Submitted to: Metabolomics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/3/2010
Publication Date: 9/18/2010
Citation: Smith, E.D., Rudell Jr, D.R. 2010. Metabolic profiling of ethephon-treated sweet cherry (Prunus avium L.). Metabolomics. doi: 10.1007/s11306-010-0238-3. Interpretive Summary: Reduced labor availability and increasing costs has made sweet cherry mechanical harvest especially enticing. Most mechanical harvesting systems require consistent and timely separation of the stem from the fruit. The ethylene releasing products containing ethephon can provoke fruit separation when applied to cherries 2 weeks prior to harvest. This study assessed the impacts of ethephon on abscission and changes in fruit chemistry and quality. It was found that ethephon induced changes in natural fruit chemicals responsible for color, sourness, and sweetness as well as those that may be intermediates in the production of these chemicals.
Technical Abstract: Increasing costs and decreasing labor availability for sweet cherry harvest in Washington State, USA, has reinvigorated commercial and research interest of mechanized harvest. Ethephon (2-chloroethyl phosphonic acid) can be used to improve fruit abscission for mechanical harvest. Our previous work shows that 3.5 L ha-1 ethephon enhances red color and reduces firmness of ‘Bing’. In the current study, we used metabolic profiling of ‘Bing’, Chelan’, and ‘Skeena’ fruit meso and exocarp tissue to better understand underlying quality-related metabolism associated with ethephon application. Trees were treated using air-blast sprayer 13 to 14 days prior to harvest and fruit samples were harvested every 7-10 days starting at least 17 days prior to commercial harvest. Nearly 200 identified and partially characterized metabolites from mesocarp and exocarp tissue were characterized and evaluated. Principal component analysis models revealed changes in the metabolome associated with both natural ripening and ethephon-induced changes, including associations to key color, acid, and sugar components, such as 3-glucoside, malic acid and sugar metabolism.