Functions of ABC transporters in plant growth and development

•ABC transporters are critical for plant growth and development.•New alleles of known ABC transporters have revealed novel physiological roles.•Studies of ABC transporters with substrate biosynthesis enzymes were fruitful. ABC transporters are essential for plant development, playing roles in processes such as gametogenesis, seed development, seed germination, organ formation, and secondary growth. ABC transporters are directly energized by ATP and can transport complex organic materials against concentration gradients; thus, they are uniquely suited to provide the complex building blocks required for the development of specialized plant cells. We review recent progress in our understanding of the contribution ABC transporters make to the growth and development of plants, including their roles in protective layer formation and in transporting phytohormones.