FIGURE 2.

Upregulated genes in shoots of lettuce grown over a period of nine weeks in soils with long-term organic (HU-org, BIODYN) in comparison to mineral (HU-min, CONMIN) fertilization history. The 2^–ΔΔCt method (Livak and Schmittgen, 2001) was employed for relative quantification (n = 4) by qPCR (see section “Materials and Methods”). Means ± standard errors of four independent replicates showing relative changes in gene expression of plants grown under long-term organic vs. mineral fertilization. Only genes showing significant (p ≤ 0.05) differences in ΔCt values between organic vs. mineral fertilization within each site as revealed by Tukey’s HSD pairwise test are shown (denoted by asterisks). Gene names, putative functions and primer sequences are described in Supplementary Table 1.