Agrobacterium rhizogenes-transformed roots of Medicago truncatula for the study of nitrogen-fixing and endomycorrhizal symbiotic associations
Agrobacterium rhizogenes-transformed roots of Medicago truncatula for the study of nitrogen-fixing and endomycorrhizal symbiotic associations
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DOI：
10.1094/mpmi.2001.14.6.695
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发表时间：
2001-06-01
影响因子：
3.5
通讯作者：
Barker, DG
中科院分区：
文献类型：
--
作者：
Boisson-Dernier, A;Chabaud, M;Barker, DG
蒺藜苜蓿是一种二倍体自花受精豆科植物，目前正被开发为研究根系内共生关系的模式植物，包括菌根化和菌根定殖。对这种植物的一个重要要求是在根组织中快速引入和分析嵌合基因构建体的可能性。为此，我们建立并优化了一种方便的发根农杆菌介导的转化方法。蒺藜这种不寻常的协议，其中包括接种的切片幼苗胚根，结果在快速和有效的毛状根器官发生和随后的发展，蓬勃发展的“复合植物。“此外，我们发现卡那霉素可用于选择直接与感兴趣的基因构建体共转化毛状根。M.蒺藜复合植物毛状根具有与正常根相似的形态，并且可以被它们的固氮共生伙伴苜蓿中华根瘤菌（Sinorhizobium meliloti）成功地分化。此外，时空表达的结瘤因子响应报告pMtENOD 11-gusA毛状根表皮组织中观察到的根癌农杆菌转化线是不可区分的。M，蒺藜毛状根外植体可以在体外繁殖，我们证明，这些克隆线可以由内生真菌，如球囊霉根内皮层细胞内形成丛枝的殖民。我们的结果表明，M.蒺藜毛状根是研究转基因修饰根内共生关系的一个特别有吸引力的系统。
Medicago truncatula, a diploid autogamous legume, is currently being developed as a model plant for the study of root endosymbiotic associations, including nodulation and mycorrhizal colonization. An important requirement for such a plant is the possibility of rapidly introducing and analyzing chimeric gene constructs in root tissues. For this reason, we developed and optimized a convenient protocol for Agrobacterium rhizogenes-mediated transformation of M. truncatula. This unusual protocol, which involves the inoculation of sectioned seedling radicles, results in rapid and efficient hairy root organogenesis and the subsequent development of vigorous "composite plants." In addition, we found that kanamycin can be used to select for the cotransformation of hairy roots directly with gene constructs of interest. M. truncatula composite plant hairy roots have a similar morphology to normal roots and can be nodulated successfully by their nitrogen-fixing symbiotic partner, Sinorhizobium meliloti. Furthermore, spatiotemporal expression of the Nod factor-responsive reporter pMtENOD11-gusA in hairy root epidermal tissues is indistinguishable from that observed in Agrobacterium tumefaciens-transformed lines. M, truncatula hairy root explants can be propagated in vitro, and we demonstrate that these clonal lines can be colonized by endomycorrhizal fungi such as Glomus intraradices with the formation of arbuscules within cortical cells. Our results suggest that M. truncatula hairy roots represent a particularly attractive system with which to study endosymbiotic associations in transgenically modified roots.