【目的】探讨脂氧合酶(LOX)在香蕉果实成熟过程中的作用。【方法】选取1000μL·L^-1丙烯处理采后不同时间(采后10h和48h)的香蕉果实,并分析果皮中MaLOX、MaACS和MaACO等基因表达,LOX活性变化、乙烯释放及其与果实成熟的关系。【结果】采后48h的香蕉果实,经丙烯处理后果皮中LOX活性及基因表达在成熟前呈先下降后升高的趋势,且先于乙烯高峰、MaACS和MaACO基因表达峰出现。丙烯处理虽能诱导采后10h的香蕉果实果皮中MaACS和MaACO基因的表达,但不能提高果皮中LOX活性和促进果实成熟。【结论】推测香蕉果实在成熟进程中,果皮中LOX和ACO、ACS协同调控香蕉果实乙烯的产生及跃变峰的形成,进而调控果实的成熟。
[Objective] The role of lipoxygenase (LOX) in banana fruit ripening was studied. [Method] Fruit ripened naturally and fruit treated with 1 000 μL·L^-1 propylene for 10 h and 48 h after harvest were used as experimental materials. LOX activity and the expression patterns of MaLOX, MaACS, MaACO genes and ethylene production and its relation to fruit ripening were analyzed. [Result] The results showed that the peak of LOX activity and transcript accumulation firstly decreased, then increased, moreover, the increase in LOX activity and transcript accumulation appeared earlier than that of mRNA accumulations of MaACS and MaACO gene in the peel of propylene treated fruit at 48 h after harvest. Although propylene could induce the accumulations of MaACS and MaACO gene in the fruit of propylene treated fruit at 10h after harvest, but could not increase LOX activity and transcript accumulation, and thus could not accelerate banana fruit ripening. [Conclusion] These results suggest that LOX, ACS and ACO are likely to play a role in regulating the climacteric ethylene production and banana fruit ripening coordinately.