紫果猕猴桃果实紫色形成的关键调控机制研究

Known as the king of fruits, kiwifruit has a high nutritional value and health effects. The fruit of Actinidia arguta var. purpurea was purple, because of containing secondary metabolites anthocyanins. These anthocyanins not only changed fruit color, but also have a variety of functions, such as anti-oxidation, anti-mutation, protecting liver and inhibiting tumor cells. These advantages make A. arguta var. purpurea become a higher valuable berry than blueberry. But the ecological conditions of the area of kiwifruit cultivars are different, and the flesh coloring of A. arguta var. purpurea is sensitive to the environmental conditions, which become a key restricted factor in promoting A. arguta var. purpurea. Thus, in-depth study of the biosynthesis and molecular regulatory mechanism of fruit anthocyanins, is in urgent need to lay an important theoretical basis for A. arguta var. purpurea’s fruit coloration, molecular breeding and artificial cultivation. The transcriptome sequencing analysis of A. arguta var. purpurea fruit will be conducted, and the related genes with different expression will be screened and analyzed in the anthocyanin metabolism branch. Further, the R2R3-MYB, bHLH transcription factors regulated the F3'H and DFR genes, will be critically analyzed about their regulatory mechanisms, which will reveal the anthocyanin synthesis molecular regulatory pattern in A. arguta var. purpurea.

猕猴桃作为水果之王，其果实具有极高的营养价值与保健作用。紫果猕猴桃（Actinidia arguta var. purpurea）果实呈紫红色，是因其含有一种次生代谢物-花青素。该类物质不仅能改善果实颜色，还具有抗氧化、抗突变、保护肝脏、抑制肿瘤细胞发生等多种功能。这使紫果猕猴桃成为一种比蓝莓价值更高的浆果。但我国各猕猴桃主栽区的生态条件差异很大，紫果猕猴桃的果肉着色易受到环境条件的影响，这成为限制紫果猕猴桃推广的关键因素。因此，急需研究其果实花青素的合成和分子调控机制，为其果实着色、分子育种、人工栽培奠定重要的理论基础。我们通过对紫果猕猴桃果实转录组的测序分析，筛选分析花青素代谢分支相关的差异基因，并进一步针对调控F3'H和DFR关键基因的R2R3-MYB、bHLH类转录因子，分析其调控机制，揭示紫果猕猴桃花青素苷合成的分子调控模式。

猕猴桃作为水果之王，其果实具有极高的营养价值与保健作用。紫果猕猴桃（Actinidia arguta var. purpurea）果实呈紫红色，是因其含有一种次生代谢物-花青素。该类物质不仅能改善果实颜色，还具有抗氧化、抗突变、保护肝脏、抑制肿瘤细胞发生等多种功能。紫果猕猴桃在猕猴桃多色系中具有重要意义，也是目前市场上猕猴桃缺少的色系之一。我们开展了紫果猕猴桃果实转录组的测序分析，获得了丰富的转录组数据。通过对紫果猕猴桃果实转录组的测序分析，筛选分析花青素代谢分支相关的差异基因，并进一步针对调控DFR和ANS关键基因的R2R3-MYB、bHLH类转录因子进行分析，挖掘到了一个R2R3-MYB类转录因子。分析该转录因子的调控机制中，发现其是一个新颖的负调控因子，揭示了其在紫果猕猴桃花青素苷合成的调控模式。在紫果猕猴桃研究过程中，我们还发现了一种抗肿瘤提取物，并申请了发明专利。本项目的研究，揭示了紫果猕猴桃果实花青素代谢具有更多的调控机制，同时也反映了紫色系猕猴桃具有更独特的食药用价值。