Exploring metabolic and genetic diversity in tomato secondary metabolites

Exploring metabolic and genetic diversity in tomato secondary metabolites

Bibliographic Details
Main Author: Dzakovich, Michael Paul
Language:English
Published: The Ohio State University / OhioLINK 2020
Subjects:
Horticulture
Tomato
health
breeding
genetics
metabolites
metabolism
phytochemicals
steroidal alkaloids
steroidal glycoalkaloids
liver
transcriptomics
metabolomics
GWAS
QTL
chromatography
mass spectrometry
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=osu1595608017506091
id ndltd-OhioLink-oai-etd.ohiolink.edu-osu1595608017506091
record_format oai_dc
collection NDLTD
language English
sources NDLTD
topic Horticulture
Tomato
health
breeding
genetics
metabolites
metabolism
phytochemicals
steroidal alkaloids
steroidal glycoalkaloids
liver
transcriptomics
metabolomics
GWAS
QTL
chromatography
mass spectrometry
spellingShingle Horticulture
Tomato
health
breeding
genetics
metabolites
metabolism
phytochemicals
steroidal alkaloids
steroidal glycoalkaloids
liver
transcriptomics
metabolomics
GWAS
QTL
chromatography
mass spectrometry
Dzakovich, Michael Paul
Exploring metabolic and genetic diversity in tomato secondary metabolites
author Dzakovich, Michael Paul
author_facet Dzakovich, Michael Paul
author_sort Dzakovich, Michael Paul
title Exploring metabolic and genetic diversity in tomato secondary metabolites
title_short Exploring metabolic and genetic diversity in tomato secondary metabolites
title_full Exploring metabolic and genetic diversity in tomato secondary metabolites
title_fullStr Exploring metabolic and genetic diversity in tomato secondary metabolites
title_full_unstemmed Exploring metabolic and genetic diversity in tomato secondary metabolites
title_sort exploring metabolic and genetic diversity in tomato secondary metabolites
publisher The Ohio State University / OhioLINK
publishDate 2020
url http://rave.ohiolink.edu/etdc/view?acc_num=osu1595608017506091
work_keys_str_mv AT dzakovichmichaelpaul exploringmetabolicandgeneticdiversityintomatosecondarymetabolites
_version_ 1719457632737034240
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-osu15956080175060912021-08-03T07:15:53Z Exploring metabolic and genetic diversity in tomato secondary metabolites Dzakovich, Michael Paul Horticulture Tomato health breeding genetics metabolites metabolism phytochemicals steroidal alkaloids steroidal glycoalkaloids liver transcriptomics metabolomics GWAS QTL chromatography mass spectrometry <p>Tomatoes (<i>Solanum lycopersicum</i>) are an important crop for economic and nutritional reasons that biosynthesize a multiplicity of metabolites, also known as phytochemicals. Through epidemiological studies, it has been posited that certain phytochemicals present in tomatoes, such as carotenoids, may be responsible for observed health benefits, including reduced risk for certain cancers. However, whole tomato consumption offers additional benefits over supplementation with individual phytochemicals. The overarching focus of my dissertation research is to develop novel methodologies to measure tomato phytochemicals of interest, determine how tomato phytochemicals affect mammalian tissues where they are deposited, and explore the diversity and genetic basis for biosynthesis of tomato steroidal glycoalkaloids. The specific objectives of my dissertation are: 1) Develop a high-throughput extraction and analysis workflow suitable for plant breeders to determine how carotenoid pathway intermediates are affected by natural variation; 2) Determine how dietary tomato consumption affects metabolism by quantifying transcriptome and metabolome alterations in mouse liver tissue; 3a) Develop and validate a high-throughput method to extract and quantify potentially health-promoting tomato steroidal alkaloids; and 3b) Quantify natural phenotypic variation of potentially health-promoting tomato steroidal alkaloids and describe the underlying genetic architecture. </p><p>For objective 1, I hypothesized that a high throughput extraction and analysis method for tomato carotenoids could be developed that would more quickly produce comparable data to traditional methods. Methods developed can extract 12 samples/hour and separate phytoene, phytofluene, β-carotene (and isomers), all-trans-lycopene (and isomers) in 4.2 minutes (Dzakovich et al., 2019). Novel methodology developed as part of this objective resulted in the fastest available chromatographic method that separates typical tomato carotenoids. Subpopulations of tomatoes with varying carotenoid profiles were able to be discerned using both methods making this workflow suitable for breeders who need to make fast, data driven decisions. </p><p>In objective 2, I hypothesized that tomato consumption would affect gene expression by way of altering the chemical composition of the liver. Overall, tomato consumption had a small effect on gene transcription, though of differentially expressed genes, those related to Phase I/II xenobiotic metabolism, were differentially regulated by tomato consumption and type. Moreover, the chemical profiles of liver tissue were altered by tomato consumption and I confirmed the identities of two steroidal alkaloids with authentic standards. Additionally, I tentatively identified 17 masses of Phase I/II tomato steroidal alkaloid metabolites. These compounds may be bioactive <i>in vivo</i> and many are reported for the first time. </p><p>For objective 3a, I developed and validated a comprehensive, quantitative extraction and mass spectrometry-based analysis method for tomato steroidal alkaloids and analyzed a variety of tomato based products commonly consumed by Americans and available in grocery stores. The method I developed was able to extract 16 samples in 20 minutes and separate 18 steroidal glycoalkaloids derived from 9 masses in 13 minutes. </p><p>In objective 3b, I assembled a diversity panel comprised of 107 accessions of red-fruited tomato species selected to maximize genetic diversity, and applied my high throughput steroidal alkaloid extraction and analysis workflow. I hypothesized that steroidal alkaloids would be most diverse in wild tomato germplasm. A genome-wide association study (GWAS) revealed quantitative trait loci (QTL) associated with various steroidal alkaloids and these QTL were confirmed in a separate biparental mapping population. Early and late steroidal alkaloid pathway intermediates were differentially regulated by QTL on chromosome 3 (early) and chromosomes 10 and 11 (late). Information generated from this hypothesis added to the incomplete literature surrounding tomato steroidal alkaloids and created genetic resources useful for creation of germplasm designed for nutritional intervention studies. </p><p>The findings in this dissertation have led to the development of new analytical methodologies, revealed novel information about the chemodiversity of tomato phytochemicals in both fruits and mammalian tissue, identified wild sources of diversity in tomato steroidal alkaloids, and developed genetic material that can be used for both fine mapping experiments and tomato material that can be used in clinical trials testing hypotheses about tomato consumption and human health.</p> 2020 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1595608017506091 http://rave.ohiolink.edu/etdc/view?acc_num=osu1595608017506091 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

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