A non–cell–autonomous mutation regulating juvenility in maize

Abstract

The transition from a juvenile to an adult phase of shoot growth in plants involves coordinated changes in a large number of morphological and physiological traits, including the ability of the plant to undergo sexual reproduction. Although the environmental, nutritional and chemical factors that influence this process (phase change) have been intensively studied for many years, its basic mechanism is still unknown^1,2. An analysis of the genetic regulation of phase change has been facilitated by the identification of several mutations of maize (Teopodl, Tp2, Tp3 and Corngrass) that prolong the expression of a juvenile developmental programme^3,4. All of these mutations have a striking atavistic phenotype, the most dramatic feature of which is the transformation of reproductive structures into leaves or leaf-like structures. Here I report that X-ray-induced sectors expressing the wild-type allele of Tp1 in otherwise mutant plants possess a mutant rather than a wild-type phenotype. This non-cell-autonomous behaviour is highly unusual and suggests that Tp1 controls the production or distribution of a diffusible factor(s) that regulates juvenile development.