Tissue-specific transcriptome analysis in nodules of Lotus japonicus
Tissue-specific transcriptome analysis in nodules of Lotus japonicus
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莲子根瘤组织特异性转录组分析
DOI：
10.1094/mpmi-01-12-0011-r
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
et al
中科院分区：
文献类型：
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作者：
Takanashi;K.;et al
豆科植物可以与根瘤菌在根瘤中建立共生固氮（SNF），其中根瘤菌感染的细胞与未感染的细胞以镶嵌模式共存。在豆科植物的成熟根瘤内，宿主植物细胞与其常驻细菌之间的碳和氮营养物质进行积极交换。为了阐明根瘤中SNF相关的代谢动力学，使用激光显微镜分离来自模式豆科植物百脉根的根瘤的三个组织，并通过代表21，495个基因的60-mer长度的寡核苷酸阵列进行转录组分析。在我们的组织特异性分析中，许多基因被鉴定为以空间特异性方式在结节中表达。其中，编码代谢酶的基因根据其功能进行了分类，详细的数据分析表明，一个次级代谢途径在根瘤皮层中被高度激活。特别是，一些代谢基因的苯丙烷途径被发现为高表达的基因伴随着那些编码推定的转运蛋白的次级代谢产物。这些数据表明，参与SNF的苯丙素类化合物的一种新的生理功能。此外，选择了5个代表性基因，并通过启动子-β-葡萄糖醛酸酶实验表征了详细的组织特异性表达。我们的研究结果提供了一个新的数据来源，研究结节分化和组织特异性生理功能的结节。
Legume plants can establish symbiotic nitrogen fixation (SNF) with rhizobia mostly in root nodules, where rhizobia-infected cells are accompanied by uninfected cells in a mosaic pattern. Inside the mature nodules of the legume, carbon and nitrogen nutrients between host plant cells and their resident bacteria are actively exchanged. To elucidate the metabolite dynamics relevant for SNF in nodules, three tissues from a nodule of a model legume,Lotus japonicus, were isolated using laser microdissesction, and transcriptome analysis was done by an oligoarray of 60-mer length representing 21,495 genes. In our tissue-specific profiling, many genes were identified as being expressed in nodules in a spatial-specific manner. Among them, genes coding for metabolic enzymes were classified according to their function, and detailed data analysis showed that a secondary metabolic pathway was highly activated in the nodule cortex. In particular, a number of metabolic genes for a phenylpropanoid pathway were found as highly expressed genes accompanied by those encoding putative transporters of secondary metabolites. These data suggest the involvement of a novel physiological function of phenylpropanoids in SNF. Moreover, five representative genes were selected, and detailed tissue-specific expression was characterized by promoter-β-glucuronidase experiments. Our results provide a new data source for investigation of both nodule differentiation and tissue-specific physiological functions in nodules.