|YOO, JINGI - Washington State University|
|TORRES, CAROLINA - Washington State University|
Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/29/2021
Publication Date: 8/9/2021
Citation: Yoo, J., Rudell Jr, D.R., Torres, C. 2021. Comparative analysis of metabolomic differences between the sunburn and sunscald disorder on 'Packham’s triumph’ pear [abstract]. American Society of Horticulture Science Meeting. Paper No. 35625.
Technical Abstract: Sunburn and sunscald are physiological disorder caused by excessive exposure to sunlight. These disorders have been well described and studied in apples but poorly or not at all in pears. On apples, sunburn appears in the orchard, whereas sunscald gradually develops during cold storage. The objective of this study was to study the metabolomic differences of pears with sunburn and sunscald (described for the first time). Pears from 3 different orchards, located in a hot and dry growing region of Chile, were classified according to sunburn level (light, moderate, and severe) at commercial harvest. Sunscald incidence and severity (light, moderate, and severe) was evaluated after 6 months. Peel was removed from both healthy and damaged peel of fruit from each category. Metabolomic analyses were performed on peel with the goal of approaching a non-targeted, unbiased assessment of freely soluble metabolites regardless of polarity or volatility. Accordingly, content of 379 primary and secondary metabolites were detected. Elevated levels of 76 metabolites were associated with sunburn severity and 144 metabolites with sunscald. In addition, levels of 260 and 278 metabolites were different between healthy and damaged tissue in sunburned and sunscalded fruit, respectively. Sunburn severity was highly correlated with photosystem-related metabolites, while sunscalded tissue had higher levels of diacylglycerides, pentacyclic triterpenoic acids, conjugated trienols, and a-amyrin acyl esters. Conversely, acylated steryl glycosides, fatty acids, and volatile alcohol content was elevated in both disorders.