J Plant Physiol 171(17):1586-1590. (Nov 2014)
Transposon-mediated Mutation of CYP76AD3 Affects Betalain Synthesis and Produces Variegated Flowers in Four O'Clock (Mirabilis Jalapa)
Mariko Suzuki, Taira Miyahara, Hiroko Tokumoto, Takashi Hakamatsuka, Yukihiro Goda, Yoshihiro Ozeki, Nobuhiro Sasaki

The variegated flower colors of many plant species have been shown to result from the insertion or excision of transposable elements into genes that encode enzymes involved in anthocyanin synthesis. To date, however, it has not been established whether this phenomenon is responsible for the variegation produced by other pigments such as betalains. During betalain synthesis in red beet, the enzyme CYP76AD1 catalyzes the conversion of L-dihydroxyphenylalanine (DOPA) to cyclo-DOPA. RNA sequencing (RNA-seq) analysis indicated that the homologous gene in four o'clock (Mirabilis jalapa) is CYP76AD3. Here, we show that in four o'clock with red perianths, the CYP76AD3 gene consists of one intron and two exons; however, in a mutant with a perianth showing red variegation on a yellow background, a transposable element, dTmj1, had been excised from the intron. This is the first report that a transposition event affecting a gene encoding an enzyme for betalain synthesis can result in a variegated flower phenotype.

Mirabilis bibliography