Solanum hjertingii, a wild potato species, does not exhibit enzymatic browning nor blackspot. Blackspot and enzymatic browning are physiological disorders that are caused by the reaction of the enzyme polyphenol oxidase with phenolic substrates, resulting in discoloration of tuber cortex. We determined that S. hjertingii has a low amount of at least one of the polyphenol oxidases in its tubers compared to S. tuberosum. Less than 5 μg of S. tuberosum polyphenol oxidase protein, as determined from Western blot staining, had measurable enzymatic activity. In contrast, S. hjertingii protein with comparable staining had no detectable activity.
Bibliographical noteFunding Information:
Research partially supported by NSF/BIR grant no. 9214615. We thank John Bamberg for providing us with seeds, Justin Dagen for providing us with tubers, and Michelle Hunt and John Steffens for the PPO antibody and cDNA.
- chlorogenic acid
- enzymatic browning