How different organs are formed from small sets of undifferentiated precursor cells is a key question in developmental biology. To understand the molecular mechanisms underlying organ specification in plants, we studied the function of the homeotic selector genes APETALA3 (AP3) and PISTILLATA (PI), which control the formation of petals and stamens during Arabidopsis flower development. To this ...

Flowers are prized as objects of great beauty and diversity, and are commercially valuable (~US$4.5 billion in international trade yearly) and highly perishable. Biologically, flower petals have an important role in the lifecycle of plants, as they protect immature reproductive structures, then provide the attraction and accessibility needed for pollination to occur. Flower petal cell wall cons...

There is no doubt that people find flowers beautiful. Surprisingly, we know very little about the actual properties which make flowers so appealing to humans. Although the evolutionary aesthetics provides some theories concerning generally preferred flower traits, empirical evidence is largely missing. In this study, we used an online survey in which residents of the Czech Republic (n = 2006) r...

Preliminary study on Ipomoea phylogeny shows that species selection may influence flower-color evolution in this genus. Evolutionary transitions between pigmented flower and white flower appear to be highly asymmetrical. White-flowered lineages are less speciose than their pigmented sister clade and evolutionary transitions to white flowers occurred almost exclusively at the tip of phylogeny. A...

Developmental genetic pathways involved in flower formation in model plants such as Arabidopsis and maize enable us to identify genes, gene families, and gene networks that are involved in the regulation of flower initiation, growth and differentiation. These genes can then function as “candidate genes” and their expression, function, and biochemical interactions can be explored in other lineag...

The regulatory mechanisms underlying bud breaking (scale leaf elongation) and flowering in the lateral flower buds of Japanese pear (Pyrus pyrifolia Nakai 'Kosui') are unknown. To more fully characterize these processes, we treated pear trees with different amounts of chilling initiated at different times. Chilling for ∼900 h at 6 °C always induced bud breaking (scale elongation in ≥70% lateral...

to study the effect of plant density and planting pattern on iranian ox-tongue, an experiment carried out with two factors: planting pattern (square and rectangular pattern) and plant density (2, 4, 6, 8 plant m-2) in a factorial test performed based on rcbd in 3 replications during 2009-2010 in latmahalleh eshkevarat village in guilan province, iran. characteristics that measured included: dry...

Flower-like ZnO nanostructures were synthesized by decomposing Zn(OH)2 in 1,4- butanediol at 105 °C for 36 h. Size of flower-like ZnO nanostructure can be controlled by pH of the aqueous solution. In the preparation of flower-like ZnO nanostructure, zinc nitrate was used as a precursor. The morphology and microstructure of flower-like ZnO nanostructure have been characterized by scanning electr...

BACKGROUND Understanding the mode and mechanisms of the evolution of the angiosperm flower is a long-standing and central problem of evolutionary biology and botany. It has essentially remained unsolved, however. In contrast, considerable progress has recently been made in our understanding of the genetic basis of flower development in some extant model species. The knowledge that accumulated t...

We present a model for the gradual evolution towards dioecy in cosexual plants with geitonogamous selfing. We show how geitonogamous selfing (i.e., transfer of pollen between flowers on the same plant) can facilitate the evolution of dioecy (i.e., separate male and female individuals) in cosexual plants (i.e., both sexual functions on the same plant). We study the effect of parameters such as i...