Jasmonate: Preventing the Maize Tassel from Getting in Touch with His Feminine Side

Reproduction of angiosperm plants is central to many aspects of global ecosystem biology and has been a determining factor in the rise and success of world civilizations. Many plants have developed mechanisms that favor out-crossing rather than self-fertilization. In maize (Zea mays), separate male and female flowers develop on a single plant. Sex determination in the male floral structure, the tassel, depends on signaling through the tasselseed (ts) pathway. Mutations affecting this pathway, such as ts1 and ts2, cause development of female flowers on the tassel. Cloning of ts1 and identification of the TS1 protein as an enzyme involved in jasmonate synthesis have revealed that jasmonate, an oxylipin plant hormone derived from linolenic acid, is an essential signal in determining male identity in the maize tassel.