The presence of this improved mechanism for homogenization of mitochondrial distribution and contents appears essential in SAM meristematic cells of Arabidopsis and most likely other plants, because these cells give rise to the floral meristem (Fig. 1C), the germ lines, and ultimately—and most importantly—the female gametes. In Arabidopsis and many other species, the female gametes are responsible for the exclusive transmission of all of their chondriome to the newly formed zygote and thus to the new generations.16,17
In this context, the presence of such a homogenizing mechanism in SAM cells is critically important for preserving the stability of the mitochondrial traits that have to be passed on to future gametes and embryos, i.e., to prevent speciation.