FIG. 5.

Competitive PCR for quantification of hyd1 transcripts in compatible versus low-compatibility ectomycorrhiza. Since the amounts of fungus were different in both interactions, the quantities of mycorrhizal RNA containing equal amounts of fungal RNA were first determined. Using 100 ng of compatible (top row) and 190 ng of low-compatibility (bottom row) RNA, a competitive PCR was performed, amplifying the transcripts for hyd1 present in the mRNA (lower bands) as well as a larger, genomic fragment (upper bands) added in defined amounts to the sample. Equal quantities for competitor and intrinsic mRNA signals were used to determine amounts of specific mRNA in total fungal RNA.