Gene Expression in Poplar Tissues

The RNA of 84 K poplar (P. alba × P. glandulosa) leaves, stems, roots, buds, phloem, and xylem was extracted using a plant RNA extraction kit (Accurate Biology, Hunan, China) and converted into cDNA using a reverse transcription kit (Accurate Biology, Hunan, China). Primers were designed by Premier 5.0 and synthesized by TSINGKE Biology Co., Ltd. (Chengdu, China). PtrUBQ and PtrActin were used as internal reference genes, and cDNA was used as a template for RT-qPCR amplification (He et al., 2018 (link), 2019 (link)). Five biological replicates and four technical replicates were performed for each sample. PCR was performed on a Bio-Rad CFX96 instrument (Bio-Rad, Hercules, United States) and the 2^–ΔΔCt algorithm was used to analyze the results (Livak and Schmittgen, 2001 (link)).