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981.
982.
以凡纳滨对虾的对虾素3(Lv\|PEN\|3)基因作为研究对象,分别进行了大肠杆菌重组表达载体的构建、重组蛋白的诱导表达与亲和纯化,以及多克隆抗体的制备等研究。研究结果显示:Lv\|PEN\|3可以被大肠杆菌正确表达,而且该重组蛋白具有良好的免疫刺激作用,可以刺激家兔产生相应的抗体。  相似文献   
983.
Late blight caused by Phytophthora infestans is one of the most devastating diseases of the potato crop. Resistance breeding and current fungicides are unable to control the rapidly evolving P. infestans and new control strategies are urgently needed. This study examined mechanisms of dl ‐β‐aminobutyric acid (BABA)‐induced resistance (IR) in the potato–P. infestans system. Leaves from two cultivars that differ in their degree of resistance, Bintje and Ovatio, were analysed after foliar treatment with BABA. Rapid activation of various defence responses and a significant reduction in P. infestans growth were observed in leaves treated with BABA. In the more resistant cultivar, Ovatio, the activation was both faster and stronger than in Bintje. Microscopic analysis of leaves treated with BABA revealed induction of small hypersensitive response (HR)‐like lesions surrounded by callose, as well as production of hydrogen peroxide (H2O2). Molecular and chemical analyses revealed soluble phenols such as arbutin and chlorogenic acid and activation of PR‐1. These results show a direct activation of defence responses in potato, rather than priming as reported for other plant species. They also show that the efficiency of BABA‐IR differs between cultivars, which highlights the importance of taking all aspects into consideration when establishing new methods for disease management.  相似文献   
984.
Downy mildew, caused by Plasmopara viticola, is one of the most destructive diseases of grapevine and is controlled with intense application of chemical fungicides. Treatment with Trichoderma harzianum T39 (T39) or benzothiadiazole‐7‐carbothioic acid S‐methyl ester (BTH) has been previously shown to activate grapevine resistance to downy mildew and reduce disease symptoms in the Pinot noir cultivar. However, enhancement of plant resistance can be affected by several factors, including plant genotype. In order to further extend the use of resistance inducers against downy mildew, the physiological and molecular properties of T39‐ and BTH‐activated resistance in different cultivars of table and wine grapes were characterized under greenhouse conditions. T39 treatment reduced downy mildew symptoms, but the degree of efficacy differed significantly among grapevine cultivars. However, efficacy of BTH‐activated resistance was consistently high in the different cultivars. Expression profiles of defence‐related genes differed among cultivars in response to resistance inducers and to pathogen inoculation. T39 treatment enhanced the expression of defence‐related genes in the responsive cultivars, before and after P. viticola inoculation. A positive correlation between the efficacy of T39 and the expression level of defence‐related genes was found in Primitivo and Pinot noir plants, while different genes or more complex processes were probably activated in Sugraone and Negroamaro. The data reported here suggest that the use of a responsive cultivar is particularly important to maximize the efficacy of resistance inducers and new natural inducers should be explored for the less responsive cultivars.  相似文献   
985.
大丽轮枝菌蛋白激发子PevD1诱导棉花抗病性及作用机理   总被引:3,自引:0,他引:3  
 PevD1是一种大丽轮枝菌(Verticillium dahliae)分泌蛋白,具有激发烟草过敏反应(HR)和系统获得性抗病(SAR)的功能。为明确蛋白PevD1诱导棉花抗病性及其作用机制,本文利用大肠杆菌表达、纯化的PevD1诱导棉苗植株,检测棉苗对大丽轮枝菌的抗性及免疫应答反应。结果表明,大肠杆菌表达的PevD1重组蛋白不是棉花品种“新陆早42号”的致萎因子,叶片注射8 μg/mL PevD1蛋白诱导3 d后根部接种大丽轮枝菌,15 d后PevD1处理组病害减轻率达35.04%。PevD1能诱导棉花叶片抗性早期信号分子H2O2产生和NO积累,维管束细胞壁加厚、木质素和酚类物质的积累。另外,PevD1处理能提高防御酶PAL、POD和PPO活性,提高棉花抗性基因和木质素合成相关基因PAL、C4H1、4CL的转录水平。说明PevD1通过激发棉花免疫系统而提高抗病性,该研究不仅为利用PevD1蛋白激发子控制棉花黄萎病提供了科学依据,同时也为阐明棉花与大丽轮枝菌互作机理提供了理论基础。  相似文献   
986.
