• 1
    Long, S.R. (1989) Rhizobium-legume nodulation: Life together in the underground. Cell 56, 203214.
  • 2
    Long, S.R. (1996) Rhizobium symbioses: nod factors in perspective. Plant Cell 8, 18851898.
  • 3
    Kijne, J.W. (1992) The Rhizobium infection process. In Biological Nitrogen Fixation (Stacey, G. Burris, R.H. & Evans, H.J., eds), pp. 293398. Chapman, New York, USA.
  • 4
    Fisher, R.F. & Long, S.R. (1992) Rhizobium-plant signal exchange. Nature 357, 655660.
  • 5
    van Rhijn, P.V. & Vanderleyden, J. (1995) The Rhizobium-plant symbiosis. Microbiol. Rev. 59, 124142.
  • 6
    Vasse, J., de Billy, F., Camuts, S. & Truchet, G. (1990) Correlation between ultrastructural differentiation of bacteroids and nitrogen fixation in alfalfa nodules. J. Bacteriol. 172, 42954306.
  • 7
    Dénarié, J., Debellé, F. & Rosenberg, C. (1992) Signaling and host range variation in nodulation. Annu. Rev. Microbiol. 46, 497531.
  • 8
    Broughton, W.J., Jabbouri, S. & Perret, X. (2000) Keys to symbiotic harmony. J. Bacteriol. 182, 56415652.
  • 9
    Noel, K.D. & Duelli, D.M. (2000) Rhizobium lipopolysaccharide and its role in symbiosis. In Prokaryotic Nitrogen Fixation: a Model System for Analysis of Biological Process (Triplett, E.W., ed.), pp. 415431. Horizon Scientific press, Wymondham, UK.
  • 10
    Jabbouri, S, Hannin, M., Fellay, R., Quesada-Vincens, D., Ruehs, B.L., Carlson, R.W. & Broughton, W.J. (1996) Rhizobium species NGR234 host-specificity of nodulation locus III contains nod and fix genes. In Biology of Plant–Microbe Interactions (Stacey, G. Mullin, B. & Gresshoff, P.M., eds), pp. 319324. International Society for Plant–Microbe Interactions, St Paul, MN, USA.
  • 11
    Carlson, R.W., Reuhs, B.L., Forsberg, L.S. & Kannenberg, E.L. (1999) Rhizobial cell surface carbohydrates: their structures, biosynthesis, and functions. In Genetics of Bacterial Polysaccharides (Goldberg, J.B., ed.) pp. 5390. CRC Press, Boca Raton, FL, USA.
  • 12
    Spaink, H.P. (2000) Root nodulation and infection factors produced by rhizobial bacteria. Annu. Rev. Microbiol. 54, 257288.
  • 13
    Gray, X.J., Zhan, H., Levery, S.B., Battisti, L., Rolfe, B.G. & Leigh, J.A. (1991) Heterologous exopolysaccharide production in Rhizobium sp. strain NGR234 and consequences for nodule development. J. Bacteriol. 173, 30663077.
  • 14
    Becker, A. & Pühler, A. (1998) Production of exopolysaccharides. In The Rhizobiaceae (Spaink, H.P., Kondorosi, A. & Hooykaas, J.J., eds), pp. 97118. Kluwer Academic Publishers, Dordrecht, the Netherlands.
  • 15
    Chakravorty, A.K., Zurkowski, W., Shine, J. & Rolfe, B.G. (1982) Symbiotic nitrogen fixation: molecular cloning of Rhizobium genes involved in exopolysaccharides synthesis and effective nodulation. J. Mol. Appl. Genet 1, 582596.
  • 16
    Chen, H., Batley, M., Redmond, J. & Rolfe, B.G. (1985) Alteration of effective nodulation properties of a fast-growing broad host range Rhizobium due to changes in exopolysaccharide synthesis. J. Plant Physiol. 120, 331349.
  • 17
    Leigh, J.A., Singer, E.R. & Walker, G.C. (1985) Exopolysaccharide-deficient mutants of Rhizobium meliloti that form ineffective nodules. Proc. Natl Acad. Sci. 82, 62316235.
  • 18
    Borthakur, D., Barber, C.E., Lamb, J.W., Daniels, M.J., Dowie, J.A. & Johnston, A.W.B. (1986) A mutation that blocks exopolysaccharide synthesis prevents nodulation of peas by Rhizobium leguminosarum but not of beans by Rhizobium phaseoli and is corrected by cloned DNA from the phytopathogen Xanthomonas. Mol. General Genet. 203, 320323.
