenotonsillectomy. This randomized, controlled and blinded trial evaluated a strategy of pain control individualized to the results of a fentanyl test, rather than the results of polysomnography, in children after adenotonsillectomy. METHODS: A total of 280 children (3-10 years old) undergoing elective adenotonsillectomy were randomized into an individualized protocol (IP) group or a conservative protocol (CP) group. All patients received a fentanyl test before extubation. Pain was assessed every 10 min in the recovery room, and rescue morphine was given when the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) score was > 6. In the IP group, the dose of rescue morphine was individualized to the results of the fentanyl test (10 µg/kg in the case of a positive result and 50 µg/kg in the case of a negative result). In the CP group, the dose was fixed (25 µg/kg). The primary outcome was the percentage of patients requiring at least one medical intervention. The secondary outcome was the median duration of CHEOPS scores > 6. RESULTS: Fewer patients in the IP group than in the CP group required medical interventions [11.9% (16/134) vs 22.3% (29/130), P = 0.025]. The median duration of CHEOPS scores > 6 was shorter in the IP group than in the CP group [20 (95% CI: 17 to 23) min vs 30 (95% CI: 28 to 32) min, P <  0.001]. CONCLUSIONS: Compared with a conservative dosing approach, this individualized protocol may improve analgesia without a significant increase in respiratory adverse events. TRIAL REGISTRATION: ClinicalTrials.gov NCT02990910 , registered on 13/12/2016.

Genome-Wide Identification and Analysis of MKK and MAPK Gene Families in Brassica Species and Response to Stress in Brassica napus.

Mitogen-activated protein kinase (MAPK) cascades are common and conserved signal transduction pathways and play important roles in various biotic and abiotic stress responses and growth and developmental processes in plants. With the advancement of sequencing technology, more systematic genetic information is being explored. The work presented here focuses on two protein families in Brassica species: MAPK kinases (MKKs) and their phosphorylation substrates MAPKs. Forty-seven MKKs and ninety-two MAPKs were identified and extensively analyzed from two tetraploid (B. juncea and B. napus) and three diploid (B. nigra, B. oleracea, and B. rapa) Brassica species. Phylogenetic relationships clearly distinguished both MKK and MAPK families into four groups, labeled A-D, which were also supported by gene structure and conserved protein motif analysis. Furthermore, their spatial and temporal expression patterns and response to stresses (cold, drought, heat, and shading) were analyzed, indicating that BnaMKK and BnaMAPK transcript levels were generally modulated by growth, development, and stress signals. In addition, several protein interaction pairs between BnaMKKs and C group BnaMAPKs were detected by yeast two-hybrid assays, in which BnaMKK3 and BnaMKK9 showed strong interactions with BnaMAPK1/2/7, suggesting that interaction between BnaMKKs and C group BnaMAPKs play key roles in the crosstalk between growth and development processes and abiotic stresses. Taken together, our data provide a deeper foundation for the evolutionary and functional characterization of MKK and MAPK gene families in Brassica species, paving the way for unraveling the biological roles of these important signaling molecules in plants.

A Genome-Wide Survey of MATE Transporters in Brassicaceae and Unveiling Their Expression Profiles under Abiotic Stress in Rapeseed.

The multidrug and toxic compound extrusion (MATE) protein family is important in the export of toxins and other substrates, but detailed information on this family in the Brassicaceae has not yet been reported compared to Arabidopsis thaliana. In this study, we identified 57, 124, 81, 85, 130, and 79 MATE genes in A. thaliana, Brassica napus, Brassica oleracea, Brassica rapa, Brassica juncea, and Brassica nigra, respectively, which were unevenly distributed on chromosomes owing to both tandem and segmental duplication events. Phylogenetic analysis showed that these genes could be classified into four subgroups, shared high similarity and conservation within each group, and have evolved mainly through purifying selection. Furthermore, numerous B. napusMATE genes showed differential expression between tissues and developmental stages and between plants treated with heavy metals or hormones and untreated control plants. This differential expression was especially pronounced for the Group 2 and 3 BnaMATE genes, indicating that they may play important roles in stress tolerance and hormone induction. Our results provide a valuable foundation for the functional dissection of the different BnaMATE homologs in B. napus and its parental lines, as well as for the breeding of more stress-tolerant B. napus genotypes.

Genome-Wide Analysis of Phosphorus Transporter Genes in Brassica and Their Roles in Heavy Metal Stress Tolerance.

Phosphorus transporter (PHT) genes encode H2PO4-/H+ co-transporters that absorb and transport inorganic nutrient elements required for plant development and growth and protect plants from heavy metal stress. However, little is known about the roles of PHTs in Brassica compared to Arabidopsis thaliana. In this study, we identified and extensively analyzed 336 PHTs from three diploid (B. rapa, B. oleracea, and B. nigra) and two allotetraploid (B. juncea and B. napus) Brassica species. We categorized the PHTs into five phylogenetic clusters (PHT1-PHT5), including 201 PHT1 homologs, 15 PHT2 homologs, 40 PHT3 homologs, 54 PHT4 homologs, and 26 PHT5 homologs, which are unevenly distributed on the corresponding chromosomes of the five Brassica species. All PHT family genes from Brassica are more closely related to Arabidopsis PHTs in the same vs. other clusters, suggesting they are highly conserved and have similar functions. Duplication and synteny analysis revealed that segmental and tandem duplications led to the expansion of the PHT gene family during the process of polyploidization and that members of this family have undergone purifying selection during evolution based on Ka/Ks values. Finally, we explored the expression profiles of BnaPHT family genes in specific tissues, at various developmental stages, and under heavy metal stress via RNA-seq analysis and qRT-PCR. BnaPHTs that were induced by heavy metal treatment might mediate the response of rapeseed to this important stress. This study represents the first genome-wide analysis of PHT family genes in Brassica species. Our findings improve our understanding of PHT family genes and provide a basis for further studies of BnaPHTs in plant tolerance to heavy metal stress.