Rapid Changes in Composition and Contents of Cuticular Hydrocarbons in Sitobion avenae (Hemiptera: Aphididae) Clones Adapting to Desiccation Stress.

Cuticular hydrocarbons (CHCs) are diverse in insects, and include variable classes of cuticular lipids, contributing to waterproofing for insects under desiccation environments. However, this waterproofing function of CHCs is still not well characterized in aphids. In this study, we compared CHC profiles for desiccation-resistant and nonresistant genotypes of the grain aphid, Sitobion avenae (Fabricius), in responses to desiccation. Our result showed that a total of 27 CHCs were detected in S. avenae, and linear alkanes (e.g., n-C29) were found to be the predominant components. Long-chain monomethyl alkanes were found to associate closely with water loss rates in S. avenae in most cases. Resistant genotypes of both wing morphs had higher contents of short-chain n-alkanes under control than nonresistant genotypes, showing the importance of short-chain n-alkanes in constitutive desiccation resistance. Among these, n-C25 might provide a CHC signature to distinguish between desiccation-resistant and nonresistant individuals. Compared with linear alkanes, methyl-branched CHCs appeared to display higher plasticity in rapid responses to desiccation, especially for 2-MeC26, implying that methyl-branched CHCs could be more sensitive to desiccation, and play more important roles in induced desiccation-resistance. Thus, both constitutive and induced CHCs (linear or methyl-branched) can contribute to adaptive responses of S. avenae populations under desiccation environments. Our results provide substantial evidence for adaptive changes of desiccation resistance and associated CHCs in S. avenae, and have significant implications for aphid evolution and management in the context of global climate change.

[Geochemical Patterns and Source Analysis of Soil Heavy Metals in an Iron and Manganese Ore Area of Longyan City].

Bedrock and soil samples from different soil profile layers were collected in an iron and manganese ore area of Longyan City and total amounts of Pb, Cd, and As were determined. The geochemical patterns of three heavy metal elements in the soil were studied using ordinary Kriging interpolation and their sources were also analyzed. High concentrations of Pb and As were found near the mining area to the west, at the intersection of two rivers in the middle, and near the waste rock heap in the east of the study area, while the main area of Cd contamination is located near to the mining areas and ore dressing plant. Based on a horizontal section, the content of Pb, Cd, and As in soils from the high-value region of each layer decreased with horizontal distance from the mining area. Vertically, the concentrations of heavy metals in different soil layers were significantly correlated. Near the mining area, Pb, Cd, and As concentrations first increased and then decreased with depth. In other high-value regions, the concentrations of these three heavy metals decreased with soil profile depth. These heavy metals inherit the characteristics of the deposit and bedrock during the weathering process, and the content of Pb and As in the soil at different depths was significantly positively correlated with granite and diorite content. Although As has been artificially influenced by mining, this influence does not appear to be strong; parent rock in the study area shows higher concentrations of heavy metals, while at the same time, the Pb and Cd content of soil is significantly higher than in the rock indicating the influence of human activities including mining, transportation, and agricultural production. Further attention should now be paid to the quality and safety of agricultural products, crop growth, and possible environmental risks in the study area.

Pollution, sources and environmental risk assessment of heavy metals in the surface AMD water, sediments and surface soils around unexploited Rona Cu deposit, Tibet, China.

The pollution by heavy metals (HMs) of mining is a widespread problem in the world. However, the pollution by HMs around unexploited deposits (virgin fields) has been studied rarely, especially in Tibet, China. Water, sediments and surface soils were collected to investigate the concentrations of HMs around unexploited Rona Cu deposit in Tibet, China. Furthermore, geochemical fractions of these elements were also analyzed. Pollution and environmental risk introduced by HMs accumulation were assessed using pollution indices, geo-accumulation (Igeo), potential ecological risk index and risk assessment code (RAC). Results indicated that the pH values of Rona tributary river ranged from 2.70 to 3.08, and the average concentrations of Cu and Zn were 2114.00 ± 65.89 and 1402.14 ± 27.36 µg L-1, respectively, exceeding their standard limits. The concentrations (mg kg-1) of Cu, Zn and As ranged in 19.01-1763.10, 62.00-543.06 and 11.12-61.78 for sediments, respectively, and 154.60-1489.35, 55.38-344.74 and 10.05-404.03 for surface soils, respectively, exceeding their standard limits. According to RAC, almost all Cu, Zn and As near low risk status. However, Cd ranged from medium to very high risk in sediments, and low to high risk in surface soils. Statistical analysis suggested that Cu, Pb, Zn, As and Cd in sediments and surface soils may mainly derive from Rona deposit, whereas Cr and Hg may primarily originate from lithogenic sources. The results indicated that very high concentrations of HMs could be occurred in surface water, sediments and surface soils around unexploited deposits. Especially at high-altitude Tibet, the high environmental risk of HMs deserves more attention.

Hydroxysafflor yellow A attenuates high glucose-induced pancreatic ß-cells oxidative damage via inhibiting JNK/c-jun signaling pathway.

Pancreatic ß-cells apoptosis and dysfunction induced by glucose toxicity were attributed to the formation of excess oxidative damage. Some studies have found that hydroxysafflor yellow A has strong effects to scavenge oxidative stress and inhibit apoptosis. In order to explore the influence of HSYA on oxidative stress induced by high glucose and the potential mechanisms, we set up a high glucose damage model and induced oxidative stress in INS-1 rat insulinoma cells. N-acetylcysteine was added as a group of oxidative stress scavenger. After 72 h of cultivation, the related indexes of oxidative stress (reactive oxygen species, catalase, glutathione peroxidase, lipid peroxidation, and superoxide dismutase), apoptosis (caspase3, parp) and the function of glucose stimulated insulin secretion were determined. In addition, the signaling pathway proteins of C-Jun NH2 -terminal kinases (JNK), phosphorylated JNK, C-jun, phosphorylated C-jun were evaluated. Fluorescence microscopy, qRT-PCR, western blotting were the main methods used in the experiment. Our results showed that hydroxysafflor yellow A reduced pancreatic ß-cells apoptosis by attenuating oxidative damage, and JNK/c-Jun signaling pathway was involved. It indicated a significant mechanism for the positive impacts of HSYA on oxidative stress induced by high glucose, and provide important basis for using HSYA in diabetic prevention and therapy.