Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/2012
Publication Date: 7/31/2012
Citation: Gapper, N., Hertog, M., Nicolai, B., Watkins, C., Giovannoni, J.J., Mattheis, J.P., Lee, J., Leisso, R.S., Buchanan, D.A., Rudell Jr, D.R. 2012. Candidate biomarker discovery and selection for ‘Granny Smith' superficial scald risk management and diagnosis, poster board. American Society of Horticulture Science Meeting. Interpretive Summary:
Technical Abstract: Discovery of candidate biomarkers for superficial scald, a peel disorder that develops during storage of susceptible apple cultivars, is part of a larger project aimed at developing biomarker-based risk-management and diagnostic tools for multiple apple postharvest disorders (http://www.tfrec.wsu.edu/pages/posttools/Home). Diphenylamine (DPA) treatment and 1-methylcyclopropene (1-MCP) treatment both reduce or eliminate superficial scald development. Untargeted metabolic and gene expression profiling reveal transcriptomic and metabolomic changes that DPA treatment, 1-MCP treatment, and storage duration all provoke during cold storage that precede and are potentially indicative of post-storage quality, appearance, and treatment effectiveness. Our candidate selection process begins with contrasting metabolomes and transcriptomes of untreated apples with apples treated with DPA or 1-MCP to include biomarkers that may be employed in tools used to assess scald risk and distinguish superficial scald from other peel disorders. Partial Least Square Regression (PLSR) analysis and ranking (Variable Importance in Projection; VIP) of the difference in individual metabolite and transcript levels between control and DPA treated fruit was used for this initial selection. Over 1000 expressed genes and metabolites related to DPA treatment were selected using this protocol. Candidate biomarkers will undergo rigorous experimental validation to select those that best reflect scald risk status in a range of experimental conditions known to affect scald development as well as in a commercial setting.