  • 19
    Breedveld, M.W., Canters Cremers, H.C.J., Batley, M., Posthumus, M.A., Zevenhuizen, L.P.T.M., Wijffelman, C.A. & Zehnder, A.J.B. (1993) Polysaccharides synthesis in relation to nodulation behaviour of Rhizobium leguminosarum. J. Bacteriol. 175, 750757.
  • 20
    Djordjevic, S.P., Chen, H., Batley, M., Redmond, J.W. & Rolfe, B.G. (1987) Nitrogen fixation ability of exopolysaccharide synthesis mutants of Rhizobium sp. strain NGR234 and Rhizobium trifolii is restored by the addition of homologous exopolysaccharides. J. Bacteriol. 169, 5360.
  • 21
    Diebold, R. & Noel, K.D. (1989) Rhizobium leguminosarum exopolysaccharide mutants: biochemical and genetic analyses and symbiotic behaviour on three hosts. J. Bacteriol. 171, 48214827.
  • 22
    Kim, C.H., Tully, R.E. & Keister, D.L. (1989) Exopolysaccharide-deficient mutants of Rhizobium fredii HH303 which are symbiotically effective. Appl. Environ. Microbiol. 55, 18521859.
  • 23
    Leigh, J.A., Reed, J.W., Hanks, J.F., Hirsch, A.M. & Walker, G.C. (1987) Rhizobium meliloti mutants that fail to succinylate their calcofluor-binding exopolysaccharide are defective in nodule invasion. Cell 51, 579587.
  • 24
    Hotter, G.S. & Scott, B. (1991) Exopolysaccharide mutants of Rhizobium loti are fully effective on a determinate nodulating host but are ineffective on an indeterminate nodulating host. J. Bacteriol. 173, 851859.
  • 25
    Leigh, J.A. & Coplin, D.L. (1992) Exopolysaccharides in plant–bacterial interactions. Annu. Rev. Microbiol. 46, 307346.
  • 26
    Stacey, G., So, J.S., Roth, L.E., Lakshmi, S.K.B. & Carlson, R.W. (1991) A lipopolysaccharide mutant of Bradyrhizobium japonicum that uncouples plant from bacterial differentiation. Mol. Plant-Microbe Interact. 4, 332340.
  • 27
    Reuber, B.L., Long, S. & Walker, G.C. (1991) Regulation of Rhizobium meliloti exo genes in free-living cells and in plants examined by using TnphoA fusions. J. Bacteriol. 173, 426434.
  • 28
    Karr, D.B., Liang, R.T., Reuhs, B.L. & Emerich, D.W. (2000) Altered exopolysaccharides of Bradyrhizobium japonicum mutants correlate with impaired soybean lectin binding, but not with effective nodule formation. Planta 211, 218226.
  • 29
    Reinhold, B.B., Chan, S.Y., Reuber, T.L., Marra, A., Walker, G.C. & Reinhold, V.N. (1994) Detailed structural characterization of succinoglycan, the major symbiotically important exopolysaccharide of Rhizobium meliloti strain Rm1021. J. Bacteriol. 176, 19972002.
  • 30
    Leigh, J.A. & Lee, C.C. (1988) Characterization of polysaccharides of Rhizobium meliloti exo mutants that form ineffective nodules. J. Bacteriol. 170, 33273332.
  • 31
    Leigh, J.A. & Walker, G.C. (1994) Exopolysaccharides of Rhizobium: synthesis, regulation and symbiotic function. Trends Genet 10, 6367.
  • 32
    Reuber, B.L. & Walker, G.C. (1993) Biosynthesis of succinoglycan, a symbiotically important exopolysaccharide of Rhizobium meliloti. Cell 74, 269280.
  • 33
    Reuhs, B.L., Carlson, R.W. & Kim, J.S. (1993) Rhizobium fredii and Rhizobium meliloti produce 3-deoxy-D-manno-2-octulosonic acid-containing polysaccharides that are structurally analogous to group II K antigens (capsular polysaccharides) found in Escherichia coli. J. Bacteriol. 175, 35703580.
  • 34
    Battisti, L., Lara, J.C. & Leigh, J.A. (1992) Specific oligosaccharide form of the Rhizobium meliloti exopolysaccharide promotes nodule invasion in alfalfa. Proc. Natl Acad. Sci. USA 89, 56255629.
  • 35
    Yang, C., Signer, E.R. & Hirsch, A.M. (1992) Nodules initiated by Rhizobium meliloti exopolysaccharide mutants lack a discrete, persistent nodule meristem. Plant Physiol. 98, 143151.
