Submitted to: Cereal Conference Royal Australian Chemical Institute Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 9, 2007
Publication Date: October 1, 2007
Citation: Morris, C.F., Beecher, B.S. 2007. Polyphenol Oxidase Gene Structure in Wheat and Related Species. Proceedings of the 57th Australian Cereal Chemistry Conference., 5-10 August, 2007. Panozzo, J.F., and Black, C.K. (eds). Melbourne, Victoria, pp.57-60. Interpretive Summary: In “Polyphenol Oxidase Gene Structure in Wheat and Related Species,” Craig F. Morris and Brian Beecher explain their research on PPO in wheat. As PPO results in the discoloring of Asian noodles, Morris and Beecher argue, it is important to better understand the gene structure of PPO. The materials, methods, and results of Beecher’s Morris’ research on PPO give molecular evidence to hypothesize that a PPO mulitgene family structure and organization exists in wheat, adding to the discussion and understanding of PPO genetics in wheat.
Technical Abstract: Since PPO is known to be the major cause of browning reactions that discolour Asian noodles and other wheat products, a better understanding of PPO gene structure should contribute to minimizing the deleterious effects of PPO via wheat breeding and improvement. A PPO gene model has emerged that identifies two clusters of three genes each, that is, the genes in wheat exist in two evolutionary/expression groups: kernel and >green tissue= (paralogous loci). This paper describes our recent progress on the kernel PPO gene structure and copy number, including evidence for gene duplication events (Massa et al. 2007). Furthermore, the number of sequences obtained for bread and durum wheat was higher than the number expected for orthologous loci. Nucleotide and structural diversity, together with well-resolved phylogenetic trees, provided molecular evidence to support the hypothesis of a PPO multigene family structure and organization in wheat.