Control of sexuality by the <i>sk1</i>-encoded UDP-glycosyltransferase of maize.

Abstract

Sex determination in maize involves the production of staminate and pistillate florets from an initially bisexual floral meristem. Pistil elimination in staminate florets requires jasmonic acid signaling, and functional pistils are protected by the action of the <i>silkless 1</i> (<i>sk1</i>) gene. The <i>sk1</i> gene was identified and found to encode a previously uncharacterized family 1 uridine diphosphate glycosyltransferase that localized to the plant peroxisomes. Constitutive expression of an <i>sk1</i> transgene protected all pistils in the plant, causing complete feminization, a gain-of-function phenotype that operates by blocking the accumulation of jasmonates. The segregation of an <i>sk1</i> transgene was used to effectively control the production of pistillate and staminate inflorescences in maize plants.