  • 36
    Cheng, H.P. & Walker, G.C. (1998) Succinoglycan is required for initiation and elongation of infection threads during nodulation of alfalfa by Rhizobium meliloti. J. Bacteriol. 180, 51835191.
  • 37
    Glazebrook, J. & Walker, G.C. (1989) A novel exopolysaccharide can function in place of calcofluor-binding exopolysaccharides in nodulation of alfalfa by Rhizobium meliloti. Cell 56, 661672.
  • 38
    Putnoky, P., Petrovics, G., Kereszt, A., Grosskopf, E., Ha, D.T.C., Banfalvi, Z. & Kondorosi, A. (1990) Rhizobium meliloti lipopolysaccharide and exopolysaccharide can have the same function in the plant–bacterium interaction. J. Bacteriol. 172, 54505458.
  • 39
    Pellock, B.J., Cheng, H.P. & Walker, G.C. (2000) Alfalfa root nodule invasion efficiency is dependent on Sinorhizobium meliloti polysaccharides. J. Bacteriol. 182, 43104318.
  • 40
    Gonzalez, J.E., Reuhs, B.L. & Walker, G.C. (1996) Low molecular weight EPS II of Rhizobium meliloti allows nodule invasion in Medicago sativa. Proc. Natl Acad. Sci. USA 93, 86368641.
  • 41
    Philip-Hollingsworth, S., Hollingsworth, R.I. & Dazzo, F.B. (1989) Host-range related structural features of the acidic extra cellular polysaccharides of Rhizobium trifolii and Rhizobium leguminosarum. J. Biol. Chem. 264, 14611466.
  • 42
    Philip-Hollingsworth, S., Hollingsworth, R.I., Dazzo, F.B., Djordjevic, M.A. & Rolfe, B.G. (1989) The effect of interspecies transfer of Rhizobium host-specific nodulation genes on acidic polysaccharide structure and in situ binding by host lectin. J. Biol. Chem. 264, 57105714.
  • 43
    O'Neill, M.A., Darvill, A.G. & Albersheim, P. (1991) The degree of esterification and points of substitution by O-acetyl and O-(3-hydroxybutanoyl) groups in the acidic extracellular polysaccharides secreted by Rhizobium leguminosarum biovars viciae, trifolii, and phaseoli are not related to host range. J. Biol. Chem. 266, 95499555.
  • 44
    van Workum, W.A.T., van Slageren, S., van Brussel, A.A.N. & Kijne, J.W. (1998) Role of exopolysaccharides of Rhizobium leguminosarum bv. viciae as host plant-specific molecules required for infection thread formation during nodulation of Vicia sativa. Mol. Plant-Microbe Interact 11, 12331241.
  • 45
    Niehaus, K., Kapp, D. & Pühler, A. (1993) Plant defense and delayed infection of alfalfa pseudonodules induced by an exopolysaccharide (EPSI-deficient Rhizobium meliloti mutant. Planta 190, 415425.
  • 46
    Niehaus, K., Baier, R., Kohring, B., Flashl, E. & Pühler, A. (1997) Symbiotic suppression of the Medicago sativa plant defence system by Rhizobium meliloti oligosaccharides. In Biological Fixation of Nitrogen for Ecology and Sustanaible Agriculture (Legoki, A., Bothe, H. & Pühler, A., eds), pp. 110114. Springer Verlag, Heidelberg, Germany.
  • 47
    Skorupska, A., Bialek, U., Urbanik-Sypniewska, T. & van Lammeren, A. (1995) Two types of nodules induced on Trifolium pratense by mutants of Rhizobium leguminosarum bv. trifolii deficient in exopolysaccharide production. J. Plant Physiol. 147, 93100.
  • 48
    Rolfe, B.G., Carlson, R.W., Ridge, R.W., Dazzo, F.B., Mateos, P.F. & Pankhurst, C.E. (1996) Defective infection and nodulation of clovers by exopolysaccharide mutants of Rhizobium leguminosarum bv Trifolii. Aust. J. Plant. Physiol. 23, 285303.
  • 49
    van Workum, W.A.T., van Brussel, A.A.N., Tak, T., Wijffelmann, C.A. & Kijne, J.W. (1995) Ethylene prevents nodulation of Vicia sativa ssp. nigra by exopolysaccharide deficient mutants of Rhizobium leguminosarum bv Viciae. Mol. Plant-Microbe Interact. 8, 278285.
