Räsänen L A, Heikkilä-Kallio U, Suominen L, Lipsanen P, Lindström K
Department of Microbiology, University of Helsinki, Finland.
Mol Plant Microbe Interact. 1991 Nov-Dec;4(6):535-44. doi: 10.1094/mpmi-4-535.
The cosmid clone pRg30, carrying common nodulation genes of Rhizobium galegae HAMBI 1174, and pRg33, a subclone of pRg30 that contains a 5.7-kb ClaI insert carrying nodDABC were conjugated into various Rhizobium nod- mutant strains and into a Ti plasmid-cured Agrobacterium tumefaciens. Complementation and expression of the nodABC genes of R. galegae were studied by following microscopically the infection process and the nodulation on different test plants. The nodABC genes of R. galegae complemented the nod- strains of other Rhizobium species. The presence of extra copies of common nod genes in the homologous R. galegae nodABC- strain induced an increased nodulation on Galega orientalis. However, the inserts of R. galegae in pRg30 and pRg33 do not carry sufficient genetic information for normal nodulation of test plants in an Agrobacterium background, because the Agrobacterium transconjugants induced root hair deformation on Galega plants, but no infection threads were detected and nodulelike structures developed only at low frequency. The Agrobacterium carrying the nodDABC of R. galegae did not cause the root hairs of Medigo sativa to deform.
携带豌豆根瘤菌HAMBI 1174常见结瘤基因的黏粒克隆pRg30以及pRg30的一个亚克隆pRg33（其包含一个携带nodDABC的5.7 kb ClaI插入片段）被接合到各种根瘤菌nod-突变菌株以及一个去除了Ti质粒的根癌农杆菌中。通过显微镜观察感染过程以及在不同测试植物上的结瘤情况，研究了豌豆根瘤菌nodABC基因的互补作用和表达情况。豌豆根瘤菌的nodABC基因对其他根瘤菌属的nod-菌株起到了互补作用。在同源的豌豆根瘤菌nodABC-菌株中存在额外拷贝的常见结瘤基因，导致在东方山羊豆上的结瘤增加。然而，pRg30和pRg33中豌豆根瘤菌的插入片段对于在根癌农杆菌背景下测试植物的正常结瘤来说，携带的遗传信息并不足够，因为根癌农杆菌接合子在山羊豆植物上诱导了根毛变形，但未检测到侵染线，且仅在低频率下形成了类瘤结构。携带豌豆根瘤菌nodDABC的根癌农杆菌并未使紫花苜蓿的根毛变形。
