John Innes Centre,Metabolic Biology,Colney, Norwich NR4 7UH, UK
Mini-biographyClaire gained B.Sc. and M.Sc. degrees in plant science, together with a teaching diploma, at University College, Dublin, before moving to Norwich, UK. She obtained a Ph.D. from the University of East Anglia, and is now a Project Leader in the Department of Metabolic Biology, John Innes Centre. Her main interests are in legume seed quality, using genetic, biochemical and metabolomic approaches to understand the consequences of variation. She is on the scientific committee of the EU-FP6 Grain Legumes Integrated Project (GLIP,
www.eugrainlegumes.org) and leads the work programme on ‘Novel approaches to alter seed composition’ within GLIP. Her research on pulse crop improvement also contributes to the Defra-funded Pulse Crop Genetic Improvement Network (
www.pcgin.org). She actively supports the development of the GL-TTP in forging strong links between research and industry.
Genetic markers for improved seed quality traits in peaC. Domoney, John Innes Centre, Colney, Norwich NR4 7UH, UK
claire.domoney@bbsrc.ac.ukSeveral distinct traits are candidates for the improvement of legume seed quality, in relation to feed and food end-use. Within the latter category, there are traits that relate to the quality of both fresh vegetable and dried seed uses. Additionally, seed constituents that promote good health are acquiring more importance as food marketing strategies.
Digestibility is of primary importance for feed manufacturers. Several pea proteins interfere directly with digestive processes or are intrinsically poorly digested. These include the trypsin/chymotrypsin inhibitors (TI), shown clearly to reduce digestibility in poultry
1. Albumin 2 (PA2) is resistant to digestion in poultry and pigs and, furthermore, has allergenic properties
2, 3. Variants for TI and PA2 genes have been identified and genetic markers designed that can be exploited in breeding programmes. The TI markers distinguish lines with high and low amounts of TI, providing a robust and reliable alternative to complex biochemical assays
4, 5. The screen is equally applicable to health-food markets, where, unlike for the feed market, high amounts of TI are desirable, based on current studies indicating that TI have positive effects on anti-carcinogenic processes in human cells
6.
A variant line lacking PA2 has been crossed with the cv. Birte, and markers developed to identify lines carrying the mutation. Initial studies suggest that there are no negative consequences for plant performance in back-cross lines that lack PA2. A gene that is related to PA2 is active during flower development, and is unaffected by the PA2 mutation.
Novel forms of TI and PA2 genes are being isolated by TILLING within the Grain Legumes Integrated Project (www.eugrainlegumes.org). Some of the novel TI genes are likely to result in very reduced TI activities.
Colour stability in seeds is relevant to the canning, frozen and dried seed markets. Within the Defra-funded Pulse Crop Genetic Improvement Network (www.pcgin.org), new alleles are being sought for some of the candidate genes implicated in this character. Forward and reverse genetic approaches are being adopted in screening for lines with improved colour retention and in identifying novel genes for enzymes involved in colour stability. Markers based on some of these genes are being developed for screening. Metabolite profiling of seeds may be adapted to assist with defining optimal stages for harvesting seeds for a number of end-uses.
1. Wiseman et al. (2006) J. Sci. Food Agric. 86, 436-444.
2. Salgado et al. (2003) J. Sci. Food Agric. 83: 1571-1580.
3. Vioque et al. (1998) J. Agric. Food Chem. 46: 3609-3613
4. Page et al. (2002) Mol. Genet. Genomics 267, 359-369.
5. Page et al. (2003) Pisum Genet. 35, 19-21.
6. Clemente et al. (2005) J. Agric. Food Chem. 53, 8979-8986.
