Molecular characterization and immunohistochemical localization of a mitogen-activated protein kinase, Accp38b, from Apis cerana cerana

The p38 mitogen-activated protein kinase (MAPK) is involved in various processes, including stress responses, development, and differentiation. However, little information on p38 MAPK in insects is available. In this study, a p38 MAPK gene, Accp38b, was isolated from Apis cerana cerana and characterized. The quantitative real-time PCR (Q-PCR) analysis revealed that Accp38b was induced by multiple stressors. Notably, the expression of Accp38b was relatively higher in the pupae phase than in other developmental phases. During the pupae phase, Accp38b expression was higher in the thorax than in the head and abdomen and higher in the fat body than in the muscle and midgut. Immunohistochemisty showed significant positive staining of Accp38b in sections from the brain, eyes, fat body, and midgut of A. cerana cerana. These results suggest that Accp38b may play a crucial role in stress responses and have multiple aspects function during development.     

Effect of ammonium-N on malic enzyme and lipid production in Rhodotorula glutinis grown on monosodium glutamate wastewater

Rhodotorula glutinis, an oil producing strain, can utilize monosodium glutamate (MSG) wastewater as a raw material for lipid production. The effects of ammonium-N in the MSG wastewater (ammonium 15,000–25,000?mg/L, COD 30,000–50,000?mg/L) on cell growth, lipid accumulation and malic enzyme activity of R. glutinis have been studied. Four initial ammonium sulfate concentrations in the medium were set, which were 20, 60, 100, and 140?g/L. With an increase in the ammonium sulfate concentration, the uptake of ammonia nitrogen and lipid accumulation increased while the biomass decreased at 72?h. The maximum value of ammonia nitrogen consumption reached 5.77?g/L for an initial ammonium sulfate concentration of 140?g/L at 72?h. In addition, 60?g/L ammonium sulfate concentration may be an appropriate concentration for R. glutinis cultivation. The activity of the malic enzyme was measured and the results showed that there was a linear relationship between the intracellular lipid content and the total malic enzyme activity.     

中国近海牡蛎系统分类研究的现状和对策

探讨了中国近海沿岸牡蛎分类的诸多疑难和热点问题,回顾了国内外包括贝类等动物的分子系统发生学研究的主要进展,分析了中国近海牡蛎系统分类目前存在的问题,重点阐述了利用分子标记等手段解决形态相似种的鉴定和种系发生关系等问题的巨大潜力,报道了利用分子标记进行牡蛎分类研究所取得的最新进展。预期经典分类学和分子系统发生学研究的交叉综合,将大力推动中国近海牡蛎的系统分类和系统发生研究的发展。     

Caragana korshinskii seedlings maintain positive photosynthesis during short-term,severe drought stress

Seedling performance may determine plant distribution, especially in water-limited environments. Plants of Caragana korshinskii commonly grow in arid and semiarid areas in northwestern China, and endure water shortage in various ways, but little is known about their performance when water shortage occurs at early growth stages. The water relations, photosynthetic activity, chlorophyll (Chl) content and proline accumulation were determined in 1-year-old seedlings growing in a 1:1 mixture of Loess soil and Perlite and subjected to (1) a water deficit for 20 days and (2) kept adequately watered throughout. The water deficit induced low (−6.1 MPa) predawn leaf water potentials (LWP), but did not induce any leaf abscission. Stomatal conductance (g _s), leaf transpiration rate (E), and net photosynthetic rate (P _N) decreased immediately following the imposition of the water deficit, while the maximal photochemical efficiency of photosystem II (PSII) (F_v/F_m) and the effective quantum yield of PSII (Φ_PSII) decreased 15 days later. An early and rapid decrease in g _s, reduced E, increased Chl (a+b) loss, increased the apparent rate of photochemical transport of electrons through PSII (ETR)/P _N, as well as a gradual increase in non-photochemical quenching of fluorescence (NPQ) and proline may have contributed to preventing Φ_PSII from photodamage. C. korshinskii seedlings used a stress-tolerance strategy, with leaf maintenance providing a clear selective advantage, considering the occasional rainfall events during the growing season.     

Nature of Enhanced Severity of Anthurium Root Rot by Diuron Treatment for Weed Control

Diuron treatment for weed control greatly increased anthurium root rot caused by Pythium splendens, P. spinosum, P. vexans and Calonectria crotalariac. Diuron in agar medium was inhibitory to the growth of mycelium, formation and germination of sporangia of P. splendens. Sporangia of P. splendens produced in diuron-amended medium did not differ in pathogenecity to anthurium roots from those produced in diuron-free medium. When diuron was applied to kill weeds in the planting medium, the population of P. splendens in it was not decreased during the test. Diuron was inhibitory to a number of micro-organisms in the platiting medium. Exudation of anthursum roots was not increased by diuron treatment. Increase in severity of anthurium root rot by diuron treatment was similar whether the experiments were performed in the presence or absence of planting medium, suggesting that the enhancing effect of diuron on root rot is mainly due to an increase in susceptibility of the host plants.