The expression levels of 15 genes identified as DGE were validated by RT-qPCR. The RNA samples used for the qRT-PCR assays were the same as those for the RNA-Seq experiments. The cDNA synthesis and qRT-qPCR reactions were performed using the SuperScript® III First-Strand Synthesis System (Thermo Fisher) and the Power SYBR® Green RT-PCR Reagents Kit, respectively, according to the manufacturer's instructions. The primers used in the assay were designed with GenScript [30]. The amplification assays were performed using a 7500 system (Applied Biosystems, USA). The rice ubiquitin 5 gene UBQ5 (GenBank accession AK061988.1) was used as the internal reference for RT-qPCR. Three technical replicates for each of the two biological replicates were performed. The relative gene expression was calculated using the 2-ΔΔCt method, and the values were expressed as the means ± standard deviations (SDs). The corresponding gene-specific primers used in the gene expression analysis are listed in S1 Table.