Organelle inheritance: understanding the basis of plastid transmission for transgenic engineering
Anja Schneider
Abstract
Plastids are DNA-containing organelles responsible for various metabolic processes in plants, including photosynthesis.In a process called plastid inheritance, proplastids are transmitted from the parental to the filial generation through reproductive tissues.Plastid inheritance varies in different plant lineages and can be studied using reciprocal test crosses and genetic markers.Uniparental plastid inheritance is common in green algae and land plants, with mechanisms that eliminate plastids and their DNA either before or after fertilisation.Postfertilisation elimination of mating type minus plastids in Chlamydomonas reinhardtii and paternal plastid elimination during male gametogenesis in Nicotiana tabacum are under nuclear control.In the genus Oenothera, however, biparental plastid inheritance may be followed by plastid-controlled elimination.Most angiosperms, including major crops, show dominant maternal inheritance, although some degree of transmission through the paternal parent, called leakage, appears to be universal.Exclusion of plastids from the pollen sperm cell provides a natural containment system for genetically modified plastid DNA in transplastomic plants, enabling diverse applications from insect resistance to pharmaceutical production.This review highlights recent findings and ongoing research in this area.Research into plastid inheritance and the exploitation of its full potential holds great promise for the advancements of agriculture.