Two plasmids other than the nodulation plasmid are necessary for formation of nitrogen‐fixing nodules by Rhizobium leguminosarum

Molecular Microbiology - Tập 4 Số 4 - Trang 567-574 - 1990
Michael F. Hynes1, N. F. McGregor1
1Soil Science Section. Agriculture Canada Research Station, Lethbridge, Alberta T1J 4B1, Canada.

Tóm tắt

SummaryA system which allows direct selection for curing of plasmids in Gram‐negative bacteria was used to generate derivatives of Rhizobium leguminosarum VF39 cured of each of six plasmids present in this strain. Phenotypes could be correlated with the absence of five of the six plasmids. The smallest plasmid, pRIeVF39a, carries genes for the production of a melanin‐like pigment as has been previously reported. Plasmid pRIeVF39d carries nodulation and nitrogen fixation genes. Curing of the plasmids pRleVF39c and pRleVF39e gave rise to strains which formed Fix− nodules on peas, lentils, and faba beans. The nodules formed by the strains cured of pRIeVF39c contained few, if any, bacteria. Analysis of washed cells by SDS‐PAGE showed that this strain is defective in lipopolysaccharide (LPS) production; the defect could be complemented by introducing plasmids from several other R. leguminosarum strains, and by the R. leguminosarum biovar phaseoli LPS gene clones pCos126 and pDel27. The nodules formed by the strain cured of pRleVF39e had a reduced symbiotic zone, an enlarged senescence zone, and an abundance of starch granules. This strain grew at a much slower rate than the wild type, was unable to grow on minimal medium, and no longer produced melanin. These defects could be complemented by at least one other Rhizobium plasmid, pRle336e, a plasmid of strain 336 which is distinct from the nodulation plasmid (pRle336c) and the plasmid (pRle336d) which could complement the LPS defect associated with the loss of pRleVF39c. This demonstrates that genes necessary for symbiosis can be carried on at least three different plasmids in R. leguminosarum.

Từ khóa


Tài liệu tham khảo

Aguilar O.M., 1985, Characterization of a Rhizobium meliloti fixation gene (fixF) located near the common nodulation region, J Bacteriol, 164, 245, 10.1128/jb.164.1.245-254.1985

Banfalvi Z., 1981, Location of nitrogen fixation genes on a high molecular weight plasmid of R. meliloti, Mol Gen Genet, 184, 318, 10.1007/BF00272925

10.1002/j.1460-2075.1989.tb03502.x

10.1099/00221287-84-1-188

10.1007/BF00425436

10.1007/BF00333974

10.1007/BF00331503

Brewin N.J., 1982, Recombinant nodulation plasmids in Rhizobium leguminosarum, J Gen Microbiol, 128, 1817

Brink B.A., 1988, Molecular Genetics of Plant‐Microbe Interactions 1988, 55

10.1016/0022-2836(84)90475-3

10.1016/0147-619X(87)90004-7

10.1099/00221287-113-2-229

10.1128/jb.171.1.8-15.1989

10.1016/S0092-8674(88)80012-6

Maagd R.A., 1989, Isolation and characterization of mutants of Rhizobium leguminosarum bv. viciae 248 with altered lipopolysaccharides: possible role of surface charge or hydrophobicity in bacterial release from the infection thread, J Bacteriol, 171, 1143, 10.1128/jb.171.2.1143-1150.1989

10.1073/pnas.83.12.4403

10.1016/0147-619X(78)90016-1

10.1128/jb.167.1.66-72.1986

10.1128/JB.170.8.3396-3403.1988

Flores M., 1987, Reiterated DNA sequences in Rhizobium and Agrobacterium spp, J Bacteriol, 169, 5393, 10.1128/jb.169.12.5782-5788.1987

Forrai T., 1983, Localization of symbiotic mutations in Rhizobium meliloti, J Bacteriol, 153, 635, 10.1128/jb.153.2.635-643.1983

10.1111/j.1365-2958.1988.tb00036.x

Hirsch A.M., 1983, Ultrastructural analysis of ineffective alfalfa nodules formed by nif::Tn5 mutants of Rhizobium meliloti, J Bacteriol, 155, 367, 10.1128/jb.155.1.367-380.1983

10.1099/00221287-113-2-219

Hirsch P.R., 1980, Physical identification of bacteriocinogenic, nodulation, and other plasmids in strains of Rhizobium leguminosarum, J Gen Microbiol, 120, 430

10.1038/291351a0

10.1016/0147-619X(85)90062-9

10.1007/BF00333262

10.1007/BF00408302

10.1016/0378-1119(89)90319-3

10.1128/jb.170.9.3793-3802.1988

Johansen D.A., 1940, Plant Microtechnique

10.1038/276634a0

10.1128/jb.171.2.929-939.1989

10.1128/jb.170.9.4257-4265.1988

10.1007/BF00384401

10.1007/BF00425428

10.1007/BF00338388

Noel K.D., 1984, Rhizobium phaseoli symbiotic mutants with transposon Tn5 insertions, J Bacteriol, 158, 148, 10.1128/jb.158.1.148-155.1984

10.1128/jb.168.3.1392-1401.1986

10.1007/BF00446751

10.1128/jb.169.5.2231-2238.1987

Rosenberg C., 1981, Genes controlling early and late functions in symbiosis are located on a megaplasmid in R. meliloti, Mol Gen Genet, 184, 326, 10.1007/BF00272926

10.1007/BF00436188

10.1128/jb.171.1.569-572.1989

Vincent J.M., 1970, A Manual for the Practical Study of Root‐nodule Bacteria

10.1128/JB.170.2.927-934.1988

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Molecular Microbiology

Tập 4 Số 4

567-574

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