Rna extraction kit

The peels of the ‘Kuerle Xiangli’ were frozen in liquid nitrogen and ground into powder. The total RNA was isolated using an RNA Extraction Kit (ZOMANBIO, Beijing, China) according to the manufacturer’s instructions. Each RNA sample was subjected to DNase I to remove genomic DNA. The cDNA was synthesized according to the protocol of TransScript One-Step gDNA Removal and cDNA Synthesis SuperMix (TransGen Biotech, Beijing, China). TransStart Top Green qPCR SuperMix (TransGen Biotech, Beijing, China) was used for the RT-qPCR analysis, which was performed on Roche LightCycler 480 system (Roche, Basel, Switzerland). The pear PcTubulin gene was used as the internal control for RT-qPCR analysis. The relative expression level of each gene was determined by the 2^−ΔΔCt method [64 (link)]. Each gene expression analysis in this research was repeated three times. The specific primers used for RT-qPCR analysis are listed in Table S4.

Soybean variety “Williams 82” was used for quantitative PCR (qPCR) analysis. Soybean seeds were sown into flowerpots and after 2 weeks of growth, soybean seedlings were irrigated with 200 mM NaCl and 250 mM mannitol, respectively. A total of 0.1 g of soybean leaf blade tissue was collected at 0, 2, 4, 6, 8, 10, and 12 h after the 200 mM NaCl induced salt stress and 250 mM mannitol induced drought stress treatments, and total RNA was extracted using an RNA extraction kit (ZOMANBIO, ZP405, China). Double stranded cDNA was obtained using a cDNA synthesis kit (TIANGEN, KR118, China) (Le et al., 2011 (link)). qPCR reactions were performed on the ABI Prism 7500 real-time PCR system (Applied Biosystems, Foster City, CA, United States); the Actin (100500082) gene was used as the internal control (Jian et al., 2008 (link)). The expression levels of nine GmPP2A-B′′ genes were determined using the 2^–ΔΔCT method. All primers are listed in Supplementary Table 2.