Lin Yuanxiu, Zhang Lianxi, Zhang JiaHao, Zhang Yunting, Wang Yan, Chen Qing, Luo Ya, Zhang Yong, Li Mengyao, Wang Xiaorong, Tang Haoru
College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China.
Institute of Pomology and Olericulture, Sichuan Agricultural University, Chengdu 611130, China.
Int J Mol Sci. 2020 Nov 18;21(22):8708. doi: 10.3390/ijms21228708.
Anthocyanins are responsible for the red color of strawberry, they are a subclass of flavonoids synthesized in cytosol and transferred to vacuole to form the visible color. Previous studies in model and ornamental plants indicated members of the glutathione S-transferase () gene family were involved in vacuolar accumulation of anthocyanins. In the present study, a total of 130 genes were identified in the genome of cultivated strawberry ( × ), which were unevenly distributed across the 28 chromosomes from the four subgenomes. Evolutionary analysis revealed the expansion of family was under stable selection and mainly drove by WGD/segmental duplication event. Classification and phylogenetic analysis indicated that all the genes were clarified into seven subclasses, among which , , and belonging to Phi class were closely related to , an anthocyanin-related of wildwood strawberry, and this clade was clustered with other known anthocyanin-related . RNAseq-based expression analysis at different developmental stages of strawberry revealed that the expression of , , , , and was gradually increased during the fruit ripening, consistent with the anthocyanins accumulation. These expression patterns of those five genes were also significantly correlated with those of other anthocyanin biosynthetic genes such as , , and , as well as anthocyanin regulatory gene . These results indicated , , , , and may function in vacuolar anthocyanin accumulation in cultivated strawberry.
花青素赋予草莓红色，它们是在细胞质中合成并转移至液泡以形成可见颜色的一类黄酮类化合物。先前在模式植物和观赏植物中的研究表明，谷胱甘肽S-转移酶（GST）基因家族成员参与了花青素的液泡积累。在本研究中，在栽培草莓（Fragaria × ananassa）基因组中共鉴定出130个GST基因，它们不均匀地分布在来自四个亚基因组的28条染色体上。进化分析表明，GST家族的扩张处于稳定选择之下，主要由全基因组复制/片段重复事件驱动。分类和系统发育分析表明，所有GST基因被分为七个亚类，其中属于Phi类的FvGSTF1、FvGSTF6和FvGSTF7与森林草莓的一个花青素相关GST基因FaGST1密切相关，并且该进化枝与其他已知的花青素相关GST聚集在一起。基于RNAseq的草莓不同发育阶段的表达分析表明，FvGSTF1、FvGSTF6、FvGSTF7、FvGSTF8和FvGSTF12的表达在果实成熟过程中逐渐增加，这与花青素积累一致。这五个GST基因的这些表达模式也与其他花青素生物合成基因如FvCHS、FvCHI和FvDFR以及花青素调控基因FvMYB10的表达模式显著相关。这些结果表明，FvGSTF1、FvGSTF6、FvGSTF7、FvGSTF8和FvGSTF12可能在栽培草莓的液泡花青素积累中发挥作用。
