Fig. 4 in Alterations in nepetalactone metabolism during polyethylene glycol (PEG)- induced dehydration stress in two Nepeta species

Fig. 4. The expression of nepetalactone biosynthetic genes during PEG-induced dehydration stress in leaves of Nepeta rtanjensis (a) and N. argolica ssp. argolica (b) at 1, 3 and 6 days of PEG treatment (DPT); Obtained values for genes expression in PEG-treated plants were normalized against NrGAPDH (a) and NaGAPDH (b) as the endogenous controls and presented relative to their respective controls (expression in non-treated plants) as calibrators. Results are presented as the means ± SD of three biological replicates. Asterisks (*) denote significant differences between PEG-treated and non-treated plants (unpaired t-test, *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001). Abbreviations: GPPS- geranyl diphosphate synthase, GES- geraniol synthase, G8O- geraniol 8-oxidase, 8HGO- 8-hydroxygeraniol oxidoreductase, ISiridoid synthase, NEPS- nepetalactol-related short-chain dehydrogenase, GADPH- glyceraldehyde-3-phosphate dehydrogenase.