Chao S, Lazo G R, You F, Crossman C C, Hummel D D, Lui N, Laudencia-Chingcuanco D, Anderson J A, Close T J, Dubcovsky J, Gill B S, Gill K S, Gustafson J P, Kianian S F, Lapitan N L V, Nguyen H T, Sorrells M E, McGuire P E, Qualset C O, Anderson O D
US Department of Agriculture - Agricultural Research Service (USAD-ARS), Western Regional Research Center, Albany, CA 94170, USA.
Genome. 2006 May;49(5):531-44. doi: 10.1139/g06-003.
The US Wheat Genome Project, funded by the National Science Foundation, developed the first large public Triticeae expressed sequence tag (EST) resource. Altogether, 116,272 ESTs were produced, comprising 100,674 5' ESTs and 15 598 3' ESTs. These ESTs were derived from 42 cDNA libraries, which were created from hexaploid bread wheat (Triticum aestivum L.) and its close relatives, including diploid wheat (T. monococcum L. and Aegilops speltoides L.), tetraploid wheat (T. turgidum L.), and rye (Secale cereale L.), using tissues collected from various stages of plant growth and development and under diverse regimes of abiotic and biotic stress treatments. ESTs were assembled into 18,876 contigs and 23,034 singletons, or 41,910 wheat unigenes. Over 90% of the contigs contained fewer than 10 EST members, implying that the ESTs represented a diverse selection of genes and that genes expressed at low and moderate to high levels were well sampled. Statistical methods were used to study the correlation of gene expression patterns, based on the ESTs clustered in the 1536 contigs that contained at least 10 5' EST members and thus representing the most abundant genes expressed in wheat. Analysis further identified genes in wheat that were significantly upregulated (p < 0.05) in tissues under various abiotic stresses when compared with control tissues. Though the function annotation cannot be assigned for many of these genes, it is likely that they play a role associated with the stress response. This study predicted the possible functionality for 4% of total wheat unigenes, which leaves the remaining 96% with their functional roles and expression patterns largely unknown. Nonetheless, the EST data generated in this project provide a diverse and rich source for gene discovery in wheat.
由美国国家科学基金会资助的美国小麦基因组计划开发了首个大型的公共小麦族表达序列标签（EST）资源。共产生了116,272个EST，其中包括100,674个5' EST和15,598个3' EST。这些EST来自42个cDNA文库，这些文库是利用从植物生长发育的各个阶段收集的组织，并在不同的非生物和生物胁迫处理条件下，由六倍体面包小麦（Triticum aestivum L.）及其近缘种构建而成，这些近缘种包括二倍体小麦（T. monococcum L.和Aegilops speltoides L.）、四倍体小麦（T. turgidum L.）和黑麦（Secale cereale L.）。EST被组装成18,876个重叠群和23,034个单拷贝序列，即41,910个小麦单基因。超过90%的重叠群所含的EST成员少于10个，这意味着这些EST代表了多种不同的基因选择，并且在低水平和中高水平表达的基因都得到了充分的采样。基于聚集在1536个重叠群中的EST，运用统计方法研究基因表达模式的相关性，这些重叠群包含至少10个5' EST成员，因而代表了小麦中表达最丰富的基因。分析进一步鉴定出与对照组织相比，在各种非生物胁迫下小麦组织中显著上调（p < 0.05）的基因。尽管许多这些基因的功能注释尚无法确定，但它们可能发挥与胁迫反应相关的作用。本研究预测了占小麦单基因总数4%的基因的可能功能，其余96%的基因其功能作用和表达模式在很大程度上仍不清楚。尽管如此，该项目产生的EST数据为小麦基因发现提供了丰富多样的资源。
