Figure 4. Abscisic acid (ABA) content and expression of ABA metabolic genes in stratified embryos.

(A) ABA content in the embryo was determined as detailed in Materials and Methods. (B) Relative gene expression by quantitative real-time RT-PCR of peach genes coding for putative ABA degrading enzymes, as ABA 8′-hydroxylase and ABA glucosyltransferase (GTase), based on protein similarity to known enzymes in other species. Expression levels are relative to Actin. Data are means from three biological replicates (A) or two biological samples with 2–3 technical replicates each (B), with error bars representing standard deviation. The significant difference between treatments, using ANOVA and Multiple Range Tests with a confidence level of 95%, is indicated by different letters (a-d).