N-月桂酰乙醇胺对香石竹开放和衰老进程中花瓣微粒体膜组分和功能的调节

Regulatory Role of N-lauroylethanolamine on Microsomal Membrane Composition and Function in Petals of Carnation During the Blossoming and Senescence

【目的】探讨N-月桂酰乙醇胺[N-lauroylethanolamine,NAE(12:0)]延缓香石竹切花衰老的作用机理。【方法】以5μmol·L^(-1)NAE(12﹕0)对香石竹切花(Dianthus caryophyllusL.)‘Red Barbara’进行瓶插处理,研究瓶插试验进程中NAE(12﹕0)对花瓣微粒体膜组分和功能的影响。【结果】香石竹切花开放和衰老进程伴随着花瓣微粒体膜磷脂含量、膜脂流动性、膜脂脂肪酸不饱和指数以及膜结合酶比活力的下降,外源NAE(12﹕0)处理能在切花盛开后期至初萎发生前明显滞缓香石竹花瓣微粒体膜上述指标的下降速率,同时降低作为膜衰老可靠指标的电导率的上升幅度。【结论】NAE(12:0)延缓香石竹切花衰老的作用机理与NAE(12﹕0)对花瓣微粒体膜磷脂降解以及膜脂脂肪酸组分的调节有关,由此延缓了花瓣微粒体膜脂流动性的下降速率,降低了膜渗漏的上升幅度,并维持了膜结合酶较高的比活力,从而推迟了切花初萎的发生。

[Objective] The objective of this study was to explore the mechanism of N-lauroylethanolamine [NAE （12：0）] in regulation of cut-flower senescence. [Method] Cut carnation （Dianthus caryophyllus L.） cv. Red Barbara treated with 5 μmol·L^-1 NAE（12：0） was used to investigate the effects of NAE （12：0） on the microsomal membranes composition and function in petals. [ Result ] Phospholipids content, lipid fluidity, the index of unsaturation of fatty acids and activities of membrane enzymes decreased with time, and NAE （12：0） supplementation delayed the decreases of the above mentioned parameters at the stage from the end of blooming to the onset of wilting. Electrolyte leakage, a reliable indicator of petal senescence, was also postponed in NAE （12：0）-treated flowers. [ Conclusion]The data suggest that the mechanism of NAE （12：0） in the regulation of cut-flower senescence is involved in the regulation of NAE （12：0） on the degradation of phospholipids and changes of the fatty acid composition of microsomal membranes, which resulting in the less ion leakage, more lipid fluidity and higher activities of membrane enzymes, and thus, delaying the initial wilting of cut carnation.