Fig 3. Normalization of expression data for four genes in a plum early fruit series and in “Stoneless” and normal endocarp tissue.

Each line represents a different combination of reference genes used to normalize the values. The black line represents the non-normalized values. The DS1-DS7 and endocarp RNA samples, are listed in S3 Table and the primer sets and gene identity for PT1, PT2, PT3 and PT4 are listed in S4 Table. Stendo = ‘Stoneless” endocarp. Cendo = ‘Reine Claude de Bavay’ endocarp.