Cell-specific pathways recruited for symbiotic nodulation in the Medicago truncatula legume
Cell-specific pathways recruited for symbiotic nodulation in the Medicago truncatula legume
复制标题
DOI：
10.1016/j.molp.2022.10.021
复制
发表时间：
2022-12-05
期刊：
影响因子：
27.5
通讯作者：
Libault, Marc
中科院分区：
文献类型：
--
作者：
Cervantes-Perez, Sergio Alan;Thibivilliers, Sandra;Libault, Marc
为了了解豆科植物与土壤细菌（统称根瘤菌）之间的共生关系，人们对苜蓿（Medicago truncatula）进行了数十年的研究。这种被称为结瘤的共生关系是在根中由细菌感染根毛细胞开始的，以及从根皮质细胞、内胚层细胞和中柱鞘细胞开始的根瘤原基，导致新的根器官——根瘤的发育，细菌在根瘤中固定和吸收大气中的二氮，以造福植物。在这里，我们报道了从模拟根和接种根瘤菌的根中分离和使用细胞核进行单核RNA-seq （sNucRNA-seq）分析，以深入了解紫花苜蓿根对根瘤菌感染的早期反应。利用119个紫花苜蓿标记基因和拟南芥细胞型标记基因同源物，构建了紫花苜蓿根基因表达图谱，共包含25个簇，并将其标记为特定的细胞类型。对根毛、皮层、内胚层和中柱鞘细胞类型的研究表明，短期（48小时）接种根瘤菌后，根毛、皮层和中柱鞘细胞类型表现出最强的差异调节，不仅揭示了已知的基因和功能途径，验证了sNucRNA-seq方法，而且还揭示了许多新的基因和途径，允许在细胞类型特异性水平上对早期根共生反应进行全面分析。
Medicago truncatula is a model legume species that has been studied for decades to understand the symbiotic relationship between legumes and soil bacteria collectively named rhizobia. This symbiosis called nodulation is initiated in roots with the infection of root hair cells by the bacteria, as well as the initiation of nodule primordia from root cortical, endodermal, and pericycle cells, leading to the development of a new root organ, the nodule, where bacteria fix and assimilate the atmospheric dinitrogen for the benefit of the plant. Here, we report the isolation and use of the nuclei from mock and rhizobia-inoculated roots for the single nuclei RNA-seq (sNucRNA-seq) profiling to gain a deeper understanding of early responses to rhizobial infection in Medicago roots. A gene expression map of the Medicago root was generated, comprising 25 clusters, which were annotated as specific cell types using 119 Medicago marker genes and orthologs to Arabidopsis cell-type marker genes. A focus on root hair, cortex, endodermis, and pericycle cell types, showing the strongest differential regulation in response to a short-term (48 h) rhizobium inoculation, revealed not only known genes and functional pathways, validating the sNucRNA-seq approach, but also numerous novel genes and pathways, allowing a comprehensive analysis of early root symbiotic responses at a cell type-specific level.