Casuarina glauca prenodule cells display the same differentiation as the corresponding nodule cells
Casuarina glauca prenodule cells display the same differentiation as the corresponding nodule cells
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DOI：
10.1094/mpmi.2000.13.1.107
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发表时间：
2000-01-01
影响因子：
3.5
通讯作者：
Pawlowski, K
中科院分区：
文献类型：
--
作者：
Laplaze, L;Duhoux, E;Pawlowski, K
最近的系统发育研究表明，所有能够进入根瘤与固氮细菌共生的植物都可以追溯到一个共同的祖先（D。E. Soltis，P. S. Soltis，D. R. Morgan，S. M.斯文森，B。C. Mullin，J. M. Dowd和P.G. Martin，Proc. Natl. Acad. Sci. USA，92：2647-2651，1995）。然而，由来自不同组的植物形成的根瘤在根瘤器官发生和结构上不同。在大多数组中，结节器官发生涉及皮层细胞分裂的诱导。在豆科植物中，这些分裂导致根瘤原基的形成，而在非豆科植物中，它们导致由感染和未感染细胞组成的所谓前根瘤的形成。结节原基的形成不涉及前结节细胞，前结节的功能尚不清楚。在这里，我们研究分化的放线菌prenodule细胞相比，结节细胞的共生体，我们的研究结果表明，prenodule代表原始的共生器官，其细胞类型显示相同的特性，作为他们的结节对应。最后，结合根瘤共生体的演化讨论了这一结果。
Recent phylogenetic studies have implied that all plants able to enter root nodule symbioses with nitrogen-fixing bacteria go back to a common ancestor (D. E. Soltis, P. S. Soltis, D. R. Morgan, S. M. Swensen, B. C. Mullin, J. M. Dowd, and P. G. Martin, Proc. Natl. Acad. Sci. USA, 92:2647-2651, 1995), However, nodules formed by plants from different groups are distinct in nodule organogenesis and structure. In most groups, nodule organogenesis involves the induction of cortical cell divisions. In legumes these divisions lead to the formation of a nodule primordium, while in non-legumes they lead to the formation of a so-called prenodule consisting of infected and uninfected cells. Nodule primordium formation does not involve prenodule cells, and the function of prenodules is not known. Here, we examine the differentiation of actinorhizal prenodule cells in comparison to nodule cells with regard to both symbionts, Our findings indicate that prenodules represent primitive symbiotic organs whose cell types display the same characteristics as their nodule counterparts. The results are discussed in the contest of the evolution of root nodule symbioses.