Tolerance and stress response of sclerotiogenic <Emphasis Type="Italic">Aspergillus oryzae</Emphasis> G15 to copper and lead

Aspergillus oryzae G15 was cultured on Czapek yeast extract agar medium containing different concentrations of copper and lead to investigate the mechanisms sustaining metal tolerance. The effects of heavy metals on biomass, metal accumulation, metallothionein (MT), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were evaluated. Cu and Pb treatment remarkably delayed sclerotial maturation and inhibited mycelial growth, indicating the toxic effects of the metals. Cu decreased sclerotial biomass, whereas Pb led to an increase in sclerotial biomass. G15 bioadsorbed most Cu and Pb ions on the cell surface, revealing the involvement of the extracellular mechanism. Cu treatment significantly elevated MT level in mycelia, and Pb treatment at concentrations of 50–100 mg/L also caused an increase in MT content in mycelia. Both metals significantly increased MDA level in sclerotia. The variations in MT and MDA levels revealed the appearance of heavy metal-induced oxidative stress. The activities of SOD, CAT, and POD varied with heavy metal concentrations, which demonstrated that tolerance of G15 to Cu and Pb was associated with an efficient antioxidant defense system. In sum, the santioxidative detoxification system allowed the strain to survive in high concentrations of Cu and Pb. G15 depended mostly on sclerotial differentiation to defend against Pb stress.     

Centromere structure and function analysis in wheat–rye translocation lines

1RS.1BL translocations are centric translocations formed by misdivision and have been used extensively in wheat breeding. However, the role that the centromere plays in the formation of 1RS.1BL translocations is still unclear. Fluorescence in situ hybridization (FISH) was applied to detect the fine structures of the centromeres in 130 1RS.1BL translocation cultivars. Immuno‐FISH, chromatin immunoprecipitation (ChIP)‐qPCR and RT‐PCR were used to investigate the functions of the hybrid centromeres in 1RS.1BL translocations. New 1R translocations with different centromere structures were created by misdivision and pollen irradiation to elucidate the role that the centromere plays in the formation of 1RS.1BL translocations. We found that all of the 1RS.1BL translocations detected contained hybrid centromeres and that wheat‐derived CENH3 bound to both the wheat and rye centromeres in the 1RS.1BL translocation chromosomes. Moreover, a rye centromere‐specific retrotransposon was actively transcribed in 1RS.1BL translocations. The frequencies of new 1RS hybrid centromere translocations and group‐1 chromosome translocations were higher during 1R misdivision. Our study demonstrates the hybrid nature of the centromere in 1RS.1BL translocations. New 1R translocations with different centromere structures were created to help understand the fusion centromere used for wheat breeding and for use as breeding material for the improvement of wheat.     

Clinical and Pathologic Features of a Suspected Selenium Deficiency in Captive Plains Zebras

Previous studies have shown that selenium (Se) deficiency is associated with nutritional myopathy, known as white muscle disease (WMD), in horses. However, correlations between Se deficiency and clinical findings, such as hematologic biochemical values and pathological features, have not been evaluated in captive plains zebras. The purpose of the present study was to investigate the clinical and pathologic features that may be caused by a Se deficiency in the captive plains zebra. Clinical findings, feed analyses, hematologic biochemical analyses, response to treatment, and pathologic examination were assessed in six affected plains zebras. The dietary concentration of Se in feed was also tested. Sudden death occurred in two cases during the first day of the onset of symptoms. Two zebras died at 4 days and two zebras survived after treatment. The clinical signs in affected animals were characterized by general weakness, astasia, and abnormal postural positions. The Se concentration in hay from the breeding stable was low, based on the reference value. Glutathione peroxidase (GSH-Px) activity was lower compared with the equine reference value. Multiple areas of subcutaneous steatitis and pale skeletal muscle and myocardium were revealed at gross necropsy. Degeneration and necrosis of myocardial and skeletal muscles, as well as congestion of the liver, lung, and kidney were found via histopathological examination. No suspected bacterial infections were found. Feed analyses, response to treatment, serum GSH-Px activity, and pathological features suggest that Se deficiency may have caused the disease in the six affected captive plains zebra.     

