all hz SNP calls along the 3P Q. robur genome see Plomion et al 2018 Nature Plants for details. Quercus robur sample 3P heterozygous calls

Oaks are an important part of our natural and cultural heritage (Supplementary Note 1). Not only are they ubiquitous in our most common landscapes 1 , they have also supplied human societies with invaluable services, including food and shelter, since prehistoric times 2 . With 450 species spread throughout Asia, Europe and America 3 , oaks constitute a critical global renewable resource. The longevity of oaks (several hundred years) probably underlies their emblematic cultural and historical importance. Such long-lived sessile organisms must persist in the face of a wide range of abiotic and biotic threats over their lifespans. We investigated the genomic features associated with such a long lifespan, by sequencing, assembling, and annotating the oak genome. We then used the growing number of whole-genome sequences for plants (including tree and herbaceous species) to investigate the parallel evolution of genomic characteristics potentially underpinning tree longevity. A further consequence of the long lifespan of trees is their accumulation of somatic mutations (SMs) during mitotic divisions of the stem cells present in the shoot apical meristems. Empirical 4 and modeling 5 approaches have shown that intra-organismal genetic heterogeneity can be selected 6 and provides direct fitness benefits in the arms race with short-lived pests and pathogens, through a patchwork of intra-organismal phenotypes 7 . However, there is no clear proof that large-statured trees consist of a genetic mosaic of clonally distinct cell lineages within and between branches. Through this case study of oak, we demonstrate the accumulation-transmission of SMs and the expansion of R-gene families in trees.