  • 50
    Parniske, M., Kosch, K., Werner, D. & Müller, P. (1993) ExoB mutants of Bradyrhizobium japonicum with reduced competitivity on Glycine max. Mol. Plant-Microbe Interact. 6, 99106.
  • 51
    Parniske, M., Schmidt, P.E., Kosch, K. & Müller, P. (1994) Plant defense response of host plants with determinate nodules induced by EPS defective exoB mutants of Bradyrhizobium japonicum. Mol Plant-Microbe Interact. 7, 631638.
  • 52
    Schmidt, P.E., Parniske, M. & Werner, D. (1992) Production of the phytoalexin glyceollin I by soybean roots in response to symbiotic and pathogenic infection. Bot. Acta 105, 1825.
  • 53
    Breedveld, M.W. & Miller, K.J. (1994) Cyclic β-glucans of members of the family. Rhizobiaceae. Microbiol. Rev. 58, 145161.
  • 54
    Breedveld, M.W. & Miller, K.J. (1998) Cell surface β-glucans. In The Rhizobiaceae (Spaink, H.P., Kondorosi, A. & Hooykaas, J.J., eds), pp. 8196. Kluwer Academic Publishers, Dordrecht, the Netherlands.
  • 55
    Gore, R.S. & Miller, K.J. (1992) Cell surface carbohydrates of micro aerobic, nitrogenase-active, continuous cultures of Bradyrhizobium sp. strain 32H1. J. Bacteriol. 174, 78387840.
  • 56
    Bhagwat, A.A., Tully, R.E. & Keister, D.L. (1992) Isolation and characterization of an ndvB locus from Rhizobium fredii. Mol. Microbiol. 6, 21592165.
  • 57
    Inon de Iannino, N. & Ugdale, R.A. (1993) Biosynthesis of cyclic beta-(1–3), beta-(1–6) glucan in Bradyrhizobium spp. Arch. Microbiol. 159, 3038.
  • 58
    Gore, R.S. & Miller, K.J. (1993) Cyclic β-1,6–1,3 glucans are synthesized by Bradyrhizobium japonicum bacteroids within soybean (Glycine max) root nodules. Plant Physiol. 102, 191194.
  • 59
    Dylan, T., Helinski, D.R. & Ditta, G.S. (1990) Symbiotic pseudo-revertants of Rhizobium meliloti ndv mutants. J. Bacteriol. 172, 14001408.
  • 60
    Bhagwat, A.A. & Keister, D.L. (1995) Site directed mutagenesis of the α(1>3), α(1>6)-d-glucan synthesis locus of Bradyrhizobium japonicum. Mol. Plant-Microbe Interact. 8, 366370.
  • 61
    Bhagwat, A.A., Mithofer, A., Pfeffer, P.E., Kraus, C., Spickers, N., Hotchkiss, A., Ebel, J. & Keister, D.L. (1999) Further studies of the role of cyclic beta-glucans in symbiosis. An NdvC mutant of Bradyrhizobium japonicum synthesizes cyclodekakis-(1,3)-beta-glucosyl. Plant Physiol. 119, 10571064.
  • 62
    Dunlap, J., Minami, E., Bhagwat, A.A., Keister, D.L. & Stacey, G. (1996) Nodule development induced by mutants of Bradyrhizobium japonicum defective in cyclic B-glucan synthesis. Mol. Plant Microbe Interact. 9, 546555.
  • 63
    Miller, K.J., Hadley, J.A. & Gustine, D.L. (1994) Cyclic β-1,6–1,3-glucans of Bradyrhizobium japonicum USDA 110 elicit isoflavonoid production in soybean (Glycine max) host. Plant Physiol. 104, 917923.
  • 64
    Collinge, D.B., Kragh, K.M., Mikkelsen, J.D., Nielsen, K.K., Rasmussen, U. & Vad, K. (1993) Plant chitinases. Plant J. 3, 3140.
  • 65
    Mithöfer, A., Bahgwat, A.A., Feger, M. & Ebel, J. (1996) Suppression of fungal β-glucan-induced plant defense in soybean (Glycine max L.) by cyclic 1,3–1,6-β-glucans for the symbiont Bradirhizobium japonicum. Planta 199, 270275.
  • 66
    Mithöfer, A., Bahgwat, A.A., Keister, D.L. & Ebel, J. (2001) Bradyrhizobium japonicum mutants defective in cyclic α-glucanes synthesis show enhanced sensitivity to plant defense responses. Z. Naturforsch. 56c, 581584.
