QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions

The allocation of carbon and nitrogen resources to the synthesis of plant proteins, carbohydrates, and lipids is complex and under the control of many genes; much remains to be understood about this process. QQS (Qua-Quine Starch; At3g30720), an orphan gene unique to Arabidopsis thaliana, regulates metabolic processes affecting carbon and nitrogen partitioning among proteins and carbohydrates, modulating leaf and seed composition in Arabidopsis and soybean. Here the universality of QQS function in modulating carbon and nitrogen allocation is exemplified by a series of transgenic experiments. We show that ectopic expression of QQS increases soybean protein independent of the genetic background and original protein content of the cultivar. Furthermore, transgenic QQS expression increases the protein content of maize, a C4 species (a species that uses 4-carbon photosynthesis), and rice, a protein-poor agronomic crop, both highly divergent from Arabidopsis. We determine that QQS protein binds to the transcriptional regulator AtNF-YC4 (Arabidopsis nuclear factor Y, subunit C4). Overexpression of AtNF-YC4 in Arabidopsis mimics the QQS-overexpression phenotype, increasing protein and decreasing starch levels. NF-YC, a component of the NF-Y complex, is conserved across eukaryotes. The NF-YC4 homologs of soybean, rice, and maize also bind to QQS, which provides an explanation of how QQS can act in species where it does not occur endogenously. These findings are, to our knowledge, the first insight into the mechanism of action of QQS in modulating carbon and nitrogen allocation across species. They have major implications for the emergence and function of orphan genes, and identify a nontransgenic strategy for modulating protein levels in crop species, a trait of great agronomic significance

Synthesis of CoFe2O4/Peanut Shell Powder Composites and the Associated Magnetic Solid Phase Extraction of Phenoxy Carboxylic Acid Herbicides in Water

The magnetic biochar material CoFe2O4/PCPS (peanut shell powder) was prepared based on the hybrid calcination method. The properties of prepared composites and the extraction effect of magnetic solid phase extraction on phenoxy carboxylic acid herbicides were assessed. The morphology, crystal structure, specific surface area, and pore size distribution of the material were analysed using a transmission electron microscope (TEM), infrared Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and N2 absorption surface analysis (BET). The results of the magnetic solid phase extraction of a variety of phenoxy carboxylic acid herbicides in water using CoFe2O4/PCPS composites showed that, when the mass ratio of CoFe2O4 and PCPS was 1:1, 40 mg of the composite was used, and the adsorption time was 10 min at pH 8.50. Methanol was used as the eluent, and the recovery rates of the three phenoxy carboxylic acid herbicides were maintained at 81.95–99.07%. Furthermore, the actual water sample analysis results showed that the established method had good accuracy, stability, and reliability

Selenium status of children in Kashin-Beck disease endemic areas in Shaanxi, China: assessment with mercury

The causes of Kashin-Beck disease (KBD) in children are multifactorial, and particular consideration has been given to childhood selenium (Se) deficiency. In this study, dietary intake of Se and mercury (Hg) was determined at KBD areas to investigate the Se status and risks. Therefore, total Hg and Se levels were investigated in scalp hair samples and in daily intake food samples of 150 schoolchildren in Yongshou County of Shaanxi, China. The results showed that the average concentration of Se in children's hair has risen to 302 ng g(-1) and significantly increased compared to the data reported decades ago. Children at KBD endemic areas likely have improved Se status due to the Se supplementation in food at recent decades. However, all the children in the study areas still showed lower Se status compared to those in other non-KBD areas of China. The probable daily intake of Se in the study areas was still lower after stopping Se supplementation in food at KBD areas, which is 17.96 mu g day(-1). Food produced locally cannot satisfy the lowest demand for Se nutrition for local residents. If the interactions of Se-Hg detoxification are considered, Hg intake from food exacerbates Se deficiency at the KBD areas

Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China

To evaluate the mercury (Hg) exposure level of children located in a Hg mining area, total Hg concentrations and speciation were determined in hair and urine samples of children in the Wanshan Hg mining area, Guizhou Province, China. Rice samples consumed by these same children were also collected for total mercury (THg) and methyl-mercury (MeHg) analysis. The geometric mean concentrations of THg and MeHg in the hair samples were 1.4 (range 0.50–6.0) μg/g and 1.1 (range 0.35–4.2) μg/g, respectively, while the geometric mean concentration of urine Hg (UHg) was 1.4 (range 0.09–26) μg/g Creatinine (Cr). The average of the probable daily intake (PDI) of MeHg via rice consumption was 0.052 (0.0033–0.39) µg/kg/day, which significantly correlated with the hair MeHg concentrations (r = 0.55, p < 0.01), indicating that ingestion of rice is the main pathway of MeHg exposure for children in this area. Furthermore, 18% (26/141) of the PDIs of MeHg exceeded the USEPA Reference Dose (RfD) of 0.10 µg/kg/day, indicating that children in this area are at a high MeHg exposure level. This paper for the first time evaluates the co-exposure levels of IHg and MeHg of children living in Wanshan mining area, and revealed the difference in exposure patterns between children and adults in this area

Mercury bioaccumulation and its toxic effects in rats fed with methylmercury polluted rice

Recent evidence indicated that methylmercury (MeHg) contaminated rice can be a significant source of MeHg human exposure, but the health implications are not known. The objective of this study was to study the kinetics, speciation, and effects of MeHg contaminated rice using a rat model. Five groups of adult Sprague-Dawley rats (n = 10 in each group) were fed control rice, low (10 ng/g MeHg) and high (25 ng/gMeHg) MeHg contaminated rice. Two groups of the positive control were fed control rice spiked with the same levels of MeHgCl. Shortterm exposure to low level of spiked MeHgCl stimulated the growth of male rats while long-term exposure to spiked MeHgCl inhibited the growth in female rats. There was no temporal variation of total mercury (THg) concentrations in the rat fecal samples from each group, and the THg concentrations significantly correlated with the inorganic Hg concentrations in the feeding rice. There were significant differences in the accumulation of THg and MeHg among different groups and different organs. THg and MeHg concentrations in the kidney were the highest among the organs examined. The blood and brain had high percentages of THg as MeHg, which indicates that MeHg can easily pass through the blood-brain barrier and has a high affinity for brain tissue. Exposure to rice containing 25 ng/g MeHg decreased antioxidant function and damaged the nervous system in rats, but no significant effects were found in the group fed with rice containing 10 ng/g MeHg. MeHgCys in rice is less toxic than spiked MeHgCl to rats. The toxicity of MeHg both decided by its concentration and speciation. (c) 2018 Elsevier B.V. All rights reserved

Inverse Association between Organic Food Purchase and Diabetes Mellitus in US Adults

Background: The organic food market has grown rapidly worldwide in the past 15 years. However, evidence concerning the health effects of organic foods is scarce. We evaluated the cross-sectional association of organic food purchase, as a proxy of organic food consumption, with diabetes in a nationally representative population. Methods: We included 8199 participants aged ≥20 years from the National Health and Nutrition Examination Survey 2007⁻2008 and 2009⁻2010. Organic food purchase and frequency were ascertained by questionnaires. Diabetes was defined as a self-reported physician diagnosis or a hemoglobin A1c level ≥6.5% or both. We used logistic regression with sample weights to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). Results: Individuals who reported purchasing organic foods were less likely to have diabetes compared to those who did not report organic food purchase. After adjustment for age, gender, race/ethnicity, family history of diabetes, socioeconomic status, and dietary and lifestyle factors, the OR of diabetes associated with organic food purchase was 0.80 (95% CI 0.68⁻0.93). The association remained significant after additional adjustment for BMI with OR of 0.80 (0.69⁻0.94). Conclusions: In a nationally representative population, frequent organic food purchase was inversely associated with diabetes prevalence in adults in the United States

