1-Aminocyclopropane-1-carboxylic acid (ACC) is a disubstituted cyclic α-amino acid in which a cyclopropane ring is fused to the Cα atom of the amino acid. It is a white solid. Many cyclopropane-substituted amino acids are known, but this one occurs naturally.[2][verification needed] Like glycine, but unlike most α-amino acids, ACC is not chiral.
ACC also exhibits ethylene-independent signaling that plays a critical role in pollination and seed production by activating proteins similar to those involved in nervous system responses in humans and animals. More specifically, ACC signaling promotes secretion of the pollen tubechemoattractant LURE1.2 in ovularsporophytic tissue thus enhancing pollen tube attraction. Additionally, ACC activates Ca2+-containing ion currents via glutamate receptor-like (GLR) channels in root protoplasts.[6]
^Brackmann F, de Meijere A (November 2007). "Natural Occurrence, Syntheses, and Applications of Cyclopropyl-Group-Containing α-Amino Acids. 1. 1-Aminocyclopropanecarboxylic Acid and Other 2,3-Methanoamino Acids". Chemical Reviews. 107 (11): 4493–4537. doi:10.1021/cr078376j. PMID17944521.
^Yang S, Hoffman N (1984). "Ethylene biosynthesis and its regulation in higher plants". Annu. Rev. Plant Physiol. 35: 155–189. doi:10.1146/annurev.pp.35.060184.001103.