  • 67
    Forsberg, L.S. & Reuhs, B. (1997) Structural characterization of the K antigens from Rhizobium fredii USDA257: evidence for a common structural motif, with strain-specific variation, in the capsular polysaccharides of Rhizobium spp. J. Bacteriol. 179, 53665371.
  • 68
    Forsberg, L.S. & Carlson, R.W. (1998) The structures of the lipopolysaccharides from Rhizobium etli strains CE358 and CE359 – the complete structure of the core region of R. etli lipopolysaccharides. J. Biol. Chem. 273, 27472757.
  • 69
    Reuhs, B.L., Williams, M.N.V., Kim, J.S., Carlson, R.W. & Cote, F. (1995) Suppression of the Fix phenotype of Rhizobium meliloti exoB mutants by lpsZ is correlated to a modified expression of the K-polysaccharide. J. Bacteriol. 177, 42894296.
  • 70
    Campbell, G.O., Reuhs, B.L. & Walker, G.C. (1998) Different phenotypic classes of Sinorhizobium meliloti mutants defective in synthesis of K antigen. J. Bacteriol. 180, 54325436.
  • 71
    Reuhs, B.L., Geller, D.P., Kim, J.S., Fox, J.E., Kolli, V.S. & Pueppke, S.G. (1998) Sinorhizobium fredii and Sinorhizobium meliloti produce structurally conserved lipopolysaccharides and strain-specific K antigens. Appl. Environ. Microbiol. 64, 49304938.
  • 72
    Kereszt, A., Kiss, E., Reuhs, B.L., Carlson, R.W., Kondorosi, A. & Putnoky, P. (1998) Novel rkp gene clusters of Sinorhizobium meliloti involved in capsular polysaccharide production and invasion of the symbiotic nodule: the rkpK gene encodes a UDP-Glucose dehydrogenase. J. Bacteriol. 180, 54265431.
  • 73
    Becquart-de-Kozak, I., Reuhs, B.L., Buffard, D., Breda, C., Kim, J.S., Esnault, R. & Kondorosi, A. (1997) Role of the K-antigen sub-group of capsular polysaccharide in the early recognition process between Rhizobium meliloti and alfalfa leaves. Mol Plant-Microbe Interact. 10, 114123.
  • 74
    Williams, M.N.V., Hollingsworth, R.I., Klein, S. & Signer, E.R. (1990) The symbiotic defect of Rhizobium meliloti exopolysaccharide mutants is suppressed by lpsZ+, a gene involved in lipopolysaccharide synthesis. J. Bacteriol. 172, 26222632.
  • 75
    Kiss, E., Kereszt, A., Barta, F., Stephens, S., Reuhs, B.L., Kondorosi, A. & Putnoky, P. (2001) The rkp3 gene region of Sinorhizobium meliloti Rm41 contains strain specific genes that determine K-antigene structure. Mol. Plant-Microbe Interact. 14, 13951403.
  • 76
    Carrion, M., Bhat, U.R., Reuhs, B. & Carlson, R.W. (1990) Isolation and characterization of the lipopolysaccharides from Bradyrhizobium japonicum. J. Bacteriol. 172, 17251731.
  • 77
    Price, N.P.J. (1999) Carbohydrate determinants of Rhizobium-legume symbioses. Carbohydr. Res. 317, 19.
  • 78
    Carlson, R.W., Reuhs, B., Chen, T.B., Bhat, U.R. & Noel, K.D. (1995) Lipopolysaccharide core structures in Rhizobium etli and mutants deficient in O-antigen. J. Biol. Chem. 270, 1178311788.
  • 79
    Bhat, U.R., Carlson, R.W., Busch, M. & Mayer, H. (1991) Distribution and phylogenetic significance of 27-hydroxy-octacosanoicacid in lipopolysaccharides from bacteria belonging to the alpha-2 subgroup of Proteobacteria. Int. J. Syst. Bacteriol. 41, 213217.
  • 80
    Bhat, U.R., Mayer, H., Yokota, A., Hollingsworth, R.I. & Carlson, R.W. (1991) Occurrence of lipid A variants with 27-hydroxyoctacosanoic acid in lipopolysaccharides from members of the family Rhizobiaceae. J. Bacteriol. 173, 21552159.
  • 81
    Choma, A. (1999) Fatty acid composition of Mesorhizobium huakuii lipopolysaccharides. Identification of 27-oxooctacosanoic acid. FEMS Microbiol. Lett. 177, 257262.
