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University of Cambridge

Petal cell shape and flower-pollinator interaction in Nicotiana

Abstract

dc:description.abstract

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.

Degree

thesis:*
Name dc:type.qualificationname
Doctor of Philosophy (PhD)
Level dc:type.qualificationlevel
Doctoral
Grantor dc:publisher.institution
University of Cambridge
Year dc:date.issued
2020

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Doria Ramirez, Maria Gabriela
Advisor dc:contributor.advisor
  • Glover, Beverley

Subjects

dc:subject × 50

Rights

dc:rights
Language dc:language
en

Identifiers

dc:identifier.*
Author Identifier
0000-0002-8144-1144
OAI identifier oai:identifier
oai:www.repository.cam.ac.uk:1810/301823

Chain of custody

source
Harvested from
Cambridge University
Base URL
api.repository.cam.ac.uk/server/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Doria Ramirez, Maria Gabriela. Petal cell shape and flower-pollinator interaction in Nicotiana. Doctoral thesis, University of Cambridge, 2020. https://doi.org/10.17863/CAM.48891