水稻几丁质酶的原核表达、复性及体外抑菌活性的研究

利用RT-PCR反应,从纹枯菌诱导的水稻叶片cDNA中克隆了1个水稻几丁质酶基因RC7的全长编码序列（ORF）。通过亚克隆方法,RC7与原核表达载体pGEX-4T-1上的GST融合,构建成GST-RC7重组蛋白的原核表达载体pGST-RC7,然后,将其转化到大肠杆菌细胞中。经异丙基-β-D-硫代半乳糖苷（IPTG）诱导,获得了以包涵体形式高效表达的GST-RC7。经过洗涤、溶解（变性）、复性及纯化等处理,包涵体中GST-RC7得到溶解、复性和纯化。纯化的复性GST-RC7蛋白具有几丁质酶活性。对6种重要作物病原真菌进行体外抑菌活性分析的结果表明, RC7可显著抑制水稻纹枯病菌、小麦纹枯菌、小麦赤霉菌、棉花黄萎菌、烟草赤星菌的菌丝生长,说明RC7可作为上述植物病害抗性基因育种的重要基因。     

Feline Sporotrichosis in the Southern Region of Rio Grande Do Sul,Brazil: Clinical,Zoonotic and Therapeutic Aspects

Clinical cases of feline sporotrichosis, originating in the Pelotas region and diagnosed at the Laboratory of Infectious Diseases (UFPel), were studied in the period from 2002 to 2006. The animals were evaluated according to the clinical forms of the mycosis, time of lesion appearance, severity of the clinical diagnosis and evolution of cutaneous lesions throughout the treatment period. Mycological analyses, carried out through direct examination, cultivation of tissue samples and exudates of feline lesions all confirmed the diagnosis of sporotrichosis in the 15 animals under study. The cutaneous dissemination form was observed in 10 animals, of which three showed prostration, anorexia and dehydration. The zoonosis occurred in 20% of case studies, and the pet owners and one attendant at a veterinary clinic were infected, developing the fixed and disseminated cutaneous forms. The treatment of mycosis was carried out with itraconazole, 10 mg kg^?1, once a day, on 12 animals. The cure of the clinical symptoms was observed on 50% of the felines. This study demonstrates a good clinical response of felines with sporotrichosis, when they were treated itraconazole and calls the attention for the incidence of human sporotrichosis on people related to the veterinary activity as well as for pet owners.     

疯草内生真菌Undifilum oxytropis次级代谢产物分析

为阐明疯草内生真菌Undifilum oxytropis次级代谢产物的化学组成,为其生物活性研究和开发利用提供依据,以本实验室保存的疯草内生真菌Undifilum oxytropis为研究菌株,采用察氏液体培养基对该菌发酵培养30d,收集菌丝体和发酵液,按照植物化学成分传统预试方法进行预试。在此基础上用不同极性有机溶剂梯度萃取得到菌丝体和发酵液石油醚相、氯仿相、乙酸乙酯相和正丁醇相,经薄层色谱检测及气相检测方法对其次级代谢产物进行初步分析。系统预试表明,Undifilum oxytropis发酵产物中含有生物碱、蛋白质、酚类与鞣质、黄酮类、醌类、挥发油和油脂等物质;薄层色谱检测发现,Undifilum oxytropis发酵产物中至少含有5种化合物,且菌丝体和发酵液正丁醇相均有苦马豆素及其类似物存在;气相色谱分析Undifilum oxytropis发酵液中苦马豆素含量为5.17×10~(-3)g/L。疯草内生真菌Undifilum oxytropis发酵产物含有苦马豆素等多种次级代谢产物。     

内生真菌对高寒草地紫花针茅凋落物分解的影响

禾草内生真菌对于提高宿主植物对生物和非生物胁迫的耐性发挥着积极作用,然而,禾草内生真菌共生体凋落物分解对于草地生态系统养分循环的影响仍不清楚.本研究以紫花针茅为研究对象,比较带内生真菌(E+)与不带内生真菌(E-)植株凋落物分解过程中重量及全氮、木质素和纤维素含量,以及木质素:N、纤维素:N与全氮、木质素和纤维素残留率...     

