水杨酸延缓猕猴桃果实采后衰老与精氨酸分解代谢的关系  

Relationship between Salicylic Acid Delaying Postharvest Senescence and Arginine Catabolism in Kiwifruit

作　　者：苏金龙 王小璐 李素方 李姚瑶 王婷 高慧 SU Jinlong;WANG Xiaolu;LI Sufang;LI Yaoyao;WANG Ting;GAO Hui(College of Food Science and Engineering, Northwest University, Xi'an 710069, China;Quality and Safety Inspection and Monitoring Center for Agricultural Products,Xi'an 710038,China)

机构地区：[1]西北大学食品科学与工程学院,西安710069 [2]西安市灞桥区农产品质量安全检验监测中心,西安710038

出　　处：《西北植物学报》2020年第10期1714-1721,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金青年基金(31401550);西安市科技计划(20193042YF030NS030)。

摘　　要：采用1.0 mmol·L^-1水杨酸(SA)处理‘徐香’猕猴桃果实,测定果实在常温(23±2)℃贮藏过程中失重率、硬度、多聚半乳糖醛酸酶(PG)活性和丙二醛(MDA)含量,以及精氨酸分解代谢相关酶活性和物质含量的变化,探究SA处理延缓猕猴桃果实采后衰老的作用机理。结果显示:(1)与对照(不处理)相比,贮藏第20天时,SA处理果实的失重率较对照降低13.77%,硬度较对照提高78.25%,表明SA处理有效抑制了猕猴桃果实硬度和鲜重的下降。(2)贮藏第20天时,SA处理果实的PG活性(13.61μg·g^-1·h^-1)显著低于对照(16.77μg·g^-1·h^-1);猕猴桃果实中的MDA含量在贮藏第15天时差异最大,SA处理较对照降低33.40%。(3)与对照相比,在贮藏过程中SA处理显著促进了果实中鸟氨酸的累积以及精氨酸脱羧酶和鸟氨酸脱羧酶活性的升高,同时抑制了多胺氧化酶和二胺氧化酶活性,并显著提高了猕猴桃果实中多胺(腐胺、精胺、亚精胺)的累积。(4)与对照相比,SA处理显著诱导了猕猴桃果实中一氧化氮合酶活性的增强,并促进了果实中一氧化氮(NO)的累积,且在贮藏第5天以后果实中的NO含量显著高于对照。研究发现,SA能够显著延缓常温下猕猴桃果实的采后衰老进程,这可能与SA触发了果实中精氨酸分解代谢的不同途径有关。‘Xuxiang’kiwifruit were pretreated with 1.0 mmol·L^-1 salicylic acid(SA)and then weight loss,firmness,polygalacturonase(PG)activity,malondialdehyde(MDA)content,as well as enzyme activities and substances contents related to arginine catabolism were measured during ambient storage(23±2)℃for investigating the mechanism of SA on delaying postharvest senescence of kiwifruit.The results showed:(1)weight loss and firmness of SA treated fruit were 13.77%lower and 78.25%higher than that of control at 20 d,indicating that SA treatment effectively inhibited the decrease of firmness and fresh weight.(2)At 20 d,the PG activity of SA-pretreated fruit(13.61μg·g^-1·h^-1)was significantly lower than that of the control(16.77μg·g^-1·h^-1);The difference of MDA content in kiwifruit reached the maximum at 15 d of storage,and the MDA content of SA treatment was 33.40%lower than that of control.(3)Compared to control,SA treatment markedly improved the content of ornithine and the activities of arginine decarboxylase and ornithine decarboxylase.Meanwhile,SA treatment inhibited the activities of polyamine oxidase and diamine oxidase,and prominently increased the accumulation of polyamines(putrescine,spermine,spermidine)in kiwifruit during the whole storage.(4)In comparison with control fruit,SA treatment notably induced the enhancement of nitric oxide synthase activity in kiwifruit and promoted the accumulation of nitric oxide(NO)in fruit,and the content of NO in fruit was significantly higher than that of control after the 5 d of storage.The above results showed that SA-mediated delay of postharvest senescence in kiwifruit at ambient storage,which may be associated with its trigger of different pathways of arginine catabolism.

关 键 词：猕猴桃 采后衰老 水杨酸 精氨酸分解代谢 

分 类 号：Q945.6+6[生物学—植物学]