State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China.
Shaanxi Research Center of Apple Engineering and Technology, Yangling 712100, China.
Int J Mol Sci. 2018 Oct 12;19(10):3133. doi: 10.3390/ijms19103133.
The red color of apples () is an attractive trait for consumers. The green skinned "Granny Smith" cultivar develops red pigmentation after bagging treatment. DNA methylation plays an important role in various developmental processes in plants. To explore the possible functions of DNA methylation in the pigmentation of bagged "Granny Smith" apples, we first analyzed the anthocyanin content of fruit skin following treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC). The results revealed an increase in anthocyanin content in bagged fruits following 5-aza-dC treatment, while no anthocyanins were detected in unbagged fruits. In addition, 8482 differentially expressed genes between 5-aza-dC-treated and control groups were identified in bagged fruits by RNA sequencing, including genes encoding transcription factors, enzymes related to anthocyanin accumulation, and methylases. Changes in the expression of these genes may be responsible for 5-aza-dC-induced red pigmentation in bagged fruits of "Granny Smith". The findings provide novel evidence for the involvement of DNA methylation in the red pigmentation of non-red-skinned apples.
苹果的红色外观（）对消费者具有吸引力。经过套袋处理后，绿皮的“嘎啦”品种会出现红色素沉着。DNA 甲基化在植物的各种发育过程中起着重要作用。为了探究 DNA 甲基化在套袋“嘎啦”苹果着色中的可能作用，我们首先分析了经 DNA 甲基转移酶抑制剂 5-氮杂-2'-脱氧胞苷（5-aza-dC）处理后果实果皮中的花青素含量。结果表明，5-aza-dC 处理后套袋果实中的花青素含量增加，而未套袋果实中则未检测到花青素。此外，通过 RNA 测序在套袋果实中鉴定出 5-aza-dC 处理组和对照组之间有 8482 个差异表达基因，包括编码转录因子、与花青素积累相关的酶和甲基转移酶的基因。这些基因表达的变化可能是 5-aza-dC 诱导套袋“嘎啦”果实红色素沉着的原因。研究结果为 DNA 甲基化参与非红皮苹果的红色素沉着提供了新的证据。
