文献类型：期刊文献

英文题名：Genome-Wide Analysis of the Polyphenol Oxidase Gene Family in Olea europaea Provides Insights into the Mechanism of Enzymatic Browning in Olive Fruit

作者：Liu, Qingqing[1,2,3] Wang, Chenhe[1,2,3] Cui, Qizhen[1,2,3] Fan, Yutong[1,2,3] Zhang, Jianguo[1,2,3] Rao, Guodong[1,2,3]

第一作者：Liu, Qingqing

通信作者：Rao, GD[1];Rao, GD[2];Rao, GD[3]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Collaborat Innovat Ctr Sustainable Forestry Southe, Nanjing 210037, Peoples R China;[3]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat, Natl Forestry & Grassland Adm, Beijing 100091, Peoples R China

年份：2023

卷号：12

期号：9

外文期刊名：ANTIOXIDANTS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001075827900001)】；

基金：This work was supported by Fundamental Research Funds for the Central Non-profit Research Institution of the Chinese Academy of Forestry (CAFYBB2021QC001).

语种：英文

外文关键词：Olea europaea; fruit browning; polyphenol oxidase; monophenolase activity; diphenolase activity; gene expression

摘要：Browning of olive (Olea europaea L.) fruit reduces the sensory and nutritional qualities of olive oil, thereby increasing production costs. Polyphenol oxidases (PPOs) are the key enzymes that catalyze phenolic substance oxidation and mediate enzymatic browning in olive fruit, but the exact regulatory mechanism remains unclear. The main challenge is the lack of comprehensive information on OePPOs at the genome-wide level. In this study, 18 OePPO genes were identified. Subsequently, we performed a bioinformatic analysis on them. We also analyzed the expression patterns and determined the relationship among browning degree, PPO activity, and expression of OePPOs in the fruits of three olive varieties. Based on our analysis, we identified the four most conserved motifs. OePPOs were classified into two groups, with OePPOs from Group 1 showing only diphenolase activity and OePPOs from Group 2 exhibiting both mono-/diphenolase activities. Seven pairs of gene duplication events were identified, and purifying selection was found to have played a critical role in the evolution of the OePPO gene family. A positive correlation was observed between the browning degree of olive fruit and PPO activity across different olive varieties. Moreover, two important genes were found: OePPO-5 the main effector gene responsible for fruit browning, and OePPO-8, a key gene associated with specialized metabolite synthesis in the olive fruit. In short, our discoveries provide a basis for additional functional studies on OePPO genes and can help elucidate the mechanism of enzymatic browning in olive fruit in the future.