Analysis of the Promoter Activity of Aco1 in Rice

Abstract

Phytochrome (phy) has been shown to be the major photoreceptor involved in photomorphogenetic and physiological responses in plants, and there are three rice genes for phy (PHYA, PHYB and PHYC). Our previous study showed that one of the genes encoding ethylene biosynthetic enzymes, Aco1, was highly expressed in phyAphyBphyC mutants compared to the wild-type (WT) (Kiyota et al., PCP 46: s168, 2005). In this study, we report expression analysis of the Aco1 promoter:GUS constructs in rice. The GUS genes driven by a series of 5'-truncated Aco1 promoters were introduced into both WT and phyAphyBphyC mutant plants to compare the Aco1 promoter activities between them. In phyAphyBphyC mutants, the GUS activity was higher than that in WT plants, although the localization of GUS activity was similar. On the other hand, a GUS activity site specific to WT plants was found in elongated internodes at heading.