Grafting with rootstocks induces extensive transcriptional re-programming in the shoot apical meristem of grapevine

Grafting is widely used in the agriculture of fruit-bearing crops; rootstocks are known to confer differences in scion biomass in addition to improving other traits of agricultural interest. However, little is known about the effect of rootstocks on scion gene expression. The

The choice of rootstock genotype had little effect on the gene expression in the shoot apex; this could suggest that auto- and hetero-grafting was the major factor regulating gene expression.

The rootstocks increased stem biomass or conferred increased vigor by the end of the first growth cycle. Globally hetero-grafting two different genotypes together triggered an increase in shoot apex gene expression; however no genes were differentially expressed between the two hetero-grafts. The functional categories related to DNA, chromatin structure, histones, flavonoids and leucine rich repeat containing receptor kinases were the most enriched in the up-regulated genes in the shoot apex of hetero-grafted plants. Conclusions: The choice of rootstock genotype had little effect on the gene expression in the shoot apex; this could suggest that auto- and hetero-grafting was the major factor regulating gene expression.