BBSRC Renewable Industrial Products from Rapeseed (RIPR) Programme

Oilseed rape is commercially viable because a co-product can be exploited (a protein-rich feed for animals) in addition to the primary product (oil). However, many other valuable products could be extracted and exploited commercially, adding value to the crop. This opportunity is particularly important for emerging industrial applications of rapeseed oil (such as thermally-stable oil types produced recently by JIC), where the product must compete on price with mineral oil if it is to be successful commercially and hence adopted sufficiently widely to realize the associated environmental benefits. The serial purification of co-products is termed "bio-refining". Emerging opportunities include tocopherols (vitamin E) and phytosterols (cholesterol lowering compounds) from rapeseed oil, waxes (with aphid-repellent properties and those with medical properties) from pod walls and stems, and functional polysaccharides (including high-value stabilisers, surfactants and barriers) from stems. Although the biosynthetic pathways involved in the synthesis of these compounds are known to some extent from studies conducted in species such as Arabidopsis thaliana, the quantitative control of their accumulation (key to yield of the compounds) is not understood. Such products have not been foci for crop improvement by breeders, so there is no improved germplasm and no molecular markers are available to aid breeding. Similarly, the efficiency with which fertilizer is used by rapeseed is poorly understood, but its optimization is essential for the commercial production of substitutes for mineral oil as fertilizer is both expensive and potentially damaging to the environment. The approach of associating disease or other traits with DNA sequence variation has become a key tool in human genetics and has also been applied successfully in a few plants. The drawback for most crops is that the traditional approach has been expensive. However, recent advances in sequencing technology and genomics has led to the emergence of a technology termed Associative Transcriptomics, which makes this approach accessible for most crops. In this approach, the search for DNA sequence variation is focussed on gene sequences and variation for gene expression is also exploited; both providing very large sets of potential "markers" for trait variation. The technology has been proven recently using a small genetic diversity panel of Brassica napus (the species that includes oilseed rape as one of its crop types) and is ready for scale-up to a full and widely-used genetic diversity panel, i.e. that termed the ASSYST panel. This approach is ideally suited to the initial genetic analysis of traits for which little is know as it quickly enables the estimation of genetic complexity, the development of hypotheses for the control of traits and produces molecular markers that can be used to assist breeding. The proposed research aims to exploit Associative Transcriptomics to identify genes associated with the control of a range of bio-refining targets and fertilizer use traits. Data will all be made publicly available. The annotations of genes showing either sequence or expression variation associated with trait variation will be examined. Hypotheses will be developed for both the control of the pathways involved and predictive capabilities of molecular markers arising from the identified relationships between gene sequence and/or expression variation and trait variation. These will be tested by the quantitative analysis of traits following the inter-crossing of different plant lines from the collection and/or the selection and testing of plant lines from a population chemically treated to induce gene sequence variation. Using the knowledge gained, mathematical models will be developed to help industry estimate economic and environmental consequences of the development of optimised new cultivars.