Abstract
Ribosomal RNA genes were exploited as markers to identify somatic hybrids between Solanum tuberosum cv. Brodick and wild diploid Solanum species, S. megistacrolobum, S. sanctae-rosae and S. sparsipilum and DNA methylation as a possible regulatory factor in gene expression was investigated. Specific restriction enzyme/probe combinations revealed useful polymorphisms in the conserved coding and variable intergenic spacer regions of the ribosomal RNA genes. Some intermediate ribosomal RNA gene profiles indicate hybridity whereas others were characteristic of S. tuberosum cv. Brodick. This evidence is suggestive of somatic exchange/re-arrangement between the NOR region of S. sanctae-rosae and S. tuberosum cv. Brodick. Ribosomal RNA gene copy number analysis of the somatic hybrids did not reveal hexaploid values suggesting that these products are not symmetric hybrids derived from the parental diploid and tetraploid plants. The results indicate site-specific methylation of ribosomal RNA gene sequences for the parental plants; while some somatic hybrids display a reduction, others show an increase. The significance of the findings for somatic cell genetics and plant breeding studies is discussed.
Similar content being viewed by others
References
Arumuganathan K, Earle ED: Nuclear DNA content of some important plant species. Plant Mol Biol Rep 9(3): 208–218 (1991).
Baird E, Cooper-Bland S, Waugh R, De, Maine M, Powell W: Molecular characterisation of inter-and intra-specific somatic hybrids of potato using randomly amplified polymorphic DNA (RAPD) markers. Mol Gen Genet 233: 469–475 (1992).
Ball SG, Seilleur P: Characterisation of somaclonal variations in potato: a biochemical approach. In: Semal J (ed) Somaclonal Variation and Crop Improvement, pp. 229–235. Martinus Nijhoff Publishers, Dordrecht/Lancaster (1986).
Barr SNR: Potato improvement by somatic hybridisation. Ph.D. Thesis, University of Dundee, UK (1996).
Birch RG: Plant transformation: problems and strategies for practical application. Annu Rev Plant Physiol Plant Mol Biol 48: 297–326 (1997).
Bonierdale M: Molecular map of the potato (Solanum tuberosum) 2ND = 48. In: O'Brien SJ (ed) Genetic Maps: Locus Maps of Complex Genomes, 6th ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY (1993).
Bonierdale MW, Plaisted RL, Tanksley SD: RFLP maps based on a common set of clones reveal modes of chromosomal evolution in potato and tomato. Genetics 120: 1095–1103 (1988).
Borisjuk N, Borisjuk, Petjuch G, Hemleben V: Comparison of nuclear ribosomal RNA genes among Solanum species and other Solanaceae. Genome 37: 271–279 (1994).
Borisjuk NV, Momot VP, Gleba Y: Novel class of rDNA repeat units in somatic hybrids between Nicotiana and Atropa. Theor Appl Genet 76: 108–112 (1988).
Britt AB: DNA damage and repair in plants. Annu Rev Plant Physiol Plant Mol Biol 47: 75–100 (1996).
Carputo D, Cardi T, Chiari T, Ferraiolo G, Frusciante L: Tissue culture response in various wild and cultivated Solanum germplasm accessions for exploitation in potato breeding. Plant Cell Tiss Organ Cult 41: 151–158 (1995).
Dean C, Schmidt R: Plant genomes: a current molecular description. Annu Rev Plant Physiol Plant Mol Biol 46: 395–418 (1995).
Duncan RR: Tissue culture-induced variation and crop improvement. In: Sparks DL (ed) Advances in Agronomy, vol 58, pp. 201–240. Academic Press, New York (1997).
Ferreira DI, Zelcer A: Advances in protoplast research on Solanum. Int Rev Cytol 115: 1–65 (1990).
Foulger D, Jones MGK: Improved efficiency of genotypedependent regeneration from protoplasts of important potato cultivars. Plant Cell Rep 5: 72–76 (1986).
Galun E: Plant protoplasts as physiological tools. Annu Rev Plant Physiol 32: 237–266 (1981).
Gerlach WL, Bedbrook JR: Cloning and characterisation of ribosomal RNA genes from wheat and barley. Nucl Acids Res 7: 1869–1885 (1979).
Gleba Y, Kolesnik NN, Meshkene IV, Cherep NN, Paroke AS: Transmission genetics of the somatic hybridisation process in Nicotiana. Theor Appl Genet 69: 121–128 (1984).
