Abstract

Flower color is one of the most important qualitative characteristics of ornamental horticultural plants, which mainly depends on anthocyanins and carotenoids. Modification of flower color in ornamental plants involves many aspects, including complicated structural gens, transcription factors and metabolic pathways. Anthocyanins are important secondary metabolites in the flavonoid biosynthesis pathway, which mainly derive from six anthocyanidins. Anthocyanin has antioxidant activity, protects plants and performs some other functions. Studying the genes and regulatory factors in the biosynthesis pathway will contribute to cultivating novel flower color plants and to improving plants’ resistance. To date, a series of structural and regulatory genes that are involved in anthocyanin synthesis and color formation have been reported, whose functions have also been revealed. Some color-related transgenic flowers have been successfully obtained. Carotenoids are the source of the yellow pigments in the petals of many flowers. The carotenoid biosynthesis pathway as well as its major enzymes and genes are conducive to regulate its biosynthesis via genetic engineering methods and thereby changing the color of flowers. In this paper, we review the plant flower color in terms of mechanisms of plant pigment formation, classification of flower color, biosynthesis pathway, and genes related to anthocyanin formation. Subsequently, we analyze the regulating mechanism of the expression of these genes, including transcription regulation and post-transcription regulation. The methods and achievements in flower color improvement in recent years are summarized. Finally, analyzing the molecular regulatory network in flower color formation provides a theoretical basis for the improvement and modification of flower color.

摘要

花色是观赏园艺植物最重要的定性特征之一，主要依赖于花青素和类胡萝卜素。观赏植物花色的改变涉及多个方面，包括复杂的结构基因、转录因子和代谢途径。花青素是类黄酮生物合成途径中重要的次生代谢产物，主要来源于六种花青素。花青素具有抗氧化活性，保护植物并执行一些其他功能。研究生物合成途径中的基因和调控因子，将有助于培育新型花色植物，提高植物的抗逆性。迄今为止，已经报道了一系列参与花青素合成和颜色形成的结构和调控基因，其功能也已显露。已成功获得一些与颜色相关的转基因花卉。类胡萝卜素是许多花朵花瓣中黄色色素的来源。类胡萝卜素生物合成途径及其主要酶和基因有利于调节其生物合成通过基因工程方法，从而改变花朵的颜色。本文从植物色素形成机制、花色分类、生物合成途径以及与花青素形成相关的基因等方面对植物花色进行了综述。随后，我们分析了这些基因表达的调控机制，包括转录调控和转录后调控。总结了近年来在花色改良方面的方法和成果。最后，分析花色形成的分子调控网络，为花色的改良和修饰提供理论依据。