PETALEVODEVO · Resurrection of Developmental Pathways in the Evolution of the Petal
FP7 — People (Marie Curie Actions)
- Duration
- 2009-10-01 → 2012-09-30
- EU contribution
- €75,000
- Participants
- 1
- Scheme
- MC-IRG
Lines connect the coordinator with its partners.
Results in brief
Resurrection of Developmental Pathways in the Evolution of the Petal
Angiosperms or flowering plants are the most diverse and widespread of land plants. Dominating most of the world’s habitats, they represent all of the major human crop plants. Flowers are the reproductive structures of angiosperms and facilitate numerous ecological and evolutionary interactions. A near constant feature in flowers, petals are crucial in attracting and interacting with pollinators; an estimated 35% of global crop production depends on petal-mediated animal pollination. Understanding how petals have evolved and how they contribute to the evolutionary success of angiosperms is a major goal in plant biology, while genetic manipulation of petals has been shown to influence agricultural success and crop yield. Our project concerned the evolution of petals in a group of flowering plants, the Caryophyllales, that contain numerous charismatic plants, like Cacti and ‘Living Stones’. We previously determined that following a loss of petals in the Caryophyllales, petals have subsequently re-evolved 9 times. Our goal was to develop the system to better understand the genetic pathways underlying the multiple origins of petals. Many of the novel petals that have evolved in the Caryophyllales develop from sterilised male organs – the stamens. We were consequently interested in the relationship between the origin of these petals and the stamens that give rise to them. We sought to describe the numerous separate instances in which stamens are transformed into petals, to better understand the forces that influence this transition. Conical cells on the surface of petals significantly enhance the attractiveness of a flower to its pollinators in a number of ways. They enhance colour saturation, provide tactile cues, reduce petal reflexing and increase petal temperature. We sought to understand how these conical cells appear on novel petals in the Caryophyllales, by understanding the evolutionary history of the subgroup 9 R2R3 MYB genes responsible for specifying these conical cells. Finally we investigated the complex evolution of a novel form of pigmentation in the Caryophyllales – the betalains – and explore their possible role colouring petals and attracting pollinators. http://www.plantsci.cam.ac.uk/research/beverleyglover.html
Data: CORDIS, © European Union
Project objective
Our project concerns the evolution of petal conical cells in a group of flowering plants, the Caryophyllales. The fellow has determined that following a loss of petals in the Caryophyllales, petals have subsequently re-evolved 9 times. Conical cells, which perform a vital role in interacting with pollinators, often occur on these re-evolved petals. The host has demonstrated that MIXTA-like R2R3 MYB genes specify conical cells in distant lineages of flowering plants. We hypothesise that recurrent evolution of these conical cells in separate occurrences of re-evolved petals is due to repeated recruitment of the MIXTA-like R2R3 MYB genes. We will test this hypothesis by isolating R2R3 MYB genes from 3 species representing distinct evolutions of the petal in the Caryophyllales. We will conduct phylogenetic analyses to determine if the same or distinct lineages of R2R3 MYB genes have been recruited to specify conical cells. We will assess if the genes are expressed in the conical cells. We will perform a transformation assay into tobacco to determine if the MIXTA-like R2R3 MYB genes are functioning as in other flowering plants. We will analyse the function of the genes in vivo, through RNAi and overexpresssion. The host’s collaborators demonstrated that MIXTA-like R2R3 MYB genes are directly activated by the transcription factors APETALA3 and PITILLATA, to induce conical cells. However, the fellow has shown that APETALA3 and PISTILLATA are often absent from these re-evolved petals. We ask how MIXTA-like R2R3 MYB genes are turned on if APETALA3 and PISTILLATA are absent. We will answer this by analyzing the promoters of the R2R3 MYB genes to identify novel regulatory elements. The fellow’s expertise on Caryophyllales petal evolution, combined with the host’s expertise on MIXTA-like R2R3 MYB genes enables an interdisciplinary approach. It is an important study for the emerging field of evolutionary developmental biology, and will enhance scientific research in the EU.
Original text from CORDIS.
Participants
- THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGECoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union