Transcriptome dynamics of Arabidopsis thaliana root penetration by the oomycete pathogen Phytophthora parasitica
Transcriptome dynamics of Arabidopsis thaliana root penetration by the oomycete pathogen Phytophthora parasitica
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DOI：
10.1186/1471-2164-15-538
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发表时间：
2014-06-29
期刊：
影响因子：
4.4
通讯作者：
Gourgues, Mathieu
中科院分区：
文献类型：
--
作者：
Attard, Agnes;Evangelisti, Edouard;Gourgues, Mathieu
背景：卵菌是一组丝状微生物，包括动物和植物病原体，并造成重大的农业损失。疫霉可以感染自然生态系统中的大多数作物和植物。尽管它们具有巨大的经济和生态重要性，但目前还没有有效的方法来限制这些物种造成的破坏。需要新的解决方案，它们的发展将需要我们对这些病原体感染的分子事件的理解有所提高。在这项研究中，我们描述了土传病原菌疫霉（Phytophthora parasitica）侵入植物时激活的遗传程序。结果：利用公共数据库中提供的所有寄生拟南芥序列，我们生成了一个定制的寡核苷酸阵列，并对拟南芥感染的早期事件进行了转录组学分析。我们描述了生物阶段，从附着胞介导的病原体渗透到根部到植物中第一个死细胞的发生。我们确定了一系列在宿主渗透过程中被瞬时调制的序列。令人惊讶的是，我们观察到编码涉及脂质和糖代谢的蛋白质的基因整体下调，而控制氨基酸运输的功能上调。我们还发现，在寄主渗透和随后的坏死阶段，寄生蜂表达了不同组的基因。细胞壁降解酶和其他与致病性有关的蛋白质（包括RXLR效应物）的差异表达模式尤为明显。通过与GFP的转录融合转化，我们发现在第一个植物细胞的侵染过程中，一个RXLR编码基因在附着胞和侵染菌丝中表达。结论：我们已经确定了寄生蜂入侵植物细胞初期激活的遗传程序。我们发现，一组特定的蛋白质，包括效应器，被动员渗透和促进感染。我们通过附着胞和感染菌丝检测到RXLR编码基因的表达，强调了这种结构在宿主细胞操纵中的作用。
Background: Oomycetes are a group of filamentous microorganisms that includes both animal and plant pathogens and causes major agricultural losses. Phytophthora species can infect most crops and plants from natural ecosystems. Despite their tremendous economic and ecologic importance, few effective methods exist for limiting the damage caused by these species. New solutions are required, and their development will require improvements in our understanding of the molecular events governing infection by these pathogens. In this study, we characterized the genetic program activated during penetration of the plant by the soil-borne pathogen Phytophthora parasitica.Results: Using all the P. parasitica sequences available in public databases, we generated a custom oligo-array and performed a transcriptomic analysis of the early events of Arabidopsis thaliana infection. We characterized biological stages, ranging from the appressorium-mediated penetration of the pathogen into the roots to the occurrence of first dead cells in the plant. We identified a series of sequences that were transiently modulated during host penetration. Surprisingly, we observed an overall down regulation of genes encoding proteins involved in lipid and sugar metabolism, and an upregulation of functions controlling the transport of amino acids. We also showed that different groups of genes were expressed by P. parasitica during host penetration and the subsequent necrotrophic phase. Differential expression patterns were particularly marked for cell wall-degrading enzymes and other proteins involved in pathogenicity, including RXLR effectors. By transforming P. parasitica with a transcriptional fusion with GFP, we showed that an RXLR ecoding gene was expressed in the appressorium and infectious hyphae during infection of the first plant cell.Conclusion: We have characterized the genetic program activated during the initial invasion of plant cells by P. parasitica. We showed that a specific set of proteins, including effectors, was mobilized for penetration and to facilitate infection. Our detection of the expression of an RXLR encoding gene by the appressorium and infection hyphae highlights a role of this structure in the manipulation of the host cells.