Zhang Wei, Xiong Tao, Ye Fan, Chen Jia-Hui, Chen Yu-Rui, Cao Jia-Jia, Feng Zhi-Guo, Zhang Zai-Bao
College of Life Science, Xinyang Normal University, Xinyang, Henan, China; Henan Key Laboratory of Tea Plant Biology, Xinyang Normal University, Xinyang, Henan, China.
College of Life Science, Xinyang Normal University, Xinyang, Henan, China.
Gene. 2023 Jun 5;868:147385. doi: 10.1016/j.gene.2023.147385. Epub 2023 Mar 22.
Oleosins play essential roles in stabilization of lipid droplets (LDs) and seed oil production. However, evolution of this gene family has not been reported in Theaceae, a large plant family that contains many important tea and oil tea species. In this study, a total of 65 oleosin genes were identified in nine genome-sequenced Theaceae species. Among these genomes, the gene number of oleosin showed significant difference, with Camellia sinensis var. sinensis cv. Shuchazao and Camellia lanceoleosa displayed more oleosin numbers than other species. Phylogenetic analyses revealed that Theaceae oleosin genes were classified into three clades (U, SL, SH) respectively. Proteins within the same clade had similar gene structure and motif composition. Segmental duplication was the primary driving force for the evolution of oleosin genes in Shuchazao (SCZ), Huangdan (HD), C.lanceoleosa (Cla), and wild tea (DASZ). Synteny analysis showed that most oleosin genes displayed inter-species synteny among tea and oil tea species. Expression analysis demonstrated that oleosin genes were specifically expressed in seed and kernel of Huangdan (HD) and C.lanceoleosa. Moreover, expression divergence was observed in paralogous pairs and ∼1-2 oleosin genes in each clade have become activate. This study leads to a comprehensive understanding of evolution of oleosin family in Theaceae, and provides a rich resource to further address the functions of oleosin in tea and oil tea species.
油体蛋白在脂滴（LDs）的稳定和种子油生产中发挥着重要作用。然而，在包含许多重要茶树和油茶物种的大科山茶科中，该基因家族的进化尚未见报道。在本研究中，在9个已测序基因组的山茶科物种中共鉴定出65个油体蛋白基因。在这些基因组中，油体蛋白的基因数量显示出显著差异，其中中华变种茶树品种舒茶早和柳叶茶的油体蛋白数量比其他物种更多。系统发育分析表明，山茶科油体蛋白基因分别分为三个进化枝（U、SL、SH）。同一进化枝内的蛋白质具有相似的基因结构和基序组成。片段重复是舒茶早（SCZ）、黄旦（HD）、柳叶茶（Cla）和野生茶（DASZ）中油体蛋白基因进化的主要驱动力。共线性分析表明，大多数油体蛋白基因在茶树和油茶物种之间表现出种间共线性。表达分析表明，油体蛋白基因在黄旦（HD）和柳叶茶的种子和种仁中特异性表达。此外，在旁系同源对中观察到表达差异，每个进化枝中约有1-2个油体蛋白基因被激活。本研究有助于全面了解山茶科油体蛋白家族的进化，并为进一步研究油体蛋白在茶树和油茶物种中的功能提供了丰富的资源。