  • 82
    Choma, A., T. Urbanik-Sipniewska, R. Russa, J. Kutkowska & Mayer H. (2000) Occurrence and taxonomic significance of oxo-fatty acids in lipopolysaccharides from members of Mesorhizobium. System. Appl. Microbiol. 23, 185190.
  • 83
    Russa, R., Urbanik-Sipniewska, T., Lindstrom, K. & Mayer, H. (1995) Chemical characterization of two lipopolysaccharides species isolated from Rhizobium loti NZP2213. Arch. Microbiol. 163, 345351.
  • 84
    Que, N.L.S., Ribeiro, A.A. & Raetz, C.R.H. (2000) Two-dimensional NMR spectroscopy and structures of six Lipid A species from Rhizobium etli CE3′. J. Biol. Chem. 275, 2801728027.
  • 85
    Que, N.L.S., Lin, S., Cotter, R.J. & Raetz, C.R.H. (2000) Purification and mass spectrometry of six lipid A species from the bacterial endosymbiont Rhizobium etli. J. Biol. Chem. 275, 2800628016.
  • 86
    Bhat, U.R., Krishnaiah, B.S. & Carlson, R.W. (1991) Re-examination of the structures of the lipopolysaccharides core oligosaccharides from Rhizobium leguminosarum biovar. Phaseoli. Carbohydr. Res. 220, 219227.
  • 87
    Carlson, R.W., Garci, F., Noel, D. & Hollingsworth, R. (1989) The structures of the LPS core components from Rhizobium leguminosarum biovar phaseoli and two of its symbiotic mutants, CE 109, and CE 309. Carbohydr. Res. 195, 101110.
  • 88
    Bhat, U.R., Forsberg, S.L. & Carlson, R.W. (1994) Structure of lipid A component of Rhizobium leguminosarum bv. Phaseoli lipopolysaccharide. J. Biol. Chem. 269, 1440214410.
  • 89
    Carlson, R.W., Hollingsworth, R.L. & Dazzo, F.B. (1988) A core oligosaccharide component from the lipopolysaccharide of Rhizobium trifolii ANU843. Carbohydr. Res. 176, 127135.
  • 90
    Carlson, R.W. & Krishnaiah, B.S. (1992) Structures of the oligosaccharides obtained from the core regions of the lipopolysaccharides of Bradyrhizobium japonicum 61A101c and its symbiotically defective lipopolysachharide mutant, JS314. Carbohydr. Res. 231, 205219.
  • 91
    Wang, Y. & Hollingsworth, R.I. (1994) The structure of the O-antigenic chain of the lipopolysaccharide of Rhizobium trifolii 4s. Carbohydr. Res. 260, 305317.
  • 92
    Gil-Serrano, A.M., González-Jiménez, I., Mateo, P.T., Bernabé, M., Jiménez-Barbero, J., Megias, M. & Romero-Vázquez, M.J. (1995) Structural analysis of the O-antigen of the lipopolysaccharide of Rhizobium tropici CIAT899. Carbohydr. Res. 275, 285294.
  • 93
    Forsberg, L.S., Bhat, U.R. & Carlson, R.W. (2000) Structural characterisation of the LPS from Rhizobiumetli strain CE3. J. Biol. Chem. 275, 1885118863.
  • 94
    Reuhs, B.L., Kim, J.S., Badgett, A. & Carlson, R.W. (1994) Production of cell-associated polysaccharides of Rhizobium fredii USDA205 is modulated by apigenin and host root extract. Mol. Plant. Microbe Interact. 7, 240247.
  • 95
    Dazzo, F.B., Truchet, G.L., Hollingsworth, R.I., Hrabak, E.M., Pankratz, H.S., Philip-Hollingsworth, S., Salzwedel, J.L., Chapman, K., Appenzeller, L., Squartini, A., Gerhold, D. & Orgambide, G. (1991) Rhizobium LPS modulates infection thread development in white clover root hairs. J. Bacteriol. 173, 53715384.
  • 96
    Perotto, S., Brewin, N.J. & Kannenberg, E.L. (1994) Cytological evidence for a host defence response that reduces cell and tissue invasion in pea nodules by lipopolysaccharides-defective mutants of Rhizobium leguminosarum strain 3841. Mol. Plant-Microbe Interact. 7, 99112.
  • 97
    Albus, U., Baier, R., Holst, O., Pühler, A. & Niehaus, K. (2001) Suppression of an elicitor-induced oxidative burst in Medicago sativa cell-cultures by Sinorhizobium meliloti lipopolysaccharides. New Phytologist 151, 597606.
