Characterization of Gene Expression in Rice

The growth of ZS97 was maintained under routine field management in Wuhan (30°52′N, 114°32′E), China. To be consistent with the samples used in the previous microarray data (see Supplementary Table S1), the samples were harvested from ZS97 plants at the corresponding stages, including seedlings (three-leaf stage, Z12), young shoots (seedlings with two tillers, Z13), young roots (seedlings with 2 tillers, Z14), mature sheaths (secondary branch primordium differentiation stage, Z17), young flag leaves (5 days before heading, Z19), old flag leaves (14 days after heading, Z20), young panicles (4–5 cm, Z24), old panicles (heading stage, Z25), young stems (5 days before heading, Z26), spikelets (3 days after pollination, Z29), and endosperms (7 days after pollination, Z31). Calli (15 days after induction, Z4) were obtained after callus induction using ZS97 seeds. Total RNA was isolated from each sample with the TRIzol reagent (Invitrogen, Carlsbad, CA, USA), according to the manufacturer's instructions. The total RNA was treated with RNase-free DNase I (New England Biolabs, Ipswich, MA, USA) to eliminate genomic DNA contamination. Quantitative real-time PCR (qRT-PCR) was performed with the same procedures as previously reported [11 (link)]. The primers used in the present study are listed in Supplementary Table S2.