Scientists at the Max Planck Institute of Molecular Plant Physiology in Potsdam (Germany) analyzed the inheritance of chloroplasts under different environmental conditions in almost 4 million tobacco plants. Contrary to the prevailing view that chloroplasts are only passed on by the mother plant, paternal chloroplasts can also be transmitted to the offspring under cold conditions, raising the possibility that the chloroplasts of the two parents exchange genetic material with each other. The new findings will facilitate the targeted use of chloroplast-encoded traits in plant breeding, and they also open up new perspectives for evolutionary research. The study was published in Nature Plants.