  • 98
    Kannenberg, E.L. & Carlson, R.W. (2001) Lipid A and O-chain modifications cause Rhizobium lipopolysaccharides to become hydrophobic during bacteroid development. Mol. Microbiol. 39, 379391.
  • 99
    Fraysse, N., Jabbouri, S., Treilhou, M., Couderc, C. & Poinsot, V. (2002) symbiotic conditions induce structural modifications of S. sp. NGR234 surface polysaccharides. Glycobiology 12, 741748.
  • 100
    Lagares, A., Caetano-Anollès, G., Niehaus, K., Lorenzen, J., Ljunggren, H.D., Pühler, A. & Favelukes, G. (1992) A Rhizobium meliloti lipopolysaccharide mutant altered in competitiveness for nodulation on alfalfa. J. Bacteriol. 174, 59415952.
  • 101
    Lagares, A., Hozbor, D.F., Niehaus, K., Otero, A.J., Lorenzen, J. & Pühler, A. (2001) Genetic characterization of a Sinorhizobium meliloti chromosomal region in lipopolysaccharide biosynthesis. J. Bacteriol. 183, 12481258.
  • 102
    Campell, G.R.O., Reuhs, B.L. & Walker, G.C. (2002) Chronic intracellular infection of alfalfa nodules by Sinorhizobium meliloti requires correct lipopolysaccharide core. Proc. Natl Acad. Sci. USA 99, 39383943.
  • 103
    Carlson, R.W. (1984) The heterogeneity of Rhizobium lipopolysaccharides. J. Bacteriol. 58, 10121017.
  • 104
    Carlson, R.W., Kalembasa, S., Turowski, D., Pachori, P. & Noel, K.D. (1987) Characterization of the lipopolysaccharide from a Rhizobium phaseoli mutant that is defective in infection thread development. J. Bacteriol. 169, 49234928.
  • 105
    Carlson, R.W., Shatters, R., Duh, J.L., Turnbull, E., Hanley, B., Rolfe, B.G. & Djordjevic, M.A. (1987) The isolation and partial characterization of the lipopolysaccharides from several Rhizobium trifolii mutants affected in root hair infection. Plant Physiol. 84, 421427.
  • 106
    Choma, A., Sowinski, P. & Mayer, H. (2000) Structure of the O-specific polysaccharide of Mesorhizobium huakuii IFO15243T. Carbohydr. Res. 329, 459464.
  • 107
    Gao, M., D'Haeze, W., De Rycke, R., Wolucka, B. & Holsters, M. (2001) Knockout of an Azorhizobial dTDP-L-Rhamnose synthase affects lipopolysaccharide and extracellular polysaccharide production and disables symbiosis with Sesbania rostrata. Mol Plant-Microbe Interact. 14, 857866.
  • 108
    Allaway, D., Calvaco, S., Saini, S., Hocking, P., Lodwig, E.M., Leonard, M.E. & Poole, P.S. (2000) Identification of a putative LPS-associated cation exporter from Rhizobium leguminosarum bv. Viciae. FEMS Microbiol. Lett. 186, 4753.
  • 109
    Brink, B.A., Miller, J., Carlson, R.W. & Noel, K.D. (1990) Expression of Rhizobium leguminosarum CFN42 genes for lipopolysaccharide in strains derived from different R. leguminosarum soil isolates. J. Bacteriol. 172, 548555.
  • 110
    Noel, K.D., Van den Bosch, K.A. & Kulpaca, B. (1986) Mutations in Rhizobium phaseoli that lead to arrested development of infection threads. J. Bacteriol. 168, 13921401.
  • 111
    Noel, K.D., Forsberg, L.S. & Carlson, R.W. (2000) Varying the abundance of O-antigen in Rhizobium etli and its effect on symbiosis with Phaseolus vulgaris. J. Baceriol. 182, 53175324.
  • 112
    Noel, K.D., Duelli, D.M., Tao, H. & Brewin, N.J. (1996) Antigenic change in the lipopolysaccharide of Rhizobium etli CFN42 induced by exudates of Phaseolus vulgaris. Mol. Plant-Microbe Interact. 9, 180186.
  • 113
    Clover, R.H., Kieber, J. & Signer, E.R. (1989) Lipopolysaccharide mutants of Rhizobium meliloti are not defective in symbiosis. J. Bacteriol. 171, 39613967.