pHBA对菜心炭疽病的诱导抗性及植株生理特性的影响   总被引:2,自引:0,他引:2  
 以菜心品种为材料,设置不同浓度对羟基苯甲酸(pHBA)处理,并通过人工接种炭疽病菌,研究pHBA对菜心炭疽病的诱导抗性作用机理。结果表明,在菜心生长发育过程中根系可以分泌出pHBA。pHBA对菜心的生长、产量形成和炭疽病的发生有明显的影响。适宜浓度的pHBA处理可促进菜心生长,提高植株对炭疽病的抗性,显著地降低病情指数(DI),提高菜薹产量,但当pHBA积累到一定浓度时,就对菜心植株产生自毒作用,提高DI和降低菜薹产量。炭疽病菌的感染破坏了植株细胞膜,增强细胞膜透性水平,诱导产生病程相关蛋白(几丁质酶、β-1,3-葡聚糖酶)和细胞壁物质(木质素、富含羟脯氨酸糖蛋白(HRGP))。适宜浓度的pHBA处理可抑制炭疽病菌对细胞膜透性的伤害,加强诱导提高几丁质酶活性、β-1,3-葡聚糖酶活性、木质素含量和HRGP含量,引起细胞壁木质化加强,增加了菜心植株对炭疽病的诱导抗病能力,从而阻止病原菌进一步侵入和扩散,抑制炭疽病菌对菜心产量造成的损失。  相似文献   
987.
Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), can differentiate into cells of the three germ layers, suggesting that PSCs have great potential for basic developmental biology research and wide applications for clinical medicine. Genuine ESCs and iPSCs have been derived from mice and rats, but not from livestock such as the pig—an ideal animal model for studying human disease and regenerative medicine due to similarities with human physiologic processes. Efforts to derive porcine ESCs and iPSCs have not yielded high-quality PSCs that can produce chimeras with germline transmission. Thus, exploration of the unique porcine gene regulation network of preimplantation embryonic development may permit optimization of in vitro culture systems for raising porcine PSCs. Here we summarize the recent progress in porcine PSC generation as well as the problems encountered during this progress and we depict prospects for generating porcine naive PSCs.  相似文献   
988.
为进一步确认含蛋白酶、几丁质酶、脂肪酶和淀粉酶的诱导酶发酵液对球孢白僵菌(Beauveria bassiana)菌株毒力的影响,将高毒力菌株B5、Bxs与低毒力菌株B11、BZ分别制成1×107个/mL孢悬液(I型)、孢悬液+诱导酶发酵液(V∶V=1∶1;II型)、孢悬液+灭菌诱导酶发酵液(V∶V=1∶1;III型),用浸渍法分别测定I型、II型与III型3种液体对松墨天牛(Monochamus alternatus)幼虫的毒力。结果表明:分别含有蛋白酶、几丁质酶和脂肪酶的诱导酶发酵液Ⅱ型液体,其LT50值与Ⅲ型液体LT50间的差异均为极显著(P0.01),而含淀粉酶的差异不显著。分别含有4种酶的诱导酶发酵液的Ⅲ型与Ⅰ型液体相比,LT50值之间也存在极显著差异(P0.01)。可见:含蛋白酶、几丁质酶和脂肪酶的诱导酶发酵液对球孢白僵菌毒力具有极显著的增效作用;经过酶灭活的4种诱导酶发酵液增效作用也极显著。  相似文献   
989.
尤颖哲 《福建水产》2016,(6):481-485
在人工育苗的过程中,对亲贝进行促熟培育获得高质量受精卵是开展规模化育苗的关键。波纹巴非蛤(Paphia undulata)亲贝存在性成熟同步率低、产卵不集中的问题,研究对波纹巴非蛤亲贝分别进行室内水泥池和室外土池人工暂养促熟培育,经5、10、15、20 d的暂养促熟培育后,采用阴干、流水刺激的方法诱导产卵,比较不同的暂养促熟方法和促熟培育时间对亲贝的性腺发育及催产效果的影响。结果表明:用室外土池人工促熟法,波纹巴非蛤亲贝性腺发育的成熟情况比室内水泥池促熟法好、死亡率低;且经室外土池人工促熟培育10 d,亲贝的性腺发育情况及催产效果最佳。  相似文献   
990.
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