Molecular Mechanism of Cuscuta Haustorium Specialization Inferences from Transcriptome and Metabolome Analysis

Cuscuta australis R. Br. is a parasitic herbaceous plant that obtains nutrients by forming specialized structures called haustoria to invade host plants.

In this study, we elucidated the differences in the gene expression regulation and metabolic characteristics between Cuscuta australis and Glycine max (Glycine max (L.) Merr. Var Williams) through comprehensive transcriptomic and metabolomic analyses.

The results demonstrated significant differences in the gene expression and metabolic features between the haustorium and the distal stem segments. The differentially expressed genes absorbed by Cuscuta australis from the soybean host influence amino acid metabolism, and the expression of the S-adenosylmethionine decarboxylase gene may affect the production of 5'-methylthioadenosine. A high expression of the chalcone synthase enzyme could lead to an increased daidzein content. Many Glycine max genes were also integrated into Cuscuta australis within the haustorium.

This study systematically analyzed, for the first time, the significant differences in gene expression and metabolic characteristics between the haustoria and distal stem segments of Cuscuta. It also explored the nutrient absorption mechanisms of the host plant. Additionally, the research discovered that Cuscuta can absorb a substantial amount of host genes and adapt to its parasitic lifestyle through differential gene expression and metabolic changes. These findings provide important insights into the parasitic mechanisms of Cuscuta australis and lay the foundation for the development of effective control strategies.