Increased expression of microRNA-378a-5p in acute ethanol exposure of rat cardiomyocytes

Alcohol abuse is a risk factor for a distinct form of congestive heart failure, known as alcoholic cardiomyopathy (ACM). Here, we investigate how microRNAs may participate in the induction of cardiomyocyte apoptosis associated with ethanol exposure in vitro. Increasing the concentrations of ethanol to primary rat cardiomyocytes resulted in elevated apoptosis assessed by annexin V and propidium iodide staining, and reduced expression of an enzyme for alcohol detoxification aldehyde dehydrogenase 2 (ALDH2). These ethanol effects were accompanied by a substantial elevation of miR-378a-5p. Driving miR-378a-5p overexpression in cardiomyocytes decreased ALDH2. The specific interaction of miR-378a-5p with the 3’UTR of ALDH2 was examined by luciferase reporter assays, and we found that miR-378a-5p activity depends on a complementary base pairing at the 3′-UTR region of ALDH2 mRNA. Finally, ethanol-induced apoptosis in cardiomyocytes was attenuated in the presence of anti-miR378a-5p. Collectively, these data implicate a likely involvement of miR-378a-5p in the stimulation of cardiomyocyte apoptosis through ALDH2 gene suppression, which might play a potential role in the pathogenesis of ACM.     

Protein deprivation decreases male survival and the intensity of sexual antagonism in southern field crickets Gryllus bimaculatus

Recent theory predicts that the magnitude of sexual antagonism should depend on how well populations are adapted to their environment. We tested this idea experimentally by comparing intersexual genetic correlations for adult survival in pedigreed populations of southern field crickets (Gryllus bimaculatus) raised on naturally balanced (free‐choice) vs. imbalanced (protein‐deprived) diets. We tested for (1) sex differences in nutritional intake and preference, (2) sex‐specific effects of protein deprivation on survival and (3) diet dependence of the level of sexual antagonism. Adult males and females consumed a similar amount of protein, but protein deprivation decreased male survival but not female survival. Protein deprivation appeared to decrease the degree of sexual antagonism as intersexual genetic correlations were significantly lower than 1 only for the complementary free‐choice diet group but close to 1 for the protein‐deficient diet group. Our findings thereby implied that variation in nutritional environments can alter the magnitude of sexual antagonism. This research represents an important step towards understanding the relationship between sexual antagonism and adaptation in heterogeneous environments.     

Indirubin-3-Oxime Prevents H<Subscript>2</Subscript>O<Subscript>2</Subscript>-Induced Neuronal Apoptosis via Concurrently Inhibiting GSK3β and the ERK Pathway

Oxidative stress-induced neuronal apoptosis plays an important role in many neurodegenerative disorders. In this study, we have shown that indirubin-3-oxime, a derivative of indirubin originally designed for leukemia therapy, could prevent hydrogen peroxide (H₂O₂)-induced apoptosis in both SH-SY5Y cells and primary cerebellar granule neurons. H₂O₂ exposure led to the increased activities of glycogen synthase kinase 3β (GSK3β) and extracellular signal-regulated kinase (ERK) in SH-SY5Y cells. Indirubin-3-oxime treatment significantly reversed the altered activity of both the PI3-K/Akt/GSK3β cascade and the ERK pathway induced by H₂O₂. In addition, both GSK3β and mitogen-activated protein kinase inhibitors significantly prevented H₂O₂-induced neuronal apoptosis. Moreover, specific inhibitors of the phosphoinositide 3-kinase (PI3-K) abolished the neuroprotective effects of indirubin-3-oxime against H₂O₂-induced neuronal apoptosis. These results strongly suggest that indirubin-3-oxime prevents H₂O₂-induced apoptosis via concurrent inhibiting GSK3β and the ERK pathway in SH-SY5Y cells, providing support for the use of indirubin-3-oxime to treat neurodegenerative disorders caused or exacerbated by oxidative stress.     

Life cycle environmental assessment of industrial hazardous waste incineration and landfilling in China

Purpose

The improper handling of industrial hazardous waste (IHW), which comprises large amounts of toxic chemicals, heavy metals, or irradiation substances, is a considerable threat to human health and the environment. This study aims to quantify the life cycle environmental impacts of IHW landfilling and incineration in China, to identify its key factors, to improve its potential effects, and to establish a hazardous waste disposal inventory.

