Exploring information exchange betweenThesium chinenseand its hostPrunella vulgaristhrough joint transcriptomic and metabolomic analysis

Background: Thesium chinense known as “plant antibiotic” is a facultative root hemi-parasitic herb while Prunella vulgaris can serve as its host. However, the molecular mechanisms underlying the communication between T. chinense and its host remained largely unexplored. The aim of this study was to provide a comprehensive view of transferred metabolites and mobile mRNAs between T. chinense and P. vulgaris . Results: The wide-target metabolomic and transcriptomic analysis identified 5 transferred metabolites and 668 mobile genes between T. chinense and P. vulgaris , as well as haustoria formation related 56 metabolites and 189 genes. Furthermore, we inferred a regulatory network that might be involved in haustoria formation, and 18 genes promoting haustoria formation and 1 gene inhibiting it were identified as a consequence. There were 4 metabolites (ethylsalicylate, eriodictyol-7-O-glucoside, aromadendrin-7-O-glucoside and pruvuloside B) that are transferred from P. vulgaris to T. chinense , whereas 2-ethylpyrazine was transferred from T. chinense to P. vulgaris . Conclusions: These results suggested that there was an extensive exchange of information with P. vulgaris including transferred metabolites and mobile mRNAs, which might facilitate the haustoria formation and parasition of T. chinense . Author summary T. chinense known as “plant antibiotic” is a facultative root hemi-parasitic herb while P. vulgaris can serve as its host. Currently, the information exchange between T. chinense and its host remained unknown, and a comprehensive view of transferred metabolites and mobile mRNAs between T. chinense and its host is critical so that appropriate chemical and genetic improvement can be used to facilitate haustoria formation and successful parasitism. Here, we employ the conjoint wide-target metabolomic and transcriptomic analysis to explore the information exchange between T. chinense and P. vulgaris. We identified 5 transferred metabolites and 668 mobile genes between T. chinense and P. vulgaris , as well as haustoria formation related 56 metabolites and 189 genes. Our study provides new insights into the complex interplay between parasite and host during parasitism.