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Expression and stability of a Rhizobium leguminosarum bv. trifolii Sym plasmid in R. meliloti and Agrobacterium tumefaciens and its effect on clover-bacterium symbiosis

✍ Scribed by Dr. G. Miksch; P. Lentzsch


Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
466 KB
Volume
30
Category
Article
ISSN
0233-111X

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✦ Synopsis


The Rhizobiwn legutninosariint bv. trrfolii Sym plasmid pRtr5a was transferred by conjugation to R . nieliloti strains deleted or mutated in the nod and.fir genes, and also to a plasmid-less strain of Agrobacterium runie/ucieris. The plasmid transfer led to the elimination of the resident cryptic plasmid of the R. melilori recipients. The Sym plasmid of the recipients was only eliminated in the case of a deletion. In some cases the transferred plasmid was instable. The nod and n i j / / i ~ genes of R . leguniinosaruni bv. trifolii were expressed in R . nieliloti and somewhat delayed in A . tumejuciens. A high level of nitrogen fixation on clover was only found in R . nieliloti containing pRtr5a. However, this occurred only if the nif/fiv genes of the recipient had been deleted before. Inoculation of clover with this R. nielilori strain resulted in a higher dry matter production in comparison to clover inoculated with the donor strain.