Skip to main content
PMC home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1991 Mar 1;88(5):1602–1605. doi: 10.1073/pnas.88.5.1602

Gene silencing in a polyploid homosporous fern: paleopolyploidy revisited.

G J Gastony 1
PMCID: PMC51072  PMID: 11607154

Abstract

Because of their high chromosome numbers, homosporous vascular plants were considered paleopolyploids until recent enzyme electrophoretic studies rejected this hypothesis by showing that they express only diploid numbers of isozymes. In polyploid sporophytes of the homosporous fern pelleae rufa, however, progressive diminution of phosphoglucoisomerase activities encoded by one ancestral genome culminates in tetraploid plants exhibiting a completely diploidized electrophoretic phenotype for this enzyme. The demonstration that such gene silencing can make a polyploid fern look isozymically like a diploid questions the validity of isozyme evidence for testing the paleopolyploid hypothesis and supports the proposed role of polyploidization followed by genetic diploidizaton in the evolutionary history of homosporous pteridohytes.

Full text

PDF
1603

Images in this article

1603Image
on p.1603

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chapman R. H., Klekowski E. J., Jr, Selander R. K. Homoeologous Heterozygosity and Recombination in the Fern Pteridium aquilinum. Science. 1979 Jun 15;204(4398):1207–1209. doi: 10.1126/science.204.4398.1207. [DOI] [PubMed] [Google Scholar]
  2. Gottlieb L. D. Conservation and duplication of isozymes in plants. Science. 1982 Apr 23;216(4544):373–380. doi: 10.1126/science.216.4544.373. [DOI] [PubMed] [Google Scholar]
  3. Hart G. E. Genetics and evolution of multilocus isozymes in hexaploid wheat. Isozymes Curr Top Biol Med Res. 1983;10:365–380. [PubMed] [Google Scholar]
  4. Haufler C. H., Soltis D. E. Genetic evidence suggests that homosporous ferns with high chromosome numbers are diploid. Proc Natl Acad Sci U S A. 1986 Jun;83(12):4389–4393. doi: 10.1073/pnas.83.12.4389. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Jones T. W., Gottlieb L. D., Pichersky E. Reduced enzyme activity and starch level in an induced mutant of chloroplast phosphoglucose isomerase. Plant Physiol. 1986 Jun;81(2):367–371. doi: 10.1104/pp.81.2.367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Jones T. W., Pichersky E., Gottlieb L. D. Enzyme activity in ems-induced null mutations of duplicated genes encoding phosphoglucose isomerases in clarkia. Genetics. 1986 May;113(1):101–114. doi: 10.1093/genetics/113.1.101. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Klekowski E. J., Jr, Baker H. G. Evolutionary significance of polyploidy in the pteridophyta. Science. 1966 Jul 15;153(3733):305–307. doi: 10.1126/science.153.3733.305. [DOI] [PubMed] [Google Scholar]
  8. Pichersky E., Gottlieb L. D. Evidence for duplication of the structural genes coding plastid and cytosolic isozymes of triose phosphate isomerase in diploid species of clarkia. Genetics. 1983 Oct;105(2):421–436. doi: 10.1093/genetics/105.2.421. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Pichersky E., Soltis D., Soltis P. Defective chlorophyll a/b-binding protein genes in the genome of a homosporous fern. Proc Natl Acad Sci U S A. 1990 Jan;87(1):195–199. doi: 10.1073/pnas.87.1.195. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Wolf P. G., Haufler C. H., Sheffield E. Electrophoretic Evidence for Genetic Diploidy in the Bracken Fern (Pteridium aquilinum). Science. 1987 May 22;236(4804):947–949. doi: 10.1126/science.236.4804.947. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES