Something old, something new: Conservation of the ethylene precursor 1-amino-cyclopropane-1-carboxylic acid as a signaling molecule

In seed plants, 1-amino-cyclopropane-1-carboxylic acid (ACC) is the well-known precursor of the plant hormone ethylene. In nonseed plants, the current view is that ACC is produced but is inefficiently converted to ethylene. Distinct responses to ACC that are uncoupled from ethylene biosynthesis have been discovered in diverse aspects of growth and development in liverworts and angiosperms, indicating that ACC itself can function as a signal. Evolutionarily, ACC may have served as a signal before acquiring its role as the ethylene precursor in seed plants. These findings pave the way for unraveling a potentially conserved ACC signaling pathway in plants and have ramifications for the use of ACC as a substitute for ethylene treatment in seed plants.

Automated summary

Research has found that ACC, a precursor of the plant hormone ethylene, can function as a signal in nonseed plants, even though it is inefficiently converted to ethylene. Distinct responses to ACC have been observed in different aspects of growth and development in liverworts and angiosperms, suggesting that ACC itself may have served as a signal before becoming the ethylene precursor in seed plants. These findings open up the possibility of uncovering a conserved ACC signaling pathway in plants and have implications for the use of ACC as a substitute for ethylene treatment in seed plants.