[Effect of napthalene on the DNA methylation patterns and level in rice (Oryza sativa L.)].

In this study,two elite rice inbred lines, Nipponbare and Mastumae were selected and irrigated with naphthalene solution with different concentrations. Epigenetic instabilities in the blade of the plants in tillering and heading stage were assessed by MSAP marks. The results showed that naphthalene exposure induced epigenetic variations in all the samples based on different levels and patterns of DNA methylation. The changes of the percentage of 5-methylcytosine have no regulation. In total 1051 sites tested,the variation of 16.56 percentage of Nipponbare has significant difference compared with the variation of 12.08 percentage of Mastumae,which showed that the capability to resist naphthalene pollution was related to genotype and Mastumae was stronger than Nipponbare in the capability to resist naphthalene pollution. The variations of DNA methylation in different genotypes and different growth periods have significant differences. In general, the frequencies of demethylation (0.48%-10.41%) were higher than hypermethylation (0.10%-1.92%). We concluded that DNA demethylation might be one part of in plants mechanism to resist naphthalene pollution in plants.

[Stress and biological response of naphthalene on the antioxidant defense system in visceral mass of zebrafish (Danio rerio)].

With the acute toxicity test, we obtained the median lethal concentration (LC50) of naphthalene to the zebrafish for 96 h, which was 11.8 mg x L(-1). Then we set up five treatments(0, 1/6 LC50, 1/4 LC50, 1/3 LC50 and 1/2 LC50) and exposed zebrafish to these treatments for 0.5, 1, 2, 4, 7 and 14d respectively to study the effects of naphthalene on the antioxidant defense system in visceral mass of zebrafish. The results showed that GSH, GPx and GST were very sensitive to naphthalene and were inhibited or induced at 0.5 d exposure. The activities of GPx were induced on the whole after 0.5 d, but were inhibited at higher concentration treatments (1/3 LC50 and 1/2 LC50 treatments) at 14 d exposure; while the activities of GST and the contents of GSH were almost lower than that of the control. The activities of SOD were induced first and then inhibited after 2 d; the activities of CAT were inhibited almost in the all treatments after 1 d. The effects of naphthalene on the antioxidant defense system in visceral mass of zebrafish could be used as biomarkers to estimate the biological effect of fish exposed to polycyclic aromatic hydrocarbons.

Eco-physiological characteristics of alfalfa seedlings in response to various mixed salt-alkaline stresses.

Soil salinization and alkalization frequently co-occur in nature, but little is known about the mixed effects of salt-alkaline stresses on plants. An experiment with mixed salts (NaCl, Na(2)SO(4), NaHCO(3) and Na(2)CO(3)) and 30 salt-alkaline combinations (salinity 24-120 mmol/L and pH 7.03-10.32) treating Medicago sativa seedlings was conducted. The results demonstrated that salinity and alkalinity significantly affected total biomass and biomass components of seedlings. There were interactive effects of salt composition and concentration on biomass (P

Diaqua-bis(9-oxo-4,5-diaza-fluoren-3-olato-κN,O)cadmium(II).

The title compound, [Cd(C(11)H(5)N(2)O(2))(2)(H(2)O)(2)], is a mononuclear complex consisting of a Cd(II) atom, two 3-hydr-oxy-4,5-diaza-fluoren-9-one ligands and two coordinated water mol-ecules. The Cd(II) atom, lying on a twofold axis, displays a distorted octa-hedral coordintion. Adjacent mol-ecules are linked by O-H⋯O hydrogen bonds and π-π inter-actions [centroid-centroid distance = 3.84 (1) Å], leading to a one-dimensional chain. Weak C-H⋯O hydrogen bonds connect the chains into a two-dimensional supra-molecular structure.

[Comparative research on Cd removal from water by different kinds of seedlings].

Ecological effects of Cd removal from water and the changes of physiological and biochemical indexes of seedlings of maize, sunflower and castor-oil plant were investigated. The results showed that (1) with the trial time lasting, Cd content in solution decreased, and the processes of Cd removal by seedlings of each concentration were almost completed in 48 hours. The removal effects of sunflower and castor-oil plant were better than those of maize at 1 mg x L(-1) and 2 mg x L(-1) Cd, whereas the best removal effects at 5 mg x L(-1) and 10 mg x L(-) Cd were those of castor-oil plant, followed by maize and sunflower. (2) Root absorbed the most proportion of Cd by all these three kinds of seedlings at every treatment. The ability of Cd accumulation by the three kinds of seedlings could be drawn as follow sunflower> castor-oil plant > maize. (3) The physiological and biochemical indexes of seedlings exposed to Cd for 72 hours had changed to different degree compared with control. The root activity and the proline content of sunflower both have significant relations with Cd accumulation, and the plasma membrane permeability and the proline content of castor-oil plant both have significant positive relations with Cd accumulation. Maize, sunflower and castor-oil plant could endure certain concentration of Cd, and the tolerance of sunflower and castor-oil plant are both greater than that of maize through general analysis of Cd accumulation and the changes of physiological and biochemical indexes.

Effects of temperature and discharge parameters on ozone concentration of negative corona discharge.

The relationship of the ozone generation and the heating power, corona wire surface temperature, discharge electrode and netting electrode was studied during the negative corona discharge. The experimental results showed that the ozone concentration reduced with applied voltage decrease. With heating power increase, the ozone concentration of unit current decreased at exponential rate and it almost change no longer over 0.40 W. Under given temperature, the lower the applied voltage was, the smaller the ozone concentration was; while under given applied voltages, only over 11 kV could decrease with the surface temperature increase. The ozone concentration decreased with the lengthening of corona wire, and could reduced to 10 ppb under experimental condition of 14.2 kV; it also decreased with the shortening of wire diameter, and could decrease 67% at best in the given condition. Moreover, it decreased with the increasing size of netting electrode mesh. At the anion current of 1.65 microA, the ozone concentration of 5.0 x 5.0 cm2 is only 41% of that of 3.3 x 3.3 cm2.