DNA ELEMENTS RESPONSIVE TO AUXIN

Genes induced by the plant hormone auxin are probably involved in the execution of vital cellular functions and developmental processes. Exp erimental approaches designed to elucidate the molecular mechanisms of auxin action have focused on auxin perception, genetic dissection of the signaling apparatus and specific gene activation. Auxin-responsive promoter elements of early genes provide molecular tools for probing auxin signaling in reverse. Functional analysis of several auxin-speci fic promoters of unrelated early genes suggests combinatorial utilizat ion of both conserved and variable elements. These elements are arrang ed into autonomous domains and the combination of such modules generat es uniquely composed promoters. Modular promoters allow for auxin-medi ated transcriptional responses to be revealed in a tissue- and develop ment-specific manner.