Additional file 1: Table S1. Genotyping result of seedlings. Fig. S1. Suspension rice cell morphology of the WT, two OsMYBS2RNAi only lines, S2Ri2 and S2Ri6, two mGM-CSF only lines, G3 and G5, and two mGM-CSF/OsMYBS2RNAi lines, GS2Ri1 and GS2Ri4. Fig. S2. Abundance of rmGM-CSF in mGM-CSF/OsMYBS2RNAi transgenic rice suspension cell lines was higher than that in mGM-CSF only transgenic lines. Fig. S3. PCR-based detection of αAmy3::mGM-CSF and Ubi::OsMYBS2RNAi chimeric genes in selected F5 progeny derived from self-pollination of the F4 population.