*4.9. Measurement of Chlorophyll Fluorescence*

Chlorophyll fluorescence was imaged using a modulated imaging chlorophyll fluorometer (the Imaging PAM M-Series Chlorophyll Fluorometer System, Heinz-Walz Instruments, Effeltrich, Germany) according to the instructions. The rice leaves were adapted in the dark for 30 min prior to the fluorescence assay, and minimum fluorescence yield (F0), maximum fluorescence yield (Fm) and nonphotochemical quenching (NPQ), and maximal quantum yield of PSII photochemistry (Fv/Fm) were then determined according to the method of Zhou et al. [75].
