AINTEGUMENTA-LIKE proteins: hubs in a plethora of networks

• Various gene networks involve AIL genes to steer plant development.
• AILs regulate embryogenesis, meristem development, organ initiation and growth.
• AILs interact with auxin pathways at multiple levels throughout plant development.
• AIL proteins exert their functions in a dosage-dependent manner.

Members of the AINTEGUMENTA-LIKE (AIL) family of APETALA 2/ETHYLENE RESPONSE FACTOR (AP2/ERF) domain transcription factors are expressed in all dividing tissues in the plant, where they have central roles in developmental processes such as embryogenesis, stem cell niche specification, meristem maintenance, organ positioning, and growth. When overexpressed, AIL proteins induce adventitious growth, including somatic embryogenesis and ectopic organ formation. The Arabidopsis (Arabidopsis thaliana) genome contains eight AIL genes, including AINTEGUMENTA, BABY BOOM, and the PLETHORA genes. Studies on these transcription factors have revealed their intricate relationship with auxin as well as their involvement in an increasing number of gene regulatory networks, in which extensive crosstalk and feedback loops have a major role.