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41.
M A DITA J V DIE† B ROMÁN† F KRAJINSKI‡ H KÜSTER§ M T MORENO† J I CUBERO# & D RUBIALES 《Weed Research》2009,49(S1):66-80
Orobanche crenata is a root parasitic weed that is a major constraint for grain and forage legume cultivation in Mediterranean and West Asia. Only moderate to low levels of incomplete resistance of complex inheritance has been identified so far in legume crops, which has hampered genetic and genomic analysis. In the present study, we provide a gene expression profile of roots of the model legume Medicago truncatula in response to infection by O. crenata . M. truncatula accessions SA27774 (complete resistance acting at early penetration stages) and SA4087 (incomplete late acting resistance mediated by necrosis of parasite tubercle) were inoculated with O. crenata seeds in a semi-sterile dish system. Roots were harvested at 15 (first contacts of the parasitism structures with the host roots), 21 (initial stage of parasite tubercle formation on SA4087) and 35 (prior necrosis of well-developed parasite tubercle of on SA4087) days post-inoculation. Array hybridisations revealed several hundred genes up-regulated in response to O. crenata infection. Gene expression patterns suggest that resistance mechanisms activated in both genotypes are temporally and spatially different and resemble those associated with plant resistance to microbial pathogens. Regulated genes identified here represent a comprehensive resource that can be used as a support to breeding strategies for resistance. 相似文献
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New technologies based on microarray methods have begun to feature widely in carbohydrate chemistry and biology. These ‘glycoarray’ techniques, which in a number of cases emulate what has been achieved with DNA microarrays, allow for high throughput, quantitative analysis of protein–carbohydrate interactions. Lectin, antibody and enzyme specificity have been evaluated with these new techniques, which also extend to the detection of viruses and bacteria, and serodiagnosis of infection. In the plant field, high throughput mapping of cell wall carbohydrate structures has been reported, giving information not only on the localisation of given glycans within a plant, but also allowing systematic comparison between mutants and species. This review outlines some of the basic principles of ‘glycoarrays’ and illustrates recent reports of their development and application. 相似文献
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Several typical supervised clustering methods such as Gaussian mixture model-based supervised clustering （GMM）, k- nearest-neighbor （KNN）, binary support vector machines （SVMs） and multiclass support vector machines （MC-SVMs） were employed to classify the computer simulation data and two real microarray expression datasets. False positive, false negative, true positive, true negative, clustering accuracy and Matthews＇ correlation coefficient （MCC） were compared among these methods. The results are as follows： （1） In classifying thousands of gene expression data, the performances of two GMM methods