RNA-extraction
Three separate biological replicates for RNA sequencing and two separate biological replicates for expression studies, each consisting of three individual leaf samples each from three different plants, were ground under liquid nitrogen using mortar and pestle. Each sample was dissolved in 1 ml of Trizol reagent and heated at 65 ºC for 5 min. The samples were then centrifuged at 13000 g for 5 min at 4 ºC. RNA was isolated using the Qiagen Plant RNA extraction kit following the manufacturer’s instructions. The extracted RNA was further purified using a DNase I digestion kit (Qiagen DNaseI kit) according to the product manual. Extracted RNAs with 260/280 values of 2.0-2.2 and 260/230 valuse of 1.8-2.0 were selected for downstream analysis. Illumina TruSeq kit 2.0 was used to prepare cDNA libraries for paired-end sequencing on an Illumina HiSeq 2500 platform. The sequencing was carried out at Macrogen Inc. (South Korea).