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991.
ABSTRACT Aflatoxins are carcinogens produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops such as maize (Zea mays L.). Resistant maize genotypes have been identified, but the incorporation of resistance into commercial lines has been slow due to the lack of selectable markers. Here we report the identification of potential markers in resistant maize lines using a proteomics approach. Kernel embryo proteins from each of two resistant genotypes have been compared with those from a composite of five susceptible genotypes using large format two-dimensional gel electrophoresis. Through these comparisons, both quantitative and qualitative differences have been identified. Protein spots have been sequenced, and based on peptide sequence homology analysis, are categorized as follows: storage proteins (globulin 1 and globulin 2), late embryogenesis abundant (LEA) proteins related to drought or desiccation (LEA3 and LEA14), water- or osmo-stress related proteins (WSI18 and aldose reductase), and heat-stress related proteins (HSP16.9). Aldose reductase activity measured in resistant and susceptible genotypes before and after infection suggests the importance of constitutive levels of this enzyme to resistance. Results of this study point to a correlation between host resistance and stress tolerance. The putative function of each identified protein is discussed. 相似文献
992.
Abstract We have previously shown that both atopic and normal dogs generate an IgG response to antigens of Malassezia pachydermatis . The aim of this study was to compare IgE responses to separated proteins of M. pachydermatis in 28 atopic dogs with Malassezia dermatitis and 22 clinically normal dogs using Western immunoblotting. Six different detection systems were evaluated in order to assess sensitivity and eliminate nonspecific binding and cross-reactivity. The protocol yielding the best results utilized a monoclonal mouse antidog IgE, an alkaline phosphatase conjugated goat antimouse IgG which had been passed through a canine IgG column 3 times, a chemiluminescent substrate and a digital imaging system. Proteins of 45, 52, 56 and 63 kDa were recognized by more than 50% of the atopic dog sera and thus represented major allergens. Only a minority of normal dogs showed faint IgE binding to these proteins. The results indicate that the majority of atopic dogs with Malassezia dermatitis have a greater IgE response than normal dogs, suggesting an IgE-mediated immune response may be clinically important in the pathogenesis of the disease. 相似文献
993.
Deahl KL Cooke LR Black LL Wang TC Perez FM Moravec BC Quinn M Jones RW 《Pest management science》2002,58(9):951-958
In recent years, late blight, caused by Phytophthora infestans (Mont) De Bary, has increased in severity in many parts of the world, and this has been associated with migrations which have introduced new, arguably more aggressive, populations of the pathogen. In Taiwan, late blight has been endemic on outdoor tomato crops grown in the highlands since the early 1900s, but recent epidemics have been more damaging. To ascertain the present status of the Taiwanese population of P infestans, 139 isolates of the pathogen collected and maintained by the Asian Vegetable Research and Development Center (AVRDC) were characterized using mating type, metalaxyl sensitivity, allozyme genotype, mitochondrial haplotype and RFLP fingerprinting. Up to 1997, all isolates were found to belong to the old clonal lineage of P infestans (US-1 and variants), but in isolates from 1998 a new genotype appeared, and by 2000 this had apparently completely displaced the old population. This new genotype was an A1 mating type and has the dilocus allozyme genotype 100/100/111, 100/100 for the loci coding for glucose-6-phosphate isomerase and peptidase, respectively. These characters, together with RG57 fingerprinting, indicated that these isolates belonged to the US-11 clonal lineage, a minority (11%) being a previously unreported variant of US-11. Whereas metalaxyl-resistant isolates were not detected in the old population, 96% of the new genotypes proved resistant, with the remainder being intermediate in sensitivity. It may be inferred from this sudden, marked change in the characteristics of the Taiwanese P infestans that a new population of the pathogen was introduced around 1997-98 and that this may well have already been metalaxyl-resistant when it arrived, although a role for in situ selection cannot be excluded. 相似文献
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The dorsal lingual surface of a black rhinoceros (Diceros bicornis) was examined by scanning electron microscopy. The tongue was about 30 cm in length. There were about 60 vallate papillae on both sides. Filiform, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue. The papillae had a hair-like shape. The fungiform papillae were round in shape, and more densely distributed on the lingual apex. No foliate papillae were seen on the dorsal surface. The vallate papillae were located on both sides of the posterior end of the lingual body. Each papilla was surrounded by a groove. 相似文献
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用960羽1日龄双鬼头肉鸭研究了一种固体发酵复合酶(AllzymeSSF)在玉米-豆粕及玉米-小麦-豆粕型日粮中的应用效果,考察了添加该复合酶对肉鸭屠宰性能、血清生化指标的影响。试验结果表明,不同处理对49日龄肉鸭的半净膛率、全净膛率、腿肌率、胸肌率没有显著影响(P>0.05)。玉米-小麦-豆粕型日粮的屠宰率略高于玉米-豆粕型日粮;玉米-豆粕及玉米-小麦-豆粕型日粮中添加200PU/kgAllzymeSSF降低了腹脂率(P<0.05);玉米-豆粕型日粮中添加300PU/kgAllzymeSSF及玉米-小麦-豆粕型日粮中添加200PU/kgAllzymeSSF提高了血清磷的含量(P<0.05);玉米-小麦-豆粕型日粮中添加200PU/kgAllzymeSSF提高了血清球蛋白的含量(P<0.05)。 相似文献