Effect of Pichia membranaefaciens in combination with salicylic acid on postharvest blue and green mold decay in citrus fruits

The separate or combined effects of Pichia membranaefaciens and salicylic acid (SA) on the control of blue and green mold decay in citrus fruits were investigated. Results indicate that combining P. membranaefaciens (1 × 10⁸ CFU ml⁻¹) with SA (10 μg ml⁻¹) either in a point-inoculated or dipped treatment provided a more effective control of blue and green mold than separately applying yeast or SA. SA (10 μg ml⁻¹) did not significantly affect P. membranaefaciens growth in vitro but slightly increased the yeast population in fruit wounds. P. membranaefaciens plus SA effectively enhanced the phenylalanine ammonia-lyase, peroxidase, polyphenoloxidase, chitinase, and β-1,3-glucanase activities and stimulated the synthesis of phenolic compounds. The combined treatment did not impair quality parameters such as weight loss or titratable acidity, but resulted in low average natural infection incidence and increased total soluble solids and ascorbic acid contents in citrus fruits after 14 d at 20 °C.     

Electron Density Sharpening as a General Technique in Crystallographic Studies

Sharpening is a powerful method to restore the details from blurred electron density in crystals with high overall temperature factors (B-factors). This valuable technique is currently not optimally used because of the uncertainty in the scope of its application and ambiguities in practice. We performed an analysis of ~ 2000 crystal data sets deposited in the Protein Data Bank and show that sharpening improves the electron density map in many cases across all resolution ranges, often with dramatic enhancement for mid- and low-resolution structures. It is effective when used with either experimental or model phases without introducing additional bias. Our tests also provide a practical guide for optimal sharpening. We further show that anisotropic diffraction correction improves electron density in many cases but should be used with caution. Our study demonstrates that a routine practice of electron density sharpening may have a broad impact on the outcomes of structural biology studies.     

Glutamate metabolism in the brain of young rats exposed to organic and inorganic lead

The synthesis of glutamate and its conversion to glutamine and GABA were studied using labelled glucose in cerebral cortex, cerebellum and brainstem of rats intoxicated acutely with tetraethyl lead and chronically with lead acetate. To assess the interconversion and the synaptosomal accumulation of these amino acids, the labelling of glutamate, glutamine and GABA were measured in whole tissue and synaptosomes after giving labelled glutamate. The radioactive carbon dioxide production from labelled glutamate by brain slices was measured to evaluate the oxidation of glutamate. The tissue levels of glutamate, glutamine and GABA and the activity of glutamate decarboxylase were also measured in both conditions.In inorganic lead toxicity, even though the glutamate pool size was reduced, the glutamate-glutamine cycling between synaptosomes and astrocytes was increased. The oxidation of glutamate and the glutamate-GABA cycling were reduced. These findings suggest that brain tries to maintain the endogenous glutamate levels by decreasing the oxidation of glutamate and increasing the uptake systems and the cycling through glutamine in inorganic lead toxicity. In organic lead toxicity, the glutamate pool as well as glutamate turnover was reduced markedly resulting in complete distortion of glutamate metabolism.     

Glycomics and Proteomics Approaches to Investigate Early Adenovirus–Host Cell Interactions

Adenoviruses as most viruses rely on glycan and protein interactions to attach to and enter susceptible host cells. The Adenoviridae family comprises more than 80 human types and they differ in their attachment factor and receptor usage, which likely contributes to the diverse tropism of the different types. In the past years, methods to systematically identify glycan and protein interactions have advanced. In particular sensitivity, speed and coverage of mass spectrometric analyses allow for high-throughput identification of glycans and peptides separated by liquid chromatography. Also, developments in glycan microarray technologies have led to targeted, high-throughput screening and identification of glycan-based receptors. The mapping of cell surface interactions of the diverse adenovirus types has implications for cell, tissue, and species tropism as well as drug development. Here we review known adenovirus interactions with glycan- and protein-based receptors, as well as glycomics and proteomics strategies to identify yet elusive virus receptors and attachment factors. We finally discuss challenges, bottlenecks, and future research directions in the field of non-enveloped virus entry into host cells.     

