Oral immunization of mice with transgenic tomato fruit expressing respiratory syncytial virus-F protein induces a systemic immune response

Respiratory syncytial virus (RSV) is one of the most important pathogens of infancy and early childhood. Here a fruit-based edible subunit vaccine against RSV was developed by expressing the RSV fusion (F) protein gene in transgenic tomato plants. The F-gene was expressed in ripening tomato fruit under the control of the fruit-specific E8 promoter. Oral immunization of mice with ripe transgenic tomato fruits led to the induction of both serum and mucosal RSV-F specific antibodies. The ratio of immunoglobulin subclasses produced in response to immunization suggested that a type 1 T-helper cell immune response was preferentially induced. Serum antibodies showed an increased titer when the immunized mice were exposed to inactivated RSV antigen.     

Edible insects in China: Utilization and prospects

The use of edible insects has a long history in China, where they have been consumed for more than 2000 years. In general, the level of acceptance is high for the consumption of insects in China. Many studies on edible insects have been conducted in the last 20 years, and the scope of the research includes the culture of entomophagy and the identification, nutritional value, farming and breeding of edible insects, in addition to food production and safety. Currently, 324 species of insects from 11 orders are documented that are either edible or associated with entomophagy in China, which include the common edible species, some less commonly consumed species and some medicinal insects. However, only approximately 10 to 20 types of insects are regularly consumed. The nutritional values for 174 species are available in China, including edible, feed and medicinal species. Although the nutritional values vary among species, all the insects examined contain protein, fat, vitamins and minerals at levels that meet human nutritional requirements. Edible insects were, and continue to be, consumed by different ethnic groups in many parts of China. People directly consume insects or food products made from insects. The processing of products from insect protein powder, oil and chitin, and the development of healthcare foods has been studied in China. People also consume insects indirectly by eating livestock that were fed insects, which may be a more acceptable pathway to use insects in human diets. Although limited, the data on the food safety of insects indicate that insects are safe for food or feed. Incidences of allergic reactions after consuming silkworm pupae, cicadas and crickets have been reported in China. Insect farming is a unique breeding industry in rural China and is a source of income for local people. Insects are reared and bred for human food, medicine and animal feed using two approaches in China: the insects are either fully domesticated and reared completely in captivity or are partially raised in captivity, and the insect habitat is manipulated to increase production. Depending on the type of relationship the insect has with humans, plants and the environment, different farming strategies are used. The social and scientific communities must work together to promote the use of insects as food and feed.     

Differential response of NaCl-Resistant mutants of the cyanobacterium Nostoc muscorum to salinity and osmotic stresses

Summary In the parent strain of Nostoc muscorum, the percentage survival, nitrogenase activity and oxygenic photosynthesis were severely impaired by NaCl (ionic) and sucrose (non-ionic) stresses. Spontaneously occurring NaCl-Resistant mutant clones of the cyanobacterium N. muscorum were found to exhibit differential responses under ionic and non-ionic stresses. One of the mutants (NaCl-R) was found to show resistance in terms of percentage survival, nitrogenase activity and oxygenic photosynthesis under saline (ionic) as well as osmotic (non-ionic) stresses and showing compatible solute strategy for such adaptation. Another mutant (Na⁺-R) was found to show resistance only to salinity stress and showed an enhanced Na⁺-efflux system driven by H⁺. The Na⁺-R mutant differed from the NaCl-R mutant strain in the sense that it was sucrose sensitive.     

食用蕈菌硒多糖研究进展

食用蕈菌硒多糖是无机硒与蕈菌多糖结合而成的有机硒化合物,兼有二者的活性。该文综述了食用蕈菌硒多糖的组成分析、提取、分离纯化以及生理功能、应用现状等方面的研究进展。     

Osmotic responses of unicellular blue-green algae (cyanobacteria): changes in cell volume and intracellular solute levels in response to hyperosmotic treatment

Abstract Changes in cell volume and solute content upon hyperosmotic shock have been studied for six unicellular blue-green algae (cyanobacteria): Synechococcus PCC 6301, PCC 6311; Synechocystis PCC 6702, PCC 6714, PCC 6803 and PCC 7008. The extent of change in volume was shown to be dependent upon the solute used to establish the osmotic gradient, with cells in NaCl showing a reduced shrinkage when compared to cells in media containing added sorbitol and sucrose. Uptake of extracellular solutes during hyperosmotic shock was observed in Synechocystis PCC 6714, with maximum accumulation of external solutes in NaCl and minimum solute uptake in sucrose solutions. Conversely, solute loss from the cells (K⁺ and amino acids) was greatest in sucrose-containing media and least in NaCl. The results show that these blue-green algae do not behave as ‘ideal osmometers’ in media of high osmotic strength. It is proposed that short-term changes in plasmalemma permeability in these organisms may be due to transient membrane instability resulting from osmotic imbalance between the cell and its surrounding fluid at the onset of hyperosmotic shock.     

