Fruit Integrative Modelling (FRIM)

Lead Research Organisation: University of Oxford
Department Name: Plant Sciences

Abstract

Commercial fruit production is under significant pressure from environmental stresses, exacerbated by climate change, but also from changes in the consumer's demand for taste and nutritional value. One of the key goals of fruit biology is therefore to understand the factors that influence the contents of the ripe fruit that influence flavour and quality. Both genetic and environmental factors have a strong and multifaceted influence on fruit quality. They usually act and interact in such a complex way that it is extremely difficult to study their effects experimentally. It is possible to generate experimentally-derived models of fruit development in response to environmental conditions, but such models alone do not reveal how the genetic variation between different tomato cultivars, which acts on biochemical and cellular processes, affects the outcome. At a different level, it is also possible to make models of the metabolism inside the developing fruit which can predict how fast different components of the tomato are being made, but such models do not incorporate the cumulative effects of the environmental influences on the plant and fruit. The aim of this project is to combine these two modelling approaches so that it is possible to predict how the fruit of particular genetic variants will develop under a variety of environmental conditions, and in that way to select rationally tomato strains with desirable qualities.

Technical Summary

One of the key goals of fruit biology is therefore to understand the factors that influence the levels of metabolites in cells and tissues, ultimately with a view to manipulating these levels for improvement of fruit traits. Both genetic and environmental factors have a strong and multifaceted influence on fruit quality. They usually act and interact in such a complex way that it is extremely difficult to study their effects experimentally. To circumvent such difficulty, we will build an integrative model of fruit metabolism in Tomato, encompassing central carbon metabolism (sucrose metabolism, starch metabolism, glycolysis, and organic acid metabolism), energy metabolism and sub-cellular compartmentation, throughout development and maturation, with light intensity, water availability and temperature as input variables, and sugar and organic acid contents as outputs. There are three major components of the project: (1) To build a kinetic model encompassing the routes carbon takes, once imported into the fruit cells from the source organs of the mother plant. (2) To integrate the kinetic model with a phenomenological 'virtual fruit' model predicting sugar and organic acid contents as functions of time, light intensity, temperature and water availability. (3) To obtain large-scale experimental measures of the consequences of altered environmental conditions. The building of an integrative model will improve the understanding of fruit metabolism, by pinpointing crucial steps as related to sometimes complex but realistic environmental inputs. This could open the way to novel breeding programs in which advantageous combinations of alleles would be selected. In addition such a model will provide a powerful tool to match ideal environmental conditions to given tomato varieties grown under controlled conditions to yield optimal fruit quality.

Planned Impact

WHO WILL BENEFIT FROM THIS RESEARCH? Ultimately, the beneficiaries of this research will be consumers through the availability of new varieties of tomato with improved fruit qualities (such as taste and nutritional properties). However, to reach this stage, considerable industrial translation of the research outputs will be required. Thus, links to Agribusiness to exploit the insights gained from the metabolic modelling in this project will be essential for the impact of this work. Ultimately, the use of defined genetic markers to modify compositional traits in elite commercial tomato varieties will generate economic benefit. While most Agribusinesses are global concerns, we will endeavour to seek links with business with activities in the EU such that the economic benefit goes to the relevant home nations. HOW WILL THEY BENEFIT FROM THIS RESEARCH This project is likely to generate IP that could be exploited in commercial tomato breeding programmes. We will seek to capitalise on this IP through arrangements with relevant Agribusiness. A consortium agreement will be put into place between the partners of the project to safeguard ownership and rights of the research organisations involved and to set out the division of IP rights and related revenues between the partners. Strategies to exploit IP and negotiations with industry will be lead by the technology transfer offices of the partner institutions. We will pursue mechanisms for exploitation that minimise delays or stalemates due to jointly-owned IP. For example, revenue-sharing agreements in which IP is licensed to commercial partners in return for a license to continue internal research and development work. PLAN TO MAXIMISE IMPACT Collectively, the partners in the project have an outstanding track record of attracting industrial monies (see Impact plan) and strong links with relevant Agribusiness, seed companies, growers and supermarkets. To ensure that these organisations are aware of the project and the potential for exploitation, each partner will visit their industrial contacts (listed in full in the 'Impact plan') to present the project and for initial discussion about potential collaborations. Already, Syngenta UK have expressed an interest in the project and preliminary discussions are under way.
 
Description Only my specific contribution to the consortium is considered - which was to provide data on the kinetics of intracellular metabolite transport and metabolite data to parameterize the integrated tomato model being constructed by the rest of the consortium. The main findings were:

1. Changes in the kinetic parameters of metabolite transporters during fruit ripening have provided new insight into the steps that control metabolite accumulation. Unexpectedly, it was revealed that mitochondrial citrate transport exerts more control over citrate accumulation than tonoplast transport. The converse was true for malate.

2. Related to this, it was shown that a specific mitochondrial isoform of aconitase, responsible for citrate metabolism, exerts considerable control over citrate accumulation.

3. Collectively this work has provided new information on biochemical targets for manipulating fruit flavour via altered metabolite accumulation and highlights the importance of mitochondrial metabolism and transport for fruit citrate accumulation.
Exploitation Route The integrated tomato model from this project will reveal the biochemical steps within the fruit that have the greatest influence over fruit yield and accumulation of flavor-related metabolites. Follow-on funding will be sought to undertake genetic experiments to test these model predictions and test the efficacy of genetic manipulation of specific genes for increasing fruit yield and improving fruit flavor.
Sectors Agriculture, Food and Drink

 
Description formed part of a dataset for multi-scale modelling of tomato fruit development and chemical composition.
First Year Of Impact 2014
Sector Agriculture, Food and Drink
 
Description Fascination of plants day 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Oxford University organises an annual exhibition at the Harcourt Aboretum as part of the international 'Fascination of plants' day. Postdocs employed on my BBSRC grants contributed displays to this exhibition explaining our research on tomatoes.
Year(s) Of Engagement Activity 2011,2012,2013