Grafting-induced transcriptome changes and long-distance mRNA movement in the potato/Datura stramonium heterograft system

Grafting potato into Solanaceae plants has been used as an efficient method to solve such problems as a short flowering period, low fruit setting rate, and sterility in potato crossbreeding. However, the molecular mechanisms governing grafting-induced phenotypic variations have not been elucidated. In this study, one potato cultivar and wild Datura stramonium served as scion (StS) and rootstock (DsR), respectively. Phenotypic analysis showed that the fertility of StS was visibly improved in comparison with self-grafted potato (St). Comparative transcriptome profiling revealed that 1490 differentially expressed genes were identified in StS compared with St, and some of these genes appear to be involved in pathways related to genome damage and genotoxic stress response. We reported the comprehensive identification of mRNA movement between DsR and StS, indicating that 111 transcripts of DsR were delivered to StS. Conversely, the 1968 mRNAs were transported from StS to DsR. Based on GO analysis, some of these mobile transcripts had a biological role in regulating pollen tube development and fruit morphogenesis. This work provides abundant transcriptome profile data for potato scions and reveals that three key transcripts moving from rootstock to scion may be responsible for improving the fertility of potatoes.