Transformed Hairy Roots of Discaria trinervis: A Valuable Tool for Studying Actinorhizal Symbiosis in the Context of Intercellular Infection
Transformed Hairy Roots of Discaria trinervis: A Valuable Tool for Studying Actinorhizal Symbiosis in the Context of Intercellular Infection
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DOI：
10.1094/mpmi-03-11-0078
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发表时间：
2011-11-01
影响因子：
3.5
通讯作者：
Svistoonoff, Sergio
中科院分区：
文献类型：
--
作者：
Imanishi, Leandro;Vayssieres, Alice;Svistoonoff, Sergio
在导致根瘤共生的感染机制中，细胞间感染途径可能是最古老的，但也是最不具特征的。细胞间感染已在三脉盘孢（Discaria trinervis）中描述，该植物是属于蔷薇目的放线根植物。为了阐明Frankia细菌胞间感染的分子机制，我们建立了一种有效的遗传转化方法。基于发根农杆菌的trinervis。我们发现，复合植物与转基因表达绿色荧光蛋白的根可以特异性和有效地由Frankia菌株BCU 110501。固氮速率和反馈抑制根瘤形成的氮在对照和复合植物相似。为了挑战转化系统，将来自蒺藜苜蓿（Medicago truncatula）的基因MtE启动子11导入D.三脉的MtEscherichi11：：GUS的表达与根皮层和发育中的根瘤的薄壁组织中的感染区有关。利用分子工具研究细胞间感染的能力为了解固氮根瘤共生体中感染过程的演变开辟了新的途径。
Among infection mechanisms leading to root nodule symbiosis, the intercellular infection pathway is probably the most ancestral but also one of the least characterized. Intercellular infection has been described in Discaria trinervis, an actinorhizal plant belonging to the Rosales order. To decipher the molecular mechanisms underlying intercellular infection with Frankia bacteria, we set up an efficient genetic transformation protocol for D. trinervis based on Agrobacterium rhizogenes. We showed that composite plants with transgenic roots expressing green fluorescent protein can be specifically and efficiently nodulated by Frankia strain BCU110501. Nitrogen fixation rates and feedback inhibition of nodule formation by nitrogen were similar in control and composite plants. In order to challenge the transformation system, the MtEnod11 promoter, a gene from Medicago truncatula widely used as a marker for early infection-related symbiotic events in model legumes, was introduced in D. trinervis. MtEnod11::GUS expression was related to infection zones in root cortex and in the parenchyma of the developing nodule. The ability to study intercellular infection with molecular tools opens new avenues for understanding the evolution of the infection process in nitrogen-fixing root nodule symbioses.