Interplant signal transduction between dodder (<i>Cuscuta</i>) and their hosts

Parasitic plants partly or completely depend on their host plants for growth and development. Through haustoria, parasitic plants extract water and nutrients from their hosts. However, there is also evidence that various biomolecules, including systemic signals, mRNAs, small RNAs (sRNAs), and proteins, are transferred between parasites and host plants and even among host plants commonly connected by a parasite. Many of these biomolecules transferred among plants may confer specific functions to recipient plants, altering their physiology and/or ecology. In this review, we summarize the current understanding of interplant systemic signaling between hosts and dodder (Cuscuta, Convolvulaceae), including the physiological and ecological functions of interplant systemic signals and the mechanisms underlying these functions. Next, transfer of mRNAs, sRNAs, and proteins between hosts and dodder plants are reviewed, and the functions of these macromolecules are discussed.