ABSTRACT

Anthocyanin accumulation is responsible for the red color of the skin of apple fruits (Malus × domestica Borkh.). Environmental stimuli, such as light, temperature, soil factors, tree factors, and the application of chemicals can alter the synthesis of anthocyanins. Herein, we examined the expression of genes related to anthocyanin biosynthesis in the fruit of apple cultivars, ‘Summer Prince’ and ‘Arisoo’ at the early stage of fruit development 60 DAFB (days after full bloom). The expression of genes, which included structural and regulatory genes involved in anthocyanin biosynthesis, and light-responsive genes was determined in fruits developed under the effect of sunlight exposure for seven days. Apple fruits were divided in to: ‘reflected sunlight’, ‘bagged’, and ‘control’ groups. The expression levels of the anthocyanin synthesis-related genes were significantly different among the groups and between the shaded and reflected sides. We also determined the difference in coloration patterns in the different groups using the colorimetric coordinates method. The shaded side of apple fruits quickly turned more redder after exposure to reflected sunlight and the coloration was almost similar to that on the exposed side after the treatment. Strong correlation coefficients between anthocyanin-related gene expression levels and coloration patterns were obtained. This study shows that sunlight plays an important role in stimulating the coloration of apple fruit by regulating the expression of genes involved in anthocyanin accumulation during the early stage of fruit development. The present study assumes importance because redder fruits, generated through a non-transgenic approach would be more acceptable to consumers.

摘要

花青素的积累是苹果果实（苹果属×家蝇）皮肤红色的原因。Borkh。）。环境刺激，例如光照，温度，土壤因子，树木因子以及化学物质的应用，可能会改变花色苷的合成。在本文中，我们研究了在60 DAFB果实发育的早期（盛花后的几天）苹果品种'Summer Prince'和'Arisoo'果实中花色苷生物合成相关基因的表达。确定了在受阳光照射7天后发育的果实中基因的表达，其中包括花色苷生物合成中涉及的结构和调控基因，以及光响应性基因。苹果果实分为“反射阳光”，“袋装”和“对照”组。花色苷合成相关基因的表达水平在各组之间以及阴影侧和反射侧之间显着不同。我们还使用比色坐标法确定了不同组中着色图案的差异。苹果果实的阴影面在暴露于反射的阳光下很快变红，其颜色几乎与处理后的暴露面相似。获得了花色苷相关基因表达水平与着色模式之间的强相关系数。这项研究表明，阳光通过调节水果发育早期花色苷积累中涉及的基因的表达，在刺激苹果果实的着色中起着重要的作用。本研究之所以具有重要意义，是因为通过非转基因方法产生的红色水果更容易为消费者所接受。