Transfer of the symbiotic plasmid from Rhizobium leguminosarum biovar trifolii to Agrobacterium tumefaciens
Transfer of the symbiotic plasmid from Rhizobium leguminosarum biovar trifolii to Agrobacterium tumefaciens
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DOI：
10.2323/jgam.44.65
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发表时间：
1998-02-01
影响因子：
1.2
通讯作者：
Uchiumi, T
中科院分区：
文献类型：
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作者：
Abe, M;Kawamura, R;Uchiumi, T
本研究检查了通过转移来自豆科根瘤菌的 315 kb 巨质粒 pRt4Sa 的 Tn5-mob 标记衍生物分离的农杆菌转接合子的共生特性。 trifolii 4S（野生型菌株）以根癌农杆菌A136为受体。通过随机扩增多态性 DNA (RAPD) 分析和使用 Tn5-mob 和 nod 基因作为探针的 Southern 杂交来确定 AT4S 转接合体菌株的遗传特征。这些携带 pRt4Sa 的 AT4S 转接合子中的一些能够使正常豆类宿主白三叶草的根结节。此外，一些 AT4S 转接合体菌株能够在其他豆科植物（包括苜蓿和毛野豌豆）上诱导根瘤。尽管未发现固氮活性（乙炔还原），但在 AT4S 系列菌株诱导的三叶草和苜蓿根瘤中观察到特征性类菌分化。此外，通过追溯 pRt4Sa::Tn5-mob 从菌株 AT4Sa 转移到菌株 H1（pRt4Sa 4S 固化衍生物）获得的菌株 H1R1，在三叶草根部诱导了 Fix(+) 根瘤。这些结果表明只有 nod 基因可以在农杆菌背景中表达。
This study examined the symbiotic properties of Agrobacterium transconjugants isolated by transferring a Tn5-mob-marked derivative of the 315 kb megaplasmid pRt4Sa from Rhizobium leguminosarum by. trifolii 4S (wild-type strain) to Agrobacterium tumefaciens A136 as the recipient. The genetic characteristics of the AT4S transconjugant strains were ascertained by random amplified polymorphic DNA (RAPD) analyses and Southern hybridization using Tn5-mob and nod genes as probes. Several of these AT4S transconjugants carrying pRt4Sa were able to nodulate roots of the normal legume host, white clover. In addition, some AT4S transconjugant strains were able to induce nodules on other leguminous plants, including alfalfa and hairy vetch. A characteristic bacteroid differentiation was observed in clover and alfalfa nodules induced by the AT4S-series strains, although nitrogen-fixing activity (acetylene reduction) was not found. Furthermore, strain H1R1, obtained by retracing transfer of the pRt4Sa::Tn5-mob from strain AT4Sa to strain H1 (pRt4Sa cured derivative of 4S), induced Fix(+) nodules on clover roots. These results indicate the evidence that only nod genes can be expressed in the Agrobacterium background.