套袋对苹果果皮花青苷合成及着色的影响

套袋是提高苹果果实着色的主要技术措施之一,也是研究苹果果皮花青苷合成和基因表达的重要手段。苹果果皮花青苷的合成经由苯丙烷类代谢途径,编码苹果花青苷合成酶类的基因已得到克隆。套袋后果皮花青苷合成酶类的基因表达受到抑制,因而抑制了花青苷合成;摘袋后果皮花青苷迅速合成,与套袋后果皮光受体浓度增加和叶绿素含量降低从而提高对光的敏感度、迅速启动花青苷合成酶类的基因协同表达有关。果皮色素特别是花青苷和叶绿素的含量、比例和分布决定果实的着色状况,套袋促进果皮花青苷合成的同时大大降低了叶绿素含量,从而使果实着色鲜艳。

Effect of bagging on anthocyanin biosynthesis and pigmentation in apple skin

Bagging is one of the main strategies for improving fruit coloration in apple, and also an important tool in antho-cyanin biosynthesis and gene expression research. The apple skin anthocyanin is synthesized via phenylpropanoid pathway, and the genes encoding enzymes responsible for anthocyanin biosynthesis in apple have been cloned so far. After bagging, anthocyanin formation was greatly reduced due to the prohibition of anthocyanin biosynthesis genes' expression. Fruit bagging increased photoreceptors and decreased chlorophyll content in apple skin, which increased light sensitivity, and after bag removal, anthocyanin biosynthesis genes were coordinately expressed rapidly, characterized by the rapid formation of anthocyanin. Fruit coloration was influenced by the content, percentage and arrangement of apple skin pigments, especially anthocyanin and chlorophyll. The bagged fruit looks bright red due to the increase in anthocyanin and decrease in chlorophyll content.