The parasitic plants dodders (Cuscuta spp., Convolvulaceae) can often simultaneously parasitize two or more neighbouring hosts, forming dodder-connected plant clusters. In a dodder-connected plant cluster, salt-induced systemic priming signals are transferred from the salt-stressed host (signal donor, SD) to the other host (signal receiver, SR) through dodder and prime the SR plants for enhanced salt tolerance, but what signalling pathways regulate the dodder-mediated interplant priming signals remain unclear. In this study, using genetic analyses, we show that in dodder-connected tobacco (Nicotiana tabacum) clusters, the strigolactone (SL), reactive oxygen species (ROS) and abscisic acid (ABA) pathway in the SD plants negatively control the salt stress-induced systemic signals from SD to SR plants. Transcriptome data suggested that the salt-induced systemic signals regulated by SLs in the SD plants may also affect the ABA and ROS signalling pathway in the SR plants. Quantification of the ABA and H