Chlorophyll content and leaf RWC measurements
Chlorophyll content was measured using a SPAD-502PLUS chlorophyll meter (Konica Minolta, Kumamoto, Japan), and the leaves (the top fully expanded leaves) were measured at 10:00 a.m.
The relative water content (RWC) of leaf samples was determined as described by Yoo et al. (2010). RWC was calculated using the equation: RWC (%) = (Fresh weight − Dry weight/Turgid weight − Dry weight) ×100.