RNA Extraction and Gene Expression Analysis

Total RNA was extracted from plants grown in air or in high CO₂ using the Trizol reagent (Life Technologies). cDNA synthesis was performed using the SuperScript III First-Strand Synthesis System according to the manufacturer’s instructions (Life Technologies). Quantitative reverse transcription-PCR analysis was performed as described by Mhamdi et al. (2010) using the gene-specific primer sequences listed in Supplemental Table S2.