Ongoings in the apple watercore: First evidence from proteomic and metabolomic analysis

The presence of watercored fruit with translucent mesocarp has attracted immense attention due to its unique morphology and taste, however, the metabolic reconstruction between watercored and non-watercored tissues remain elusive. Herein, the combined proteomic and metabolomic approach was carried out to characterize the protein abundance and metabolic profile in watercored apple. Results demonstrated that carbohydrate meta-bolism was prioritized enriched in watercored apple, including highly accumulated sucrose and sugar alcohols, and the increased level of transcription factor WHIRLY2 (WHY2), which is required in sugar reallocation. More than 50% overlap of differently abundant proteins involved in calcium ion binding, starch and sucrose meta-bolism implied the involvement of calcium signaling in watercore development. Moreover, significantly lower calcium content was detected in watercored apples. Sucrose synthase (SUSY) protein, which is involved both in calcium ion binding and sugar metabolism, was the potential basis of apple watercore development, which provided a likely candidate in regulation of apparent quality.

Automated summary

The protein abundance and metabolic profile in watercored apple were characterized using a combined proteomic and metabolomic approach. The results showed that carbohydrate metabolism, including sucrose and sugar alcohol accumulation, was prioritized enriched in watercored apple. The involvement of calcium signaling in watercore development was implied by the overlap of differently abundant proteins involved in calcium ion binding, starch, and sucrose metabolism. Sucrose synthase protein, involved in calcium ion binding and sugar metabolism, was identified as a potential basis for apple watercore development.