Protein was extracted from the DDSP using a phenol/trichloracetic acid (Ph/TCA) extraction procedure, based on the methods (with some modifications) proposed by Gomez-Vidal, Tena, Lopez-Liorca, and Salinas (2008) for olive and P. dactylifera L. leaves, respectively. Ten grams of defatted DDSP was mixed with 30 ml of ice-cold acetone, vortex mixed and then centrifuged at 10,000 rpm for 10 min at 4 °C (Beckman Avanti J26-XP centrifuge). The supernatant was decanted and discarded, with the residual pellet being washed twice with ice-cold acetone and allowed to dry at room temperature. After the pellet had dried, it was ground to a fine powder using a pestle and mortar, rinsed with 15% (w/v) TCA in acetone, vortex mixed and then centrifuged at 10,000 rpm for 10 min at 4 °C. The rinsing with TCA/acetone and centrifugation was repeated three times. The pellet was then rinsed with cold 15% (w/v) TCA in water and centrifuged. The rinsing with cold TCA and centrifugation was repeated three times. The pellet was then rinsed with cold 80% (v/v) acetone followed by centrifugation, and this was also repeated three times. The pellet was then air dried.