Grafting with Different Rootstocks Induced DNA Methylation Alterations in Pecan [Carya illinoinensis (Wangenh.) K. Koch]

Rootstocks are well known to have important effects on scion growth performance. However, the involved mechanisms remain unclear. Recent studies provided some clues potential involvement of DNA methylation in grafting, which open up new horizons for exploring how rootstocks induce changes. To better understand rootstock-induced alterations, whole-genome bisulfite sequencing (WGBS) was used evaluate profiles two sets pecan grafts with different performances sizes rootstocks. The results showed that methylated cytosines accounted 24.52%–25.60% all pecan. Methylation levels CG were highest, lowest being CHH (C= cytosine; G= guanine; H = adenine, thymine, or cytosine). induced extensive alterations scions 934, 2864, and 15,789 differentially regions (DMRs) determined CG, CHG, contexts, respectively. DMR-related genes (DMGs) found participate various processes associated plant growth, among 17 DMGs found, most likely related hormone response, may play particularly roles graft regulation. This study revealed methylomes throughout genome first time, obtained abundant potentially changes scions, lays a good basis further epigenetic deeper understanding grafting grafts.