中文摘要：

【目的】为了探明荔枝ACC氧化酶（ACO）基因与荔枝幼果脱落的关系,【方法】用RT-PCR和RACE扩增技术相结合的方法进行ACO基因的克隆;在‘黑叶’荔枝花后30 d喷施100 mg·L-1萘乙酸（NAA）来进行荔枝幼果落果的处理;用荧光定量PCR技术分析ACO基因表达与荔枝幼果脱落的关系。【结果】首次从荔枝中分离得到ACO基因,并命名为Lc-ACO1。Lc-ACO1全长为1 231 bp,其中5′非编码区包含89 bp,3′非编码区包含215 bp,开放阅读框包含927 bp,编码309个氨基酸。Lc-ACO1基因含有ACO基因特有的7个保守区和9个不变氨基酸残基。100 mg·L-1萘乙酸（NAA）可以显著促进荔枝幼果的脱落,且处理后相对落果率高峰出现在第10天,而Lc-ACO1基因在离区和幼果中的表达量高峰都出现在第7天,基因表达量高峰比相对落果率高峰早出现3 d。【结论】Lc-ACO1基因可能与荔枝幼果的脱落密切相关。

英文摘要：

[Objective]In order to clarify the relationship between litchi ACC oxidase （A CO）gene and the fruitlet drop in litchi, [Method] the methods of combination of RT-PCR and RACE were used for gene cloning. 100 mg·L^-1 NAA was sprayed on 30 days after anthesis in ＇Heiye＇ litchi to analysis fruitlet ab- scission. The relationship between A CO gene expression and the fruitlet drop was studied by qRT-PCR. [Result]One litchi A CO gene named Lc-A C01 was firstly isolated from litchi. Lc-A C01, a 1 231 bp full-length cDNA sequence with 89 bp 5＇-UTR and 215 bp 3＇-UTR, coded 309 amino acids. Lc-ACO1 covered nine conserved amino residues and seven conserved regions of A CO gene. Spraying 100 mg ·L^-1 NAA on 30 days after anthesis could significantly accelerate fruitlet abscission. The peak of relative fruitlet abscission rate （RFAR） appeared on the tenth day after treatment （DAT）, while the peak of Lc-ACO1 gene expression occurred in the seventh DAT, three days earlier than that of RFAR. [Conclusion]The results indicated that Lc-A C01 might be one of the key genes controlling fruitlet drop in litchi.