Methods

Life cycle assessment was conducted using the ReCiPe model to estimate the environmental impact of IHW landfilling and incineration. The characterization factors for the human toxicity and freshwater ecotoxicity categories shown in the ReCiPe were updated based on the geographies, population, food intake, and environmental conditions in China.

Results and discussion

The overall environmental burden was mainly attributed to the carcinogen category. The national carcinogen burden in 2014 at 37.8 CTUh was dominated by diesel consumption, cement and sodium hydroxide production, direct emission, transportation, and electricity generation stages caused by direct mercury and arsenic emissions, as well as indirect chromium emission. Although the atmospheric mercury emission directly caused by IHW incineration was comparative with the emission levels of developed countries, the annual direct mercury emission accounted for approximately 0.1% of the national mercury emission.

Conclusions

The key factors contributing to the reduction of the national environmental burden include the increasing diesel and electricity consumption efficiency, the reduction of cement and sodium hydroxide use, the development of air pollutant controlling systems, the reduction of transport distance between IHW disposers to suppliers, and the improvement of IHW recycling and reuse technologies.

     

Reprogramming of the activity of the activator/dissociation transposon family during plant regeneration in rice

Many aspects of epigenetic phenomena have been elucidated via studies of transposable elements. An active transposable element frequently loses its ability to mobilize and goes into an inactive state during development. In this study, we describe the cyclic activity of a maize transposable element dissociation (Ds) in rice. In rice genome, Ds undergoes the spontaneous loss of mobility. However, an inactive state of Ds can be changed into an active state during tissue culture. The recovery of mobility accompanies not only changes in the methylation patterns of the terminal region of Ds, but also alteration in the steady state level of the activator (Ac) mRNA that is expressed by a constitutive CaMV 35S promoter. Furthermore, the Ds-reactivation process is not random, but stage-specific during plantlet regeneration. Our findings have expanded previous observations on Ac reactivation in the tissue culture of maize.     

Relationship between acrylamide concentration and enzymatic activity in an improved single fibrin zymogram gel system

Based on the zymography analysis, Bacillus sp. DJ-4 (screened from Doen-Jang, a Korean traditional fermented food) secretes seven extracellular fibrinolytic enzymes (EFEs; 68, 64, 55, 45, 33, 27, and 13 kDa) in culture broth. These seven EFEs were analyzed by newly applied SDSfibrin zymography combined with gradient polyacrylamide (SDS-FZGP). This improved gel system was used with a 5-20% acrylamide gradient in a fibrin zymogram gel for the separation of proteins with molecular masses from below 10 kDa to over 100 kDa on one gel plate. Using this system, high molecular weight bands (HMWBs) were clearly and sharply resolved. We also examined the relationship between an acrylamide concentration and the enzymatic activity of EFE using densitometric analysis.     

镉吸附细菌的分离及其对土壤镉的固定

[目的] 探究镉吸附细菌是否能够高效固定土壤有效镉（Cd）,为土壤有效Cd的微生物固定提供理论依据。[方法] 利用含Cd²⁺牛肉膏蛋白胨液体培养基对细菌进行Cd的耐受性测试筛选出镉抗性强的菌株;通过16S rRNA基因相似性及系统进化分析鉴定耐镉细菌,将菌细胞加入含CdCl₂溶液中进行Cd²⁺吸附效率测定;通过土培模拟实验,测定土壤pH、碱解氮、有效磷、速效钾、有机质、CEC、有效Cd及微生物数量来分析镉吸附细菌对镉污染土壤的影响。[结果] 从德阳鱼腥草根际土壤中分离获得的57株细菌对Cd²⁺表现出不同程度的抗性,并从中筛选出3株耐Cd优势细菌普罗威登斯菌属（Providencia）DY8、芽孢杆菌属（Bacillus）DY3和芽孢杆菌属（Bacillus）DY1-4。其对溶液中的Cd²⁺表现出较好的吸附作用,吸附效率随着Cd²⁺浓度升高而降低。DY8、DY3、DY1-4能使镉污染土壤中有效Cd含量分别降低72.11%、68.55%、62.32%,同时显著提高镉污染土壤中碱解氮、有效磷的含量。[结论] Cd污染农田土壤中含有丰富的耐Cd微生物资源,Cd吸附细菌能降低土壤中有效Cd的含量,且能有效改善土壤养分条件。