MGSC27微生物肥料对土壤作用的研究

在实验室条件下对ＭＧＳＣ２７微生物肥料施用于土壤的效果进行了研究,结果表明：ＭＧＳＣ２７微生物肥料能够提高土壤的全Ｎ、速效Ｐ、速效Ｋ含量,其微生物能够较长时期地存在于土壤中。     

SC27微生物土壤增肥剂在柑桔上的应用效果

研究了SC27微生物土壤增肥剂对柑桔产量、果实品质及树体营养结构的影响.结果表明,SC27能增强柑桔树势,提高产量,经不同用量SC27处理,增产率达7.2%～23.4%.同时,SC27还能显著提高柑桔果实品质,使单果重增加,可食率提高,糖酸比增大,可溶性固形物及Vc含量增加.根据试验结果确定,SC27在柑桔上的推荐施用量为15 mL/株3次.     

斑马鱼ddx27基因对tp53基因的调控作用

为探究斑马鱼ddx27基因对tp53基因表达的影响,根据NCBI网站在线数据库中分析得到的ddx27基因编码序列（coding sequence,CDS）,利用同源重组技术构建斑马鱼ddx27真核表达载体pCMV-3×Flag-ddx27。通过亚细胞定位试验和蛋白质免疫印迹技术验证ddx27基因的表达,并利用双荧光素酶试验验证ddx27基因的过表达对tp53基因转录活性的影响。结果显示,ddx27 CDS区及阳性克隆的电泳片段大小以及测序比对均与预期结果一致。蛋白质免疫印迹显示Ddx27重组质粒可正常表达,且蛋白大小与预测结果一致。亚细胞定位显示Ddx27蛋白表达于HEK293T细胞的细胞核中。而且,过表达pCMV-3×Flag-ddx27真核表达载体能够显著增强 tp53启动子报告基因载体pGL3-tp53-Luc的活性,为对照组的1.8倍（P<0.05）。以上结果表明,斑马鱼pCMV-3×Flag-ddx27真核表达载体构建成功,能够在哺乳动物的细胞核中表达,且ddx27基因可以促进tp53基因的表达。     

云南省昆明地区种鸡J亚群禽白血病血清学调查

[目的]了解云南省昆明地区种鸡场J亚群禽白血病的感染状况。[方法]从云南省昆明市疑似感染禽白血病的某种鸡场采集644份泄殖腔(公鸡)拭子和460份蛋清(母鸡)样品,采用ELISA法对种鸡J亚群禽白血病进行抗原检测。[结果]在检测的460份蛋清样品中,172份抗原呈阳性,阳性率为37.39%;在检测的644份泄殖腔拭子中,520份抗原呈阳性,阳性率为80.75%。A养殖场共检测644份样品,总阳性率为63.66%,其中蛋清样品的阳性率为39.13%,泄殖腔样品的阳性率为82.07%。B养殖场共检测460份样品,总阳性率为61.30%,其中蛋清样品的阳性率为34.78%,泄殖腔样品的阳性率为78.99%。此次检测结果表明云南省昆明地区种鸡群已严重感染J亚群禽白血病。[结论]该研究可为种鸡J亚群禽白血病的防治提供理论依据。     

具除草活性放线菌的分离和形态学鉴定

从土壤中分离得到17株放线菌,其中JL27菌株的发酵液上清液对反枝苋萌发抑制率达90％,对苘麻萌发抑制率达96．7％;JL12菌株的发酵液上清液对反枝苋萌发抑制率为19．67％,对苘麻萌发抑制率达100％。JL27菌株属链霉菌属金色类群。     

Cloning and expression analysis of three genes encoding ubiquitins in papaya (Carica papaya L.)

