**2.2 Plant water status and pigments measurements**

Plant water status was estimated by measuring the relative water content of leaves (RWC). The leaves were collected and immediately weighed to determine fresh weight (FW). They were then re-hydrated for 24 h at 4 ºC in darkness to determine the turgid weight (TW), and subsequently oven-dried for 24 h at 85 ºC to determine the dry weight (DW). The RWC was determined as 100 x (FW-DW)/ (TW-DW).

Total Chlorophyll and carotenoids were determined by Lichtenthaler & Wellburn´s method using 80 % (v/v) acetone as solvent.
