Breeding for nutritional traits in tomato using …tgc.ifas.ufl.edu/2013/2013/02 - Orchard.pdfBreeding for nutritional traits in tomato using naturally occurring variation in the fruit
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Breeding for nutritional traits in tomato using naturally occurring variation in the fruit specific beta-cyclase promoter Caleb Orchard, David Francis Ph.D.
Breeding for nutritional traits in tomato using naturally occurring variation in the fruit specific beta-cyclase
promoter
Caleb Orchard, David Francis Ph.D.
Presenter
Presentation Notes
Carotenoids - importance
Kopec et al. 2012
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Presentation Notes
Consumption of different carotenoids associated with: improved vitamin A status Vision Cell formation & growth Immune function a reduced risk of developing macular degeneration cognitive decline developing various types of cancer developing heart disease sunburn effect
Carotenoids in Tomato
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Different carotenoids in tomato – specifically B-carotene is due to a mutation called B Research question – do different promoters lead to different levels of BC in fruit
B
Ronen et al. 2010
Presenter
Presentation Notes
We’re focusing on this step in the pathway -> LCY-b enzyme converts lycopene to BC If BC content goes up, lycopene will go down Mention ogc Mutation in the beta cyclase enzyme either leads to increased BC levels or with Ogc, leads to increased lycopene at the expense of BC
Does variation in the promoter of the B gene lead to different levels of beta-carotene in tomato fruit?
Presenter
Presentation Notes
Does variation in the promoter of the B gene lead to different levels of B carotene in tomato fruit?
Sources of variation Juane Flammee – S. lycopersicum LA716 – S. pennellii 97L97 – S. cheesmanii
John R. Stommel. HortScience April 2001 vol. 36 no. 2 387-388
Does variation in the promoter of the B gene lead to different levels of beta-carotene in tomato fruit?
Presenter
Presentation Notes
List plant material (initial sequencing with 3 high beta varieties) Primer design, how you sequence, alignment (staden package) Sequence 2kb promoter region Make sure to focus on PROCESSING tomatoes
Promoter Variation
Promoter Variation
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This does not show the functional mutation, but instead shows variation between different colored varieties Different promoter variation, within high BC varieties, and between orange-red fruited varieties Results facilitated the development of a molecular marker for PCR based assays (B MARKER)
Promoter Variation
2010 Dalal et al., BMC Plant Biology 2010, 10:61
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Presentation Notes
Marker Development Indels may not be causal, but are diagnostic
Population Development
Recurrent Parent
• OH8245
Donor Parents
• LA3501 (M-82) • LA3502 (M-82) • Juane Flammee
Recurrent Donor
Y. Eshed and D. Zamir. Genetics. 1995 November; 141(3): 1147–1162.
BC1
BC2
BC3
Presenter
Presentation Notes
So we have variation in the promoter and we have a marker to distinguish B alleles, therefore we create a population to introgress allele… Graphic of Backcross program Circle F2
SolCAP SNP Array
Sim S-C, Van Deynze A, Stoffel K, Douches DS, et al. (2012) High-Density SNP Genotyping of Tomato (Solanum lycopersicum L.) Reveals Patterns of Genetic Variation Due to Breeding. PLoS ONE 7(9): e45520. doi:10.1371/journal.pone.0045520 http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045520
Presenter
Presentation Notes
To do marker assisted backcrossing, we must have a marker set optimized for our populations
Distribution of Progeny vs. % Recurrent Genome in BC1
% Recurrent Parent Genome
# of
Pro
geny
Average RP Genome 75.50% Population 1 74.45% Population 2 76.00% Population 3 Selections: 84.9 – 89.6% (a generation ahead)
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Proof that we can use BGS to identify individuals that are a full generation ahead
Future work / BC2
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Next Steps – Selfing, marker screening, Field trials, additional sequencing, HPLC Only include main steps – don’t give too much information
Conclusions
Multiple versions of fruit-specific beta-cyclase promoter Marker resources allow us to distinguish genetic backgrounds (M82 vs. OH8245, JF vs. OH8245) BGS facilitates selection of individuals one generation “ahead” each cycle
Plant Genetic Resources for Human Health and Nutrition
Research
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Presentation Notes
Develop varieties that growers can use We work with several collaborators at Ohio State in both the Food Science Department and Medical Center that conduct research Concerning carotenoids and nutrient uptake One purpose of the study is to develop genetic resources that can be used to test hypotheses about human adsorption, utilization and metabolism of nutrients in the food matrix. Changing carotenoid profile affects absorption – we want to provide them with a diverse range of high beta varieites We have crop to clinic research We’re also working with other kinds (tangerine)
Presenter
Presentation Notes
Pre-school age children – WHO Processing tomato’s nutrient profile and the way it’s cooked may it an ideal delivery mechanism for pro-vitamin A
Acknowledgements
• Ohio State – David Francis – Steven Schwartz – Sung-Chur Sim – Heather Merk – Nancy Huarachi – Troy Aldrich – Cassi Sewell – Rachel Kopec – Jessica Cooperstone
• UC-Davis
– Allen Van Deynze – Kevin Stoffel – Alex Kozic
• Michigan State – David Douches – Robin Buell – John Hamilton – Dan Zarka – Kelly Zarka
