Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China.
Sichuan Provincial Academy of Natural Resource Sciences, Chengdu 610015, China.
Int J Mol Sci. 2022 Oct 11;23(20):12120. doi: 10.3390/ijms232012120.
The kiwifruit ( var. purpurea) produces oval shaped fruits containing a slightly green or mauve outer exocarp and a purple-flesh endocarp with rows of tiny black seeds. The flesh color of the fruit results from a range of anthocyanin compounds, and is an important trait for kiwifruit consumers. To elucidate the molecular mechanisms involved in anthocyanin biosynthesis of the sarcocarp during fruit development, de novo assembly and transcriptomic profile analyses were performed. Based on significant Gene Ontology (GO) biological terms, differentially expressed genes were identified in flavonoid biosynthetic and metabolic processes, pigment biosynthesis, carbohydrate metabolic processes, and amino acid metabolic processes. The genes closely related to anthocyanin biosynthesis, such as phenylalanine ammonia-lyase (), chalcone synthase (), and anthocyanidin synthase (), displayed significant up-regulation during fruit development according to the transcriptomic data, which was further confirmed by qRT-PCR. Meanwhile, a series of transcription factor genes were identified among the DEGs. Through a correlation analysis. AaMYB1 was found to be significantly correlated with key genes of anthocyanin biosynthesis, especially with . Through a transient expression assay, AaMYB1 induced anthocyanin accumulation in tobacco leaves. These data provide an important basis for exploring the related mechanisms of sarcocarp anthocyanin biosynthesis in . This study will provide a strong foundation for functional studies on and will facilitate improved breeding of fruit.
猕猴桃（ var. purpurea）果实呈椭圆形，果皮外种皮稍呈绿色或淡紫色，内种皮为紫色果肉，果肉上有一排排黑色的小种子。果实的果肉颜色是由一系列花青素化合物决定的，这是猕猴桃消费者的一个重要特征。为了阐明果实发育过程中果肉中花青素生物合成的分子机制，进行了从头组装和转录组谱分析。基于显著的基因本体论（GO）生物学术语，在类黄酮生物合成和代谢过程、色素生物合成、碳水化合物代谢过程和氨基酸代谢过程中鉴定出差异表达基因。根据转录组数据，与花青素生物合成密切相关的基因，如苯丙氨酸解氨酶（）、查尔酮合酶（）和花青素合酶（），在果实发育过程中表现出显著的上调，qRT-PCR 进一步证实了这一点。同时，在 DEGs 中鉴定出了一系列转录因子基因。通过相关性分析，发现 AaMYB1 与花青素生物合成的关键基因，特别是与，显著相关。通过瞬时表达试验，AaMYB1 诱导了烟草叶片中的花青素积累。这些数据为探索猕猴桃果肉中花青素生物合成的相关机制提供了重要依据。本研究将为猕猴桃的功能研究提供坚实的基础，并有助于改良猕猴桃果实的选育。