Papaya (Carica papaya L.) fruit have a short shelf-life due to rapid ripening induced by ethylene, which usually results in a high percentage of product loss. However, little is known about the genetic mechanism of ripening and the attributes of fruit quality. Ubiquitin (UBQ) proteins have received increasing attention because they play important roles in response to ripening and in regulating certain developmental processes in plants. In the present study, three genes encoding UBQ proteins, CpUBI1, CpUBI2, and CpUBI3, were isolated from papaya fruit. The lengths of the cDNAs of CpUBI1, CpUBI2, and CpUBI3 were 1,485 bp, 1,642 bp, and 529 bp, encoding 306, 308, and 156 predicted amino acids, respectively. Sequence analysis demonstrated that the CpUBI1 and CpUBI2 proteins contained four consecutive structural domains of the UBQ superfamily, while CpUBI3 contained a ribosomal domain structure of the S27a superfamily. RT-qPCR analysis demonstrated that ethephon treatment increased CpUBI gene expression significantly, compared to 1-methylcyclopropene (1-MCP) treatment and the untreated controls. Levels of CpUBI1 and CpUBI2 gene expression were significantly higher than CpUBI3. These results suggested that CpUBI1, CpUBI2, and CpUBI3 might have different roles during papaya fruit ripening and softening.     

Effect of inhibiting release of exosomes on biological characteristics of bone marrow mesenchymal stem cells

AIM:To investigate the effect of inhibiting the release of exosomes on the biological characteristics of bone marrow mesenchymal stem cells (BM-MSCs) and the underlying mechanisms. METHODS:The exosome releasing-deficient mouse model was constructed by knockout of Rab27a using TALEN technique. The BM-MSCs were isolated and cultured. The exosomes were extracted from the culture medium using total exosome isolation kit and quantified by nanoparticle tracking analysis (NTA). The size and morphology of the exosomes were observed under transmission electron microscope. To evaluate the proliferation ability of BM-MSCs, the BM-MSCs were labeled with 5-ethynyl-2'-deoxyuridine (EdU) and the expression level of proliferating cell nuclear antigen (PCNA) was determined by Western blot. Moreover, hypoxia tolerance of BM-MSCs in vitro was evaluated via TUNEL staining and MTS assay. RESULTS:The count of exosomes released by BM-MSCs isolated from Rab27a knockout mice was significantly reduced. Inhibition of exosome release resulted in decreases in the viability of the BM-MSCs and their resistance to hypoxia. CONCLUSION:Inhibition of exosome release from the BM-MSCs results in significantly decreased proliferation ability and resistance to hypoxia.     

Studies on interactions between aluminum compounds and cellulosic fibers in water by means of27Al-NMR

Interactions between pulp fibers and aluminum compounds in pulp suspensions were studied using fibrous cellulose (FC) and fibrous carboxymethylcellulose (FCMC) powders as models of pulp fibers by X-ray fluorescence analysis and²⁷Al nuclear magnetic resonance. When deionized water was used at pH 4–5, water-soluble cationic aluminum species (Al³⁺, aluminum oligomer, and polyaluminum species) were adsorbed on the solid FCMC, forming carboxylic acid aluminum salts by cation exchange. The formation of these nondissociated pulp-COOAl type structures in paper sheets may contribute to some decreases in hydrophilic property. On the other hand, the water-soluble cationic aluminum species had nearly no interactions with hydroxyl groups of solid cellulose in the suspensions at pH 4–5. When tap water was used at pH 5–7, some aluminum components were retained on not only FCMC but also the FC sample. Probably, water-insoluble Al(OH)₃ flocs are formed in the suspensions at pH 5–7 and retained on the FC sample by simple filtration effect. Therefore, two mechanisms of the aluminum retention (i.e., electrostatic interactions and a simple filtration effect) may exist between pulp fibers and aluminum components in the practical papermaking process.This research was presented in part at the 5th annual meeting of the Japan Cellulose Society, Kyoto, July 1998     

Chemical species of Al in a gypsum-treated Kitakami Andosol

To examine the possibility that the Al₁₃ polymer ([A10₄Al₁₂(OH)24(H₂0)₁₂]⁷⁺) could be formed in soils after gypsum application, an analytical method using a cation exchange resin and ²⁷Al nuclear magnetic resonance (NMR) spectroscopy was applied to gypsum-treated Kitakami Andosol (fine, mixed, mesic, Andic Dystrochrept). The NMR spectra of the cation exchange resins which retained artificially synthesized hydroxy-AI, showed two broad peaks at 0 and 63 ppm. These results indicated that monomer and/or dimer Al and Al¹³ polymers adsorbed on the cation exchange resin could be detected with ²⁷Al NMR. The amount of polymer Al increased by gypsum application in the Kitakami soil. The NMR spectrum of this resin showed only one peak at 0 ppm indicating that the polymer Al formed in the gypsum treated Kitakami soil was not the Al¹³ polymer.