Small RNA populations reflect the complex dialogue established between heterograft partners in grapevine

Grafting is an ancient method that has been intensively used for the clonal propagation of vegetables and woody trees. Despite its importance in agriculture the physiological and molecular mechanisms underlying phenotypic changes of plants following grafting are still poorly understood. In the present study, we analyse the populations of small RNAs in homo and heterografts and take advantage of the sequence differences in the genomes of heterograft partners to analyse the possible exchange of small RNAs. We demonstrate that the type of grafting per se dramatically influences the small RNA populations independently of genotypes but also show genotype specific effects. In addition, we demonstrate that bilateral exchanges of small RNAs, mainly short interfering RNAs, may occur in heterograft with the preferential transfer of small RNAs from the scion to the rootstock. Altogether, the results suggest that small RNAs may have an important role in the phenotype modifications observed in heterografts.

Automated summary

In this study, the populations of small RNAs in homo and heterografts were analyzed, and the possible exchange of small RNAs between heterograft partners was explored by taking advantage of sequence differences in their genomes. It was found that the type of grafting and genotype have significant effects on small RNA populations. Additionally, bilateral exchanges of small RNAs, especially short interfering RNAs, were observed in heterografts with a preference for transfer from scions to rootstocks. Overall, these findings suggest that small RNAs may play an important role in the phenotype modifications observed in heterografts.