Combined Metabolome and Transcriptome Analysis Highlights the Host's Influence on Cistanche deserticola Metabolite Accumulation

The medicinal plant Ma (Orobanchaceae) is a holoparasitic angiosperm that takes life-essential materials from (C. A. Mey.) Bunge (Amaranthaceae) roots. Although many experiments have been conducted to improve the quality of , little attention has been paid to the host's influence on metabolite accumulation. In this study, transcriptomic and metabolomic analyses were performed to unveil the host's role in 's metabolite accumulation, especially of phenylethanoid glycosides (PhGs). The results indicate that parasitism by causes significant changes in roots in relation to metabolites and genes linked to phenylalanine metabolism, tryptophan metabolism and phenylpropanoid biosynthesis pathways, which provide precursors for PhGs. Correlation analysis of genes and metabolites further confirms that 's parasitism affects PhG biosynthesis in roots. Then we found specific upregulation of glycosyltransferases in haustoria which connect the parasites and hosts. It was shown that absorbs PhG precursors from the host and that glycosylation takes place in the haustorium. We mainly discuss how the host resists parasitism and how this medicinal parasite exploits its unfavorable position and takes advantage of host-derived metabolites. Our study highlights that the status of the host plant affects not only the production but also the quality of Cistanches Herba, which provides a practical direction for medicinal plant cultivation.