Transcriptional analysis of soybean isoflavone biosynthesis

The four soybean varieties Luheidou (LHD), Zhonghuang 13 (ZH13), Zhonghuang 35 (ZH35), and Nanhuizao (NHZ), varying in their isoflavone contents, were used as materials for RNA seq-analysis. About 20 seeds were harvested at different developmental stages (R5 to R8) after 7 days intervals. Each sample was set with three replications for isoflavone contents, and RNA extraction. The total RNAs were extracted using the TRIzol method. The high-quality RNA samples were sent for RNA-seq analysis to BLgene co. LTD (Beijing, China). HISAT2 was used to map the clean RNA-seq data onto the reference genome (Kim et al., 2015 (link)). FeatureCounts calculated the transcriptional abundance and gene expression count matrix (Liao et al., 2014 (link)). TPM (transcripts per million) was used as the expression level, and log10 (TPM + 1) was used to standardize it (Feng et al., 2023 (link)).