Cloutier J, Laberge S, Antoun H
Recherche en sciences de la vie et de la santé, Pavillon Charles-Eugène Marchand, Université Laval, Québec (Québec), Canada.
Mol Plant Microbe Interact. 1997 Apr;10(3):401-6. doi: 10.1094/MPMI.1997.10.3.401.
A 6.7-kb region upstream of nodBC genes in Rhizobium sp. strain N33 was shown to contain the nodAFEG genes and an open reading frame designated orfZ. The open reading frames for these genes contain 591, 282, 1209, 738, and 1,338 nucleotides respectively. Homologues of these genes were found in other rhizobia with the exception of orfZ, for which there was no counterpart found in the Genbank/EMBL database. Tn5 mutagenesis in nodEG and in the intergenic nodG-B region has shown a Nod+ phenotype on their temperate hosts Onobrychis viciifolia and Astragalus cicer. The nodules formed on O. viciifolia plants by these mutants were altered in shape and size. However, on A. cicer there was only a reduction in the number of nodules formed, compared with the wild-type strain. Sequence analysis of the orfZ-nodA and nodG-B intergenic regions indicates the presence of truncated nodD genes.
根瘤菌属N33菌株中nodBC基因上游6.7 kb的区域被证明含有nodAFEG基因和一个名为orfZ的开放阅读框。这些基因的开放阅读框分别包含591、282、1209、738和1338个核苷酸。除orfZ外，这些基因的同源物在其他根瘤菌中也有发现，而在Genbank/EMBL数据库中未发现orfZ的对应物。在nodEG和基因间区域nodG - B中进行Tn5诱变，结果表明其在温带宿主红豆草和鹰嘴紫云英上呈现出结瘤阳性表型。这些突变体在红豆草植株上形成的根瘤在形状和大小上发生了改变。然而，与野生型菌株相比，在鹰嘴紫云英上形成的根瘤数量仅有所减少。orfZ - nodA和nodG - B基因间区域的序列分析表明存在截短的nodD基因。
