RNA accumulation and genes expressed in spores of the arbuscular mycorrhizal fungus, Gigaspora rosea

RNA could be extracted from ungerminated spores of the arbuscular mycorrhizal fungus Gigaspora rosea with a maximum of yield 7 days after isolation from soil. cDNA was synthesized and used for library construction or as template for the amplification by polymerase chain reaction of fragments corresponding to several genes. Analysis of cDNA clones corresponding to fragments of ribosomal RNA genes indicated that the extracted RNA as starting material was of arbuscular mycorrhizal fungal origin. Polymerase chain reaction showed the presence of mRNA from genes encoding glyceraldehyde-3-phosphate dehydrogenase, beta-tubulin and two types of ATPases; mRNA accumulation of the glyceraldehyde-3-phosphate dehydrogenase gene was analyzed further. This is the first report of identification of expressed arbuscular mycorrhizal fungal genes in spores.