Harding K: Restriction enzyme mapping of the ribosomal RNA genes in Solanum tuberosum: potato rDNA restriction enzyme map. Euphytica 54: 245–250 (1991).
Harding K: Molecular stability of the ribosomal RNA genes in Solanum tuberosum plants recovered from slow growth and cryopreservation. Euphytica 55: 141–146 (1991).
Harding K: Detection of ribosomal RNA genes by chemiluminescence in Solanum tuberosum L.: a rapid and nonradioactive procedure for the characterisation of potato germplasm. Potato Res 35: 199–204 (1992).
Harding K: The methylation status of DNA derived from potato plants recovered from slow growth. Plant Cell Tiss Organ Cult 37: 31–38 (1994).
Harding K: Approaches to assess the genetic stability of plants recovered from in vitro culture. In: Normah MN, Narimah MK, Clyde MM (eds) Proceedings of the International Workshop on In Vitro Conservation of Plant Genetic Resources, pp. 137–170. Plant Biotechnology Laboratory, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia (1996).
Harding K: Stability of the ribosomal RNA genes in Solanum tuberosum L. plants recovered from cryopreservation. Cryo-Letters 18: 217–230 (1997).
Harding K, Benson EE: Biochemical and molecular methods for assessing damage, recovery and stability in cryopreserved plant germplasm. In: Grout BWW (ed) Genetic Preservation of Plant Cells In Vitro, pp. 103–151. Springer-Verlag. Heidelberg (1995).
Harding K, Benson EE, Roubelakis-Angelakis KA: Changes in genomic DNA and rDNA associated with the tissue culture of Vitis vinifera: a possible molecular basis for recalcitrance. Vitis 35(2): 79–85 (1996).
Hohn T, Corsten S, Rieke S, Muller M, Rothnie H: Methylation of coding region alone inhibits gene expression in plant protoplasts. Proc Natl Acad Sci USA 93: 8334–8339 (1996).
Ishige T: Somatic cell fusion between diploid potato (Solanum tuberosum) lines using transformed antibiotic selection markers. Plant Sci 112: 231–238 (1995).
Lambe P, Mutambel HSN, Fouche J-G, Deltour R, Foidart JM, Gaspar T: DNA methylation as a key process in regulation of organogenic totipotency and plant neoplastic progression. In Vitro Cell Devel Biol Plant 33(3): 155–162 (1997).
Landsmann J, Uhrig H: Somaclonal variation in Solanum tuberosum detected at the molecular level. Theor Appl Genet 71: 500–505 (1985).
Leitch AR, Heslop-Harrison JS: Ribosomal RNA gene expression and localisation in cereals. In: Sumner AT, Chandley AC (eds) Chromosomes Today, vl 2, pp. 91–100. Chapman and Hall, London (1993).
Leitch AR, Mosgoller W, Shi M, Heslop-Harrison JS: Different patterns of rDNA organisation at interphase in nuclei of wheat and rye. J Cell Sci 101: 751–757 (1992).
Liang W-Q, Fournier MJ, Synthesis of functional eukaryotic ribosomal RNAs in trans: development of a novel in vivo rDNA system for dissection ribosome biogenesis. Proc Natl Acad Sci USA 94: 2864–2868 (1997).
Lopez-Leon MD, Cabrero J, Camacho JPM: Changes in DNA methylation during development in the B chromosome NOR of the grasshopper Eyprepocnemis plorans. Heredity 74: 296–302 (1995).
Lossl A, Frei U, Wenzel G: Interaction between cytoplasmic composition and yield parameters in somatic hybrids of S. tuberosum L. Theor Appl Genet 89: 873–878 (1994).
Masuelli RW, Tanimoto EY, Brown CR, Comai L: Irregular meiosis in a somatic hybrid between S. bulbocastanum and S. tuberosum detected by species-specific PCR markers and cytological analysis. Theor Appl Genet 91: 401–408 (1995).
Mattheij WM, Puite KJ: Tetraploid potato hybrids through protoplast fusions and analysis of their performance in the field. Theor Appl Genet 83: 807–812 (1992).
Matthews D, Harding K, Wilkinson MJ, Millam S: A slot-blot hybridisation method for screening somatic hybrids. Plant Mol Biol Rep 15(1): 62–70 (1997).
Meyer P, Saedler H: Homology-dependent gene silencing in plants. Annu Rev Plant Physiol Plant Mol Biol 47: 23–48 (1996).
