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.

BcaSOD1 enhances cadmium tolerance in transgenic Arabidopsis by regulating the expression of genes related to heavy metal detoxification and arginine synthesis.

Cadmium (Cd), which is a nonessential heavy metal element for organisms, can have a severe impact on the growth and development of organisms that absorb excessive Cd. Studies have shown that Brassica carinata, a semiwild oil crop, has strong tolerance to various abiotic stresses, and RNA-seq has revealed that the B. carinata superoxide dismutase gene (BcaSOD1) likely responds to Cd stress. To elucidate the BcaSOD1 function involved in tolerance of Cd stress, we cloned the coding sequences of BcaSOD1 from a purple B. carinata accession and successfully transferred it into Arabidopsis thaliana. The subcellular localization results demonstrated that BcaSOD1 was primarily located in the plasma membrane, mitochondria and nucleus. Overexpression of BcaSOD1 in transgenic Arabidopsis (OE) effectively decreased the toxicity caused by Cd stress. Compared to the WT (wild type lines), the OE lines exhibited significantly increased activities of antioxidant enzymes (APX, CAT, POD, and SOD) after exposure to 2.5 mM CdCl2. The Cd content of underground (root) in the OE line was dominantly higher than that in the WT; however, the Cd content of aboveground (shoot) was comparable between the OE and WT types. Moreover, the qRT‒PCR results showed that several heavy metal detoxification-related genes (AtIREG2, AtMTP3, AtHMA3, and AtNAS4) were significantly upregulated in the roots of OE lines under Cd treatment, suggesting that these genes are likely involved in Cd absorption in the roots of OE lines. In addition, both comparable transcriptome and qRT-PCR analyses revealed that exogenous BcaSOD1 noticeably facilitates detoxification by stimulating the expression of two arginine (Arg) biosynthesis genes (AtGDH1 and AtGDH2) while inhibiting the expression of AtARGAH1, a negative regulator in biosynthesis of Arg. The Arg content was subsequently confirmed to be significantly enhanced in OE lines under Cd treatment, indicating that BcaSOD1 likely strengthened Cd tolerance by regulating the expression of Arg-related genes. This study demonstrates that BcaSOD1 can enhance Cd tolerance and reveals the molecular mechanism of this gene, providing valuable insights into the molecular mechanism of Cd tolerance in plants.

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.

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.

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.

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.

Comprehensive ability evaluation and trend analysis of patients with malignant intracranial tumors in the perisurgery period.

INTRODUCTION: Prognostic situations differ in patients with malignant intracranial tumors. We focused on the quality of life, ability of daily living, and cognitive function of patients in the perisurgery period and investigated the correlation between them and the prognosis of patients. MATERIALS AND METHODS: Patients with malignant intracranial tumors admitted to Peking Union Medical College Hospital from May 2018 to August 2020 for surgery were included. The evaluations were performed 6 times in the perisurgery period. The questionnaires for assessment included QLQ-C30, ADL, and so forth. RESULTS: A total of 165 patients were included (115 glioma and 50 brain metastases). Patients had their worst performance at the 7-day postsurgical assessment (EORTC QLQ-C30, ADL, HAD-D, Frail Scale, MMSE, MoCA, CSHA-FI, and NANO) and recovered at the 1-month postsurgical assessment (p < .05). Patients with left-sided tumors had significantly worse cognitive function than patients with right-sided tumors before surgery and at 7 days, 1 month, and 6 months after surgery (p < .05). The scores of QLQ-C30 and QLQ-BN20 at 1 month, 3 months, 6 months, and 1 year after surgery were used to reflect the prognosis, and the preoperative MoCA, NANO, CCI, CSHA-FI, and HAD score might predict the quality of life and nutrition status after operation. CONCLUSION: The quality of life and daily living ability of patients with malignant intracranial tumors decreased significantly 7 days after the surgery but recovered 1 month after the surgery. Patients with left hemisphere lesions had a worse cognitive function, while the ADL is associated with short-term prognosis. The comprehensive evaluation of the perisurgical period can indicate the prognosis of patients and further guide clinical decision-making.

Efficacy and safety of therapies for EGFR-mutant non-small cell lung cancer with brain metastasis: an evidence-based Bayesian network pooled study of multivariable survival analyses.

Preferable treatments for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) with brain metastasis are elusive. The study intended to estimate the relative efficacy and safety of systemic therapies. Clinical trials about therapies for EGFR-mutant, brain-metastatic NSCLC were identified. Progression-free survival (PFS) and overall survival (OS) were analysed using random effects Bayesian network meta-analyses (NMAs) on the hazard ratio (HR)-scale. Nomogram and Kaplan-Meier plots based on clinical or individual factors are displayed using data obtained from the Surveillance Epidemiology and End Results (SEER) database. Third-generation EGFR- tyrosine kinase inhibitors (EGFR-TKI) (osimertinib), EGFR-TKIs + stereotactic radiosurgery (SRS)/whole brain radiotherapy (WBRT) (gefitinib/erlotinib + SRS/WBRT), and EGFR-TKIs (erlotinib) + anti-vascular endothelial growth factor receptor (anti-VEGFR) (bevacizumab) achieved superior PFS (HR: 0.30 (0.15-0.59); HR: 0.47 (0.31-0.72); HR: 0.50 (0.21-1.21) vs. deferring SRS/WBRT) and acceptability; EGFR-TKIs + SRS/WBRT was top ranking (vs. others) for OS followed by third-generation EGFR-TKI. In the dataset cohort of 1173 brain-metastatic NSCLC patients, the 6-month, 1-year, and 3-year survival rates were 59.8%, 41.3%, and 5.6%, respectively. Race and origin, and year of diagnosis were independent predictors of OS. Survival curves showed that the OS of patients varied significantly by histology and race. Third-generation EGFR-TKI and EGFR-TKIs + SRS/WBRT are more effective and potentially acceptable for EGFR-mutant NSCLC with brain metastases balancing OS and PFS. Surgeries without adjuvant therapies cannot significantly improve the OS of brain-metastatic NSCLC patients. The study highlights importance of osimertinib in these patients and provide a reference for clinical treatments.

Pretreatment Geriatric Assessments of Elderly Patients with Glioma: Development and Implications.

Glioma is the most frequent primary brain tumor affecting adults, and the most lethal type is glioblastoma (GBM); currently, the available therapies only provide palliation. The treatments for low-grade glioma (LGG) include neurosurgical resection, watchful waiting, radiotherapy and chemotherapy, while the therapeutic strategies for high-grade glioma (HGG), particularly in elderly patients, have evolved to include radiotherapy, chemotherapy, and targeted monotherapy based on the characteristics of the investigated patients. Proper assessments aiming to predict and achieve the most satisfying prognosis among patients prior to surgery, radiotherapy, chemotherapy, targeted therapy or immunotherapy help summarize the pretreatment characteristics of patients, providing doctors comprehensive information to consider while determining whether the patients could benefit from ongoing treatments and deciding the proper treatment strategy for subsequent phases. This article aims to rigorously review the most recent evidence and discuss current mainstream assessments before the initiation of proper treatments for glioma, thus highlighting the potential necessity of pretreatment assessments.