Immature fruit abscission is a key limiting factor in Camellia oleifera Abel. (C. oleifera) yield. Ethylene is considered to be an important phytohormone in regulating fruit abscission. However, the molecular mechanism of ethylene in regulating fruit abscission in C. oleifera has not yet been studied. Here, we found that the 1-aminocyclopropane-1-carboxylic acid (ACC) content was significantly increased in the abscission zones (AZs) of abnormal fruits (AF) which were about to abscise when compared with normal fruits (NF) in C. oleifera ‘Huashuo’. Furthermore, exogenous ethephon treatment stimulated fruit abscission. The cumulative rates of fruit abscission in ethephon-treated fruits (ETH-F) on the 4th (35.0%), 8th (48.7%) and 16th (57.7%) days after treatment (DAT) were significantly higher than the control. The ACC content and 1-aminocyclopropane-1-carboxylate oxidase (ACO) activity in AZs of ETH-F were also significantly increased when compared with NF on the 4th and 8th DAT. CoACO1 and CoACO2 were isolated in C. oleifera for the first time. The expressions of CoACO1 and CoACO2 were considerably upregulated in AZs of AF and ETH-F. This study suggested that ethylene played an important role in immature fruit abscission of C. oleifera and the two CoACOs were the critical genes involved in ethylene's regulatory role.

未成熟果实脱落是油茶Abel的关键限制因素。( C. oleifera ) 产量。乙烯被认为是调节果实脱落的重要植物激素。然而，乙烯调控油茶果实脱落的分子机制尚未得到研究。在这里，我们发现与 C 中的正常果实 (NF) 相比，异常果实 (AF) 即将脱落的脱落区 (AZ) 中 1-氨基环丙烷-1-羧酸 (ACC) 的含量显着增加。油茶'华硕'。此外，外源乙烯利处理刺激果实脱落。乙烯利处理果实（ETH-F）在处理后（DAT）第4天（35.0%）、第8天（48.7%）和第16天（57.7%）的累积落果率显着高于对照。在第 4 天和第 8 天，与 NF 相比，ETH-F AZ 中的 ACC 含量和 1-氨基环丙烷-1-羧酸氧化酶 (ACO) 活性也显着增加。CoACO1和CoACO2是首次在C. oleifera中分离得到。的表达CoACO1和CoACO2在AF和ETH-F的AZS被大幅上调。本研究表明，乙烯在黄花梨未成熟果实脱落中起重要作用。C. oleifera和两个CoACOs是参与乙烯调节作用的关键基因。