Data_Sheet_1_A soybean sodium/hydrogen exchanger GmNHX6 confers plant alkaline salt tolerance by regulating Na+/K+ homeostasis.PDF

Alkaline soil has a high pH due to carbonate salts and usually causes more detrimental effects on crop growth than saline soil. Sodium hydrogen exchangers (NHXs) are pivotal regulators of cellular Na+/K+ and pH homeostasis, which is essential for salt tolerance; however, their role in alkaline salt tolerance is largely unknown. Therefore, in this study, we investigated the function of a soybean NHX gene, GmNHX6, in plant response to alkaline salt stress. GmNHX6 encodes a Golgi-localized sodium/hydrogen exchanger, and its transcript abundance is more upregulated in alkaline salt tolerant soybean variety in response to NaHCO3 stress. Ectopic expression of GmNHX6 in Arabidopsis enhanced alkaline salt tolerance by maintaining high K+ content and low Na+/K+ ratio. Overexpression of GmNHX6 also improved soybean tolerance to alkaline salt stress. A single nucleotide polymorphism in the promoter region of NHX6 is associated with the alkaline salt tolerance in soybean germplasm. A superior promoter of GmNHX6 was isolated from an alkaline salt tolerant soybean variety, which showed stronger activity than the promoter from an alkaline salt sensitive soybean variety in response to alkali stress, by luciferase transient expression assays. Our results suggested soybean NHX6 gene plays an important role in plant tolerance to alkaline salt stress.</p

Arsenic level in toenails is associated with hearing loss in humans

<div><p>Arsenic (As) pollution in drinking water is a worldwide health risk for humans. We previously showed hearing loss in young people who live in areas of As-polluted drinking water and in young mice orally treated with As. In this study, we epidemiologically examined associations between As levels in toenails and hearing in 145 Bangladeshi aged 12–55 years in 2014. Levels of As in toenails, but not those in urine, were shown to be significantly correlated with hearing loss at 4 kHz [odds ratio (OR) = 4.27; 95% confidence interval (CI): 1.51, 12.05], 8 kHz (OR = 3.91; 95% CI: 1.47, 10.38) and 12 kHz (OR = 4.15; 95% CI: 1.55, 11.09) by multivariate analysis with adjustments for age, sex, smoking and BMI. Our experimental study further showed a significant association between As levels in inner ears and nails (r = 0.8113, p = 0.0014) in mice orally exposed to As, suggesting that As level in nails is a suitable index to assess As level in inner ears. Taken together, the results of our study suggest that As level in nails could be a convenient and non-invasive biomarker for As-mediated hearing loss in humans.</p></div

Cardiopulmonary effects induced by occupational exposure to titanium dioxide nanoparticles

<p>Although some toxicological studies have reported that exposure to titanium dioxide nanoparticles (nano-TiO₂) may elicit adverse cardiopulmonary effects, related data collected from human are currently limited. The purpose of this study is to explore cardiopulmonary effects among workers who were exposed to nano-TiO₂ and to identify biomarkers associated with exposure. A cross-sectional study was conducted in a nano-TiO₂ manufacturing plant in eastern China. Exposure assessment and characterization of TiO₂ particles were performed in a packaging workshop. Physical examination and possible biomarkers for cardiopulmonary effects were examined among 83 exposed workers and 85 controls. In packaging workshop, the total mass concentration of particles was 3.17 mg/m³. The mass concentration of nanoparticles was 1.22 mg/m³ accounting for 39% of the total mass. Lung damage markers (SP-D and pulmonary function), cardiovascular disease markers (VCAM-1, ICAM-1, LDL, and TC), oxidative stress markers (SOD and MDA), and inflammation markers (IL-8, IL-6, IL-1β, TNF-α, and IL-10) were associated with occupational exposure to nano-TiO₂. Among those markers, SP-D showed a time (dose)–response pattern within exposed workers. The data strongly suggest that nano-TiO₂ could contribute, at least in part, to the cardiopulmonary effects observed in workers. The studied markers and pulmonary function tests may be useful in health surveillance for workers exposed to nanomaterials.</p

Associations between hearing levels and confounding factors including age, BMI, sex and smoking.

<p>Associations between hearing levels and confounding factors including age, BMI, sex and smoking.</p

Characteristics of the study participants.

<p>Characteristics of the study participants.</p

Association between hearing thresholds and As levels in biological samples in humans.

<p>(A) Hearing levels (mean ± SD) at 1, 4, 8 and 12 kHz in the high As group (≥ 0.60 μg/g; n = 97) and low As group (< 0.60 μg/g; n = 48) in toenails are presented. (B) Hearing levels (mean ± SD) at 1, 4, 8 and 12 kHz in the high As group (≥ 76.12 μg/L; n = 73) and low As group (< 76.12 μg/L; n = 72) in urine samples are presented. Significant differences (*p<0.05; **p < 0.01; ***p<0.001) were determined by the Mann-Whitney <i>U</i> test.</p

Adjusted ORs (95% CI) for hearing loss and As levels in biological samples (n = 145)^a.

<p>Adjusted ORs (95% CI) for hearing loss and As levels in biological samples (n = 145)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198743#t004fn002" target="_blank">^a</a>.</p

As levels in biological samples from humans.

<p>As levels in biological samples from humans.</p

Correlation between As levels in inner ear and nails in mice.

<p>Correlation between As levels in inner ears and nails was determined by Spearman correlation coefficients.</p