Abstract
A newly isolated mutant of the symbiotic bacterium Rhizobium leguminosarum bv. trifolii, Rt79, is deficient in exopolysaccharide synthesis. It induced nodules defective in nitrogen fixation on clover (Trifolium pratense L.). The expression of plant (ENOD2, leghemoglobin) and bacterial (ropA, nifH) genes was studied by in-situ hybridization. The absence of nifH transcripts was noticed. Mutant-induced nodules showed changes in nodule development, such as precocious degeneration of bacteroids and deviating bacteroid ultrastructure, from the moment that bacteria were released from infection threads, and reduction of the number of infected plant cells. Abnormal bacteroids still invaded plant cells but in the interzone between the pre-fixation zone and the nitrogen fixing zone the maturation process required for nitrogen fixation was eventually blocked. These observations as well as the gene-expression data point to a failure in bacteroid development from the onset of the infection process rather than to a sudden block in the infection process.
Similar content being viewed by others
Abbreviations
- EPS:
-
exopolysaccharide(s)
- Exo− mutant:
-
exopolysaccharide-deficient bacterium
References
Allen T, Raja S, Ganter G, Dunn K (1992) Sequential expression of two late nodulin genes in the infected cells of alfalfa root nodules. Mol Plant-Microbe Interact 5:430–434
Arnold W, Becker W, Keller M, Roxlau A, Pühler A (1994) The role of Rhizobium meliloti surface polysaccharides in the infection of Medicago sativa. Endocytobiosis Cell Res 10: 17–28
Borthakur D, Johnston AWB (1987) Sequence of psi, a gene on the symbiotic plasmid of Rhizobium phaseoli which inhibits exopolysaccharide synthesis and nodulation and demonstration that its transcription is inhibited by psr, another gene on symbiotic plasmid. Mol Gen Genet 207; 149–154
Borthakur D, Barker RF, Latchford JW, Rossen L, Johnston AW (1988) Analysis of pss genes of Rhizobium leguminosarum required for exopolysaccharide synthesis and nodulation of peas: their primary structure and their interaction with psi and other nodulation genes. Mol Gen Genet 213: 155–162
Chakravorty AK, Żukrowski W, Shine J, Rolfe BG (1982) Symbiotic nitrogen fixation: molecular cloning of Rhizobium genes involved in exopolysaccharide synthesis and effective nodulation. J Mol Appl Genet 1: 585–596
Chen H, Gray JX, Nayudu M, Djordjevic MA, Batley M, Redmond JW, Rolfe BG (1988) Five genetic loci involved in the synthesis of acidic exopolysaccharide are closely linked in the genome of Rhizobium sp. strain NGR234. Mol Gen Genet 212: 310–316
Cox KH, Goldberg RB (1988) Analysis of plant gene expression. In: Shaw CH (ed) Plant molecular biology: a practical approach. IRL Press, Oxford, pp 1–35
Dazzo FB (1982) Leguminous root nodules. In: Burns RG, Slater JH (eds) Experimental microbial ecology. Blackwell Scientific Publications, Oxford, pp 431–446
de Maagd RA, Yang W-C, Goossen-de Roo L, Mulders IHM, Roest HP, Spaink HP, Bisseling T, Lugtenberg BJJ (1994) Down-regulation of expression of the Rhizobium leguminosarum outer membrane protein gene ropA occurs abruptly in interzone II–III of pea nodules and can be uncoupled from nif gene activation. Mol Plant-Microbe Interact 7: 276–281
Deryło M, Skorupska A, Bednara J, Lorkiewicz Z (1986) Rhizobium trifolii mutants deficient in exopolysaccharide production. Physiol Plant 66: 699–704
Diebold R, Noel KD (1989) Rhizobium leguminosarum exopolysaccharide mutants: biochemical and genetic analyses and symbiotic behaviour on three hosts. J Bacteriol 171: 4821–4830