Biochemical examination of the potential eukaryotic-type protein kinase genes in the complete genome of the unicellular Cyanobacterium synechocystis sp. PCC 6803.

The complete genome of the unicellular motile cyanobacterium Synechocystis sp. PCC 6803 harbors seven putative genes for a subfamily Pkn2 of the eukaryotic-type (or "Hanks-type") protein kinase. Previously, SpkA and SpkB were shown to have protein kinase activity and to be required for cell motility. Here, the other five genes were examined. These genes, except for spkG (slr0152), were successfully expressed in Escherichia coli. Eukaryotic-type protein kinase activity of the expressed SpkC (Slr0599), SpkD (S110776) and SpkF (Slr1225) was demonstrated as autophosphorylation and phosphorylation of the general substrate proteins. SpkE (Slr1443) did not show any activity, a finding consistent with its lack of several key amino acid residues in its kinase motif. Gene-disrupted mutants showed no discernible defect in phenotype except that spkD was apparently essential for survival.     

黑木耳复合群中种类学名说明

黑木耳在我国已经有1 000多年栽培历史,是我国最重要的栽培真菌之一,多年来我国黑木耳的学名一直使用模式产地为欧洲的Auricularia auricula-judae。最近的研究表明A. auricula-judae实际为一复合种,该复合种在全球范围内有5个种。其中A. auricula-judae仅分布于欧洲;美洲有2个种,生长在针叶树上的美洲木耳A. americana和生长在阔叶树上的尚未命名的木耳。中国该类群有3个种：自然分布和栽培最广泛的黑木耳的学名应为A. heimuer,此外,短毛木耳A. villosula在我国东北也广泛分布,并有少量栽培,生长针叶树上的木耳为美洲木耳A. americana,主要分布于中国东北和华北。     

糙皮侧耳生长发育过程中漆酶基因家族的表达研究

漆酶参与木质素的降解和食用菌的生长发育。为了明晰漆酶基因在糙皮侧耳生长发育过程中的作用,本文采用real-time PCR检测了11条漆酶基因及Lacc2的小亚基sspoxa3在糙皮侧耳生长发育不同阶段的表达。其中lacc6和sspoxa3在整个生长发育阶段表达量均较高;lacc12随着原基的分化和子实体的形成大量表达,与成菇过程有关。lacc4,lacc7和lacc11在原基分化期高表达,与原基的分化有关。lacc2,lacc3和lacc8在成熟子实体阶段表达量显著上升,与子实体的分化和成熟有关。     

An oxygen-evolving complex with a simple subunit structure - ‘a water-plastoquinone oxidoreductase” - from the thermophilic cyanobacterium Synechococcus sp.

An oxygen-evolving complex has been highly purified from the thermophilic cyanobacterium Synechococcus sp. The complex, which reproducibly showed 5 major polypeptide bands of 47, 40, 35, 30 and 9 kDa on SDS-polyacrylamide gel electrophoresis and contained 3.2 Mn per Q_A, had an oxygen-evolving activity of 300–400 μmol/mg chl per h in the presence of 5 mM MnCl₂; or CaCl₂. The complex most likely represents a minimum functional unit of the photosynthetic oxygen evolution.     

EFFECTS OF POTASSIUM ON THE PHOTOSYNTHETIC RECOVERY OF THE TERRESTRIAL CYANOBACTERIUM,NOSTOC FLAGELLIFORME (CYANOPHYCEAE) DURING REHYDRATION1

Effects of potassium on the photosynthetic recovery of Nostoc flagelliforme (Berk. & Curtis) Bornet & Flahault were investigated to determine its exact role during rehydration. Potassium enhanced recovery of the ability to reduce the primary quinone‐type acceptor (Q_A) and plastoquinone (PQ) pool and the area over the fluorescence rise curve was increased by 127%. The proportions of closed PSII reaction centers at phases J and I and the net rate of closure of PSII reaction centers were decreased by, respectively, 19%, 8%, and 23% with the addition of potassium, due to changes in the ability of PSII for multiple turnovers needed to reduce the PQ pool. Potassium significantly enhanced the probability of electron transfer beyond Q_A and the recovery of electron transport flux per PSII reaction center. Electron transport from water to methyl viologen for samples rehydrated in K⁺‐free BG₁₁ medium was 54% of those with the addition of potassium. However, electron flow from water to p‐benzoquinone and from reduced 2,6‐dichlorophenol‐indophenol to methyl viologen showed little change with the addition of potassium. The fast phase and slow phase of millisecond delayed light emission and the ATP content for samples rehydrated in K⁺‐free BG₁₁ medium were, respectively, 71.6%, 50.7%, and 77.1% of those with the addition of potassium. These suggested that potassium affected electron transfer from PQ to plastocyanin through the cytochrome b₆f complex and the proton motive force across the thylakoid membranes, probably reflecting its role in charge balance during H⁺ transport by the cytochrome b₆f complex.