Fig. 4

Relative number of reads (number of reads/total number of reads) assigned to genes involved in the synthesis and metabolism of terpenoids and polyketides. Rhizosphere samples collected 12 weeks after plantlets were transferred to pots containing virgin (CO = green) and apple replant soils (ARD = red), * = p < 0.05 (DESeq2 analysis to test for differential gene abundance using negative binomial generalized linear models, p adjusted using the Bonferroni correction method for multiple pairwise comparisons). Abbreviations: coq7 = ubiquinone biosynthesis monooxygenase, entF = enterobactin synthetase component F, HMGCR = hydroxymethylglutaryl-CoA reductase, FDFT1 = farnesyl-diphosphate farnesyltransferase, hepST = heptaprenyl diphosphate synthase, AVES = type I polyketide synthase, AL1 = phytoene desaturase, mvaA = hydroxymethylglutaryl-CoA reductase, UbiD = 3-octaprenyl-4-hydroxybenzoate carboxy-lyase, menC = O-succinylbenzoate synthase, crtI = phytoene desaturase, ygbP = 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase