In particular, our microscopical data demonstrated that shoot apical meristem (SAM) and leaf primordial (LP) meristematic cells are unique in that they contain a large, “reticulate-type” of mitochondrial system that allows for the efficient intermixing of mtDNA1 (Fig. 1B). In contrast, all of the other cell types we have examined—non-dividing, differentiated leaf primordial cells, mature leaf and stem epidermal cells, root meristematic, embryo, endosperm and male gametophyte cells—produce typical small mitochondria as reported in the literature