Multi-omics Analysis Reveals Whether and how Naphthylacetic Acid Affects the Quality of Rehmannia Glutinosa

Abstract

Background: Rehmannia glutinosa (R.glutinosa) is an important medicinal plant. The tuberous root of R.glutinosa is often used as herbal medicine. Naphthylacetic acid (NAA) as expansin can improve its yield, but knowledge about gene regulation and metabolome in its root is limited.Results: Full-length transcriptome, next generation transcriptome(NGS), small RNA and degradome sequencing and metabolomics were used to elucidate whether and how NAA affected its quality.30 differential expression metabolites (DEMs) (11 upregulated, 19downregulated) were identified, but catalpol and Rehmannioside D as quality standards were unchanged in its tuberous roots under control and NAA conditions (CKs and NTs); Their NGS identified 1,113 differentially expressed transcripts (DETs) (596 upregulated, 517downregulated) verified by RT-qPCR; Small RNA sequencing identified 78miRNAs (11known, 67 novel), of which 3 were differentially expressed miRNAs (1upregulated, 2downregulated). Among them, 274 differentially expressed miRNAs target transcripts (DEMTs) were predicted found and then validated by degradome sequencing; DETs and DEMTs were mainly related to metabolism. 4 miRNA-mRNA interaction pairs that regulates 4 metabolites (2 negatively correlated, 2 positively correlated) were identified; DETs, DEMs, differentially expressed miRNAs and DEMTs involved in phenylpropanoid biosynthesis regulated metabolites.Conclusions: The identification of DETs, DEMs, differentially expressed miRNAs and DEMTs could help to elucidate the regulatory networks and molecular mechanisms important for NAA-improving root quality of R.glutinosa.