Ribosomal DNA internal transcribed spacers to estimate the proportion of Pisolithus tinctorius and Eucalyptus RNAs in ectomycorrhiza.
AUTOR(ES)
Diaz, E C
RESUMO
Ectomycorrhiza is a complex association of several types of plant and fungal cells. Differentiation of symbiotic structures is correlated with large changes in mRNA synthesis, leading to novel protein patterns. Quantification of up- and down-regulated specific transcripts is complicated by the intermingling of root and hyphal components. Determination of steady-state levels of symbiosis-regulated mRNA requires a normalization to the housekeeping RNA content of each partner. In this study, the usefulness of the internal transcribed spacer (ITS)-5.8S ribosomal DNAs (rDNAs) as molecular markers of the root colonization by fungal mycelium was assayed. The rDNA ITSs of Pisolithus tinctorius and Eucalyptus globulus were cloned by PCR amplification, and their sequences were determined. They contained the 5.8S rDNAs, and these two probes did not cross-hybridize. Steady-state levels of the ITS-5.8S rRNAs in the vegetative mycelium, in the noninfected root, and in ectomycorrhizas of E. globulus-P. tinctorius 441 were estimated at different stages of development. Colonization of roots by the mycelium provoked a large decrease in the proportion of root rRNAs. At the end of mycorrhiza formation, about 80% of the ectomycorrhizal RNA belonged to the mycobiont. The ITS-5.8S can be used as a specific probe for the estimation of fungal or plant rRNA in the symbiotic tissues and to determine whether an mRNA is down- or up-regulated in ectomycorrhiza.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=168379Documentos Relacionados
- Carbohydrate and Amino Acid Metabolism in the Eucalyptus globulus-Pisolithus tinctorius Ectomycorrhiza during Glucose Utilization1
- Low variation in ribosomal DNA and internal transcribed spacers of the symbiotic fungi of leaf-cutting ants (Attini: Formicidae)
- Functional analysis of transcribed spacers of yeast ribosomal DNA.
- Multiple heterogeneities in the transcribed spacers of ribosomal DNA from Xenopus laevis.
- Patterns of major divergence between the internal transcribed spacers of ribosomal DNA in Xenopus borealis and Xenopus laevis, and of minimal divergence within ribosomal coding regions.
