*4.6. Isolation of RNA and Quantitative Real-Time PCR*

Total RNA was extracted from rice leaves using a Column Plant RNAOUT V1.0 Kit (Tiandz Inc., Beijing, China) according to the manufacturer's instructions. The first strand of cDNA was synthesized using PrimeScriptTM RT reagent Kit with gDNA Eraser (Perfect Real Time) (TaKaRa Bio Inc., Dalian, China), following standard protocol. The quantitative real-time PCR was carried out with the diluted cDNA and SYBR Premix Ex TaqTM II (TaKaRa Bio Inc., Dalian, China) using CFX96 TouchTM Real-Time PCR Detection Systems (Bio-Rad, Chicago, USA), as described previously [70]. The relative expression level of *OsACTIN1* was normalized. The primers used for quantitative real-time PCR are listed in Supplementary Table S1.
