2.2. Growth parameters and leaf relative water content (RWC)Plants were harvested 6 h after the beginning of the light phaseand immediately separated into shoots and roots. The roots werewashed three times with cold, distilled water and blotted with filterpaper. The plant fresh weight was recorded directly with a portablebalance (Scout Pro 400g, Ohaus Corporation, NJ, USA) and the dryweight (DW) was obtained after drying the fresh organs in an ovenat 70◦C until constant weight.In order to determine the leaf relative water content (RWC), fivediscs of 1-cm diameter were sampled. The fresh mass (Mf) of thediscs was measured immediately; then, they were hydrated for 24 hat 4◦C in the dark, to determine their fully-turgid mass (Mt). Afterthis, the discs were dried at 70◦C, to obtain their dry mass (Md).The RWC was calculated as: (Mf − Md)/(Mt − Md).