The activity and expression of chitinase in the equine lung and its activity in normal horses and animals with recurrent airway obstruction

Recurrent airway obstruction (RAO) is a chronic inflammatory condition in equine lung, which may share a common immunological basis with human asthma, in which dysregulated Th2 responses occur. Mammals express chitinases and chitinase-like proteins, two of which are active enzymes, chitotriosidase and acidic mammalian chitinase (AMCase). Both enzymes are upregulated in a range of inflammatory conditions, including asthma. We investigated the activity of chitinase in bronchoalveolar lavage fluid from horses with and without RAO in response to organic dust challenges. No significant differences were found in activity, although in one study RAO animals had elevated chitinase activity that fell short of statistical significance. The pH optimum and pH lability of the activity was consistent with the presence of chitotriosidase. RT-PCR amplification of the mRNA encoding chitotriosidase and AMCase in normal equine lung showed that chitotriosidase, but not AMCase, is expressed in trachea, bronchi, and peripheral lung tissue. The gene for chitotriosidase was identified from the Equus caballus (horse) genome 1.1 database and its similarity to the same genes from other species was determined. The results of this study indicate that the involvement of chitotriosidase in RAO is uncertain.     

芒果采后主要真菌性病害及防治方法研究进展

芒果是热带、亚热带重要经济作物之一,因其独特的口感和丰富的营养价值深受消费者喜爱。由于芒果采收期正值高温多雨季节、果实采后生理代谢旺盛、采收难度大,采后运输、贮藏过程中易遭受真菌的侵染,成为限制芒果产业发展的重要因素。为防治芒果采后真菌性病害,国内外学者对芒果采后防治技术进行了研究与开发。对炭疽病、蒂腐病和曲霉病3种芒果采后主要真菌性病害的症状、危害、病原菌和发生条件进行了综述,总结了芒果采后真菌性病害的防治方法,并对芒果采后病害防治方法进行了展望,为芒果采后真菌性病害防治技术的发展提供理论基础。     

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. Oleracea spp. Capitata). IV. A resistant 18-chromosome B1 plant and its B2 progenies

Summary The somatic karyotype and meiotic chromosome behavior were studied in an 18-chromosome B₁ plant derived from backcrossing a triploid (Brassica napus x B. oleracea ssp. capitata) F₁ hybrid to cabbage. It is considered that cabbage chromosomes no. 1 and no. 7 were substituted by two shorter B. napus chromosomes. Meiotic disturbances were more apparent during the late stages of second division. Seed fertility of this plant was largely restored in the second backcrosses with both cabbage and broccoli. 18-chromosome B₂ plants resistant to race 2 of Plasmodiophora brassicae were recovered among the progenies.Contribution no. J. 725 from the Research Station, Research Branch, Agriculture Canada, St-Jean, Québec J3B 6Z8.     

真菌固态载体预处理对不灭菌玉米秸秆降解的影响

采用云芝变色栓菌(Trametes versicolor)、色精木霉菌(Trichoderma chromospermum)、深绿木霉菌(Trichoderma atroviride)和云芝变色栓菌分别与色精木霉菌、深绿木霉菌的混合菌对干黄玉米秸秆进行真菌预处理。结果显示,真菌预处理不灭菌秸秆30 d后,木质纤维素的降解率几乎可以忽略,在不灭菌的环境中,接入的真菌对秸秆本身附着的微生物群落不能形成竞争优势,造成较低的木质素降解率。而云芝变色栓菌、色精木霉菌、深绿木霉菌以及云芝变色栓菌分别与色精木霉菌、深绿木霉菌的混合菌对灭菌秸秆预处理30 d后,木质素的降解率分别为34.0%、38.1%、38.1%、39.1%及40.3%。为降低秸秆的灭菌成本,将真菌预处理30 d后的灭菌秸秆作为真菌固态载体与不灭菌秸秆按照1∶9、1∶4及1∶1的干质量比混合培养30 d,结果显示,采用云芝变色栓菌分别与色精木霉菌和深绿木霉菌的混合菌固态载体预处理不灭菌秸秆,木质素降解率可达到30%~40%。因而,真菌固态载体可以较好地适应非灭菌环境并对秸秆中的木质素进行有效降解,是一种有效降低过程成本的预处理手段。     

First report on the Dutch elm disease pathogen Ophiostoma novo‐ulmi from Latvia

During 2017, Dutch elm disease was investigated on 67 Ulmus glabra and 29 Ulmus laevis samples from 28 sites in Latvia. The presence of Ophiostoma novo‐ulmi was detected in 61.2% of the samples from U. glabra and in 34.5% of the samples from U. laevis. In 11% of cases, hybrids between subsp. novo‐ulmi and subsp. americana were identified, particularly in the sites in the southern part of Latvia. This study presents the first verified record of Ophiostoma novo‐ulmi and its subspecies in Latvia.