Kent A D, Wojtasiak M L, Robleto E A, Triplett E W
Department of Bacteriology, University of Wisconsin-Madison 53706, USA.
Appl Environ Microbiol. 1998 May;64(5):1657-62. doi: 10.1128/AEM.64.5.1657-1662.1998.
Improved nitrogen-fixing inoculum strains for leguminous crops must be able to effectively compete with indigenous strains for nodulation, enhance legume productivity compared to the productivity obtained with indigenous strains, and maintain stable expression of any added genes in the absence of selection pressure. We constructed a transposable element containing the tfx region for expression of increased nodulation competitiveness and the par locus for plasmid stability. The transposon was inserted into tetA of pHU52, a broad-host-range plasmid conferring the H2 uptake phenotype. The resulting plasmid, pHUTFXPAR, conferred the plasmid stability, trifolitoxin production, and H2 uptake phenotypes in the broad-host-range organism Sinorhizobium sp. strain ANU280. The broad applications of a transposon conferring plasmid stability are discussed.
用于豆科作物的改良固氮接种菌株必须能够与本地菌株有效竞争结瘤，与使用本地菌株获得的生产力相比提高豆科植物的生产力，并在没有选择压力的情况下维持任何添加基因的稳定表达。我们构建了一个转座子，其包含用于增加结瘤竞争力表达的tfx区域和用于质粒稳定性的par位点。该转座子被插入到pHU52的tetA中，pHU52是一种赋予H2吸收表型的广宿主范围质粒。所得质粒pHUTFXPAR在广宿主范围的中华根瘤菌属菌株ANU280中赋予了质粒稳定性、三叶毒素产生和H2吸收表型。讨论了赋予质粒稳定性的转座子的广泛应用。
