Total RNA was extracted from rice roots using TRIzol Reagent (Life Technologies Corporation, Carlsbad, CA, United States) and then purified using PureLink ® RNA Mini Kit (Life Technologies Corporation, Carlsbad, CA, United States), according to the manufacturer’s instructions. Contaminant DNA was removed on-column using PureLink ® DNase (Life Technologies Corporation, Carlsbad, CA, United States). The first-strand cDNA synthesis was carried out using the SuperScript™ III First-Strand Synthesis SuperMix for quantitative real-time PCR (qRT-PCR; Life Technologies Corporation, Carlsbad, CA, United States), according to the manufacturer’s instructions.
The qRT-PCR analysis of OsSULTR1;1 (LOC_Os03g09970) and OsSULTR1;2 was performed on the first-strand cDNA in a 20 μl reaction mixture containing GoTaq ® qPCR Master Mix (Promega) and the specific primers, using an ABI 7300 Real-Time PCR system (Applied Biosystems). The relative transcript level of each gene was calculated by the 2–ΔΔCt method using the expression of the OsS16 (LOC_Os11g03400) gene as reference. Primers for qRT-PCR are listed inSupplementary Table 1 .
The qRT-PCR analysis of OsSULTR1;1 (LOC_Os03g09970) and OsSULTR1;2 was performed on the first-strand cDNA in a 20 μl reaction mixture containing GoTaq ® qPCR Master Mix (Promega) and the specific primers, using an ABI 7300 Real-Time PCR system (Applied Biosystems). The relative transcript level of each gene was calculated by the 2–ΔΔCt method using the expression of the OsS16 (LOC_Os11g03400) gene as reference. Primers for qRT-PCR are listed in