铝胁迫下丹波黑大豆根尖细胞线粒体参与细胞凋亡的研究  

Root Tip Cell Mitochondria Involvement in Programmed Cell Death Induced by Aluminum Stress of Tamba Black Soybean(Glycinemax)

作　　者：李金金[1] 刘昂[1] 王平[1] 陈丽梅[1] 年洪娟[1] 

机构地区：[1]昆明理工大学生物工程技术研究中心,昆明650500

出　　处：《农业生物技术学报》2014年第6期712-719,共8页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金资助项目(No.31160020)

摘　　要：细胞凋亡(apoptosis)也称程序性细胞死亡(programmed cell death,PCD),对于生物体正常发育和繁殖是必不可少的,也受各种生物和非生物胁迫所调控。铝胁迫是酸性土壤中影响植物生长和限制作物产量的一个主要因子,铝对细胞的毒害之一是诱导程序性细胞死亡。本研究通过用4',6-二脒基-2-苯基吲哚(4',6-diamidino-2-phenylindole,DAPI)染色观察铝胁迫下丹波黑大豆(Glycine max)根尖细胞细胞核和线粒体中细胞色素c(cytochromec,Cytc)含量等的变化。结果表明,铝胁迫下,丹波黑大豆根尖细胞DAPI染色后细胞核在细胞边缘聚集,核内的染色质凝聚呈新月状,分布在核内周边,呈致密浓染。大豆根尖细胞线粒体中的丙二醛(malondialdehyde,MDA)含量均随着铝处理浓度和时间的增加呈上升趋势,表明大豆根尖细胞线粒体膜氧化程度增加,膜系统损害更严重。线粒体Cytc/a的比值能够反映线粒体内膜上Cytc量的变化。铝胁迫下,大豆根尖细胞线粒体膜通透性转换孔(mitochondrial permeability transition pore,MPTP)不断开放,线粒体膜电位(ΔΨm)降低,线粒体膜的完整性被破坏,促使Cyt c从线粒体内膜上脱落下来,线粒体中的Cytc/a和Cytc含量减少,Cytc有可能通过线粒体膜从线粒体释放到细胞质中。这些研究结果从细胞和生理水平揭示了线粒体和Cytc在铝诱导丹波黑大豆根尖细胞发生凋亡过程中的作用,进一步阐明了铝胁迫诱导丹波黑大豆根尖细胞凋亡的过程,加深了铝毒对植物毒害机理的认识。Programmed cell death （PCD） is essential for normal development and reproduction which is also induced by various biotic or abiotic stress. Aluminum （A1） stress is a major factor limiting plant growth andyield of crops in acid soils. One of A1 toxicity on cells is induced PCD. Whether A1 stress causes soybean cell apoptosis is still poorly understood. In this study, 4＇,6-diamidino-2-phenylindole （DAP1） staining and contentassays of mitochondrial cytochrome c （Cyt c） were performed in Tamba black soybean （Glycine max） root tip cells under A1 stresses. DAPI staining results showed that there was a nucleus aggregation in the cell edge,and nuclear chromatin condensation displayed a crescent-shaped distribution around the nucleus with dense stain. The content of mitochondrial malondialdehyde （MDA） of soybean root tip cells increased with theincreased A1 concentration and time of A1 treatment, which suggested that the degree of mitochondrial membrane oxidation increased and membrane damage became more serious. Cyt c/a can reflect the contentchange of Cyt c within the inner mitochondrial membrane. Mitochondrial permeability transition pore（MPTP） of soybean root tip cells opened unceasingly, mitochondrial membrane potential （△Ψm） decreased, mitochondrial membrane integrity was destroyed under A1 stress promoting Cyt c off from the innermitochondrial membrane. A reduced value of mitochondrial Cyt c/a and content of Cyt c under A1 stress suggested that Cyt c might be released from mitochondria to the cytoplasm through the mitochondrialmembrane. These findings, from cellular and physiological level, revealed the roles of mitochondria and Cyt c in Al-induced PCD of Tamba black soybean root tip cells, will furtherly know about PCD process induced byAI tress and toxic mechanisms of A1 to plants.

关 键 词：丹波黑大豆 铝胁迫 细胞凋亡 线粒体 细胞色素C 

分 类 号：S529[农业科学—作物学]