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Extended region of nodulation genes in Rhizobium meliloti 1021. I. Phenotypes of Tn5 insertion mutants

Journal Article · · Genetics; (United States)
OSTI ID:5355643

Rhizobium meliloti Nod/sup -/ mutant WL131, a derivative of wild-type strain 102F51, was complemented by a clone bank of wild-type R. meliloti 1021 DNA, and clone pRmJT5 was recovered. Transfer of pRmJT5 conferred alfalfa nodulation on other Rhizobium species, indicating a role in host range determination for pRmJT5. Mutagenesis of pRmJT5 revealed several segments in which transposon insertion causes delay in nodulation, and/or marked reduction of the number of nodules formed on host alfalfa plants. The set of mutants indicated five regions in which nod genes are located; one mutant, nod-216, is located in a region not previously reported to encode a nodulation gene. Other mutant phenotypes correlated with the positions of open reading frames for nodH, nodF and nodE, and with a 2.2-kb EcoRI fragment. A mutant in nodG had no altered phenotype in this strain. One nodulation mutant was shown to be a large deletion of the common nod gene region. The authors present a discussion comparing the various studies made on this extended nod gene region.

Research Organization:
Stanford Univ., CA
DOE Contract Number:
AT03-82ER12084
OSTI ID:
5355643
Journal Information:
Genetics; (United States), Journal Name: Genetics; (United States) Vol. 117:2; ISSN GENTA
Country of Publication:
United States
Language:
English