The plant surface is by default flat, and development away from this default is thought to have some function of evolutionary advantage. Although the functions of many plant epidermal cells have been described, the function of conical epidermal cells, a defining feature of petals in the majority of insect-pollinated flowers, has not. The location and frequency of conical cells have led to specu...

The KNOTTED1-like homeobox (KNOX) genes are best known for maintaining a pluripotent stem-cell population in the shoot apical meristem that underlies indeterminate vegetative growth, allowing plants to adapt their development to suit the prevailing environmental conditions. More recently, the function of the KNOX gene family has been expanded to include additional roles in lateral organ develop...

The completion of flower development in Impatiens balsamina requires continuous inductive (short-day) conditions. We have previously shown that a leaf-derived signal has a role in floral maintenance. The research described here analyzes the role of the leaf in flower development. Leaf removal treatments, in which plants were restricted to a specified number of leaves, resulted in flowers with i...

Pollinator shifts are considered to drive floral trait evolution, yet little is still known about the modifications of petal epidermal surface at a biogeographic region scale. Here we investigated how independent shifts from insects to passerine birds in the Macaronesian Islands consistently modified this floral trait (i.e. absence of papillate cells). Using current phylogenies and extensive ev...

interaction of floral pigments with metal ions can alter the final color of the petals. metal ions can affect stability of flowers final color by altering vacuolar ph and activity of enzymes involved in biosynthesis, destruction, accumulation and transition of pigments. in this study, contents of metal ions of petal tissue and their relationships with parameters of petal color analyzed and comp...

BACKGROUND Petal spurs-tubular outgrowths that collect nectar-are considered key innovations because of their ability to change pollinator specificity and so cause reproductive isolation and speciation. Spurs have arisen frequently and rapidly in many taxa. To test their potential origins, we isolated spontaneous dominant mutations at two loci, HIRZ and INA, that cause novel outgrowths from Ant...

The APETALA3 floral homeotic gene is required for petal and stamen development in Arabidopsis. APETALA3 transcripts are first detected in a meristematic region that will give rise to the petal and stamen primordia, and expression is maintained in this region during subsequent development of these organs. To dissect how the APETALA3 gene is expressed in this spatially and temporally restricted d...

This study used three-dimensional (3D) micro-computed tomography (μCT) imaging to examine petal form variation in a hybrid cross of Sinningia speciosa between a cultivar with actinomorphic flowers and a variety with zygomorphic flowers. The major objectives were to determine the genotype-phenotype associations between the petal form variation and CYCLOIDEA2-like alleles in S. speciosa (SsCYC) a...

Hierarchically structured flower leaves (petals) of many plants are superhydrophobic, but water droplets do not roll-off when the surfaces are tilted. On such surfaces water droplets are in the "Cassie impregnating wetting state", which is also known as the "petal effect". By analyzing the petal surfaces of different species, we discovered interesting new wetting characteristics of the surface ...