Abstract
We demonstrate quantification of transcript, protein and metabolite levels in Arabidopsis based on genomic DNA copy number and ploidy. We extracted total nucleic acid from 3-week-old rosette leaves of wild type in Arabidopsis, and quantified the number of transcripts by qRT-PCR using genomic DNA copy number and ploidy that was determined by the cytometoric analysis. The normalization using genomic DNA copy number and ploidy revealed that a cell of the rosette leaf had 7.5 x 103. transcripts of RBC-L, 9.9 x 103 transcripts of RBC-S and 1.4 x 106 18S rRNA. We similarly analyzed the accumulation of RBC-L and LHCP proteins in wild type based on ploidy and genomic DNA copy number that was determined by direct qPCR analysis of the extract using a DNA polymerase with tolerance to a wide range of common PCR inhibitors. We estimated the number of RBC-L protein molecules (2.63 x 108), and chlorophyll molecules (1.85 x 109) in each cell in the rosette leaf. The normalization to genomic DNA copy number and ploidy is useful for general normalization factor, and provides an easy method for determining the number of transcripts, proteins, and metabolites in a cell.
