Integrative analyses of targeted metabolome and transcriptome of Isatidis Radix autotetraploids highlighted key polyploidization-responsive regulators

Background Isatidis Radix, the root of Isatis indigotica Fort. (Chinese woad) can produce a variety of efficacious compound with medicinal properties. The tetraploid I. indigotica plants exhibit superior phenotypic traits, such as greater yield, higher bioactive compounds accumulation and enhanced stress tolerance. In this study, a comparative transcriptomic and metabolomic study on Isatidis Radix autotetraploid and its progenitor was performed. Results Through the targeted metabolic profiling, 283 metabolites were identified in Isatidis Radix, and 70 polyploidization-altered metabolites were obtained. Moreover, the production of lignans was significantly increased post polyploidization, which implied that polyploidization-modulated changes in lignan biosynthesis. Regarding the transcriptomic shift, 2065 differentially expressed genes (DEGs) were identified as being polyploidy-responsive genes, and the polyploidization-altered DEGs were enriched in phenylpropanoid biosynthesis and plant hormone signal transduction. The further integrative analysis of polyploidy-responsive metabolome and transcriptome showed that 1584 DEGs were highly correlated with the 70 polyploidization-altered metabolites, and the transcriptional factors TFs-lignans network highlighted 10 polyploidy-altered TFs and 17 fluctuated phenylpropanoid pathway compounds. Conclusions These results collectively indicated that polyploidization contributed to the high content of active compounds in autotetraploid roots, and the gene-lignan pathway network analysis highlighted polyploidy-responsive key functional genes and regulators.

Automated summary

This study revealed that polyploidization contributed to the increased content of active compounds in autotetraploid roots and modulated lignan biosynthesis. The integrative analysis showed a close correlation between polyploidy-responsive metabolites and differentially expressed genes, highlighting key functional genes and regulators in the gene-lignan pathway network.