TRANSFER OF THE SYMBIOTIC ABILITY OF RHIZOBIUM INTO NON-SYMBIOTIC N_2-FIXING BACTERIA.

将根瘤菌的共生能力转移到非共生 N_2-固定细菌中。

• 批准号: 61540491
• 负责人: ABE MIKIKO
• 金额: $ 1.02万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61540491/
• 关键词: Non-symbiotic N_2-fixing bacteria; Rhizobium-leguminous plant; Nodulation gene(nod); Host specific gene(hsn); Gene library; Nod-gene; Hsn-gene; Triparental mating; 根粒バクテリア; 窒素固定能; バクテロイド; 根粒形成変異株; レグヘモグロビン合成; 遺伝子ライブラリー; 広宿主域

The atomospheric nitrogen is fixed and utilized symbiotically by Rhizobium nodulated leguminous plant or non-symbiotically by free-living N_2-fixing bacteria(for example;Azotobacter,Klebsiella etc.) in rhizosphere. The utilization effeciency of fixed nitrogen in symbiotic system as Rhizobium-leguminous plant is higher than in non-symbiotic system as N_2-fixing bacteria.Nitrogen fixation in non-symbiotic bacterial cells is stable under oxigen containing atomosphere, though Rhizobium cannot fix nitrogen under free-living state and in air. The establishment of symbiotic system with the cells, undisturbed N_2-fixation in air, and plants may have many benefical merits. Then, the analysis of nodulation mechanism of Rhizobium was performed in the first step.Rhizobium trifolii Qnl(Nod^+,Fix^-), a mutant derived from R. trifolii 4S(Nod^+,Fix^+,wild type), formed pseudonodules on Trifolium repens, however the one formed normal nodules on Phaseolus vulgaris except lacking of nitrogen fixing ability. It was supposed that strain Qn1 confused host specificity-gene(hsn) from the region of nod-gene. Gene library of total DNA from R. trifolii 4S was prepared for obtaining normal nodulation gene as probe. Nod-gene has been screening out from the gene library by triparental-mating technique using a mutant, R. trifolii H1(sym-plasmid cured), as a recipient. Nod region from strain Qn1 will be able to determine by hybridization with the nod-gene probe and also analyse the hsn region including in nod-gene.We obtained prospects of success that the confused host specific nodulation gene containing in strain Qn1 transfers to non-symbiotic N_2-fixing bacteria in this study.

大气氮由豆科植物根瘤菌共生固定利用，或由自由生活的固氮菌(如固氮菌、克雷伯氏菌等)非共生利用。在根际。根瘤菌-豆科植物共生系统中固氮的利用率高于非共生系统中的固氮菌。在含氧大气中，非共生细菌细胞的固氮作用稳定，但在自由生活状态下和空气中根瘤菌不能固氮。与细胞共生体系的建立、空气中原状固氮和植物共生可能具有许多有益的优点。在此基础上，对根瘤菌的结瘤机理进行了初步分析。三叶根瘤菌4S(nod^+，Fix^+，野生型)的突变体QNL(nod^+，Fix^-)在三叶草上形成假结节，而在四季豆上形成正常结瘤，但缺乏固氮能力。推测Qn1株在nod基因区域混淆了宿主特异性基因(Hsn)。为获得正常结瘤基因作为探针，建立了三叶红曲霉总DNA文库。利用三亲交配技术，利用突变体R.trifolii H1作为受体，从基因文库中筛选出nod基因。通过与nod基因探针杂交可以确定菌株Qn1的nod区，也可以分析包括nod基因在内的HSn区。本研究获得了将菌株Qn1中混乱的寄主特异性结瘤基因转移到非共生固氮细菌中的成功前景。

项目成果

Mikiko Abe;Shiro Higashi;Toshiki Uchiumi: Canadian Journal of Microbiology. (1988)

Mikiko Abe；Shiro Higashi；Toshiki Uchiumi：加拿大微生物学杂志。

Mikiko Abe, Keiji Matsubayashi, Toshiki Uchiumi, Shiro Higashi: "Leghemoglobin gene in the legume-DNA induced by the infection of Rhizobium."

Mikiko Abe、Keiji Matsubayashi、Toshiki Uchiumi、Shiro Higashi：“根瘤菌感染诱导豆科植物 DNA 中的豆血红蛋白基因。”

Mikiko Abe, Toshiki Uchiumi, Shiro Higashi: "The nodules of Phaseolus vulgaris by Rhizobium trifolii Qn1, pseudonodulation mutant from Rhizobium trifolii 4S." Canadian Journal of Microbiology. (1988)

Mikiko Abe、Toshiki Uchiumi、Shiro Higashi：“三叶根瘤菌 Qn1 的菜豆根瘤，来自三叶根瘤菌 4S 的假结节突变体。”

Mikiko Abe, Takashi Futamura, Toshiki Uchiumi, Shiro Higashi: "The analysis of the nodulation gene of Rhizobium."

Mikiko Abe、Takashi Futamura、Toshiki Uchiumi、Shiro Higashi：“根瘤菌结瘤基因的分析。”