CAJ | 학술논문

在人参(Panax ginseng C.A.Meyer)悬浮细胞质膜上测出了NAD(P)H氧化酶活性.这类NAD(P)H氧化酶活性可以被金瓜炭疽细胞壁激发子(Cle)诱导.Cle处理还能诱导人参悬浮细胞的氧进发、促进人参悬浮细胞的皂苷合成、提高苯丙氨酸解氨酶(PAL)的活力、以及诱导查尔式酮酶(CHS)的累积和细胞壁上抗性相关蛋白基因脯氨酸富裕蛋白基因hrgp(Hydroxyprolin-rich glycoproteins)的表达.当用哺乳动物白细胞质膜NADPH氧化酶的特异性抑制剂二亚苯基碘(Diphenylene iodonium,DPI)与奎吖因(quinacrine)预处理人参悬浮细胞30min后,Cle诱导的H2O2释放与Cle激活的质膜NAD(P)H氧化酶活性被抑制,同时Cle诱导的PAL活性及CHS的积累下降,皂苷合成与hrgp的表达被抑制.由此推测:人参细胞质膜NAD(P)H氧化酶与哺乳动物白细胞质膜NADPH氧化酶有很大的相似性.在Cle激发人参悬浮细胞产生氧进发的过程中,NAD(P)H氧化酶活性被诱导从而导致H2O2的产生,H2O2作为第二信使,激活苯丙氨酸途径,诱发人参皂苷的合成及hrgp防御基因的表达.这一过程中还涉及到Ca2+内流,胞内Ca2+浓度的升高,蛋白磷酸化与去磷酸化.人参细胞质膜NAD(P)H氧化酶在人参细胞对Cle的反应过程中起一种介导作用.因此可能存在由Cle刺激,NAD(P)H氧化酶被诱导,H2O2释放,到人参细胞产生激发反应这样一个由外及内的级联反应.
재인삼(Panax ginseng C.A.Meyer)현부세포질막상측출료NAD(P)H양화매활성.저류NAD(P)H양화매활성가이피금과탄저세포벽격발자(Cle)유도.Cle처리환능유도인삼현부세포적양진발、촉진인삼현부세포적조감합성、제고분병안산해안매(PAL)적활력、이급유도사이식동매(CHS)적루적화세포벽상항성상관단백기인포안산부유단백기인hrgp(Hydroxyprolin-rich glycoproteins)적표체.당용포유동물백세포질막NADPH양화매적특이성억제제이아분기전(Diphenylene iodonium,DPI)여규아인(quinacrine)예처리인삼현부세포30min후,Cle유도적H2O2석방여Cle격활적질막NAD(P)H양화매활성피억제,동시Cle유도적PAL활성급CHS적적루하강,조감합성여hrgp적표체피억제.유차추측:인삼세포질막NAD(P)H양화매여포유동물백세포질막NADPH양화매유흔대적상사성.재Cle격발인삼현부세포산생양진발적과정중,NAD(P)H양화매활성피유도종이도치H2O2적산생,H2O2작위제이신사,격활분병안산도경,유발인삼조감적합성급hrgp방어기인적표체.저일과정중환섭급도Ca2+내류,포내Ca2+농도적승고,단백린산화여거린산화.인삼세포질막NAD(P)H양화매재인삼세포대Cle적반응과정중기일충개도작용.인차가능존재유Cle자격,NAD(P)H양화매피유도,H2O2석방,도인삼세포산생격발반응저양일개유외급내적급련반응.
NAD(P) H oxidases were detected in suspension cultured cells of ginseng (Panax ginseng C.A.Meyer). The activities of these enzymes were induced by an elicitor (Cle) extracted from cell walls of Colletotrichum lagerarium. In addition, Cle induced an oxidative burst and enhanced the synthesis of saponin, activity of phenylalanine ammonialyase (PAL), accumulation of chalcone synthase (CHS) and the transcription of a hydroxyproline-rich glycoprotein gene ( hrgp ). Pre-treatments with DPI and quinacrine ( two inhibitors of mammalian neutrophil plasma membrane NADPH oxidase) for 30 min prior to Cle addition blocked the NAD(P)H oxidase activity induced by Cle. These inhibitors also inhibited the release of H2O2, the synthesis of saponin, PAL activity and CHS accumulation. Our data revealed homology between plasma membrane NAD(P) H oxidases of mammalian neutrophil cells and ginseng suspension cells. They also indicated that Cleactivated NAD(P)H oxidases catalysed the release of H2O2 and that H2O2 was functioning as a second messenger stimulating PAL activity, saponin synthesis and hrgp transcription. Elevations of Ca2 + and protein phosphorylation/dephosphorylation were required for this defense process. We propose that NAD(P)H oxidases mediate the processes of Cle-induced defense responses in ginseng suspensions, and postulate the existence of a signalling cascade including extracellular Cle stimulation, activation of plasma membrane NAD(P)H oxidases,release of H2O2, and the intracellular responses of metabolism and gene transcription in ginseng suspension cells.