Isolation and characterization of expressed sequence tags (ESTs) from subtracted cDNA libraries of Pennisetum glaucum seedlings
Isolation and characterization of expressed sequence tags (ESTs) from subtracted cDNA libraries of Pennisetum glaucum seedlings
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DOI：
10.1007/s11103-007-9193-4
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发表时间：
2007-08-01
影响因子：
5.1
通讯作者：
Reddy, Malireddy K.
中科院分区：
文献类型：
--
作者：
Mishra, Rabi N.;Reddy, Palakolanu Sudhakar;Reddy, Malireddy K.
珍珠谷子(Pennisetum Glucum)是一种耐逆境的牧草和粮食作物。在这里，我们通过对克隆的单程测序，从消减的cDNA文库中鉴定对非生物(盐度、干旱和寒冷)胁迫反应的差异调控转录本。总共2,494个EST序列被聚类并组装成1,850个独特序列的集合，包括224个重叠群和1,626个单态序列。通过序列比较，可以确定许多EST的推测功能。具有应激相关功能的基因除了编码未知功能的EST外，还包括参与细胞防御非生物应激的基因和参与应激反应信号和转录的蛋白质的转录本。这些都为阐明它们在非生物胁迫中的作用提供了新的候选基因。选择的38个基因的相对mRNA丰度，通过实时定量RT-PCR进行量化，表明存在一个复杂的基因调控网络，该网络以动力学特有的方式对基因表达进行调控，以响应不同的非生物胁迫。值得注意的是，在构建的这些消减的cDNA文库中，管家和非靶基因有效地减少了。这些EST序列是逆境相关基因的丰富来源，揭示了逆境反应转录组的主要部分，这将为进一步研究狼尾草对恶劣环境的适应性奠定基础。
Pearl millet (Pennisetum glaucum), used as forage and grain crop is a stress tolerant species. Here we identify differentially regulated transcripts in response to abiotic (salinity, drought and cold) stresses from subtracted cDNA libraries by single-pass sequencing of cDNA clones. A total of 2,494 EST sequences were clustered and assembled into a collection of 1,850 unique sequences with 224 contigs and 1,626 singleton sequences. By sequence comparisons the putative functions of many ESTs could be assigned. Genes with stress related functions include those involved in cellular defense against abiotic stresses and transcripts for proteins involved in stress response signaling and transcription in addition to ESTs encoding unknown functions. These provide new candidate genes for investigation to elucidate their role in abiotic stress. The relative mRNA abundance of 38 selected genes, quantified using real time quantitative RT-PCR, demonstrated the existence of a complex gene regulatory network that differentially modulates gene expression in a kinetics-specific manner in response to different abiotic stresses. Notably, housekeeping and non-target genes were effectively reduced in these subtracted cDNA libraries constructed. These EST sequences are a rich source of stress-related genes and reveal a major part of the stress-response transcriptome that will provide the foundation for further studies into understanding Pennisetum's adaptability to harsh environmental conditions.