Large-scale analysis of gene expression profiles during early stages of root nodule formation in a model legume, Lotus japonicus
Large-scale analysis of gene expression profiles during early stages of root nodule formation in a model legume, Lotus japonicus
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DOI：
10.1093/dnares/11.4.263
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发表时间：
2004-08-31
期刊：
影响因子：
4.1
通讯作者：
Tabata, S
中科院分区：
文献类型：
--
作者：
Kouchi, H;Shimomura, K;Tabata, S
利用从豆科植物莲花中分离到的18,144个非冗余表达序列标签(EST)，分析了模式豆科植物莲花固氮瘤形成早期的基因表达谱。共有1,076个基因在侵染中生根瘤菌、根瘤原基起始、根瘤器官发生和固氮开始的连续阶段显著加速表达。这些基因包括32个根瘤蛋白和根瘤蛋白同源基因，以及一些参与光合作用产物分解代谢和固定氮同化的基因，这些基因以前在许多豆科植物的根瘤中大量表达。我们还发现了大量新的根瘤特异或增强基因，其中包括参与许多细胞过程的基因，如膜运输、防御反应、植物激素合成和反应、信号转导、细胞壁合成和转录调控。值得注意的是，我们的数据表明，根瘤菌-豆科植物相互作用早期阶段的基因表达谱与根瘤发育的后续阶段有很大不同。在侵染过程中大量诱导了一些参与对病原菌和其他胁迫的防御反应的基因，但在随后的根瘤形成过程中这些基因的表达受到抑制。这些结果为研究结瘤和共生固氮的分子机制提供了全面的数据来源。
Gene expression profiles during early stages of formation of symbiotic nitrogen-fixing nodules in a model legume Lotus japonicus were analyzed by means of a cDNA array of 18,144 non-redundant expressed sequence tags (ESTs) isolated from L. japonicus. Expression of a total of 1,076 genes was significantly accelerated during the successive stages that represent infection of Mesorhizobium loti, nodule primordium initiation, nodule organogenesis, and the onset of nitrogen fixation. These include 32 nodulin and nodulin-homolog genes as well as a number of genes involved in the catabolism of photosynthates and assimilation of fixed nitrogen that were previously known to be abundantly expressed in root nodules of many legumes. We also identified a large number of novel nodule-specific or enhanced genes, which include genes involved in many cellular processes such as membrane transport, defense responses, phytohormone synthesis and responses, signal transduction, cell wall synthesis, and transcriptional regulation. Notably, our data indicate that the gene expression profile in early steps of Rhizobium-legume interactions is considerably different from that in subsequent stages of nodule development. A number of genes involved in the defense responses to pathogens and other stresses were induced abundantly in the infection process, but their expression was suppressed during subsequent nodule formation. The results provide a comprehensive data source for investigation of molecular mechanisms underlying nodulation and symbiotic nitrogen fixation.