The class B organ identity genes, APETALA3 and PISTILLATA, are required to specify petal and stamen identity in the Arabidopsis flower. We show here that the activities of these two genes are sufficient to specify petals and stamens in flowers, in combination with the class A and C genes, respectively. Flowers of plants constitutively expressing both PISTILLATA and APETALA3 under the control of...

We have investigated the effects on plant development of mutations in the Arabidopsis thaliana CLAVATA1 gene. In clavata1 plants, vegetative, inflorescence and floral meristems are all enlarged relative to wild type. The apical meristem can fasciate in the more severe mutant alleles, and this fasciation can occur prior to the transition to flowering. Flowers of clavata1 plants can have increase...

Floral herbivory may have deleterious effects on the reproductive success of flowering plants. However, plants may evolve floral traits that allow them to defend against herbivory in particular conditions. A bumblebee-pollinated subalpine herb, Pedicularis rex (Orobanchaceae), endemic to southwest China, has cup-like bracts that fill with rainwater, which submerges its corolla tubes. We hypothe...

This article is derived from a broad, twenty-year study of ethnobotany and folk medicine among pastoral nomads in the Middle East which took place from 1984 to 2004. The article presents examples of different treatments of diseases and disorders of the urinary tract carried out by healer herbalists. The preparation of remedies includes boiling infusions, extraction of dry or fresh leaves, flowe...

BACKGROUND A huge variety of plant forms can be found in nature. This is particularly noticeable for inflorescences, the region of the plant that contains the flowers. The architecture of the inflorescence depends on its branching pattern and on the relative position where flowers are formed. In model species such as Arabidopsis thaliana or Antirrhinum majus the key genes that regulate the init...

This paper describes a simple model intended as a first step towards a quantitative theory of the flower. It divides both flowers and their visitors into two categories: the flowers may either produce a substantial volume of nectar ("secretors") or none ("cheaters"), while the insects either attempt to discriminate between them and enter only secretors ("selectors") or enter any flower encounte...

Abscission is a process in plants for shedding unwanted organs such as leaves, flowers, fruits, or floral organs. Shedding of leaves in the fall is the most visually obvious display of abscission in nature. The very shape plants take is forged by the processes of growth and abscission. Mankind manipulates abscission in modern agriculture to do things such as prevent pre-harvest fruit drop prior...

How do plants position their leaves and flowers around the stem in such regular patterns? Auxin is well established as an essential regulator. Now, the modification of a structural cell wall component is shown to have a dramatic impact.

You may have noticed that there are lots of different kinds of plants in your own backyard or neighborhood, and you may even have heard of the concept of evolution. But have you ever wondered what forces have contributed to creating all these plants, with different shapes and colors, all over the world? Or how scientists hope to understand and explain how so many kinds of life came to be over m...

1-Phenylethanol (1PE) is a major aromatic volatile in tea (Camellia sinensis) flowers, whereas it occurs in a much smaller amounts in leaves. Enzymes involved in the formation of 1PE in plants and the reason why 1PE differentially accumulates in plants is unknown. In the present study, enzymes in the last step leading from acetophenone to 1PE were isolated from tea flowers by traditional bioche...