Show simple item record

dc.contributor.authorCanto Pastor, Alex
dc.date.accessioned2018-03-07T15:57:38Z
dc.date.available2018-03-07T15:57:38Z
dc.date.issued2018-03-24
dc.date.submitted2017-12-11
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/273780
dc.description.abstractRNA silencing is a major regulator of gene expression in plants, controlling from development to transposable element silencing and stress responses. As part of the silencing machinery, micro (mi)RNAs orchestrate silencing of their targets, either directly or through cascades of secondary small interfering (si)RNAs. To investigate the role of RNA silencing in plant immunity, I chose to focus on the miR482/2118 family, because of its diversity and presence in many plant species since the appearance of seed plants, with most genomes containing several copies, and because its members target sequences conserved in a family of disease resistance genes known Nucleotide biding site leucine-rich repeat (NLR) genes. In this dissertation, I wanted to address the extent to which the miRNA family and its derived phasiRNAs regulate expression of defence genes as well as contribute to quantitative resistance in crops. I explore the structural differences of miR482/2118 members in Solanum lycopersicum and show that they are functionally significant and affect their target preferences. My approach was based on small RNA sequencing and degradome data to characterize targets of these miRNAs, including the recently discovered tomato TAS5 locus. I also generated transgenic tomatoes constitutively expressing target mimic RNAs that sequester different miR482/2118 members. These tomato mimic RNA lines were less susceptible than their non-transgenic precursors to pathogens Phytophthora infestans and Pseudomonas syringae. Additionally, I investigated the role of small RNAs and their effector proteins during vegetative and reproductive development in tomato. I employed transcript and small RNA sequencing and CRISPR-Cas9 techniques of gene editing to investigate the impact of these factors in gamete viability and transposable element silencing in vegetative meristems. The results presented here provide new evidence about the extent that RNA silencing contributes to the regulation of vital processes in plants. My study primarily explores the extent to which structural differences between the members of the miR482/2118 family affect their range of action, and the use of target mimics against these miRNAs as biotechnological approach for enhancing disease resistance in highly bred cultivars.
dc.description.sponsorshipMy work on this thesis was supported by the European Research Council Advanced Investigator Grant ERC-2013-AdG 340642 awarded to Professor David Baulcombe
dc.language.isoen
dc.rightsNo Creative Commons licence (All rights reserved)
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectsmall RNA
dc.subjectmicroRNA
dc.subjectSolanum lycopersicum
dc.subjectmolecular biology
dc.subjectplant sciences
dc.subjectphasiRNA
dc.subjectmeristem
dc.subjectslyAGO5
dc.titleSmall RNAs in Tomato: from defence to development
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentPlant Sciences
dc.date.updated2018-03-07T11:32:34Z
dc.identifier.doi10.17863/CAM.20845
dc.contributor.orcidCanto Pastor, Alex [0000-0001-8571-1116]
dc.publisher.collegeDarwin
dc.type.qualificationtitlePhD in Plant Sciences
cam.supervisorBaulcombe, David
cam.supervisor.orcidBaulcombe, David [0000-0003-0780-6878]
rioxxterms.freetoread.startdate2019-03-07


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record