Effect of treated wastewater on growth and secondary metabolites production of two Eucalyptus species

Concerning root and leaf secondary metabolite profiles, changes in both plant part extract compositions were observed according to irrigation type, though these were weak compared to plant species identity. Common metabolic patterns following TWW irrigation could be showed in both species like for example the increase of quercetin glucosinnapate in leaf extracts or the decrease of two peduncalagin isomers detected as major compounds in the same extracts. Though some differences were also observed, particularly, E. occidentalis had more compounds decreased in its roots than E. camaldulensis when irrigated with TWW while in leaves the tendency was inverted. Total phenolic content was decreased in both species and for both plant parts, but this diminution was more pronounced in E. occidentalis roots. We also noticed modifications in soil parameters after TWW exposure and some were dependant on the species of Eucalyptus like for example soil organic matter content which increased with TWW in the case of E. occidentalis, whereas it decreased for E. camaldulensis. All these results let us hypothesize that E. occidentalis possess better adaptation capabilities to TWW irrigation than E. camaldulensis and that these might be related to changes in root metabolism.