Betalains are pigments that replace anthocyanins in the majority of families of the plant order Caryophyllales. Betalamic acid is the common chromophore of betalains. The key enzyme of the betalain biosynthetic pathway is an extradiol dioxygenase that opens the cyclic ring of dihydroxy-phenylalanine (DOPA) between carbons 4 and 5, thus producing an unstable seco-DOPA that rearranges nonenzymati...

Spring gardens will soon bloom with an abundance of flowering plants—from cultivated roses to hillside wildflowers. The diversity among flowering plants is remarkable, and even within a single plant, you find an assortment of shapes and sizes. Plant organs—leaves and petals, for instance—clearly have distinct forms and functions and are subject to different evolutionary pressures. Yet scientist...

Senescence of carnation flowers is characterized by autocatalytic ethylene production from petals and subsequent wilting of the petals. Recent studies on the regulation of ethylene production and wilting in senescing carnation petals revealed that (1) petal senescence is triggered by ethylene evolved from the gynoecium during natural senescence, (2) ethylene production in the gynoecium is induc...

Cyclamen persicum (cyclamen) is a commercially valuable, winter-blooming perennial plant. We cloned two cyclamen orthologues of AGAMOUS (AG), CpAG1 and CpAG2, which are mainly expressed in the stamen and carpel, respectively. Cyclamen flowers have 5 petals, but expression of a chimeric repressor of CpAG1 (CpAG1-SRDX) caused stamens to convert into petals, resulting in a flower with 10 petals. B...

A cDNA encoding a polygalacturonase-inhibitor-like protein (PGIP) was isolated from cotton flower cDNA library. The cDNA, designated GhPS1 (GenBank accession No. ABO47744), encodes a protein with 370 amino acids that shares high similarity with the known plant PGIPs. Fluorescent microscopy indicated that GhPS1 protein localizes on the cell membranes as well as in cytoplasm. Real-time quantitati...

Petals appear in many angiosperm taxa, yet when and how these attractive organs originated remains unclear. Phylogenetic reconstructions based on morphological data suggest that petals have evolved multiple times during the radiation of the angiosperms. Based on the diversity of petal morphologies, it is likely that the developmental programmes specifying petal identity are distinct in differen...