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...

Sexual reproduction in flowering plants depends on the evocation of flowers, which, in general, consist of four whorls of organs: sepals, petals, anthers, and pistil. Sepals and petals can be regarded as initially protective organs. During the first stage of floral development, meiosis occurs in the anthers and the pistil while these organs are still enclosed by the sepals. Petals, the organs o...

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...

We report a catalyst-free synthesis of cantilevered carbon nanosheet extensions, or petals, from graphite fibers by microwave plasma CVD. Results reveal that the petals grow from the fiber surface layers while preserving graphitic continuity from fiber to the petals. Subtraction of Raman signatures from pristine and decorated fibers reveals a convolution of two underlying peaks at 2687 and 2727...

Chalcone synthase is a key and often rate-limiting enzyme in the biosynthesis of anthocyanin pigments that accumulate in plant organs such as flowers and fruits, but the relationship between CHS expression and the petal coloration level in different cultivars is still unclear. In this study, three typical crabapple cultivars were chosen based on different petal colors and coloration patterns. T...

Autophagy is one of the main mechanisms of degradation and remobilization of macromolecules, and it appears to play an important role in petal senescence. However, little is known about the regulatory mechanisms of autophagy in petal senescence. Autophagic processes were observed by electron microscopy and monodansylcadaverine staining of senescing petals of petunia (Petunia hybrida); autophagy...

We describe the effects of four recessive homeotic mutations that specifically disrupt the development of flowers in Arabidopsis thaliana. Each of the recessive mutations affects the outcome of organ development, but not the location of organ primordia. Homeotic transformations observed are as follows. In agamous-1, stamens to petals; in apetala2-1, sepals to leaves and petals to staminoid peta...