  • 114
    Lipsanen, P. & Lindstrom, K. (1989) Lipopolysaccharide and protein patterns of Rhizobium sp. Galega. FEMS Microbiol. Lett. 58, 323328.
  • 115
    Sindhu, S.S., Brewin, N.J. & Kannenberg, E.L. (1990) Immunochemical analysis of lipopolysaccharides from free-living and endosymbiotic forms of Rhizobium leguminosarum. J. Bacteriol. 172, 18041813.
  • 116
    Kannenberg, E.L., Perotto, S., Bianciotto, V., Rathbun, E.A. & Brewin, N.J. (1994) Lipopolysaccharide epitope expression of Rhizobium bacteroids as revealed by in situ immunolabelling of pea root nodule sections. J. Bacteriol. 176, 20212032.
  • 117
    Reuhs, B.L., Stephens, S.B., Geller, D.P., Kim, J.S., Glenn, J., Przytycki, J. & Ojanen-Reuhs, T. (1999) Epitope identification for a panel of anti-Sinorhizobium meliloti monoclonal antibodies and application to the analysis of K-antigen and LPS from bacteroids. Appl. Env. Microbiol. 65, 51865191.
  • 118
    Freiberg, C., Fellay, R., Bairoch, A., Broughton, W.J., Rosenthal, A. & Perret, X. (1997) Molecular basis of symbioses between Rhizobium and legumes. Nature 387, 397401.
  • 119
    Streeter, J.G., Salminen, S.O., Whitmoyer, R.E. & Carlson, R.W. (1992) Formation of novel polysaccharides by Bradyrhizobium japonicum bacteroids in soybean nodules. Appl. Environ. Microbiol. 58, 606613.
  • 120
    An, J., Carlson, R.W., Glushka, J. & Streeter, J.G. (1995) The structure of a novel polysaccharide produced by Bradyrhizobium species within soybean nodules. Carbohydr. Res. 269, 303317.
  • 121
    Guentas, L., Pheulpin, P., Michaud, P., Heyraud, A., Gey, C., Courtois, B. & Courtois, J. (2001) Structure of a polysaccharide from a Rhizobium species containing 2-deoxy-β-d-arabino-hexuronic acid. Carbohydr. Res. 332, 167173.
  • 122
    Gray, X.J. & Rolfe, B.G. (1990) Exopolysaccharide production in Rhizobium and its role in invasion. Mol. Microbiol. 4, 14251431.
  • 123
    Mendrygal, K.E. & Gonzales, J.E. (2000) Environmental regulation of exopolysaccharide production in Rhizobium meliloti. J. Bacteriol. 182, 599606.
  • 124
    Dusha, I., Austin, S. & Dixon, R. (1999) The upstream region of the nodD3 gene of Sinorhizobium meliloti carries enhancer sequences for the transcriptional activator NtrC. FEMS Microbiol. Lett. 179, 491499.
  • 125
    Brewin, N.J. (1998) Tissue and cell invasion by Rhizobium: the structure and development of infection threads and symbiosomes. In The Rhizobiaceae (Spaink, H.P., Kondorosi, A. & Hooykaas, J.J., eds), pp. 417429. Kluwer Academic Publishers, Dordrecht, the Netherlands.
  • 126
    Lerouge, I. & Vanderleyden, J. (2001) O-antigen structural variation: mechanisms and possible roles in animal/plant–microbe interactions. FEMS Microbiol. Rev. 26, 1747.
  • 127
    Oke, V. & Long, S.R. (1999) Bacteroid formation in the Rhizobium-legume symbiosis. Current Opinion Microbiol. 2, 641646.
  • 128
    Rodriguez-Carvajal, M.A., Tejero-Mateo, P., Espartero, J.L., Ruiz-Sainz, J.E., Buendia-Claveria, A.M., Ollero, F.J., Yang, S.S. & Gil-Serrano, A.M. (2001) Determination of the chemical structure of the capsular polysaccharide of strain B33, a fast-growing soya bean-nodulating bacterium isolated from an arid region of China. Biochem. J. 357, 505511.
  • 129
    Gil-Serrano, A.M., Rodriguez-Carvajal, M.A., Tejero-Mateo, P., Espartero, J.L., Menendez, M., Corzo, J., Ruiz-Sainz, J.E. & Buendia-Claverias, A. (1999) Structural determination of a 5-acetamido-3,5,7,9-tetradeoxy-7-(3-hydroxy-butyramido)-l-glycero-l-manno-nonulosonic acid-containing homopolysaccharide isolated from Sinorhizobium fredii HH103. Biochem. J. 342, 527535.