Comparative physiological and transcriptomic analyses reveal ascorbate and glutathione coregulation of cadmium toxicity resistance in wheat genotypes.

BACKGROUND: Cadmium (Cd) is a heavy metal with high toxicity that severely inhibits wheat growth and development. Cd easily accumulates in wheat kernels and enters the human food chain. Genetic variation in the resistance to Cd toxicity found in wheat genotypes emphasizes the complex response architecture. Understanding the Cd resistance mechanisms is crucial for combating Cd phytotoxicity and meeting the increasing daily food demand. RESULTS: Using two wheat genotypes (Cd resistant and sensitive genotypes T207 and S276, respectively) with differing root growth responses to Cd, we conducted comparative physiological and transcriptomic analyses and exogenous application tests to evaluate Cd detoxification mechanisms. S276 accumulated more H2O2, O2-, and MDA than T207 under Cd toxicity. Catalase activity and levels of ascorbic acid (AsA) and glutathione (GSH) were greater, whereas superoxide dismutase (SOD) and peroxidase (POD) activities were lower in T207 than in S276. Transcriptomic analysis showed that the expression of RBOHA, RBOHC, and RBOHE was significantly increased under Cd toxicity, and two-thirds (22 genes) of the differentially expressed RBOH genes had higher expression levels in S276 than inT207. Cd toxicity reshaped the transcriptional profiling of the genes involving the AsA-GSH cycle, and a larger proportion (74.25%) of the corresponding differentially expressed genes showed higher expression in T207 than S276. The combined exogenous application of AsA and GSH alleviated Cd toxicity by scavenging excess ROS and coordinately promoting root length and branching, especially in S276. CONCLUSIONS: The results indicated that the ROS homeostasis plays a key role in differential Cd resistance in wheat genotypes, and the AsA-GSH cycle fundamentally and vigorously influences wheat defense against Cd toxicity, providing insight into the physiological and transcriptional mechanisms underlying Cd detoxification.

Characterization and Genomic Analysis of Marinobacter Phage vB_MalS-PS3, Representing a New Lambda-Like Temperate Siphoviral Genus Infecting Algae-Associated Bacteria.

Marinobacter is the abundant and important algal-associated and hydrocarbon biodegradation bacteria in the ocean. However, little knowledge about their phages has been reported. Here, a novel siphovirus, vB_MalS-PS3, infecting Marinobacter algicola DG893(T), was isolated from the surface waters of the western Pacific Ocean. Transmission electron microscopy (TEM) indicated that vB_MalS-PS3 has the morphology of siphoviruses. VB_MalS-PS3 was stable from -20 to 55°C, and with the latent and rise periods of about 80 and 10 min, respectively. The genome sequence of VB_MalS-PS3 contains a linear, double-strand 42,168-bp DNA molecule with a G + C content of 56.23% and 54 putative open reading frames (ORFs). Nineteen conserved domains were predicted by BLASTp in NCBI. We found that vB_MalS-PS3 represent an understudied viral group with only one known isolate. The phylogenetic tree based on the amino acid sequences of whole genomes revealed that vB_MalS-PS3 has a distant evolutionary relationship with other siphoviruses, and can be grouped into a novel viral genus cluster with six uncultured assembled viral genomes from metagenomics, named here as Marinovirus. This study of the Marinobacter phage vB_MalS-PS3 genome enriched the genetic database of marine bacteriophages, in addition, will provide useful information for further research on the interaction between Marinobacter phages and their hosts, and their relationship with algal blooms and hydrocarbon biodegradation in the ocean.

Risk factors for delirium: are therapeutic interventions part of it?

Background: Delirium is associated with increased morbidity and mortality in critically ill patients. Research on risk factors for delirium allows clinicians to identify high-risk patients, which is the basis for early prevention and diagnosis. Besides the risk factors for delirium that are commonly studied, here we more focused on the less-studied therapeutic interventions for critically ill patients which are potentially modifiable. Materials and methods: A total of 320 non-comatose patients admitted to the ICU for more than 24 hrs during 9 months were eligible for the study. Delirium was screened once daily using the CAM-ICU. Demographics, admission clinical data, and daily interventions were collected. Results: Ninety-two patients (28.75%) experienced delirium at least once. Delirious patients were more likely to have longer duration of mechanical ventilation, ICU stay, and hospital stay. Most of the less-studied therapeutic interventions were linked to delirium in the univariate analysis, including gastric tube, artificial airway, deep intravenous catheter, arterial line, urinary catheter, use of vasoactive drugs, and sedative medication. After adjusting with age and ICU length of stay, mechanical ventilation (OR: 5.123; 95% CI: 2.501-10.494), Acute Physiology and Chronic Health Evaluation (APACHE) II score≥20 at admission (OR: 1.897; 95% CI: 1.045-3.441), and gastric tube (OR: 1.935, 95% CI: 1.012-3.698) were associated with increased risk of delirium in multivariate analysis. Conclusion: Delirium was associated with prolonged mechanical ventilation, ICU stay, and hospital stay. Multivariate risk factors were gastric tube, mechanical ventilation, and APACHE II score. Although being a preliminary study, this study suggests the necessity of earliest removal of tubes and catheters when no longer needed.

Perceptions, attitudes, and current practices regards delirium in China: A survey of 917 critical care nurses and physicians in China.

The purpose of this study is to assess the knowledge, attitudes, and managements regarding delirium of intensive care nurses and physicans, and to assess the perceived barriers related to intensive care unit (ICU) delirium monitoring in China. A descriptive survey was distributed to 1156 critical care nurses and physicians from 74 tertiary and secondary hospitals across Shandong province, China. The overall response rate was 86.18% (n = 917). The majority of respondents (88%) believed that deirium was associated with prolonged mechanical ventilation, and 79.72% thought delirium was associated with prolonged length of hospitalization. Only 14.17% of respondents believed that delirium was common in the ICU setting. Only 25.62% of the respondents reported routine screening of ICU delirium, and only 15.81% utilized Confusion Assessment Method for Intensive Care Unit screening tools. "Lack of appropriate screening tools" and "time restraints" were the most common perceived barriers. 45.4% of the participants had never received any education on ICU delirium. In conclusion, most nurses and physicians consider ICU delirium to be a serious problem, but lack knowledge on delirium and monitor this condition poorly. The survey infers a disconnection between the perceived significance and current monitoring of ICU delirium. There is a critical unmet need for in-service education on ICU delirium for physicians and nurses in China.