Abstract
Tomato golden mosaic virus (TGMV), a member of the geminivirus group, has a genome consisting of two DNA molecules designated the A and B components. Both are required for infectivity in healthy plants, although the former has been shown to replicate independently in transgenic plants containing tandem direct repeats of the A genome component. In the studies presented here, petunia plants transgenic for either both components (A×B hybrids) or the A component alone were examined for the presence of virus particles and encapsidated, single stranded viral DNA. The results of DNase protection experiments and direct observation of extracts from transgenic plants by electron microscopy indicate that single stranded TGMV DNA is in both cases packaged into paired particles identical to those obtained from virus-infected plants. DNase-treated virions isolated from A×B hybrid petunia are infectious when inoculated onto healthy Nicotiana benthamiana. Likewise, virions obtained from transgenic A petunia are infectious for plants transgenic for the B component.
Our observations of TGMV replication in transgenic plants indicate that TGMV A DNA encodes all viral functions necessary for the replication and encapsidation of viral DNA. The possible role of the B component in TGMV replication is discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bisaro DM, Hamilton WDO, Coutts RHA, Buch KW: Molecular cloning and characterization of the two DNA components of tomato golden mosaic virus. Nucl Acid Res 10: 4913–4922 (1982).
Cohen S, Duffus JE, Larsen RC, Liv MY, Flock RA: Purification, serology and vector relationships of squash leaf curl virus, a whitefly-transmitted geminivirus. Phytopathology 73: 1669–1673 (1983)
Francki RIB, Hatta T, Grylls NE, Grivell CJ: The particle morphology and some other properties of chloris striate mosaic virus. Ann Appl Biol 91: 51–59 (1979).
Francki RIB, Hatta T, Boccardo G, Randles JW: The composition of chloris striate mosaic virus, a geminivirus. Virology 101: 233–241 (1980).
Francki RIB, Milne RG, Hatta T: Atlas of Plant Viruses Vol. 1. Boca Raton, Florida: CRC Press Inc. (1985).
Goodman RM, Shock TL, Haber S, Browning KS, Bowers GRJr. The composition of bean golden mosaic virus and its single-stranded DNA genome. Virology 106: 168–172 (1980).
Hamilton WDO, Bisaro DM, Buck KW: Identification of novel DNA forms in tomato golden mosaic virus infected tissue. Evidence for a two component viral genome. Nucl Acids Res 10: 4901–4912 (1982).
Hamilton WDO, Bisaro DM, Coutts RHA, Buck KW: Demonstration of the bipartite nature of the genome of a single-stranded DNA plant virus by infection with the cloned DNA components. Nucl Acids Res 11: 7387–7396 (1983).
Hamilton WDO, Stein VE, Coutts RHA, Buck KW: Complete nucleotide sequence of the infectious cloned DNA components of tomato golden mosaic virus: potential coding regions and regulatory sequences. EMBO J 3: 2197–2205 (1984)
Harrison BD: Advances in geminivirus research. Ann Rev Phytophathol 23: 55–82 (1985).
Howarth AJ, Caton J, Bossert M, Goodman RM: Nucleotide sequence of bean golden mosaic virus and a model for gene regulation in geminiviruses. Proc Natl Acad Sci (USA) 82: 3572–3576 (1985).
Larsen RC, Duffus JE: A simplified procedure for the purification of curly top virus and the isolation of its monomer and dimer particles. Phytopathology 73: 114–118 (1983).
MacDowell SW, Coutts RHA, Buck KW: Molecular characterization of subgenomic single-stranded and double-stranded DNA forms isolated from plants infected with tomato golden mosaic virus. Nucl Acids Res 14: 7967–7984 (1986).
Magyarrosy AC: Beet curly top virus from phloem exudate of Amsinckia douglasiana. Ann Appl Biol 96: 295–299 (1980).
Millineaux PM, Donson J, Stanley J, Boulton MI, Morris-Krsinich BAM, Markham PG, Davies JW: Computer analysis identifies sequence homologies between potential gene products of maize streak virus and those of cassava latent virus and tomato golden mosaic virus. Plant Mol Biol 5: 125–131 (1985).
Rogers SG, Bisaro DM, Horsch RB, Fraley RT, Hoffmann NL, Brand L, Elmer JS, Lloyd AM: Tomato golden mosaic virus A component DNA replicates autonomously in transgenic plants. Cell 45: 593–600 (1986).
Sequeira JC, Harrison BD: Serological studies on cassava latent virus Ann Appl Biol 101: 33–42 (1982).
Stanley J: Infectivity of the cloned geminivirus genome requires sequences from both DNAs. Nature 305: 643–645 (1983).
Stanley J: The molecular biology of geminiviruses. Adv Virus Res 30: 139–177 (1985).
Stanley J, Gay MR: Nucleotide sequence of cassava latent virus DNA. Nature 301: 260–262 (1983).
Stanley J, Davies JW: Structure and function of the DNA genome of geminiviruses. In: Davies JW (ed.). Molecular Plant Virology. Vol II, Replication and Gene Expression, pp. 191–218. Boca Raton, FL: CRC Press (1985).
Stanley J, Townsend R: Characterization of DNA forms associated with cassava latent virus infection. Nucl Acids Res 13: 2189–2206 (1985).
Stanley J, Markham PG, Callis RJ, Pinner MS: The nucleotide sequence of an infectious clone of the geminivirus beet curly top virus. EMBO J 5: 1761–1767 (1986).
Stein VE, Coutts RHA, Buck KW: Serological studies on tomato golden mosaic virus, a geminivirus. J Gen Virol 64: 2493–2498 (1983).
Sunter G: Studies on the supercoiled form of tomato golden mosaic virus DNA. PhD Thesis, Imperial College, London (1985).
Townsend R, Stanley J, Curson SJ, Short MN: Major polyadenylated transcripts of cassava latent virus and location of the gene encoding coat protein. EMBO J 4: 33–37 (1985).
Townsend R, Watts J, Stanley J: Synthesis of viral DNA forms in Nicotiana plymbaginifolia protoplasts inoculated with cassava latent virus (CLV); evidence for the independent replication of one component of the CLV genome. Nucle Acids Res 14: 1253–1265 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sunter, G., Gardiner, W.E., Rushing, A.E. et al. Independent encapsidation of tomato golden mosaic virus A component DNA in transgenic plants. Plant Mol Biol 8, 477–484 (1987). https://doi.org/10.1007/BF00017993
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00017993