Djordjevic SP, Chen H, Redmond JW, Rolfe BG (1987) Nitrogen fixing ability of exopolysaccharide synthesis mutants of Rhizobium sp. strain NGR234 and Rhizobium trifolii is restored by the addition of homologous exopolysaccharides. J Bacteriol 169: 53–60
Finan TM, Hirsch AM, Leigh AJ, Johansen E, Kuldau GA, Deegan S, Walker GC, Singer ER (1985) Symbiotic mutants of Rhizobium meliloti that uncouple plant from bacterial differentiation. Cell 40: 869–877
Franssen HJ, Vijn I, Yang WC, Bisseling T (1992) Developmental aspects of the Rhizobium-legume symbiosis. Plant Mol Biol 19: 89–107
Leigh JA, Coplin D (1992) Exopolysaccharides in plant-bacterial interactions. Annu Rev Microbiol 46: 307–346
Leigh JA, Walker G (1994) Exopolysaccharide of Rhizobium: synthesis, regulation and symbiotic function. Trends Genet 10: 63–67
Long SR (1989) Rhizobium-legume nodulation: life together in the underground. Cell 56: 203–214
Nap J-P, Bisseling T (1990) Nodulin function and nodulin gene regulation in root nodule development. In: Gresshoff PM (ed) Molecular biology of symbiotic nitrogen fixation. CRC Press, Boca Raton, pp 181–229
Niehaus K, Kapp D, Pühler A (1993) Plant defence and delayed infection of alfalfa pseudonodules induced by an exopolysaccharide (EPS I)-deficient Rhizobium meliloti mutant. Planta 190: 415–425
Pühler A, Arnold W, Becker A, Roxlau A, Keller M, Kapp D, Lagares A, Lorenzen J, Niehaus K (1993) The role of Rhizobium meliloti surface polysaccharides in nodule development. In: Palacios R, Mora J, Newton E (eds) New horizons in nitrogen fixation. Kluwer Academic Publishers, The Netherlands, pp 207–212
Scheres B, van Engelen F, van der Knaap E, van de Wiel C, van Kammen A, Bisseling T (1990) Sequential induction of nodulin gene expression in the developing pea nodule. Plant Cell 8: 687–700
Skorupska A, Deryło M, Golinowski W (1991) The region for exopolysaccharide synthesis in Rhizobium leguminosarum biovar trifolii is located on the non-symbiotic plasmid. Acta Biochim Polon 38: 423–435
Van de Wiel C, Norris JH. Bochenek B, Dickstein R, Bisseling T, Hirsch AM (1990a) Nodulin gene expression and ENOD2 localization in effective, nitrogen fixing and ineffective, bacteria free nodules of alfalfa (Medicago sativa). Plant Cell 2: 1009–1017
Van de Wiel C, Scheres B, Franssen H, van Lierop MJ, van Lammeren A, van Kammen A, Bisseling T (1990b) The early nodulin transcript ENOD2 is located in the nodule parenchyma (inner cortex) of pea and soybean root nodules. EMBO J 9: 1–7
Vasse J, De Billy F, Camut S, Truchet G (1990) Correlation between ultrastructural differentiation of bacteroids and nitrogen fixation in alfalfa nodules. J Bacteriol 172: 4295–4306
Vincent JM (1970) A manual for the practical study of the rootnodule bacteria. Blackwell Scientific Publications, Oxford
Yang W-C, Horvath B, Hontelez J, van Kammen A, Bisseling T (1991) In situ localization of Rhizobium mRNAs in pea root nodules: nifA and nifH localization. Mol Plant-Microbe Interact 4: 464–468
Author information
Authors and Affiliations
Corresponding author
Additional information
The authors are indebted to Sybout Massalt, Paul van Snippenburg and Allex Haasdijk for photography and artwork.
Rights and permissions
About this article
Cite this article
Białek, U., Skorupska, A., Yang, W.C. et al. Disturbed gene expression and bacteroid development in Trifolium pratense root nodules induced by a Tn5 mutant of Rhizobium leguminosarum bv. trifolii defective in exopolysaccharide synthesis. Planta 197, 184–192 (1995). https://doi.org/10.1007/BF00239955
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00239955