Nieuwkoop A J, Banfalvi Z, Deshmane N, Gerhold D, Schell M G, Sirotkin K M, Stacey G
J Bacteriol. 1987 Jun;169(6):2631-8. doi: 10.1128/jb.169.6.2631-2638.1987.
By using cloned Rhizobium meliloti, Rhizobium leguminosarum, and Rhizobium sp. strain MPIK3030 nodulation (nod) genes as hybridization probes, homologous regions were detected in the slow-growing soybean symbiont Bradyrhizobium japonicum USDA 110. These regions were found to cluster within a 25-kilobase (kb) region. Specific nod probes from R. meliloti were used to identify nodA-, nodB-, nodC-, and nodD-like sequences clustered on two adjacent HindIII restriction fragments of 3.9 and 5.6 kb. A 785-base-pair sequence was identified between nodD and nodABC. This sequence contained an open reading frame of 420 base pairs and was oriented in the same direction as nodABC. A specific nod probe from R. leguminosarum was used to identify nodIJ-like sequences which were also contained within the 5.6-kb HindIII fragment. A nod probe from Rhizobium sp. strain MPIK3030 was used to identify hsn (host specificity)-like sequences essential for the nodulation of siratro (Macroptilium atropurpureum) on a 3.3-kb HindIII fragment downstream of nodIJ. A transposon Tn5 insertion within this region prevented the nodulation of siratro, but caused little or no delay in the nodulation of soybean (Glycine max).
通过使用克隆的苜蓿根瘤菌、豌豆根瘤菌和根瘤菌属MPIK3030菌株的结瘤（nod）基因作为杂交探针，在生长缓慢的大豆共生体日本慢生根瘤菌USDA 110中检测到同源区域。这些区域被发现聚集在一个25千碱基（kb）的区域内。来自苜蓿根瘤菌的特异性nod探针用于鉴定聚集在两个相邻的3.9 kb和5.6 kb HindIII限制性片段上的nodA、nodB、nodC和nodD样序列。在nodD和nodABC之间鉴定出一个785个碱基对的序列。该序列包含一个420个碱基对的开放阅读框，并且与nodABC的方向相同。来自豌豆根瘤菌的特异性nod探针用于鉴定也包含在5.6 kb HindIII片段中的nodIJ样序列。来自根瘤菌属MPIK3030菌株的nod探针用于在nodIJ下游的一个3.3 kb HindIII片段上鉴定对大翼豆（Macroptilium atropurpureum）结瘤至关重要的宿主特异性（hsn）样序列。该区域内的转座子Tn5插入阻止了大翼豆的结瘤，但对大豆（Glycine max）的结瘤几乎没有延迟或没有延迟。
