空气放电处理诱导尖孢镰刀菌孢子的凋亡过程  

Apoptotic Process of Fusarium oxysporum Spores Induced by Air Discharge

作　　者：刘梦蝶[1] 姜慧雯 李洁[1,2,3] 严守雷 王清章[1,2,3] LIU Mengdie;JIANG Huiwen;LI Jie;YAN Shoulei;WANG Qingzhang(College of Food Science and Technology,Huazhong Agricultural University,Wuhan 430070,China;Key Laboratory of Environment Correlative Dietology,Ministry of Education,Huazhong Agricultural University,Wuhan 430070,China;Aquatic Vegetable Preservation and Processing Technology Engineering Center of Hubei Province,Wuhan 430070,China)

机构地区：[1]华中农业大学食品科学技术学院,湖北武汉430070 [2]华中农业大学环境食品学教育部重点实验室,湖北武汉430070 [3]湖北省水生蔬菜保鲜加工工程技术研究中心,湖北武汉430070

出　　处：《食品科学》2021年第9期22-30,共9页Food Science

基　　金：中央高校基本科研业务费专项资金项目(2662018JC020)。

摘　　要：尖孢镰刀菌是莲藕采后的主要腐败菌。本研究采用空气放电技术对从腐烂莲藕分离到的尖孢镰刀菌进行处理,以孢子致死过程中存在的典型凋亡特征为切入点,详细探究空气放电处理下尖孢镰刀菌以线粒体为核心的凋亡进程。实验设置3个处理组,分别以臭氧含量6.87 mg/m^(3)、负离子含量5×10~6 ions/cm~3、臭氧6.87 mg/m^(3)+负离子5×10^(6)ions/cm^(3)处理尖孢镰刀菌,以未经处理的尖孢镰刀菌作为对照组,检测孢子凋亡、活性氧簇(reactive oxygen species,ROS)荧光强度、线粒体膜电位、胞浆和线粒体Ca^(2+)浓度、半胱天冬氨酸酶(metacaspase)活力。结果表明:空气放电处理后,孢子内ROS含量增多,线粒体膜电位下降,即发生膜电位去极化;胞浆Ca^(2+)浓度先迅速上升后下降,最终趋于稳定,线粒体内Ca^(2+)浓度大幅升高后减幅稳定上升;同时凋亡过程中还会引起Metacaspase的激活。其中负离子处理组只出现孢子凋亡,臭氧处理组和臭氧、负离子同时处理组出现孢子凋亡和坏死。通过实验结果可推断空气放电首先引起孢子内ROS的积累和Ca^(2+)浓度的增加,线粒体ROS的产生引起线粒体膜电位的去极化,导致细胞色素c从线粒体释放到细胞质,激活Metacaspase,最终导致孢子凋亡。Fusarium oxysporum is the major postharvest spoilage fungus of lotus roots.In this study,air discharge technology was used to treat Fusarium oxysporum isolated from rotten lotus roots.The typical apoptotic characteristics occurring during spore inactivation were used as the cut-in point to investigate the apoptotic process of Fusarium oxysporum with focus on mitochondria under air discharge treatment.The experiment was set up with three treatments,including 6.87 mg/m^(3)ozone,5×10^(6)ions/cm^(3)negative ion and their combination;untreated Fusarium oxysporum was used as the control group to detect apoptosis,fluorescence intensity of reactive oxygen species(ROS),mitochondrial membrane potential(Δψm),cytosolic and mitochondrial calcium ion concentrations,and metacaspase activity.Results showed that air discharge treatment increased intracellular ROS level and decreased mitochondrial membrane potential leading to membrane potential depolarization.Cytosolic calcium ion concentration first increased rapidly,then decreased,and finally remained stabled,while the mitochondria Ca^(2+)increased first sharply and then slowly.Meanwhile,metacaspase was activated in the process of apoptosis.Only apoptosis was observed in the negative ion treatment group,while both apoptosis and necrosis were observed in the other two groups.It can be inferred from the experimental results that air discharge could cause the accumulation of intracellular ROS and an increase in Ca^(2+)concentration in spores so that the production of mitochondrial ROS could cause the depolarization of mitochondrial membrane potential,thereby leading to the release of cytochrome c from the mitochondria into the cytoplasm,activating metacaspase and eventually inducing apoptosis in spores.

关 键 词：空气放电 尖孢镰刀菌 凋亡 坏死 

分 类 号：TS201.3[轻工技术与工程—食品科学]