Millam S, Payne L, Mackay GR: The integration of protoplastfusion derived material into a potato breeding programme, a review of progress and problems. Euphytica 85: 451–455 (1995).
Oberwalder B, Rou B, Schilde-Rentschler L, Hemleben V, Ninnemann H: Asymmetric fusion between wild and cultivated species of potato (Solanum spp.): detection of asymmetric hybrids and genome elimination. Theor Appl Genet 94: 1104–1112 (1997).
Pehu E, Thomas M, Poutala T, Karp A, Jones MGK: Speciesspecific sequences in the genus Solanum: identification, characterisation and application to study somatic hybrids S. brevidens and S. tuberosum. Theor Appl Genet 80: 693–698 (1990).
Penner GA, Lee SJ, Bezte LJ, Ugali E: Rapid RAPD screening of plant DNA using dot blot hybridisation. Mol Breed 2: 7–10 (1996).
Pental D, Mukhopadhyay A, Grover A, Pradham AK: A selection method for the synthesis of triploid hybrids by fusion of microspore protoplasts (n) with somatic cell protoplasts (2n). Theor Appl Genet 46: 237–243 (1988).
Petyuch GP, Borisyuk NV, Kuchko AA, Gleba YY: Variability of ribosomal RNA genes amongst potato protoplast-derived plants. Abstract A4-78, VIIth International Congress on Plant Tissue and Cell Culture, p. 163 (1990).
Phillips RL, Kaeppler SM, Olhoft, P. Genetic instability of plant tissue cultures: breakdown of normal controls. Proc Natl Acad Sci USA 91: 5222–5226 (1994).
Pijnacker LP, Ferwerda MA: Nucleolar organiser function in developing potato calli. Theor Appl Genet 82: 587–592 (1991).
Pinto FM, Chupeau Y, Cabrera VM: Molecular genetic characterisation of plant somatic hybrids. In Vitro Cell Devel Biol 31: 96–100 (1995).
Rogers SO, Honda S, Bendich AJ: Variation in the ribosomal RNA genes among individuals of Vicia faba. Plant Mol Biol 6: 339–345 (1986).
Rutgers E, Ramulu KS, Dijkhuis P, Blaas J, Krens FA Verhoeven HA: Identification and molecular analysis of transgenic potato chromosomes transferred to tomato through microplast fusion. Theor Appl Genet Genomics 94: 1053–1059 (1997).
Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY (1989).
Schweizer G, Borisjuk N, Borisjuk L, Stadler M, Stelzer T, Schilde L, Hemleden V: Molecular analysis of highly repeated genome fractions in Solanum and their use as markers for the characterization of species and cultivars. Theor Appl Genet 85: 801–808 (1993).
Sneller CH, Miles JW, Hoyt JM: Agronomic performance of soybean plant introductions and their genetic similarity to elite lines. Crop Sci 37: 1595–1600 (1997).
Torres-Ruiz R, Hemleben V: Pattern and degree ofmethylation in ribosomal RNA genes of Cucurbita pepo L. Plant Mol Biol 26: 1167–1179 (1994).
Turner SJ. New sources of resistance to potato cyst-nematodes in the Commonwealth Potato Collection. Euphytica 42: 145–153 (1989).
van Blokland R, ten Lohuis M, Meyer P: Condensation of chromatin in transcriptional regions of an inactivated plant transgene: evidence for an active role of transcription in gene silencing. Mol Gen Genet 257: 1–13 (1997).
Wilkinson MJ: Genome evolution in potatoes. In: Bradshaw JE, Mackay GR (eds) Potato Genetics, pp. 43–67. CAB International, University Press, Cambridge, UK (1994).
Xu Y-S: Production and characterisation of somatic hybrids between Solanum tuberosum L. and S. brevidens. Publication N:r38. University of Helsinki, Helsinki, Finland (1993).
Xu Y-S, Clarke MS, Pehu E: Use of RAPD markers to screen somatic hybrids between Solanum tuberosum and S. brevidens. Plant Cell Rep 12: 107–109 (1993).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Harding, K., Millam, S. Analysis of ribosomal RNA genes in somatic hybrids between wild and cultivated Solanum species. Molecular Breeding 5, 11–20 (1999). https://doi.org/10.1023/A:1009618311294
Issue Date:
DOI: https://doi.org/10.1023/A:1009618311294