Use of Mercury Isotopes to Quantify Mercury Exposure Sources in Inland Populations, China

International audienc

Human Body Burden and Dietary Methylmercury Intake: The Relationship in a Rice-Consuming Population

Rice can be the main route of methylmercury (MeHg) exposure for rice-consuming populations living in area where mercury (Hg) is mined. However, the current risk assessment paradigm for MeHg exposure is based on epidemiological data collected from fish-consuming populations. This study was designed to evaluate the relationship between dietary MeHg intake and human body burden in a rice -consuming population from the Wanshan Hg mining area in China. Hair MeHg concentrations averaged 2.07 ± 1.79 μg/g, and the average blood MeHg concentration across the study area ranged from 2.20 to 9.36 μg/L. MeHg constituted 52.8 ± 17.5% and 71.7 ± 18.2% of total Hg (THg) on average in blood and hair samples, respectively. Blood and hair MeHg concentrations, rather than THg, can be used as a proxy of human MeHg exposure. Hair MeHg levels showed no significant monthly variation; however, hair THg can be impacted by inorganic Hg exposure. The toxicokinetic model of MeHg exposure based on fish consumption underestimated the human hair MeHg levels, and this may be a consequence of the high hair-to-blood MeHg ratio (361 ± 105) in the studied rice-consuming population. The use of risk assessment models based on fish consumption may not be appropriate for inland mining areas where rice is the staple food

Association of Low‐Density Lipoprotein Cholesterol Levels with More than 20‐Year Risk of Cardiovascular and All‐Cause Mortality in the General Population

Background Current cholesterol guidelines have recommended very low low‐density lipoprotein cholesterol (LDL‐C) treatment targets for people at high risk of cardiovascular disease (CVD). However, recent observational studies indicated that very low LDL‐C levels may be associated with increased mortality and other adverse outcomes. The association between LDL‐C levels and long‐term risk of overall and cardiovascular mortality among the U.S. general population remains to be determined. Methods and Results This prospective cohort study included a nationally representative sample of 14 035 adults aged 18 years or older, who participated in the National Health and Nutrition Examination Survey III 1988–1994. LDL‐C levels were divided into 6 categories: <70, 70–99.9, 100–129.9, 130–159.9, 160–189.9 and ≥190 mg/dL. Deaths and underlying causes of deaths were ascertained by linkage to death records through December 31, 2015. Weighted Cox proportional hazards regression models were used to estimate the hazard ratios (HR) of mortality outcomes and its 95% CIs. During 304 025 person‐years of follow up (median follow‐up 23.2 years), 4458 deaths occurred including 1243 deaths from CVD. At baseline, mean age was 41.5 years and 51.9% were women. Very low and very high levels of LDL‐C were associated with increased mortality. After adjustment for age, sex, race and ethnicity, education, socioeconomic status, lifestyle factors, C‐reactive protein, body mass index, and other cardiovascular risk factors, individuals with LDL‐C<70 mg/dL, compared to those with LDL‐C 100–129.9 mg/dL, had HRs of 1.45 (95% CI, 1.10–1.93) for all‐cause mortality, 1.60 (95% CI, 1.01–2.54) for CVD mortality, and 4.04 (95% CI, 1.83–8.89) for stroke‐specific mortality, but no increased risk of coronary heart disease mortality. Compared with those with LDL‐C 100–129.9 mg/dL, individuals with LDL‐C≥190 mg/dL had HRs of 1.49 (95% CI, 1.09–2.02) for CVD mortality, and 1.63 (95% CI, 1.12–2.39) for coronary heart disease mortality, but no increased risk of stroke mortality. Conclusions Both very low and very high LDL‐C levels were associated with increased risks of CVD mortality. Very low LDL‐C levels was also associated with the high risks of all‐cause and stroke mortality. Further investigation is needed to elucidate the optimal range of LDL‐C levels for CVD health in the general population