Petal cell shape and flower-pollinator interaction in Nicotiana
Creators: name: Doria Ramirez, Maria Gabriela
Publisher: name: Apollo - University of Cambridge Repository
Year: 2020
Subjects: Agrobacterium tumefaciens
angiosperms
artificial flowers
Atacama Desert
bee learning
bee pollination
bee vision
bee hexagon
bird pollination
Bombus terrestris
bumblebees
conical cells
differential conditioning
epidermal cells
evo-devo
evolution
floral features
flowering plants
flowers
foraging speed
fower development
function
gene expression
gene regulation
gene sequencing
Juan Fernandez Islands
MIXTA genes
MYB genes
moth pollination
Nicotiana
Nicotiana benthamiana
Nicotiana bonariensis
Nicotiana cordifolia
Nicotiana forgetiana
Nicotiana solanifolia
Nicotiana tabacum
petal cell shape
petal texture
phylogenetics
plant evolution
plant molecular biology
plant tissue culture
pollination
pollinator behaviour
pollination sysndrome
protein function
R2R3 Subgroup 9 MYB
Solanaceae
tobacco
transcription factors

description: Petal epidermal cell shape has been shown to affect pollination success in flowering plants. Conical epidermal cells may increase grip for insect pollinators and enhance flower colouration compared to non-conical cells. Nicotiana (Solanaceae) presents a diverse range of petal cell shapes. Interestingly, sister species in at least two phylogenetically distinct clades of the genus have contrasting petal epidermal cell shapes (conical vs. non-conical). This project aims to further understand character evolution of petal cell shape in Nicotiana and its implications in pollination systems, combining tools of molecular biology, morphology and pollinator behaviour experiments. First, using a candidate gene approach, I explore in parallel the molecular mechanisms involved in petal cell shape differentiation of sister species with contrasting cell shape N. cordifolia and N. solanifolia (Section Paniculatae) and N. bonariensis and N. forgetiana (Section Alatae). Subgroup 9 R2R3 MYB transcription factors are potentially responsible for the molecular control of petal cell shape. Differential expression of subgroup 9 R2R3 MYBs in petals of the sister species, rather than sequence differences in these genes, might be explaining the contrasting cell morphologies. Next, I develop an Agrobacterium tumefaciens mediated transformation protocol for the non-model species N. forgetiana, a methodological advance crucial for further exploration of the molecular mechanisms and functional implications of petal cell shape. Lastly, I explore how petal colour and petal cell shape interact in the perception of flowers by model pollinator Bombus terrestris using biomimetic artificial flowers. Pollinator behaviour experiments indicate that the bumblebees can discriminate flowers with conical from flowers with non-conical surfaces, on a red and on a white background, using visual cues alone as well as tactile cues alone. This investigation improves our understanding of the molecular mechanisms involved in petal epidermal cell morphogenesis and of the functional implications of petal cell shape in the interaction flower-pollinator in Nicotiana.
description: Cambridge International Trust and the Newton-Caldas Fund partnership between the British Council (UK) and Colciencias (Colombia)