have the maximal clustering accuracy and the least overall FP＋FN error numbers on the basis of the assumption that the whole set of microarray data are a finite mixture of multivariate Gaussian distributions. Furthermore, when the number of training sample is very small, the clustering accuracy of GMM-Ⅱ method has superiority over GMM- Ⅰ method. （2） In general, the superior classification performance of the MC-SVMs are more robust and more practical, which are less sensitive to the curse of dimensionality, and not only next to GMM method in clustering accuracy to thousands of gene expression data, but also more robust to a small number of high-dimensional gene expression samples than other techniques. （3） Of the MC-SVMs, OVO and DAGSVM perform better on the large sample sizes, whereas five MC-SVMs methods have very similar performance on moderate sample sizes. In other cases, OVR, WW and CS yield better results when sample sizes are small. So, it is recommended that at least two candidate methods, choosing on the basis of the real data features and experimental conditions, should be performed and compared to obtain better clustering result. 相似文献
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DNA微阵列技术是近年来发展起来的一种功能基因组学研究技术。随着这项新技术的建立和日趋完善及其在植物病理学研究中的应用,为病原细菌致病机理的研究带来了新思路并开辟了新途径。利用DNA微阵列技术,检测病原细菌在不同生长条件下和在侵染植物过程中的基因转录谱,可以从基因组水平上鉴定出新的与毒性和适应性相关的基因及其表达调控网络,有助于阐明这些基因的生物学功能及其机理。本文结合本实验室近几年来的相关研究结果,综述DNA微阵列技术在病原细菌转录谱研究中应用的最新进展。 相似文献
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渗透胁迫下烟草叶片基因的差异表达研究 总被引：6，自引：2，他引：4
为了解干旱胁迫下烟草的抗旱机制,采用拟南芥基因芯片检测了PEG渗透胁迫（－1.2 MPa）48 h后烟草叶片中基因表达的变化。在31 182个基因微矩阵点中,有效差异表达（ratio值≥2或≤0.5）的基因为135个,上调50个,下调85个。其中包括一些具有防御功能的上调表达基因如两个普遍胁迫蛋白（USP）和与渗透调节物质海藻糖合成有关的基因ATTPS11及多个参与复制、转录和翻译等过程的基因MAPKK、bZIP、锌指蛋白、组蛋白His1-3、脱水响应DREB转录因子、WRKY转录因子家族、分子伴侣等,MAPKK具最大上调幅度,为3.94倍（序列号为At1g51660）。而参与光合作用的6个PSⅠ的光捕获复合体中lhca3和PSⅡ的光捕获复合体中核编码基因的lcb1、lcb2、lcb5、lcb6、lcb4.2的基因表达下调。还检测到38个未知基因,它们的差异表达可能跟渗透胁迫诱导有关,是我们下一步研究的重点。通过分析这些特异表达基因,揭示出一些潜在的生物学规律,为研究烟草逆境生理学提供了有价值的信息。 相似文献
47.
水稻稻瘟病菌胁迫应答cDNA片段的表达及定位 总被引：5，自引：2，他引：3
以抗稻瘟病品系G205为材料,应用cDNA微阵列分别获得了一个受稻瘟病菌诱导的含NBS LRR的cDNA克隆（暂命名为RIM1, rice induced by Magnaporthe grisea）和一个受稻瘟病菌抑制的编码腈水解酶（Nitrilase）的cDNA克隆（暂命名为NIT）,并通过Northern得到证实。RFLP分析将RIM1和NIT分别定位于水稻第2和第3染色体上,它们均位于控制水稻稻瘟病部分抗性QTL区间。 相似文献
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基因芯片(gene chip)是依据核酸杂交原理发展的一种生物新技术,在生命科学研究领域具有重要的应用价值.本研究将不对称PCR和基因芯片两种技术相结合,构建了同步检测鸡(Gallus gallus)传染性喉气管炎病毒(Infectious laryngotracheitis virus,ILTV)、新城疫病毒(Newcastle disease virus,NDV)、传染性支气管炎病毒(Infectious bronchitis virus,IBV)的共检基因芯片.分别选取ILTV的胸苷激酶(thymidine kinase,TK)和糖蛋白B(glycoproteins B,gB)基因、NDV的融合蛋白(fusion,F)和血凝素-神经氨酸酶蛋白(haemagglutinin-neuraminidase,HN)基因以及IBV的膜蛋白(membrane,M)和核衣壳(nucleocapsid,N)基因设计引物,从重组质粒菌中扩增制备探针基因,用乙醇沉淀法纯化后点制于氨基修饰的载玻片上,制备基因芯片;靶基因用cy3标记引物,进行不对称PCR扩增,扩增的荧光标记单链产物与芯片杂交.不对称PCR结果显示,当限制性引物与非限制性引物浓度比例在1:10时ILTV-TK、NDV-HN和IBV-N的单链产物增加最多,当浓度比在1:20时,ILTV-gB、NDV-F和IBV-M的单链产物增加最多;相应的标记样品与3种病毒检测芯片杂交后,均出现较强的杂交信号,而阴性对照检测不到荧光信号,灵敏性实验表明,当DNA浓度为1.8x 104拷贝时杂交仍为阳性.本研究构建的诊断基因芯片对12份临床样品进行初步应用检测,与PCR检测技术检出率基本一致.本实验所建立的联合检测基因芯片能够快速、准确、高通量的诊断NDV-IBV-ILTV,可以应用于集约化养殖业中对多种鸡疫病病毒的检测. 相似文献
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