水杨酸调控芥菜芽苗生理及褪黑素代谢研究

Study on Regulation of Physiology and Melatonin Metabolism in Mustard Sprouts by Salicylic Acid

为探讨水杨酸(SA)处理对芥菜芽苗生理及褪黑素代谢的影响,本研究设置喷施SA处理,并以喷施蒸馏水为对照,研究发芽期间芥菜芽苗主要生理生化变化,并利用实时荧光定量PCR(qRT-PCR)技术研究褪黑素合成关键酶基因表达的变化。结果表明,SA处理抑制了芽苗生长,生物量显著下降(P<0.05),电解质渗透率、游离蛋白质含量、总抗氧化能力、谷胱甘肽过氧化物酶活性以及褪黑素含量均显著提高(P<0.05),发芽4 d芥菜芽苗的褪黑素含量达42.75 ng·g^(-1)FW。SA处理后,芥菜芽苗BjTDC 1、BjTDC 2、BjT5H 1和BjT5H 2基因的表达水平均不同程度上调,这与褪黑素含量变化趋势一致;而BjSNAT与BjASMT基因的表达与褪黑素的合成相关性低。综上所述,SA处理芥菜芽苗是富集褪黑素的有效方式。本研究结果为生产富含褪黑素的功能性芽菜提供了理论依据和技术支撑。

In the present study,the effect of salicylic acid(SA)on physiology and melatonin metabolism of mustard sprouts was investigated.The main physiological and biochemical changes of mustard sprouts during germination were analyzed by spraying SA and using distilled water as control.The changes in the gene expression of melatonin key synthetic enzymes were studied by fluorescence quantitative PCR technology.The results showed that SA treatment inhibited the growth of sprouts,resulted in a significant decrease in biomass and a significant increase in electrolyte permeability,free protein content,total antioxidant capacity,glutathione peroxidase activity,and melatonin content(P<0.05).The content of melatonin in mustard sprouts after 4 days of germination under SA treatment reached 42.75 ng·g^(-1)FW.Under SA treatment,the expression levels of BjTDC 1,BjTDC 2,BjT5H 1 and BjT5H 2 were all up-regulated with varying degrees,which was consistent with the changing trend of melatonin content,while the expressions of BjSNAT and BjASMT were not correlated with melatonin content.In conclusion,SA treatment of mustard sprouts was an effective way to enrich melatonin.The results of this research provided theoretical basis and technical support for the production of melatonin-rich functional sprouts.