Plastids are essential organelles in angiosperms and show non-Mendelian inheritance due to their evolution as endosymbionts. In approximately 80% of angiosperms, plastids are thought to be inherited from the maternal parent, whereas other species transmit plastids biparentally. How are the plastids inherited maternally, and are the mechanisms controlling? A key process seems to lie in the behavior of plastids during male gametophyte (pollen) development, with accumulating evidence indicating that the plastids themselves or their DNAs are eliminated during pollen maturation or at fertilization. In this talk, I will review the general context of plastid inheritance, and will focus on the critical role of the exonuclease involved in organelle DNA degradation. In pollen, DPD1 appears to ensure maternal inheritance of plastids. Whereas in senescent leaves, it appears to contribute to recycling of nutrients such as phosphate.