Supramolecular zippers elicit interbilayer adhesion of membranes producing cell death

Background

The fluorescent dye 10-N-nonyl acridine orange (NAO) is widely used as a mitochondrial marker. NAO was reported to have cytotoxic effects in cultured eukaryotic cells when incubated at high concentrations. Although the biochemical response of NAO-induced toxicity has been well identified, the underlying molecular mechanism has not yet been explored in detail.

3种外源诱导剂预处理对甜瓜抗病特征及其Fom 2和CHT基因表达的影响

该研究选用水杨酸(SA)、茉莉酸甲酯(MeJA)、Ca~(2+)、无菌水(对照)作为外源预处理诱导剂,以抗、感枯萎病甜瓜品种为材料,分别于诱导预处理2d后接种甜瓜枯萎菌,并于接种5、7、9d时观察发病情况,进行病情调查;在接种后1、3、5、7、9d取甜瓜叶片,分析抗病甜瓜(MR-1)和感病甜瓜(M1-15)叶片中甜瓜抗枯萎病基因(Fom-2)、几丁质酶基因(CHT)的表达变化,以探寻提高防治甜瓜枯萎病菌侵染的技术途径。结果显示:(1)外源MeJA和SA预处理接种后2品种的病情指数显著低于对照,但Ca~(2+)处理后的病情指数与对照无显著差异。(2)经外源诱导预处理接种后,MR-1和M1-15品种叶片的Fom-2和CHT基因均出现差异表达,但Ca~(2+)诱导其上调表达的效果微弱。(3)经SA、MeJA诱导预处理接种后,2品种叶片的Fom-2和CHT基因表达总体均显著高于对照;Fom-2基因的表达抗病甜瓜MR-1分别在接种后5d、7d时达到峰值,而感病甜瓜M1-15则均在接种9d时达到峰值;CHT基因的表达抗病甜瓜MR-1则均在接种后7d时达到峰值,而感病甜瓜M1-15分别在接种后7d、9d时达到峰值。(4)Ca~(2+)处理对抗、感甜瓜叶片的Fom-2和CHT基因的表达均无显著影响。(5)相关分析表明,经SA、MeJA诱导预处理接种后,甜瓜枯萎病病情指数与Fom-2和CHT基因表达量有显著的相关性;而Ca~(2+)处理效果不显著。研究表明:SA、MeJA通过诱导Fom-2、CHT基因上调表达,进而使甜瓜的抗病性提高,而Ca~(2+)处理对两基因表达和甜瓜抗病性均无显著影响。     

σ1 Receptor Subtype Is Involved in the Facilitation of Cortical Dopaminergic Transmission in the Rat Brain

Our previous studies have shown that three sigma () receptor ligands, (+)-N-allylnormetazocine ((+)-SKF-10,047), (±)-pentazocine and 1,3-di(2-tolyl)guanidine (DTG) differently regulated the dopamine (DA) transmission in the rat brain. In the present study, we attempted to clarify the role of ₁ receptor subtype in the regulation of DA transmission using a novel and selective ₁ receptor agonist, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) in the rat brain. Acute administration of SA4503 (1.0 mg/kg, p.o.) significantly increased DA and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the rat frontal cortex, but not in the other six regions, hippocampus, striatum, midbrain, cerebellum, medulla/pons and hypothalamus. The increase of cortical DA level elicited by SA4503 was fully reversed by N,N-dipropyl-2-(4-methoxy-3-(2-phenylethoxy)phenyl)ethylamine (NE-100) (0.25 mg/kg, p.o.), a putative ₁ receptor antagonist. In addition, SA4503 (1.0 mg/kg, p.o.) showed an increase of cortical L-3,4-dihydroxyphenylalanine (L-DOPA) accumulation under the inhibition of dopa decarboxylase activity with m-hydrobenzylhydrazine (NSD-1015), suggesting that SA4503 has activated the cortical DA synthesis rate. These results suggest that the ₁ receptor subtype plays an important role in the facilitation of cortical DA transmission. In addition, this phenomenon is partially involved in the augmentation of DA synthesis rate.     

Biflavones of the subfamily callitroideae,cupressaceae

Twenty species, including representatives of all 11 genera of the Callitroideae, were examined for biflavonoid content of the leafy twigs. The major biflavonoids are based on amentoflavone, cupressuflavone and hinokiflavone. Their uneven distribution amongst the genera allows the distinction of five groups. These do not correlate strongly with currently recognized tribal groupings. The affinities of these genera are discussed.