Watercore is a physiological disorder of apple expressed as fluid deposition in intercellular spaces. We analysed the watercore prone cultivar 'Fuji' to establish a link between enzymatic response and fluid accumulation in the fruit. Individual phenolic content, selected enzyme activities of the phenylpropanoid pathway, sugars and organic acids were quantified in watercore affected flesh and peel. In addition, transcriptome sequencing was performed to obtain a first insight into molecular mechanisms underlying the physiological disorder. Sampled material included: peel (HP) and flesh from healthy fruit (H), peel from watercore affected fruit (WP), healthy flesh from fruit with watercore (HW) and watercore flesh (WW) from fruit with watercore. A sorbitol increase in watercore affected apple was observed not only in the flesh but also in the peel. Moreover, two phenolic groups (hydroxycinnamic acids and flavonols) were significantly affected by watercore and their content was higher in WP in comparison to HP. Dihydrochalcone content was the highest in WW flesh. This was supported by RNA-seq data, which indicated a generally increased expression of genes from the early flavonoid pathway, sorbitol metabolism and polyphenol oxidases. Among the phenylpropanoid pathway enzymes analysed, phloretin 2′-O-glycosyltransferase was the only one exhibiting altered activity.

Watercore 是苹果的一种生理障碍，表现为细胞间隙中的液体沉积。我们分析了水核倾向的品种“富士”，以建立酶反应与果实中积液之间的联系。在受影响的果肉和果皮中量化了单个酚类含量、苯丙烷途径的选定酶活性、糖和有机酸。此外，还进行了转录组测序，以初步了解生理障碍的分子机制。采样材料包括：健康水果的果皮 (HP) 和果肉 (H)、受影响的水核果皮 (WP)、水核水果的健康果肉 (HW) 和水核水果的水核果肉 (WW)。不仅在果肉中而且在果皮中都观察到受水核影响的苹果中山梨糖醇的增加。此外，两个酚类基团（羟基肉桂酸和黄酮醇）受水核显着影响，与 HP 相比，它们在 WP 中的含量更高。二氢查尔酮含量在 WW 肉中最高。这得到了 RNA-seq 数据的支持，该数据表明来自早期类黄酮途径、山梨糖醇代谢和多酚氧化酶的基因的表达普遍增加。在分析的苯丙烷途径酶中，根皮素 2'- 这表明来自早期类黄酮途径、山梨糖醇代谢和多酚氧化酶的基因的表达普遍增加。在分析的苯丙烷途径酶中，根皮素 2'- 这表明来自早期类黄酮途径、山梨糖醇代谢和多酚氧化酶的基因的表达普遍增加。在分析的苯丙烷途径酶中，根皮素 2'-O-糖基转移酶是唯一一种表现出改变活性的酶。